* [PATCH 0/3] zram/zsmalloc promotion @ 2012-09-26 8:50 ` Minchan Kim 0 siblings, 0 replies; 30+ messages in thread From: Minchan Kim @ 2012-09-26 8:50 UTC (permalink / raw) To: Jens Axboe, Greg Kroah-Hartman Cc: Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel, Minchan Kim This patchset promotes zram/zsmalloc from staging. Both are very clean and zram have been used by many embedded product for a long time. It's time to go out of staging. Greg, Jens is already OK and Konrad wanted to put zsmalloc into lib/ instead of mm/. I think lib/ is more proper than drivers/block/zram which is suggested by Nitin. I don't know who should merge whose tree. So I will add both Greg and Jens to To. This patchset is based on next-20120926. Minchan Kim (3): zsmalloc: promote to lib/ zram: promote zram from staging zram: select ZSMALLOC when ZRAM is configured drivers/block/Kconfig | 1 + drivers/block/Makefile | 1 + drivers/block/zram/Kconfig | 26 + drivers/block/zram/Makefile | 3 + drivers/block/zram/zram.txt | 76 +++ drivers/block/zram/zram_drv.c | 785 ++++++++++++++++++++++ drivers/block/zram/zram_drv.h | 119 ++++ drivers/block/zram/zram_sysfs.c | 225 +++++++ drivers/staging/Kconfig | 4 - drivers/staging/Makefile | 2 - drivers/staging/zcache/zcache-main.c | 4 +- drivers/staging/zram/Kconfig | 25 - drivers/staging/zram/Makefile | 3 - drivers/staging/zram/zram.txt | 76 --- drivers/staging/zram/zram_drv.c | 785 ---------------------- drivers/staging/zram/zram_drv.h | 120 ---- drivers/staging/zram/zram_sysfs.c | 225 ------- drivers/staging/zsmalloc/Kconfig | 10 - drivers/staging/zsmalloc/Makefile | 3 - drivers/staging/zsmalloc/zsmalloc-main.c | 1064 ------------------------------ drivers/staging/zsmalloc/zsmalloc.h | 43 -- include/linux/zsmalloc.h | 43 ++ lib/Kconfig | 2 + lib/Makefile | 1 + lib/zsmalloc/Kconfig | 18 + lib/zsmalloc/Makefile | 1 + lib/zsmalloc/zsmalloc.c | 1064 ++++++++++++++++++++++++++++++ 27 files changed, 2367 insertions(+), 2362 deletions(-) create mode 100644 drivers/block/zram/Kconfig create mode 100644 drivers/block/zram/Makefile create mode 100644 drivers/block/zram/zram.txt create mode 100644 drivers/block/zram/zram_drv.c create mode 100644 drivers/block/zram/zram_drv.h create mode 100644 drivers/block/zram/zram_sysfs.c delete mode 100644 drivers/staging/zram/Kconfig delete mode 100644 drivers/staging/zram/Makefile delete mode 100644 drivers/staging/zram/zram.txt delete mode 100644 drivers/staging/zram/zram_drv.c delete mode 100644 drivers/staging/zram/zram_drv.h delete mode 100644 drivers/staging/zram/zram_sysfs.c delete mode 100644 drivers/staging/zsmalloc/Kconfig delete mode 100644 drivers/staging/zsmalloc/Makefile delete mode 100644 drivers/staging/zsmalloc/zsmalloc-main.c delete mode 100644 drivers/staging/zsmalloc/zsmalloc.h create mode 100644 include/linux/zsmalloc.h create mode 100644 lib/zsmalloc/Kconfig create mode 100644 lib/zsmalloc/Makefile create mode 100644 lib/zsmalloc/zsmalloc.c -- 1.7.9.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 30+ messages in thread
* [PATCH 0/3] zram/zsmalloc promotion @ 2012-09-26 8:50 ` Minchan Kim 0 siblings, 0 replies; 30+ messages in thread From: Minchan Kim @ 2012-09-26 8:50 UTC (permalink / raw) To: Jens Axboe, Greg Kroah-Hartman Cc: Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel, Minchan Kim This patchset promotes zram/zsmalloc from staging. Both are very clean and zram have been used by many embedded product for a long time. It's time to go out of staging. Greg, Jens is already OK and Konrad wanted to put zsmalloc into lib/ instead of mm/. I think lib/ is more proper than drivers/block/zram which is suggested by Nitin. I don't know who should merge whose tree. So I will add both Greg and Jens to To. This patchset is based on next-20120926. Minchan Kim (3): zsmalloc: promote to lib/ zram: promote zram from staging zram: select ZSMALLOC when ZRAM is configured drivers/block/Kconfig | 1 + drivers/block/Makefile | 1 + drivers/block/zram/Kconfig | 26 + drivers/block/zram/Makefile | 3 + drivers/block/zram/zram.txt | 76 +++ drivers/block/zram/zram_drv.c | 785 ++++++++++++++++++++++ drivers/block/zram/zram_drv.h | 119 ++++ drivers/block/zram/zram_sysfs.c | 225 +++++++ drivers/staging/Kconfig | 4 - drivers/staging/Makefile | 2 - drivers/staging/zcache/zcache-main.c | 4 +- drivers/staging/zram/Kconfig | 25 - drivers/staging/zram/Makefile | 3 - drivers/staging/zram/zram.txt | 76 --- drivers/staging/zram/zram_drv.c | 785 ---------------------- drivers/staging/zram/zram_drv.h | 120 ---- drivers/staging/zram/zram_sysfs.c | 225 ------- drivers/staging/zsmalloc/Kconfig | 10 - drivers/staging/zsmalloc/Makefile | 3 - drivers/staging/zsmalloc/zsmalloc-main.c | 1064 ------------------------------ drivers/staging/zsmalloc/zsmalloc.h | 43 -- include/linux/zsmalloc.h | 43 ++ lib/Kconfig | 2 + lib/Makefile | 1 + lib/zsmalloc/Kconfig | 18 + lib/zsmalloc/Makefile | 1 + lib/zsmalloc/zsmalloc.c | 1064 ++++++++++++++++++++++++++++++ 27 files changed, 2367 insertions(+), 2362 deletions(-) create mode 100644 drivers/block/zram/Kconfig create mode 100644 drivers/block/zram/Makefile create mode 100644 drivers/block/zram/zram.txt create mode 100644 drivers/block/zram/zram_drv.c create mode 100644 drivers/block/zram/zram_drv.h create mode 100644 drivers/block/zram/zram_sysfs.c delete mode 100644 drivers/staging/zram/Kconfig delete mode 100644 drivers/staging/zram/Makefile delete mode 100644 drivers/staging/zram/zram.txt delete mode 100644 drivers/staging/zram/zram_drv.c delete mode 100644 drivers/staging/zram/zram_drv.h delete mode 100644 drivers/staging/zram/zram_sysfs.c delete mode 100644 drivers/staging/zsmalloc/Kconfig delete mode 100644 drivers/staging/zsmalloc/Makefile delete mode 100644 drivers/staging/zsmalloc/zsmalloc-main.c delete mode 100644 drivers/staging/zsmalloc/zsmalloc.h create mode 100644 include/linux/zsmalloc.h create mode 100644 lib/zsmalloc/Kconfig create mode 100644 lib/zsmalloc/Makefile create mode 100644 lib/zsmalloc/zsmalloc.c -- 1.7.9.5 ^ permalink raw reply [flat|nested] 30+ messages in thread
* [PATCH 1/3] zsmalloc: promote to lib/ 2012-09-26 8:50 ` Minchan Kim @ 2012-09-26 8:50 ` Minchan Kim -1 siblings, 0 replies; 30+ messages in thread From: Minchan Kim @ 2012-09-26 8:50 UTC (permalink / raw) To: Jens Axboe, Greg Kroah-Hartman Cc: Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel, Minchan Kim This patch promotes the slab-based zsmalloc memory allocator from the staging tree to lib/ zcache/zram depends on this allocator for storing compressed RAM pages in an efficient way under system wide memory pressure where high-order (greater than 0) page allocation are very likely to fail. For more information on zsmalloc and its internals, read the documentation at the top of the zsmalloc.c file. Signed-off-by: Minchan Kim <minchan@kernel.org> --- drivers/staging/Kconfig | 2 - drivers/staging/Makefile | 1 - drivers/staging/zcache/zcache-main.c | 4 +- drivers/staging/zram/zram_drv.h | 3 +- drivers/staging/zsmalloc/Kconfig | 10 - drivers/staging/zsmalloc/Makefile | 3 - drivers/staging/zsmalloc/zsmalloc-main.c | 1064 ------------------------------ drivers/staging/zsmalloc/zsmalloc.h | 43 -- include/linux/zsmalloc.h | 43 ++ lib/Kconfig | 2 + lib/Makefile | 1 + lib/zsmalloc/Kconfig | 18 + lib/zsmalloc/Makefile | 1 + lib/zsmalloc/zsmalloc.c | 1064 ++++++++++++++++++++++++++++++ 14 files changed, 1132 insertions(+), 1127 deletions(-) delete mode 100644 drivers/staging/zsmalloc/Kconfig delete mode 100644 drivers/staging/zsmalloc/Makefile delete mode 100644 drivers/staging/zsmalloc/zsmalloc-main.c delete mode 100644 drivers/staging/zsmalloc/zsmalloc.h create mode 100644 include/linux/zsmalloc.h create mode 100644 lib/zsmalloc/Kconfig create mode 100644 lib/zsmalloc/Makefile create mode 100644 lib/zsmalloc/zsmalloc.c diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig index 449f04a..4316ef5 100644 --- a/drivers/staging/Kconfig +++ b/drivers/staging/Kconfig @@ -78,8 +78,6 @@ source "drivers/staging/zram/Kconfig" source "drivers/staging/zcache/Kconfig" -source "drivers/staging/zsmalloc/Kconfig" - source "drivers/staging/wlags49_h2/Kconfig" source "drivers/staging/wlags49_h25/Kconfig" diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile index a19abe5..db18726 100644 --- a/drivers/staging/Makefile +++ b/drivers/staging/Makefile @@ -34,7 +34,6 @@ obj-$(CONFIG_DX_SEP) += sep/ obj-$(CONFIG_IIO) += iio/ obj-$(CONFIG_ZRAM) += zram/ obj-$(CONFIG_ZCACHE) += zcache/ -obj-$(CONFIG_ZSMALLOC) += zsmalloc/ obj-$(CONFIG_WLAGS49_H2) += wlags49_h2/ obj-$(CONFIG_WLAGS49_H25) += wlags49_h25/ obj-$(CONFIG_FB_SM7XX) += sm7xxfb/ diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c index 52b43b7..34b2c5c 100644 --- a/drivers/staging/zcache/zcache-main.c +++ b/drivers/staging/zcache/zcache-main.c @@ -32,9 +32,9 @@ #include <linux/crypto.h> #include <linux/string.h> #include <linux/idr.h> -#include "tmem.h" +#include <linux/zsmalloc.h> -#include "../zsmalloc/zsmalloc.h" +#include "tmem.h" #ifdef CONFIG_CLEANCACHE #include <linux/cleancache.h> diff --git a/drivers/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h index 572c0b1..f6d0925 100644 --- a/drivers/staging/zram/zram_drv.h +++ b/drivers/staging/zram/zram_drv.h @@ -17,8 +17,7 @@ #include <linux/spinlock.h> #include <linux/mutex.h> - -#include "../zsmalloc/zsmalloc.h" +#include <linux/zsmalloc.h> /* * Some arbitrary value. This is just to catch diff --git a/drivers/staging/zsmalloc/Kconfig b/drivers/staging/zsmalloc/Kconfig deleted file mode 100644 index 9084565..0000000 --- a/drivers/staging/zsmalloc/Kconfig +++ /dev/null @@ -1,10 +0,0 @@ -config ZSMALLOC - tristate "Memory allocator for compressed pages" - default n - help - zsmalloc is a slab-based memory allocator designed to store - compressed RAM pages. zsmalloc uses virtual memory mapping - in order to reduce fragmentation. However, this results in a - non-standard allocator interface where a handle, not a pointer, is - returned by an alloc(). This handle must be mapped in order to - access the allocated space. diff --git a/drivers/staging/zsmalloc/Makefile b/drivers/staging/zsmalloc/Makefile deleted file mode 100644 index b134848..0000000 --- a/drivers/staging/zsmalloc/Makefile +++ /dev/null @@ -1,3 +0,0 @@ -zsmalloc-y := zsmalloc-main.o - -obj-$(CONFIG_ZSMALLOC) += zsmalloc.o diff --git a/drivers/staging/zsmalloc/zsmalloc-main.c b/drivers/staging/zsmalloc/zsmalloc-main.c deleted file mode 100644 index 09a9d35..0000000 --- a/drivers/staging/zsmalloc/zsmalloc-main.c +++ /dev/null @@ -1,1064 +0,0 @@ -/* - * zsmalloc memory allocator - * - * Copyright (C) 2011 Nitin Gupta - * - * This code is released using a dual license strategy: BSD/GPL - * You can choose the license that better fits your requirements. - * - * Released under the terms of 3-clause BSD License - * Released under the terms of GNU General Public License Version 2.0 - */ - - -/* - * This allocator is designed for use with zcache and zram. Thus, the - * allocator is supposed to work well under low memory conditions. In - * particular, it never attempts higher order page allocation which is - * very likely to fail under memory pressure. On the other hand, if we - * just use single (0-order) pages, it would suffer from very high - * fragmentation -- any object of size PAGE_SIZE/2 or larger would occupy - * an entire page. This was one of the major issues with its predecessor - * (xvmalloc). - * - * To overcome these issues, zsmalloc allocates a bunch of 0-order pages - * and links them together using various 'struct page' fields. These linked - * pages act as a single higher-order page i.e. an object can span 0-order - * page boundaries. The code refers to these linked pages as a single entity - * called zspage. - * - * Following is how we use various fields and flags of underlying - * struct page(s) to form a zspage. - * - * Usage of struct page fields: - * page->first_page: points to the first component (0-order) page - * page->index (union with page->freelist): offset of the first object - * starting in this page. For the first page, this is - * always 0, so we use this field (aka freelist) to point - * to the first free object in zspage. - * page->lru: links together all component pages (except the first page) - * of a zspage - * - * For _first_ page only: - * - * page->private (union with page->first_page): refers to the - * component page after the first page - * page->freelist: points to the first free object in zspage. - * Free objects are linked together using in-place - * metadata. - * page->objects: maximum number of objects we can store in this - * zspage (class->zspage_order * PAGE_SIZE / class->size) - * page->lru: links together first pages of various zspages. - * Basically forming list of zspages in a fullness group. - * page->mapping: class index and fullness group of the zspage - * - * Usage of struct page flags: - * PG_private: identifies the first component page - * PG_private2: identifies the last component page - * - */ - -#ifdef CONFIG_ZSMALLOC_DEBUG -#define DEBUG -#endif - -#include <linux/module.h> -#include <linux/kernel.h> -#include <linux/bitops.h> -#include <linux/errno.h> -#include <linux/highmem.h> -#include <linux/init.h> -#include <linux/string.h> -#include <linux/slab.h> -#include <asm/tlbflush.h> -#include <asm/pgtable.h> -#include <linux/cpumask.h> -#include <linux/cpu.h> -#include <linux/vmalloc.h> -#include <linux/hardirq.h> -#include <linux/spinlock.h> -#include <linux/types.h> - -#include "zsmalloc.h" - -/* - * This must be power of 2 and greater than of equal to sizeof(link_free). - * These two conditions ensure that any 'struct link_free' itself doesn't - * span more than 1 page which avoids complex case of mapping 2 pages simply - * to restore link_free pointer values. - */ -#define ZS_ALIGN 8 - -/* - * A single 'zspage' is composed of up to 2^N discontiguous 0-order (single) - * pages. ZS_MAX_ZSPAGE_ORDER defines upper limit on N. - */ -#define ZS_MAX_ZSPAGE_ORDER 2 -#define ZS_MAX_PAGES_PER_ZSPAGE (_AC(1, UL) << ZS_MAX_ZSPAGE_ORDER) - -/* - * Object location (<PFN>, <obj_idx>) is encoded as - * as single (void *) handle value. - * - * Note that object index <obj_idx> is relative to system - * page <PFN> it is stored in, so for each sub-page belonging - * to a zspage, obj_idx starts with 0. - * - * This is made more complicated by various memory models and PAE. - */ - -#ifndef MAX_PHYSMEM_BITS -#ifdef CONFIG_HIGHMEM64G -#define MAX_PHYSMEM_BITS 36 -#else /* !CONFIG_HIGHMEM64G */ -/* - * If this definition of MAX_PHYSMEM_BITS is used, OBJ_INDEX_BITS will just - * be PAGE_SHIFT - */ -#define MAX_PHYSMEM_BITS BITS_PER_LONG -#endif -#endif -#define _PFN_BITS (MAX_PHYSMEM_BITS - PAGE_SHIFT) -#define OBJ_INDEX_BITS (BITS_PER_LONG - _PFN_BITS) -#define OBJ_INDEX_MASK ((_AC(1, UL) << OBJ_INDEX_BITS) - 1) - -#define MAX(a, b) ((a) >= (b) ? (a) : (b)) -/* ZS_MIN_ALLOC_SIZE must be multiple of ZS_ALIGN */ -#define ZS_MIN_ALLOC_SIZE \ - MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS)) -#define ZS_MAX_ALLOC_SIZE PAGE_SIZE - -/* - * On systems with 4K page size, this gives 254 size classes! There is a - * trader-off here: - * - Large number of size classes is potentially wasteful as free page are - * spread across these classes - * - Small number of size classes causes large internal fragmentation - * - Probably its better to use specific size classes (empirically - * determined). NOTE: all those class sizes must be set as multiple of - * ZS_ALIGN to make sure link_free itself never has to span 2 pages. - * - * ZS_MIN_ALLOC_SIZE and ZS_SIZE_CLASS_DELTA must be multiple of ZS_ALIGN - * (reason above) - */ -#define ZS_SIZE_CLASS_DELTA 16 -#define ZS_SIZE_CLASSES ((ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) / \ - ZS_SIZE_CLASS_DELTA + 1) - -/* - * We do not maintain any list for completely empty or full pages - */ -enum fullness_group { - ZS_ALMOST_FULL, - ZS_ALMOST_EMPTY, - _ZS_NR_FULLNESS_GROUPS, - - ZS_EMPTY, - ZS_FULL -}; - -/* - * We assign a page to ZS_ALMOST_EMPTY fullness group when: - * n <= N / f, where - * n = number of allocated objects - * N = total number of objects zspage can store - * f = 1/fullness_threshold_frac - * - * Similarly, we assign zspage to: - * ZS_ALMOST_FULL when n > N / f - * ZS_EMPTY when n == 0 - * ZS_FULL when n == N - * - * (see: fix_fullness_group()) - */ -static const int fullness_threshold_frac = 4; - -struct size_class { - /* - * Size of objects stored in this class. Must be multiple - * of ZS_ALIGN. - */ - int size; - unsigned int index; - - /* Number of PAGE_SIZE sized pages to combine to form a 'zspage' */ - int pages_per_zspage; - - spinlock_t lock; - - /* stats */ - u64 pages_allocated; - - struct page *fullness_list[_ZS_NR_FULLNESS_GROUPS]; -}; - -/* - * Placed within free objects to form a singly linked list. - * For every zspage, first_page->freelist gives head of this list. - * - * This must be power of 2 and less than or equal to ZS_ALIGN - */ -struct link_free { - /* Handle of next free chunk (encodes <PFN, obj_idx>) */ - void *next; -}; - -struct zs_pool { - struct size_class size_class[ZS_SIZE_CLASSES]; - - gfp_t flags; /* allocation flags used when growing pool */ - const char *name; -}; - -/* - * A zspage's class index and fullness group - * are encoded in its (first)page->mapping - */ -#define CLASS_IDX_BITS 28 -#define FULLNESS_BITS 4 -#define CLASS_IDX_MASK ((1 << CLASS_IDX_BITS) - 1) -#define FULLNESS_MASK ((1 << FULLNESS_BITS) - 1) - -/* - * By default, zsmalloc uses a copy-based object mapping method to access - * allocations that span two pages. However, if a particular architecture - * 1) Implements local_flush_tlb_kernel_range() and 2) Performs VM mapping - * faster than copying, then it should be added here so that - * USE_PGTABLE_MAPPING is defined. This causes zsmalloc to use page table - * mapping rather than copying - * for object mapping. -*/ -#if defined(CONFIG_ARM) -#define USE_PGTABLE_MAPPING -#endif - -struct mapping_area { -#ifdef USE_PGTABLE_MAPPING - struct vm_struct *vm; /* vm area for mapping object that span pages */ -#else - char *vm_buf; /* copy buffer for objects that span pages */ -#endif - char *vm_addr; /* address of kmap_atomic()'ed pages */ - enum zs_mapmode vm_mm; /* mapping mode */ -}; - - -/* per-cpu VM mapping areas for zspage accesses that cross page boundaries */ -static DEFINE_PER_CPU(struct mapping_area, zs_map_area); - -static int is_first_page(struct page *page) -{ - return PagePrivate(page); -} - -static int is_last_page(struct page *page) -{ - return PagePrivate2(page); -} - -static void get_zspage_mapping(struct page *page, unsigned int *class_idx, - enum fullness_group *fullness) -{ - unsigned long m; - BUG_ON(!is_first_page(page)); - - m = (unsigned long)page->mapping; - *fullness = m & FULLNESS_MASK; - *class_idx = (m >> FULLNESS_BITS) & CLASS_IDX_MASK; -} - -static void set_zspage_mapping(struct page *page, unsigned int class_idx, - enum fullness_group fullness) -{ - unsigned long m; - BUG_ON(!is_first_page(page)); - - m = ((class_idx & CLASS_IDX_MASK) << FULLNESS_BITS) | - (fullness & FULLNESS_MASK); - page->mapping = (struct address_space *)m; -} - -static int get_size_class_index(int size) -{ - int idx = 0; - - if (likely(size > ZS_MIN_ALLOC_SIZE)) - idx = DIV_ROUND_UP(size - ZS_MIN_ALLOC_SIZE, - ZS_SIZE_CLASS_DELTA); - - return idx; -} - -static enum fullness_group get_fullness_group(struct page *page) -{ - int inuse, max_objects; - enum fullness_group fg; - BUG_ON(!is_first_page(page)); - - inuse = page->inuse; - max_objects = page->objects; - - if (inuse == 0) - fg = ZS_EMPTY; - else if (inuse == max_objects) - fg = ZS_FULL; - else if (inuse <= max_objects / fullness_threshold_frac) - fg = ZS_ALMOST_EMPTY; - else - fg = ZS_ALMOST_FULL; - - return fg; -} - -static void insert_zspage(struct page *page, struct size_class *class, - enum fullness_group fullness) -{ - struct page **head; - - BUG_ON(!is_first_page(page)); - - if (fullness >= _ZS_NR_FULLNESS_GROUPS) - return; - - head = &class->fullness_list[fullness]; - if (*head) - list_add_tail(&page->lru, &(*head)->lru); - - *head = page; -} - -static void remove_zspage(struct page *page, struct size_class *class, - enum fullness_group fullness) -{ - struct page **head; - - BUG_ON(!is_first_page(page)); - - if (fullness >= _ZS_NR_FULLNESS_GROUPS) - return; - - head = &class->fullness_list[fullness]; - BUG_ON(!*head); - if (list_empty(&(*head)->lru)) - *head = NULL; - else if (*head == page) - *head = (struct page *)list_entry((*head)->lru.next, - struct page, lru); - - list_del_init(&page->lru); -} - -static enum fullness_group fix_fullness_group(struct zs_pool *pool, - struct page *page) -{ - int class_idx; - struct size_class *class; - enum fullness_group currfg, newfg; - - BUG_ON(!is_first_page(page)); - - get_zspage_mapping(page, &class_idx, &currfg); - newfg = get_fullness_group(page); - if (newfg == currfg) - goto out; - - class = &pool->size_class[class_idx]; - remove_zspage(page, class, currfg); - insert_zspage(page, class, newfg); - set_zspage_mapping(page, class_idx, newfg); - -out: - return newfg; -} - -/* - * We have to decide on how many pages to link together - * to form a zspage for each size class. This is important - * to reduce wastage due to unusable space left at end of - * each zspage which is given as: - * wastage = Zp - Zp % size_class - * where Zp = zspage size = k * PAGE_SIZE where k = 1, 2, ... - * - * For example, for size class of 3/8 * PAGE_SIZE, we should - * link together 3 PAGE_SIZE sized pages to form a zspage - * since then we can perfectly fit in 8 such objects. - */ -static int get_pages_per_zspage(int class_size) -{ - int i, max_usedpc = 0; - /* zspage order which gives maximum used size per KB */ - int max_usedpc_order = 1; - - for (i = 1; i <= ZS_MAX_PAGES_PER_ZSPAGE; i++) { - int zspage_size; - int waste, usedpc; - - zspage_size = i * PAGE_SIZE; - waste = zspage_size % class_size; - usedpc = (zspage_size - waste) * 100 / zspage_size; - - if (usedpc > max_usedpc) { - max_usedpc = usedpc; - max_usedpc_order = i; - } - } - - return max_usedpc_order; -} - -/* - * A single 'zspage' is composed of many system pages which are - * linked together using fields in struct page. This function finds - * the first/head page, given any component page of a zspage. - */ -static struct page *get_first_page(struct page *page) -{ - if (is_first_page(page)) - return page; - else - return page->first_page; -} - -static struct page *get_next_page(struct page *page) -{ - struct page *next; - - if (is_last_page(page)) - next = NULL; - else if (is_first_page(page)) - next = (struct page *)page->private; - else - next = list_entry(page->lru.next, struct page, lru); - - return next; -} - -/* Encode <page, obj_idx> as a single handle value */ -static void *obj_location_to_handle(struct page *page, unsigned long obj_idx) -{ - unsigned long handle; - - if (!page) { - BUG_ON(obj_idx); - return NULL; - } - - handle = page_to_pfn(page) << OBJ_INDEX_BITS; - handle |= (obj_idx & OBJ_INDEX_MASK); - - return (void *)handle; -} - -/* Decode <page, obj_idx> pair from the given object handle */ -static void obj_handle_to_location(unsigned long handle, struct page **page, - unsigned long *obj_idx) -{ - *page = pfn_to_page(handle >> OBJ_INDEX_BITS); - *obj_idx = handle & OBJ_INDEX_MASK; -} - -static unsigned long obj_idx_to_offset(struct page *page, - unsigned long obj_idx, int class_size) -{ - unsigned long off = 0; - - if (!is_first_page(page)) - off = page->index; - - return off + obj_idx * class_size; -} - -static void reset_page(struct page *page) -{ - clear_bit(PG_private, &page->flags); - clear_bit(PG_private_2, &page->flags); - set_page_private(page, 0); - page->mapping = NULL; - page->freelist = NULL; - reset_page_mapcount(page); -} - -static void free_zspage(struct page *first_page) -{ - struct page *nextp, *tmp, *head_extra; - - BUG_ON(!is_first_page(first_page)); - BUG_ON(first_page->inuse); - - head_extra = (struct page *)page_private(first_page); - - reset_page(first_page); - __free_page(first_page); - - /* zspage with only 1 system page */ - if (!head_extra) - return; - - list_for_each_entry_safe(nextp, tmp, &head_extra->lru, lru) { - list_del(&nextp->lru); - reset_page(nextp); - __free_page(nextp); - } - reset_page(head_extra); - __free_page(head_extra); -} - -/* Initialize a newly allocated zspage */ -static void init_zspage(struct page *first_page, struct size_class *class) -{ - unsigned long off = 0; - struct page *page = first_page; - - BUG_ON(!is_first_page(first_page)); - while (page) { - struct page *next_page; - struct link_free *link; - unsigned int i, objs_on_page; - - /* - * page->index stores offset of first object starting - * in the page. For the first page, this is always 0, - * so we use first_page->index (aka ->freelist) to store - * head of corresponding zspage's freelist. - */ - if (page != first_page) - page->index = off; - - link = (struct link_free *)kmap_atomic(page) + - off / sizeof(*link); - objs_on_page = (PAGE_SIZE - off) / class->size; - - for (i = 1; i <= objs_on_page; i++) { - off += class->size; - if (off < PAGE_SIZE) { - link->next = obj_location_to_handle(page, i); - link += class->size / sizeof(*link); - } - } - - /* - * We now come to the last (full or partial) object on this - * page, which must point to the first object on the next - * page (if present) - */ - next_page = get_next_page(page); - link->next = obj_location_to_handle(next_page, 0); - kunmap_atomic(link); - page = next_page; - off = (off + class->size) % PAGE_SIZE; - } -} - -/* - * Allocate a zspage for the given size class - */ -static struct page *alloc_zspage(struct size_class *class, gfp_t flags) -{ - int i, error; - struct page *first_page = NULL, *uninitialized_var(prev_page); - - /* - * Allocate individual pages and link them together as: - * 1. first page->private = first sub-page - * 2. all sub-pages are linked together using page->lru - * 3. each sub-page is linked to the first page using page->first_page - * - * For each size class, First/Head pages are linked together using - * page->lru. Also, we set PG_private to identify the first page - * (i.e. no other sub-page has this flag set) and PG_private_2 to - * identify the last page. - */ - error = -ENOMEM; - for (i = 0; i < class->pages_per_zspage; i++) { - struct page *page; - - page = alloc_page(flags); - if (!page) - goto cleanup; - - INIT_LIST_HEAD(&page->lru); - if (i == 0) { /* first page */ - SetPagePrivate(page); - set_page_private(page, 0); - first_page = page; - first_page->inuse = 0; - } - if (i == 1) - first_page->private = (unsigned long)page; - if (i >= 1) - page->first_page = first_page; - if (i >= 2) - list_add(&page->lru, &prev_page->lru); - if (i == class->pages_per_zspage - 1) /* last page */ - SetPagePrivate2(page); - prev_page = page; - } - - init_zspage(first_page, class); - - first_page->freelist = obj_location_to_handle(first_page, 0); - /* Maximum number of objects we can store in this zspage */ - first_page->objects = class->pages_per_zspage * PAGE_SIZE / class->size; - - error = 0; /* Success */ - -cleanup: - if (unlikely(error) && first_page) { - free_zspage(first_page); - first_page = NULL; - } - - return first_page; -} - -static struct page *find_get_zspage(struct size_class *class) -{ - int i; - struct page *page; - - for (i = 0; i < _ZS_NR_FULLNESS_GROUPS; i++) { - page = class->fullness_list[i]; - if (page) - break; - } - - return page; -} - -#ifdef USE_PGTABLE_MAPPING -static inline int __zs_cpu_up(struct mapping_area *area) -{ - /* - * Make sure we don't leak memory if a cpu UP notification - * and zs_init() race and both call zs_cpu_up() on the same cpu - */ - if (area->vm) - return 0; - area->vm = alloc_vm_area(PAGE_SIZE * 2, NULL); - if (!area->vm) - return -ENOMEM; - return 0; -} - -static inline void __zs_cpu_down(struct mapping_area *area) -{ - if (area->vm) - free_vm_area(area->vm); - area->vm = NULL; -} - -static inline void *__zs_map_object(struct mapping_area *area, - struct page *pages[2], int off, int size) -{ - BUG_ON(map_vm_area(area->vm, PAGE_KERNEL, &pages)); - area->vm_addr = area->vm->addr; - return area->vm_addr + off; -} - -static inline void __zs_unmap_object(struct mapping_area *area, - struct page *pages[2], int off, int size) -{ - unsigned long addr = (unsigned long)area->vm_addr; - unsigned long end = addr + (PAGE_SIZE * 2); - - flush_cache_vunmap(addr, end); - unmap_kernel_range_noflush(addr, PAGE_SIZE * 2); - local_flush_tlb_kernel_range(addr, end); -} - -#else /* USE_PGTABLE_MAPPING */ - -static inline int __zs_cpu_up(struct mapping_area *area) -{ - /* - * Make sure we don't leak memory if a cpu UP notification - * and zs_init() race and both call zs_cpu_up() on the same cpu - */ - if (area->vm_buf) - return 0; - area->vm_buf = (char *)__get_free_page(GFP_KERNEL); - if (!area->vm_buf) - return -ENOMEM; - return 0; -} - -static inline void __zs_cpu_down(struct mapping_area *area) -{ - if (area->vm_buf) - free_page((unsigned long)area->vm_buf); - area->vm_buf = NULL; -} - -static void *__zs_map_object(struct mapping_area *area, - struct page *pages[2], int off, int size) -{ - int sizes[2]; - void *addr; - char *buf = area->vm_buf; - - /* disable page faults to match kmap_atomic() return conditions */ - pagefault_disable(); - - /* no read fastpath */ - if (area->vm_mm == ZS_MM_WO) - goto out; - - sizes[0] = PAGE_SIZE - off; - sizes[1] = size - sizes[0]; - - /* copy object to per-cpu buffer */ - addr = kmap_atomic(pages[0]); - memcpy(buf, addr + off, sizes[0]); - kunmap_atomic(addr); - addr = kmap_atomic(pages[1]); - memcpy(buf + sizes[0], addr, sizes[1]); - kunmap_atomic(addr); -out: - return area->vm_buf; -} - -static void __zs_unmap_object(struct mapping_area *area, - struct page *pages[2], int off, int size) -{ - int sizes[2]; - void *addr; - char *buf = area->vm_buf; - - /* no write fastpath */ - if (area->vm_mm == ZS_MM_RO) - goto out; - - sizes[0] = PAGE_SIZE - off; - sizes[1] = size - sizes[0]; - - /* copy per-cpu buffer to object */ - addr = kmap_atomic(pages[0]); - memcpy(addr + off, buf, sizes[0]); - kunmap_atomic(addr); - addr = kmap_atomic(pages[1]); - memcpy(addr, buf + sizes[0], sizes[1]); - kunmap_atomic(addr); - -out: - /* enable page faults to match kunmap_atomic() return conditions */ - pagefault_enable(); -} - -#endif /* USE_PGTABLE_MAPPING */ - -static int zs_cpu_notifier(struct notifier_block *nb, unsigned long action, - void *pcpu) -{ - int ret, cpu = (long)pcpu; - struct mapping_area *area; - - switch (action) { - case CPU_UP_PREPARE: - area = &per_cpu(zs_map_area, cpu); - ret = __zs_cpu_up(area); - if (ret) - return notifier_from_errno(ret); - break; - case CPU_DEAD: - case CPU_UP_CANCELED: - area = &per_cpu(zs_map_area, cpu); - __zs_cpu_down(area); - break; - } - - return NOTIFY_OK; -} - -static struct notifier_block zs_cpu_nb = { - .notifier_call = zs_cpu_notifier -}; - -static void zs_exit(void) -{ - int cpu; - - for_each_online_cpu(cpu) - zs_cpu_notifier(NULL, CPU_DEAD, (void *)(long)cpu); - unregister_cpu_notifier(&zs_cpu_nb); -} - -static int zs_init(void) -{ - int cpu, ret; - - register_cpu_notifier(&zs_cpu_nb); - for_each_online_cpu(cpu) { - ret = zs_cpu_notifier(NULL, CPU_UP_PREPARE, (void *)(long)cpu); - if (notifier_to_errno(ret)) - goto fail; - } - return 0; -fail: - zs_exit(); - return notifier_to_errno(ret); -} - -struct zs_pool *zs_create_pool(const char *name, gfp_t flags) -{ - int i, ovhd_size; - struct zs_pool *pool; - - if (!name) - return NULL; - - ovhd_size = roundup(sizeof(*pool), PAGE_SIZE); - pool = kzalloc(ovhd_size, GFP_KERNEL); - if (!pool) - return NULL; - - for (i = 0; i < ZS_SIZE_CLASSES; i++) { - int size; - struct size_class *class; - - size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA; - if (size > ZS_MAX_ALLOC_SIZE) - size = ZS_MAX_ALLOC_SIZE; - - class = &pool->size_class[i]; - class->size = size; - class->index = i; - spin_lock_init(&class->lock); - class->pages_per_zspage = get_pages_per_zspage(size); - - } - - pool->flags = flags; - pool->name = name; - - return pool; -} -EXPORT_SYMBOL_GPL(zs_create_pool); - -void zs_destroy_pool(struct zs_pool *pool) -{ - int i; - - for (i = 0; i < ZS_SIZE_CLASSES; i++) { - int fg; - struct size_class *class = &pool->size_class[i]; - - for (fg = 0; fg < _ZS_NR_FULLNESS_GROUPS; fg++) { - if (class->fullness_list[fg]) { - pr_info("Freeing non-empty class with size " - "%db, fullness group %d\n", - class->size, fg); - } - } - } - kfree(pool); -} -EXPORT_SYMBOL_GPL(zs_destroy_pool); - -/** - * zs_malloc - Allocate block of given size from pool. - * @pool: pool to allocate from - * @size: size of block to allocate - * - * On success, handle to the allocated object is returned, - * otherwise 0. - * Allocation requests with size > ZS_MAX_ALLOC_SIZE will fail. - */ -unsigned long zs_malloc(struct zs_pool *pool, size_t size) -{ - unsigned long obj; - struct link_free *link; - int class_idx; - struct size_class *class; - - struct page *first_page, *m_page; - unsigned long m_objidx, m_offset; - - if (unlikely(!size || size > ZS_MAX_ALLOC_SIZE)) - return 0; - - class_idx = get_size_class_index(size); - class = &pool->size_class[class_idx]; - BUG_ON(class_idx != class->index); - - spin_lock(&class->lock); - first_page = find_get_zspage(class); - - if (!first_page) { - spin_unlock(&class->lock); - first_page = alloc_zspage(class, pool->flags); - if (unlikely(!first_page)) - return 0; - - set_zspage_mapping(first_page, class->index, ZS_EMPTY); - spin_lock(&class->lock); - class->pages_allocated += class->pages_per_zspage; - } - - obj = (unsigned long)first_page->freelist; - obj_handle_to_location(obj, &m_page, &m_objidx); - m_offset = obj_idx_to_offset(m_page, m_objidx, class->size); - - link = (struct link_free *)kmap_atomic(m_page) + - m_offset / sizeof(*link); - first_page->freelist = link->next; - memset(link, POISON_INUSE, sizeof(*link)); - kunmap_atomic(link); - - first_page->inuse++; - /* Now move the zspage to another fullness group, if required */ - fix_fullness_group(pool, first_page); - spin_unlock(&class->lock); - - return obj; -} -EXPORT_SYMBOL_GPL(zs_malloc); - -void zs_free(struct zs_pool *pool, unsigned long obj) -{ - struct link_free *link; - struct page *first_page, *f_page; - unsigned long f_objidx, f_offset; - - int class_idx; - struct size_class *class; - enum fullness_group fullness; - - if (unlikely(!obj)) - return; - - obj_handle_to_location(obj, &f_page, &f_objidx); - first_page = get_first_page(f_page); - - get_zspage_mapping(first_page, &class_idx, &fullness); - class = &pool->size_class[class_idx]; - f_offset = obj_idx_to_offset(f_page, f_objidx, class->size); - - spin_lock(&class->lock); - - /* Insert this object in containing zspage's freelist */ - link = (struct link_free *)((unsigned char *)kmap_atomic(f_page) - + f_offset); - link->next = first_page->freelist; - kunmap_atomic(link); - first_page->freelist = (void *)obj; - - first_page->inuse--; - fullness = fix_fullness_group(pool, first_page); - - if (fullness == ZS_EMPTY) - class->pages_allocated -= class->pages_per_zspage; - - spin_unlock(&class->lock); - - if (fullness == ZS_EMPTY) - free_zspage(first_page); -} -EXPORT_SYMBOL_GPL(zs_free); - -/** - * zs_map_object - get address of allocated object from handle. - * @pool: pool from which the object was allocated - * @handle: handle returned from zs_malloc - * - * Before using an object allocated from zs_malloc, it must be mapped using - * this function. When done with the object, it must be unmapped using - * zs_unmap_object. - * - * Only one object can be mapped per cpu at a time. There is no protection - * against nested mappings. - * - * This function returns with preemption and page faults disabled. -*/ -void *zs_map_object(struct zs_pool *pool, unsigned long handle, - enum zs_mapmode mm) -{ - struct page *page; - unsigned long obj_idx, off; - - unsigned int class_idx; - enum fullness_group fg; - struct size_class *class; - struct mapping_area *area; - struct page *pages[2]; - - BUG_ON(!handle); - - /* - * Because we use per-cpu mapping areas shared among the - * pools/users, we can't allow mapping in interrupt context - * because it can corrupt another users mappings. - */ - BUG_ON(in_interrupt()); - - obj_handle_to_location(handle, &page, &obj_idx); - get_zspage_mapping(get_first_page(page), &class_idx, &fg); - class = &pool->size_class[class_idx]; - off = obj_idx_to_offset(page, obj_idx, class->size); - - area = &get_cpu_var(zs_map_area); - area->vm_mm = mm; - if (off + class->size <= PAGE_SIZE) { - /* this object is contained entirely within a page */ - area->vm_addr = kmap_atomic(page); - return area->vm_addr + off; - } - - /* this object spans two pages */ - pages[0] = page; - pages[1] = get_next_page(page); - BUG_ON(!pages[1]); - - return __zs_map_object(area, pages, off, class->size); -} -EXPORT_SYMBOL_GPL(zs_map_object); - -void zs_unmap_object(struct zs_pool *pool, unsigned long handle) -{ - struct page *page; - unsigned long obj_idx, off; - - unsigned int class_idx; - enum fullness_group fg; - struct size_class *class; - struct mapping_area *area; - - BUG_ON(!handle); - - obj_handle_to_location(handle, &page, &obj_idx); - get_zspage_mapping(get_first_page(page), &class_idx, &fg); - class = &pool->size_class[class_idx]; - off = obj_idx_to_offset(page, obj_idx, class->size); - - area = &__get_cpu_var(zs_map_area); - if (off + class->size <= PAGE_SIZE) - kunmap_atomic(area->vm_addr); - else { - struct page *pages[2]; - - pages[0] = page; - pages[1] = get_next_page(page); - BUG_ON(!pages[1]); - - __zs_unmap_object(area, pages, off, class->size); - } - put_cpu_var(zs_map_area); -} -EXPORT_SYMBOL_GPL(zs_unmap_object); - -u64 zs_get_total_size_bytes(struct zs_pool *pool) -{ - int i; - u64 npages = 0; - - for (i = 0; i < ZS_SIZE_CLASSES; i++) - npages += pool->size_class[i].pages_allocated; - - return npages << PAGE_SHIFT; -} -EXPORT_SYMBOL_GPL(zs_get_total_size_bytes); - -module_init(zs_init); -module_exit(zs_exit); - -MODULE_LICENSE("Dual BSD/GPL"); -MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); diff --git a/drivers/staging/zsmalloc/zsmalloc.h b/drivers/staging/zsmalloc/zsmalloc.h deleted file mode 100644 index de2e8bf..0000000 --- a/drivers/staging/zsmalloc/zsmalloc.h +++ /dev/null @@ -1,43 +0,0 @@ -/* - * zsmalloc memory allocator - * - * Copyright (C) 2011 Nitin Gupta - * - * This code is released using a dual license strategy: BSD/GPL - * You can choose the license that better fits your requirements. - * - * Released under the terms of 3-clause BSD License - * Released under the terms of GNU General Public License Version 2.0 - */ - -#ifndef _ZS_MALLOC_H_ -#define _ZS_MALLOC_H_ - -#include <linux/types.h> - -/* - * zsmalloc mapping modes - * - * NOTE: These only make a difference when a mapped object spans pages -*/ -enum zs_mapmode { - ZS_MM_RW, /* normal read-write mapping */ - ZS_MM_RO, /* read-only (no copy-out at unmap time) */ - ZS_MM_WO /* write-only (no copy-in at map time) */ -}; - -struct zs_pool; - -struct zs_pool *zs_create_pool(const char *name, gfp_t flags); -void zs_destroy_pool(struct zs_pool *pool); - -unsigned long zs_malloc(struct zs_pool *pool, size_t size); -void zs_free(struct zs_pool *pool, unsigned long obj); - -void *zs_map_object(struct zs_pool *pool, unsigned long handle, - enum zs_mapmode mm); -void zs_unmap_object(struct zs_pool *pool, unsigned long handle); - -u64 zs_get_total_size_bytes(struct zs_pool *pool); - -#endif diff --git a/include/linux/zsmalloc.h b/include/linux/zsmalloc.h new file mode 100644 index 0000000..de2e8bf --- /dev/null +++ b/include/linux/zsmalloc.h @@ -0,0 +1,43 @@ +/* + * zsmalloc memory allocator + * + * Copyright (C) 2011 Nitin Gupta + * + * This code is released using a dual license strategy: BSD/GPL + * You can choose the license that better fits your requirements. + * + * Released under the terms of 3-clause BSD License + * Released under the terms of GNU General Public License Version 2.0 + */ + +#ifndef _ZS_MALLOC_H_ +#define _ZS_MALLOC_H_ + +#include <linux/types.h> + +/* + * zsmalloc mapping modes + * + * NOTE: These only make a difference when a mapped object spans pages +*/ +enum zs_mapmode { + ZS_MM_RW, /* normal read-write mapping */ + ZS_MM_RO, /* read-only (no copy-out at unmap time) */ + ZS_MM_WO /* write-only (no copy-in at map time) */ +}; + +struct zs_pool; + +struct zs_pool *zs_create_pool(const char *name, gfp_t flags); +void zs_destroy_pool(struct zs_pool *pool); + +unsigned long zs_malloc(struct zs_pool *pool, size_t size); +void zs_free(struct zs_pool *pool, unsigned long obj); + +void *zs_map_object(struct zs_pool *pool, unsigned long handle, + enum zs_mapmode mm); +void zs_unmap_object(struct zs_pool *pool, unsigned long handle); + +u64 zs_get_total_size_bytes(struct zs_pool *pool); + +#endif diff --git a/lib/Kconfig b/lib/Kconfig index bb94c1b..d95da41 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -216,6 +216,8 @@ config DECOMPRESS_LZO config GENERIC_ALLOCATOR boolean +source "lib/zsmalloc/Kconfig" + # # reed solomon support is select'ed if needed # diff --git a/lib/Makefile b/lib/Makefile index 3128e35..dd26077 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -64,6 +64,7 @@ obj-$(CONFIG_CRC7) += crc7.o obj-$(CONFIG_LIBCRC32C) += libcrc32c.o obj-$(CONFIG_CRC8) += crc8.o obj-$(CONFIG_GENERIC_ALLOCATOR) += genalloc.o +obj-$(CONFIG_ZSMALLOC) += zsmalloc/ obj-$(CONFIG_ZLIB_INFLATE) += zlib_inflate/ obj-$(CONFIG_ZLIB_DEFLATE) += zlib_deflate/ diff --git a/lib/zsmalloc/Kconfig b/lib/zsmalloc/Kconfig new file mode 100644 index 0000000..b6abd31 --- /dev/null +++ b/lib/zsmalloc/Kconfig @@ -0,0 +1,18 @@ +config ZSMALLOC + tristate "Memory allocator for compressed pages" + default n + help + zsmalloc is a slab-based memory allocator designed to store + compressed RAM pages. zsmalloc uses a memory pool that combines + single pages into higher order pages by linking them together + using the fields of the struct page. Allocations are then + mapped through copy buffers or VM mapping, in order to reduce + memory pool fragmentation and increase allocation success rate under + memory pressure. + + This results in a non-standard allocator interface where + a handle, not a pointer, is returned by the allocation function. + This handle must be mapped in order to access the allocated space. + + If unsure, say N. + diff --git a/lib/zsmalloc/Makefile b/lib/zsmalloc/Makefile new file mode 100644 index 0000000..d02d3a5 --- /dev/null +++ b/lib/zsmalloc/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_ZSMALLOC) += zsmalloc.o diff --git a/lib/zsmalloc/zsmalloc.c b/lib/zsmalloc/zsmalloc.c new file mode 100644 index 0000000..2cde21e --- /dev/null +++ b/lib/zsmalloc/zsmalloc.c @@ -0,0 +1,1064 @@ +/* + * zsmalloc memory allocator + * + * Copyright (C) 2011 Nitin Gupta + * + * This code is released using a dual license strategy: BSD/GPL + * You can choose the license that better fits your requirements. + * + * Released under the terms of 3-clause BSD License + * Released under the terms of GNU General Public License Version 2.0 + */ + + +/* + * This allocator is designed for use with zcache and zram. Thus, the + * allocator is supposed to work well under low memory conditions. In + * particular, it never attempts higher order page allocation which is + * very likely to fail under memory pressure. On the other hand, if we + * just use single (0-order) pages, it would suffer from very high + * fragmentation -- any object of size PAGE_SIZE/2 or larger would occupy + * an entire page. This was one of the major issues with its predecessor + * (xvmalloc). + * + * To overcome these issues, zsmalloc allocates a bunch of 0-order pages + * and links them together using various 'struct page' fields. These linked + * pages act as a single higher-order page i.e. an object can span 0-order + * page boundaries. The code refers to these linked pages as a single entity + * called zspage. + * + * Following is how we use various fields and flags of underlying + * struct page(s) to form a zspage. + * + * Usage of struct page fields: + * page->first_page: points to the first component (0-order) page + * page->index (union with page->freelist): offset of the first object + * starting in this page. For the first page, this is + * always 0, so we use this field (aka freelist) to point + * to the first free object in zspage. + * page->lru: links together all component pages (except the first page) + * of a zspage + * + * For _first_ page only: + * + * page->private (union with page->first_page): refers to the + * component page after the first page + * page->freelist: points to the first free object in zspage. + * Free objects are linked together using in-place + * metadata. + * page->objects: maximum number of objects we can store in this + * zspage (class->zspage_order * PAGE_SIZE / class->size) + * page->lru: links together first pages of various zspages. + * Basically forming list of zspages in a fullness group. + * page->mapping: class index and fullness group of the zspage + * + * Usage of struct page flags: + * PG_private: identifies the first component page + * PG_private2: identifies the last component page + * + */ + +#ifdef CONFIG_ZSMALLOC_DEBUG +#define DEBUG +#endif + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/bitops.h> +#include <linux/errno.h> +#include <linux/highmem.h> +#include <linux/init.h> +#include <linux/string.h> +#include <linux/slab.h> +#include <asm/tlbflush.h> +#include <asm/pgtable.h> +#include <linux/cpumask.h> +#include <linux/cpu.h> +#include <linux/vmalloc.h> +#include <linux/hardirq.h> +#include <linux/spinlock.h> +#include <linux/types.h> + +#include <linux/zsmalloc.h> + +/* + * This must be power of 2 and greater than of equal to sizeof(link_free). + * These two conditions ensure that any 'struct link_free' itself doesn't + * span more than 1 page which avoids complex case of mapping 2 pages simply + * to restore link_free pointer values. + */ +#define ZS_ALIGN 8 + +/* + * A single 'zspage' is composed of up to 2^N discontiguous 0-order (single) + * pages. ZS_MAX_ZSPAGE_ORDER defines upper limit on N. + */ +#define ZS_MAX_ZSPAGE_ORDER 2 +#define ZS_MAX_PAGES_PER_ZSPAGE (_AC(1, UL) << ZS_MAX_ZSPAGE_ORDER) + +/* + * Object location (<PFN>, <obj_idx>) is encoded as + * as single (void *) handle value. + * + * Note that object index <obj_idx> is relative to system + * page <PFN> it is stored in, so for each sub-page belonging + * to a zspage, obj_idx starts with 0. + * + * This is made more complicated by various memory models and PAE. + */ + +#ifndef MAX_PHYSMEM_BITS +#ifdef CONFIG_HIGHMEM64G +#define MAX_PHYSMEM_BITS 36 +#else /* !CONFIG_HIGHMEM64G */ +/* + * If this definition of MAX_PHYSMEM_BITS is used, OBJ_INDEX_BITS will just + * be PAGE_SHIFT + */ +#define MAX_PHYSMEM_BITS BITS_PER_LONG +#endif +#endif +#define _PFN_BITS (MAX_PHYSMEM_BITS - PAGE_SHIFT) +#define OBJ_INDEX_BITS (BITS_PER_LONG - _PFN_BITS) +#define OBJ_INDEX_MASK ((_AC(1, UL) << OBJ_INDEX_BITS) - 1) + +#define MAX(a, b) ((a) >= (b) ? (a) : (b)) +/* ZS_MIN_ALLOC_SIZE must be multiple of ZS_ALIGN */ +#define ZS_MIN_ALLOC_SIZE \ + MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS)) +#define ZS_MAX_ALLOC_SIZE PAGE_SIZE + +/* + * On systems with 4K page size, this gives 254 size classes! There is a + * trader-off here: + * - Large number of size classes is potentially wasteful as free page are + * spread across these classes + * - Small number of size classes causes large internal fragmentation + * - Probably its better to use specific size classes (empirically + * determined). NOTE: all those class sizes must be set as multiple of + * ZS_ALIGN to make sure link_free itself never has to span 2 pages. + * + * ZS_MIN_ALLOC_SIZE and ZS_SIZE_CLASS_DELTA must be multiple of ZS_ALIGN + * (reason above) + */ +#define ZS_SIZE_CLASS_DELTA 16 +#define ZS_SIZE_CLASSES ((ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) / \ + ZS_SIZE_CLASS_DELTA + 1) + +/* + * We do not maintain any list for completely empty or full pages + */ +enum fullness_group { + ZS_ALMOST_FULL, + ZS_ALMOST_EMPTY, + _ZS_NR_FULLNESS_GROUPS, + + ZS_EMPTY, + ZS_FULL +}; + +/* + * We assign a page to ZS_ALMOST_EMPTY fullness group when: + * n <= N / f, where + * n = number of allocated objects + * N = total number of objects zspage can store + * f = 1/fullness_threshold_frac + * + * Similarly, we assign zspage to: + * ZS_ALMOST_FULL when n > N / f + * ZS_EMPTY when n == 0 + * ZS_FULL when n == N + * + * (see: fix_fullness_group()) + */ +static const int fullness_threshold_frac = 4; + +struct size_class { + /* + * Size of objects stored in this class. Must be multiple + * of ZS_ALIGN. + */ + int size; + unsigned int index; + + /* Number of PAGE_SIZE sized pages to combine to form a 'zspage' */ + int pages_per_zspage; + + spinlock_t lock; + + /* stats */ + u64 pages_allocated; + + struct page *fullness_list[_ZS_NR_FULLNESS_GROUPS]; +}; + +/* + * Placed within free objects to form a singly linked list. + * For every zspage, first_page->freelist gives head of this list. + * + * This must be power of 2 and less than or equal to ZS_ALIGN + */ +struct link_free { + /* Handle of next free chunk (encodes <PFN, obj_idx>) */ + void *next; +}; + +struct zs_pool { + struct size_class size_class[ZS_SIZE_CLASSES]; + + gfp_t flags; /* allocation flags used when growing pool */ + const char *name; +}; + +/* + * A zspage's class index and fullness group + * are encoded in its (first)page->mapping + */ +#define CLASS_IDX_BITS 28 +#define FULLNESS_BITS 4 +#define CLASS_IDX_MASK ((1 << CLASS_IDX_BITS) - 1) +#define FULLNESS_MASK ((1 << FULLNESS_BITS) - 1) + +/* + * By default, zsmalloc uses a copy-based object mapping method to access + * allocations that span two pages. However, if a particular architecture + * 1) Implements local_flush_tlb_kernel_range() and 2) Performs VM mapping + * faster than copying, then it should be added here so that + * USE_PGTABLE_MAPPING is defined. This causes zsmalloc to use page table + * mapping rather than copying + * for object mapping. +*/ +#if defined(CONFIG_ARM) +#define USE_PGTABLE_MAPPING +#endif + +struct mapping_area { +#ifdef USE_PGTABLE_MAPPING + struct vm_struct *vm; /* vm area for mapping object that span pages */ +#else + char *vm_buf; /* copy buffer for objects that span pages */ +#endif + char *vm_addr; /* address of kmap_atomic()'ed pages */ + enum zs_mapmode vm_mm; /* mapping mode */ +}; + + +/* per-cpu VM mapping areas for zspage accesses that cross page boundaries */ +static DEFINE_PER_CPU(struct mapping_area, zs_map_area); + +static int is_first_page(struct page *page) +{ + return PagePrivate(page); +} + +static int is_last_page(struct page *page) +{ + return PagePrivate2(page); +} + +static void get_zspage_mapping(struct page *page, unsigned int *class_idx, + enum fullness_group *fullness) +{ + unsigned long m; + BUG_ON(!is_first_page(page)); + + m = (unsigned long)page->mapping; + *fullness = m & FULLNESS_MASK; + *class_idx = (m >> FULLNESS_BITS) & CLASS_IDX_MASK; +} + +static void set_zspage_mapping(struct page *page, unsigned int class_idx, + enum fullness_group fullness) +{ + unsigned long m; + BUG_ON(!is_first_page(page)); + + m = ((class_idx & CLASS_IDX_MASK) << FULLNESS_BITS) | + (fullness & FULLNESS_MASK); + page->mapping = (struct address_space *)m; +} + +static int get_size_class_index(int size) +{ + int idx = 0; + + if (likely(size > ZS_MIN_ALLOC_SIZE)) + idx = DIV_ROUND_UP(size - ZS_MIN_ALLOC_SIZE, + ZS_SIZE_CLASS_DELTA); + + return idx; +} + +static enum fullness_group get_fullness_group(struct page *page) +{ + int inuse, max_objects; + enum fullness_group fg; + BUG_ON(!is_first_page(page)); + + inuse = page->inuse; + max_objects = page->objects; + + if (inuse == 0) + fg = ZS_EMPTY; + else if (inuse == max_objects) + fg = ZS_FULL; + else if (inuse <= max_objects / fullness_threshold_frac) + fg = ZS_ALMOST_EMPTY; + else + fg = ZS_ALMOST_FULL; + + return fg; +} + +static void insert_zspage(struct page *page, struct size_class *class, + enum fullness_group fullness) +{ + struct page **head; + + BUG_ON(!is_first_page(page)); + + if (fullness >= _ZS_NR_FULLNESS_GROUPS) + return; + + head = &class->fullness_list[fullness]; + if (*head) + list_add_tail(&page->lru, &(*head)->lru); + + *head = page; +} + +static void remove_zspage(struct page *page, struct size_class *class, + enum fullness_group fullness) +{ + struct page **head; + + BUG_ON(!is_first_page(page)); + + if (fullness >= _ZS_NR_FULLNESS_GROUPS) + return; + + head = &class->fullness_list[fullness]; + BUG_ON(!*head); + if (list_empty(&(*head)->lru)) + *head = NULL; + else if (*head == page) + *head = (struct page *)list_entry((*head)->lru.next, + struct page, lru); + + list_del_init(&page->lru); +} + +static enum fullness_group fix_fullness_group(struct zs_pool *pool, + struct page *page) +{ + int class_idx; + struct size_class *class; + enum fullness_group currfg, newfg; + + BUG_ON(!is_first_page(page)); + + get_zspage_mapping(page, &class_idx, &currfg); + newfg = get_fullness_group(page); + if (newfg == currfg) + goto out; + + class = &pool->size_class[class_idx]; + remove_zspage(page, class, currfg); + insert_zspage(page, class, newfg); + set_zspage_mapping(page, class_idx, newfg); + +out: + return newfg; +} + +/* + * We have to decide on how many pages to link together + * to form a zspage for each size class. This is important + * to reduce wastage due to unusable space left at end of + * each zspage which is given as: + * wastage = Zp - Zp % size_class + * where Zp = zspage size = k * PAGE_SIZE where k = 1, 2, ... + * + * For example, for size class of 3/8 * PAGE_SIZE, we should + * link together 3 PAGE_SIZE sized pages to form a zspage + * since then we can perfectly fit in 8 such objects. + */ +static int get_pages_per_zspage(int class_size) +{ + int i, max_usedpc = 0; + /* zspage order which gives maximum used size per KB */ + int max_usedpc_order = 1; + + for (i = 1; i <= ZS_MAX_PAGES_PER_ZSPAGE; i++) { + int zspage_size; + int waste, usedpc; + + zspage_size = i * PAGE_SIZE; + waste = zspage_size % class_size; + usedpc = (zspage_size - waste) * 100 / zspage_size; + + if (usedpc > max_usedpc) { + max_usedpc = usedpc; + max_usedpc_order = i; + } + } + + return max_usedpc_order; +} + +/* + * A single 'zspage' is composed of many system pages which are + * linked together using fields in struct page. This function finds + * the first/head page, given any component page of a zspage. + */ +static struct page *get_first_page(struct page *page) +{ + if (is_first_page(page)) + return page; + else + return page->first_page; +} + +static struct page *get_next_page(struct page *page) +{ + struct page *next; + + if (is_last_page(page)) + next = NULL; + else if (is_first_page(page)) + next = (struct page *)page->private; + else + next = list_entry(page->lru.next, struct page, lru); + + return next; +} + +/* Encode <page, obj_idx> as a single handle value */ +static void *obj_location_to_handle(struct page *page, unsigned long obj_idx) +{ + unsigned long handle; + + if (!page) { + BUG_ON(obj_idx); + return NULL; + } + + handle = page_to_pfn(page) << OBJ_INDEX_BITS; + handle |= (obj_idx & OBJ_INDEX_MASK); + + return (void *)handle; +} + +/* Decode <page, obj_idx> pair from the given object handle */ +static void obj_handle_to_location(unsigned long handle, struct page **page, + unsigned long *obj_idx) +{ + *page = pfn_to_page(handle >> OBJ_INDEX_BITS); + *obj_idx = handle & OBJ_INDEX_MASK; +} + +static unsigned long obj_idx_to_offset(struct page *page, + unsigned long obj_idx, int class_size) +{ + unsigned long off = 0; + + if (!is_first_page(page)) + off = page->index; + + return off + obj_idx * class_size; +} + +static void reset_page(struct page *page) +{ + clear_bit(PG_private, &page->flags); + clear_bit(PG_private_2, &page->flags); + set_page_private(page, 0); + page->mapping = NULL; + page->freelist = NULL; + reset_page_mapcount(page); +} + +static void free_zspage(struct page *first_page) +{ + struct page *nextp, *tmp, *head_extra; + + BUG_ON(!is_first_page(first_page)); + BUG_ON(first_page->inuse); + + head_extra = (struct page *)page_private(first_page); + + reset_page(first_page); + __free_page(first_page); + + /* zspage with only 1 system page */ + if (!head_extra) + return; + + list_for_each_entry_safe(nextp, tmp, &head_extra->lru, lru) { + list_del(&nextp->lru); + reset_page(nextp); + __free_page(nextp); + } + reset_page(head_extra); + __free_page(head_extra); +} + +/* Initialize a newly allocated zspage */ +static void init_zspage(struct page *first_page, struct size_class *class) +{ + unsigned long off = 0; + struct page *page = first_page; + + BUG_ON(!is_first_page(first_page)); + while (page) { + struct page *next_page; + struct link_free *link; + unsigned int i, objs_on_page; + + /* + * page->index stores offset of first object starting + * in the page. For the first page, this is always 0, + * so we use first_page->index (aka ->freelist) to store + * head of corresponding zspage's freelist. + */ + if (page != first_page) + page->index = off; + + link = (struct link_free *)kmap_atomic(page) + + off / sizeof(*link); + objs_on_page = (PAGE_SIZE - off) / class->size; + + for (i = 1; i <= objs_on_page; i++) { + off += class->size; + if (off < PAGE_SIZE) { + link->next = obj_location_to_handle(page, i); + link += class->size / sizeof(*link); + } + } + + /* + * We now come to the last (full or partial) object on this + * page, which must point to the first object on the next + * page (if present) + */ + next_page = get_next_page(page); + link->next = obj_location_to_handle(next_page, 0); + kunmap_atomic(link); + page = next_page; + off = (off + class->size) % PAGE_SIZE; + } +} + +/* + * Allocate a zspage for the given size class + */ +static struct page *alloc_zspage(struct size_class *class, gfp_t flags) +{ + int i, error; + struct page *first_page = NULL, *uninitialized_var(prev_page); + + /* + * Allocate individual pages and link them together as: + * 1. first page->private = first sub-page + * 2. all sub-pages are linked together using page->lru + * 3. each sub-page is linked to the first page using page->first_page + * + * For each size class, First/Head pages are linked together using + * page->lru. Also, we set PG_private to identify the first page + * (i.e. no other sub-page has this flag set) and PG_private_2 to + * identify the last page. + */ + error = -ENOMEM; + for (i = 0; i < class->pages_per_zspage; i++) { + struct page *page; + + page = alloc_page(flags); + if (!page) + goto cleanup; + + INIT_LIST_HEAD(&page->lru); + if (i == 0) { /* first page */ + SetPagePrivate(page); + set_page_private(page, 0); + first_page = page; + first_page->inuse = 0; + } + if (i == 1) + first_page->private = (unsigned long)page; + if (i >= 1) + page->first_page = first_page; + if (i >= 2) + list_add(&page->lru, &prev_page->lru); + if (i == class->pages_per_zspage - 1) /* last page */ + SetPagePrivate2(page); + prev_page = page; + } + + init_zspage(first_page, class); + + first_page->freelist = obj_location_to_handle(first_page, 0); + /* Maximum number of objects we can store in this zspage */ + first_page->objects = class->pages_per_zspage * PAGE_SIZE / class->size; + + error = 0; /* Success */ + +cleanup: + if (unlikely(error) && first_page) { + free_zspage(first_page); + first_page = NULL; + } + + return first_page; +} + +static struct page *find_get_zspage(struct size_class *class) +{ + int i; + struct page *page; + + for (i = 0; i < _ZS_NR_FULLNESS_GROUPS; i++) { + page = class->fullness_list[i]; + if (page) + break; + } + + return page; +} + +#ifdef USE_PGTABLE_MAPPING +static inline int __zs_cpu_up(struct mapping_area *area) +{ + /* + * Make sure we don't leak memory if a cpu UP notification + * and zs_init() race and both call zs_cpu_up() on the same cpu + */ + if (area->vm) + return 0; + area->vm = alloc_vm_area(PAGE_SIZE * 2, NULL); + if (!area->vm) + return -ENOMEM; + return 0; +} + +static inline void __zs_cpu_down(struct mapping_area *area) +{ + if (area->vm) + free_vm_area(area->vm); + area->vm = NULL; +} + +static inline void *__zs_map_object(struct mapping_area *area, + struct page *pages[2], int off, int size) +{ + BUG_ON(map_vm_area(area->vm, PAGE_KERNEL, &pages)); + area->vm_addr = area->vm->addr; + return area->vm_addr + off; +} + +static inline void __zs_unmap_object(struct mapping_area *area, + struct page *pages[2], int off, int size) +{ + unsigned long addr = (unsigned long)area->vm_addr; + unsigned long end = addr + (PAGE_SIZE * 2); + + flush_cache_vunmap(addr, end); + unmap_kernel_range_noflush(addr, PAGE_SIZE * 2); + local_flush_tlb_kernel_range(addr, end); +} + +#else /* USE_PGTABLE_MAPPING */ + +static inline int __zs_cpu_up(struct mapping_area *area) +{ + /* + * Make sure we don't leak memory if a cpu UP notification + * and zs_init() race and both call zs_cpu_up() on the same cpu + */ + if (area->vm_buf) + return 0; + area->vm_buf = (char *)__get_free_page(GFP_KERNEL); + if (!area->vm_buf) + return -ENOMEM; + return 0; +} + +static inline void __zs_cpu_down(struct mapping_area *area) +{ + if (area->vm_buf) + free_page((unsigned long)area->vm_buf); + area->vm_buf = NULL; +} + +static void *__zs_map_object(struct mapping_area *area, + struct page *pages[2], int off, int size) +{ + int sizes[2]; + void *addr; + char *buf = area->vm_buf; + + /* disable page faults to match kmap_atomic() return conditions */ + pagefault_disable(); + + /* no read fastpath */ + if (area->vm_mm == ZS_MM_WO) + goto out; + + sizes[0] = PAGE_SIZE - off; + sizes[1] = size - sizes[0]; + + /* copy object to per-cpu buffer */ + addr = kmap_atomic(pages[0]); + memcpy(buf, addr + off, sizes[0]); + kunmap_atomic(addr); + addr = kmap_atomic(pages[1]); + memcpy(buf + sizes[0], addr, sizes[1]); + kunmap_atomic(addr); +out: + return area->vm_buf; +} + +static void __zs_unmap_object(struct mapping_area *area, + struct page *pages[2], int off, int size) +{ + int sizes[2]; + void *addr; + char *buf = area->vm_buf; + + /* no write fastpath */ + if (area->vm_mm == ZS_MM_RO) + goto out; + + sizes[0] = PAGE_SIZE - off; + sizes[1] = size - sizes[0]; + + /* copy per-cpu buffer to object */ + addr = kmap_atomic(pages[0]); + memcpy(addr + off, buf, sizes[0]); + kunmap_atomic(addr); + addr = kmap_atomic(pages[1]); + memcpy(addr, buf + sizes[0], sizes[1]); + kunmap_atomic(addr); + +out: + /* enable page faults to match kunmap_atomic() return conditions */ + pagefault_enable(); +} + +#endif /* USE_PGTABLE_MAPPING */ + +static int zs_cpu_notifier(struct notifier_block *nb, unsigned long action, + void *pcpu) +{ + int ret, cpu = (long)pcpu; + struct mapping_area *area; + + switch (action) { + case CPU_UP_PREPARE: + area = &per_cpu(zs_map_area, cpu); + ret = __zs_cpu_up(area); + if (ret) + return notifier_from_errno(ret); + break; + case CPU_DEAD: + case CPU_UP_CANCELED: + area = &per_cpu(zs_map_area, cpu); + __zs_cpu_down(area); + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block zs_cpu_nb = { + .notifier_call = zs_cpu_notifier +}; + +static void zs_exit(void) +{ + int cpu; + + for_each_online_cpu(cpu) + zs_cpu_notifier(NULL, CPU_DEAD, (void *)(long)cpu); + unregister_cpu_notifier(&zs_cpu_nb); +} + +static int zs_init(void) +{ + int cpu, ret; + + register_cpu_notifier(&zs_cpu_nb); + for_each_online_cpu(cpu) { + ret = zs_cpu_notifier(NULL, CPU_UP_PREPARE, (void *)(long)cpu); + if (notifier_to_errno(ret)) + goto fail; + } + return 0; +fail: + zs_exit(); + return notifier_to_errno(ret); +} + +struct zs_pool *zs_create_pool(const char *name, gfp_t flags) +{ + int i, ovhd_size; + struct zs_pool *pool; + + if (!name) + return NULL; + + ovhd_size = roundup(sizeof(*pool), PAGE_SIZE); + pool = kzalloc(ovhd_size, GFP_KERNEL); + if (!pool) + return NULL; + + for (i = 0; i < ZS_SIZE_CLASSES; i++) { + int size; + struct size_class *class; + + size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA; + if (size > ZS_MAX_ALLOC_SIZE) + size = ZS_MAX_ALLOC_SIZE; + + class = &pool->size_class[i]; + class->size = size; + class->index = i; + spin_lock_init(&class->lock); + class->pages_per_zspage = get_pages_per_zspage(size); + + } + + pool->flags = flags; + pool->name = name; + + return pool; +} +EXPORT_SYMBOL_GPL(zs_create_pool); + +void zs_destroy_pool(struct zs_pool *pool) +{ + int i; + + for (i = 0; i < ZS_SIZE_CLASSES; i++) { + int fg; + struct size_class *class = &pool->size_class[i]; + + for (fg = 0; fg < _ZS_NR_FULLNESS_GROUPS; fg++) { + if (class->fullness_list[fg]) { + pr_info("Freeing non-empty class with size " + "%db, fullness group %d\n", + class->size, fg); + } + } + } + kfree(pool); +} +EXPORT_SYMBOL_GPL(zs_destroy_pool); + +/** + * zs_malloc - Allocate block of given size from pool. + * @pool: pool to allocate from + * @size: size of block to allocate + * + * On success, handle to the allocated object is returned, + * otherwise 0. + * Allocation requests with size > ZS_MAX_ALLOC_SIZE will fail. + */ +unsigned long zs_malloc(struct zs_pool *pool, size_t size) +{ + unsigned long obj; + struct link_free *link; + int class_idx; + struct size_class *class; + + struct page *first_page, *m_page; + unsigned long m_objidx, m_offset; + + if (unlikely(!size || size > ZS_MAX_ALLOC_SIZE)) + return 0; + + class_idx = get_size_class_index(size); + class = &pool->size_class[class_idx]; + BUG_ON(class_idx != class->index); + + spin_lock(&class->lock); + first_page = find_get_zspage(class); + + if (!first_page) { + spin_unlock(&class->lock); + first_page = alloc_zspage(class, pool->flags); + if (unlikely(!first_page)) + return 0; + + set_zspage_mapping(first_page, class->index, ZS_EMPTY); + spin_lock(&class->lock); + class->pages_allocated += class->pages_per_zspage; + } + + obj = (unsigned long)first_page->freelist; + obj_handle_to_location(obj, &m_page, &m_objidx); + m_offset = obj_idx_to_offset(m_page, m_objidx, class->size); + + link = (struct link_free *)kmap_atomic(m_page) + + m_offset / sizeof(*link); + first_page->freelist = link->next; + memset(link, POISON_INUSE, sizeof(*link)); + kunmap_atomic(link); + + first_page->inuse++; + /* Now move the zspage to another fullness group, if required */ + fix_fullness_group(pool, first_page); + spin_unlock(&class->lock); + + return obj; +} +EXPORT_SYMBOL_GPL(zs_malloc); + +void zs_free(struct zs_pool *pool, unsigned long obj) +{ + struct link_free *link; + struct page *first_page, *f_page; + unsigned long f_objidx, f_offset; + + int class_idx; + struct size_class *class; + enum fullness_group fullness; + + if (unlikely(!obj)) + return; + + obj_handle_to_location(obj, &f_page, &f_objidx); + first_page = get_first_page(f_page); + + get_zspage_mapping(first_page, &class_idx, &fullness); + class = &pool->size_class[class_idx]; + f_offset = obj_idx_to_offset(f_page, f_objidx, class->size); + + spin_lock(&class->lock); + + /* Insert this object in containing zspage's freelist */ + link = (struct link_free *)((unsigned char *)kmap_atomic(f_page) + + f_offset); + link->next = first_page->freelist; + kunmap_atomic(link); + first_page->freelist = (void *)obj; + + first_page->inuse--; + fullness = fix_fullness_group(pool, first_page); + + if (fullness == ZS_EMPTY) + class->pages_allocated -= class->pages_per_zspage; + + spin_unlock(&class->lock); + + if (fullness == ZS_EMPTY) + free_zspage(first_page); +} +EXPORT_SYMBOL_GPL(zs_free); + +/** + * zs_map_object - get address of allocated object from handle. + * @pool: pool from which the object was allocated + * @handle: handle returned from zs_malloc + * + * Before using an object allocated from zs_malloc, it must be mapped using + * this function. When done with the object, it must be unmapped using + * zs_unmap_object. + * + * Only one object can be mapped per cpu at a time. There is no protection + * against nested mappings. + * + * This function returns with preemption and page faults disabled. +*/ +void *zs_map_object(struct zs_pool *pool, unsigned long handle, + enum zs_mapmode mm) +{ + struct page *page; + unsigned long obj_idx, off; + + unsigned int class_idx; + enum fullness_group fg; + struct size_class *class; + struct mapping_area *area; + struct page *pages[2]; + + BUG_ON(!handle); + + /* + * Because we use per-cpu mapping areas shared among the + * pools/users, we can't allow mapping in interrupt context + * because it can corrupt another users mappings. + */ + BUG_ON(in_interrupt()); + + obj_handle_to_location(handle, &page, &obj_idx); + get_zspage_mapping(get_first_page(page), &class_idx, &fg); + class = &pool->size_class[class_idx]; + off = obj_idx_to_offset(page, obj_idx, class->size); + + area = &get_cpu_var(zs_map_area); + area->vm_mm = mm; + if (off + class->size <= PAGE_SIZE) { + /* this object is contained entirely within a page */ + area->vm_addr = kmap_atomic(page); + return area->vm_addr + off; + } + + /* this object spans two pages */ + pages[0] = page; + pages[1] = get_next_page(page); + BUG_ON(!pages[1]); + + return __zs_map_object(area, pages, off, class->size); +} +EXPORT_SYMBOL_GPL(zs_map_object); + +void zs_unmap_object(struct zs_pool *pool, unsigned long handle) +{ + struct page *page; + unsigned long obj_idx, off; + + unsigned int class_idx; + enum fullness_group fg; + struct size_class *class; + struct mapping_area *area; + + BUG_ON(!handle); + + obj_handle_to_location(handle, &page, &obj_idx); + get_zspage_mapping(get_first_page(page), &class_idx, &fg); + class = &pool->size_class[class_idx]; + off = obj_idx_to_offset(page, obj_idx, class->size); + + area = &__get_cpu_var(zs_map_area); + if (off + class->size <= PAGE_SIZE) + kunmap_atomic(area->vm_addr); + else { + struct page *pages[2]; + + pages[0] = page; + pages[1] = get_next_page(page); + BUG_ON(!pages[1]); + + __zs_unmap_object(area, pages, off, class->size); + } + put_cpu_var(zs_map_area); +} +EXPORT_SYMBOL_GPL(zs_unmap_object); + +u64 zs_get_total_size_bytes(struct zs_pool *pool) +{ + int i; + u64 npages = 0; + + for (i = 0; i < ZS_SIZE_CLASSES; i++) + npages += pool->size_class[i].pages_allocated; + + return npages << PAGE_SHIFT; +} +EXPORT_SYMBOL_GPL(zs_get_total_size_bytes); + +module_init(zs_init); +module_exit(zs_exit); + +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); -- 1.7.9.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 30+ messages in thread
* [PATCH 1/3] zsmalloc: promote to lib/ @ 2012-09-26 8:50 ` Minchan Kim 0 siblings, 0 replies; 30+ messages in thread From: Minchan Kim @ 2012-09-26 8:50 UTC (permalink / raw) To: Jens Axboe, Greg Kroah-Hartman Cc: Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel, Minchan Kim This patch promotes the slab-based zsmalloc memory allocator from the staging tree to lib/ zcache/zram depends on this allocator for storing compressed RAM pages in an efficient way under system wide memory pressure where high-order (greater than 0) page allocation are very likely to fail. For more information on zsmalloc and its internals, read the documentation at the top of the zsmalloc.c file. Signed-off-by: Minchan Kim <minchan@kernel.org> --- drivers/staging/Kconfig | 2 - drivers/staging/Makefile | 1 - drivers/staging/zcache/zcache-main.c | 4 +- drivers/staging/zram/zram_drv.h | 3 +- drivers/staging/zsmalloc/Kconfig | 10 - drivers/staging/zsmalloc/Makefile | 3 - drivers/staging/zsmalloc/zsmalloc-main.c | 1064 ------------------------------ drivers/staging/zsmalloc/zsmalloc.h | 43 -- include/linux/zsmalloc.h | 43 ++ lib/Kconfig | 2 + lib/Makefile | 1 + lib/zsmalloc/Kconfig | 18 + lib/zsmalloc/Makefile | 1 + lib/zsmalloc/zsmalloc.c | 1064 ++++++++++++++++++++++++++++++ 14 files changed, 1132 insertions(+), 1127 deletions(-) delete mode 100644 drivers/staging/zsmalloc/Kconfig delete mode 100644 drivers/staging/zsmalloc/Makefile delete mode 100644 drivers/staging/zsmalloc/zsmalloc-main.c delete mode 100644 drivers/staging/zsmalloc/zsmalloc.h create mode 100644 include/linux/zsmalloc.h create mode 100644 lib/zsmalloc/Kconfig create mode 100644 lib/zsmalloc/Makefile create mode 100644 lib/zsmalloc/zsmalloc.c diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig index 449f04a..4316ef5 100644 --- a/drivers/staging/Kconfig +++ b/drivers/staging/Kconfig @@ -78,8 +78,6 @@ source "drivers/staging/zram/Kconfig" source "drivers/staging/zcache/Kconfig" -source "drivers/staging/zsmalloc/Kconfig" - source "drivers/staging/wlags49_h2/Kconfig" source "drivers/staging/wlags49_h25/Kconfig" diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile index a19abe5..db18726 100644 --- a/drivers/staging/Makefile +++ b/drivers/staging/Makefile @@ -34,7 +34,6 @@ obj-$(CONFIG_DX_SEP) += sep/ obj-$(CONFIG_IIO) += iio/ obj-$(CONFIG_ZRAM) += zram/ obj-$(CONFIG_ZCACHE) += zcache/ -obj-$(CONFIG_ZSMALLOC) += zsmalloc/ obj-$(CONFIG_WLAGS49_H2) += wlags49_h2/ obj-$(CONFIG_WLAGS49_H25) += wlags49_h25/ obj-$(CONFIG_FB_SM7XX) += sm7xxfb/ diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c index 52b43b7..34b2c5c 100644 --- a/drivers/staging/zcache/zcache-main.c +++ b/drivers/staging/zcache/zcache-main.c @@ -32,9 +32,9 @@ #include <linux/crypto.h> #include <linux/string.h> #include <linux/idr.h> -#include "tmem.h" +#include <linux/zsmalloc.h> -#include "../zsmalloc/zsmalloc.h" +#include "tmem.h" #ifdef CONFIG_CLEANCACHE #include <linux/cleancache.h> diff --git a/drivers/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h index 572c0b1..f6d0925 100644 --- a/drivers/staging/zram/zram_drv.h +++ b/drivers/staging/zram/zram_drv.h @@ -17,8 +17,7 @@ #include <linux/spinlock.h> #include <linux/mutex.h> - -#include "../zsmalloc/zsmalloc.h" +#include <linux/zsmalloc.h> /* * Some arbitrary value. This is just to catch diff --git a/drivers/staging/zsmalloc/Kconfig b/drivers/staging/zsmalloc/Kconfig deleted file mode 100644 index 9084565..0000000 --- a/drivers/staging/zsmalloc/Kconfig +++ /dev/null @@ -1,10 +0,0 @@ -config ZSMALLOC - tristate "Memory allocator for compressed pages" - default n - help - zsmalloc is a slab-based memory allocator designed to store - compressed RAM pages. zsmalloc uses virtual memory mapping - in order to reduce fragmentation. However, this results in a - non-standard allocator interface where a handle, not a pointer, is - returned by an alloc(). This handle must be mapped in order to - access the allocated space. diff --git a/drivers/staging/zsmalloc/Makefile b/drivers/staging/zsmalloc/Makefile deleted file mode 100644 index b134848..0000000 --- a/drivers/staging/zsmalloc/Makefile +++ /dev/null @@ -1,3 +0,0 @@ -zsmalloc-y := zsmalloc-main.o - -obj-$(CONFIG_ZSMALLOC) += zsmalloc.o diff --git a/drivers/staging/zsmalloc/zsmalloc-main.c b/drivers/staging/zsmalloc/zsmalloc-main.c deleted file mode 100644 index 09a9d35..0000000 --- a/drivers/staging/zsmalloc/zsmalloc-main.c +++ /dev/null @@ -1,1064 +0,0 @@ -/* - * zsmalloc memory allocator - * - * Copyright (C) 2011 Nitin Gupta - * - * This code is released using a dual license strategy: BSD/GPL - * You can choose the license that better fits your requirements. - * - * Released under the terms of 3-clause BSD License - * Released under the terms of GNU General Public License Version 2.0 - */ - - -/* - * This allocator is designed for use with zcache and zram. Thus, the - * allocator is supposed to work well under low memory conditions. In - * particular, it never attempts higher order page allocation which is - * very likely to fail under memory pressure. On the other hand, if we - * just use single (0-order) pages, it would suffer from very high - * fragmentation -- any object of size PAGE_SIZE/2 or larger would occupy - * an entire page. This was one of the major issues with its predecessor - * (xvmalloc). - * - * To overcome these issues, zsmalloc allocates a bunch of 0-order pages - * and links them together using various 'struct page' fields. These linked - * pages act as a single higher-order page i.e. an object can span 0-order - * page boundaries. The code refers to these linked pages as a single entity - * called zspage. - * - * Following is how we use various fields and flags of underlying - * struct page(s) to form a zspage. - * - * Usage of struct page fields: - * page->first_page: points to the first component (0-order) page - * page->index (union with page->freelist): offset of the first object - * starting in this page. For the first page, this is - * always 0, so we use this field (aka freelist) to point - * to the first free object in zspage. - * page->lru: links together all component pages (except the first page) - * of a zspage - * - * For _first_ page only: - * - * page->private (union with page->first_page): refers to the - * component page after the first page - * page->freelist: points to the first free object in zspage. - * Free objects are linked together using in-place - * metadata. - * page->objects: maximum number of objects we can store in this - * zspage (class->zspage_order * PAGE_SIZE / class->size) - * page->lru: links together first pages of various zspages. - * Basically forming list of zspages in a fullness group. - * page->mapping: class index and fullness group of the zspage - * - * Usage of struct page flags: - * PG_private: identifies the first component page - * PG_private2: identifies the last component page - * - */ - -#ifdef CONFIG_ZSMALLOC_DEBUG -#define DEBUG -#endif - -#include <linux/module.h> -#include <linux/kernel.h> -#include <linux/bitops.h> -#include <linux/errno.h> -#include <linux/highmem.h> -#include <linux/init.h> -#include <linux/string.h> -#include <linux/slab.h> -#include <asm/tlbflush.h> -#include <asm/pgtable.h> -#include <linux/cpumask.h> -#include <linux/cpu.h> -#include <linux/vmalloc.h> -#include <linux/hardirq.h> -#include <linux/spinlock.h> -#include <linux/types.h> - -#include "zsmalloc.h" - -/* - * This must be power of 2 and greater than of equal to sizeof(link_free). - * These two conditions ensure that any 'struct link_free' itself doesn't - * span more than 1 page which avoids complex case of mapping 2 pages simply - * to restore link_free pointer values. - */ -#define ZS_ALIGN 8 - -/* - * A single 'zspage' is composed of up to 2^N discontiguous 0-order (single) - * pages. ZS_MAX_ZSPAGE_ORDER defines upper limit on N. - */ -#define ZS_MAX_ZSPAGE_ORDER 2 -#define ZS_MAX_PAGES_PER_ZSPAGE (_AC(1, UL) << ZS_MAX_ZSPAGE_ORDER) - -/* - * Object location (<PFN>, <obj_idx>) is encoded as - * as single (void *) handle value. - * - * Note that object index <obj_idx> is relative to system - * page <PFN> it is stored in, so for each sub-page belonging - * to a zspage, obj_idx starts with 0. - * - * This is made more complicated by various memory models and PAE. - */ - -#ifndef MAX_PHYSMEM_BITS -#ifdef CONFIG_HIGHMEM64G -#define MAX_PHYSMEM_BITS 36 -#else /* !CONFIG_HIGHMEM64G */ -/* - * If this definition of MAX_PHYSMEM_BITS is used, OBJ_INDEX_BITS will just - * be PAGE_SHIFT - */ -#define MAX_PHYSMEM_BITS BITS_PER_LONG -#endif -#endif -#define _PFN_BITS (MAX_PHYSMEM_BITS - PAGE_SHIFT) -#define OBJ_INDEX_BITS (BITS_PER_LONG - _PFN_BITS) -#define OBJ_INDEX_MASK ((_AC(1, UL) << OBJ_INDEX_BITS) - 1) - -#define MAX(a, b) ((a) >= (b) ? (a) : (b)) -/* ZS_MIN_ALLOC_SIZE must be multiple of ZS_ALIGN */ -#define ZS_MIN_ALLOC_SIZE \ - MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS)) -#define ZS_MAX_ALLOC_SIZE PAGE_SIZE - -/* - * On systems with 4K page size, this gives 254 size classes! There is a - * trader-off here: - * - Large number of size classes is potentially wasteful as free page are - * spread across these classes - * - Small number of size classes causes large internal fragmentation - * - Probably its better to use specific size classes (empirically - * determined). NOTE: all those class sizes must be set as multiple of - * ZS_ALIGN to make sure link_free itself never has to span 2 pages. - * - * ZS_MIN_ALLOC_SIZE and ZS_SIZE_CLASS_DELTA must be multiple of ZS_ALIGN - * (reason above) - */ -#define ZS_SIZE_CLASS_DELTA 16 -#define ZS_SIZE_CLASSES ((ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) / \ - ZS_SIZE_CLASS_DELTA + 1) - -/* - * We do not maintain any list for completely empty or full pages - */ -enum fullness_group { - ZS_ALMOST_FULL, - ZS_ALMOST_EMPTY, - _ZS_NR_FULLNESS_GROUPS, - - ZS_EMPTY, - ZS_FULL -}; - -/* - * We assign a page to ZS_ALMOST_EMPTY fullness group when: - * n <= N / f, where - * n = number of allocated objects - * N = total number of objects zspage can store - * f = 1/fullness_threshold_frac - * - * Similarly, we assign zspage to: - * ZS_ALMOST_FULL when n > N / f - * ZS_EMPTY when n == 0 - * ZS_FULL when n == N - * - * (see: fix_fullness_group()) - */ -static const int fullness_threshold_frac = 4; - -struct size_class { - /* - * Size of objects stored in this class. Must be multiple - * of ZS_ALIGN. - */ - int size; - unsigned int index; - - /* Number of PAGE_SIZE sized pages to combine to form a 'zspage' */ - int pages_per_zspage; - - spinlock_t lock; - - /* stats */ - u64 pages_allocated; - - struct page *fullness_list[_ZS_NR_FULLNESS_GROUPS]; -}; - -/* - * Placed within free objects to form a singly linked list. - * For every zspage, first_page->freelist gives head of this list. - * - * This must be power of 2 and less than or equal to ZS_ALIGN - */ -struct link_free { - /* Handle of next free chunk (encodes <PFN, obj_idx>) */ - void *next; -}; - -struct zs_pool { - struct size_class size_class[ZS_SIZE_CLASSES]; - - gfp_t flags; /* allocation flags used when growing pool */ - const char *name; -}; - -/* - * A zspage's class index and fullness group - * are encoded in its (first)page->mapping - */ -#define CLASS_IDX_BITS 28 -#define FULLNESS_BITS 4 -#define CLASS_IDX_MASK ((1 << CLASS_IDX_BITS) - 1) -#define FULLNESS_MASK ((1 << FULLNESS_BITS) - 1) - -/* - * By default, zsmalloc uses a copy-based object mapping method to access - * allocations that span two pages. However, if a particular architecture - * 1) Implements local_flush_tlb_kernel_range() and 2) Performs VM mapping - * faster than copying, then it should be added here so that - * USE_PGTABLE_MAPPING is defined. This causes zsmalloc to use page table - * mapping rather than copying - * for object mapping. -*/ -#if defined(CONFIG_ARM) -#define USE_PGTABLE_MAPPING -#endif - -struct mapping_area { -#ifdef USE_PGTABLE_MAPPING - struct vm_struct *vm; /* vm area for mapping object that span pages */ -#else - char *vm_buf; /* copy buffer for objects that span pages */ -#endif - char *vm_addr; /* address of kmap_atomic()'ed pages */ - enum zs_mapmode vm_mm; /* mapping mode */ -}; - - -/* per-cpu VM mapping areas for zspage accesses that cross page boundaries */ -static DEFINE_PER_CPU(struct mapping_area, zs_map_area); - -static int is_first_page(struct page *page) -{ - return PagePrivate(page); -} - -static int is_last_page(struct page *page) -{ - return PagePrivate2(page); -} - -static void get_zspage_mapping(struct page *page, unsigned int *class_idx, - enum fullness_group *fullness) -{ - unsigned long m; - BUG_ON(!is_first_page(page)); - - m = (unsigned long)page->mapping; - *fullness = m & FULLNESS_MASK; - *class_idx = (m >> FULLNESS_BITS) & CLASS_IDX_MASK; -} - -static void set_zspage_mapping(struct page *page, unsigned int class_idx, - enum fullness_group fullness) -{ - unsigned long m; - BUG_ON(!is_first_page(page)); - - m = ((class_idx & CLASS_IDX_MASK) << FULLNESS_BITS) | - (fullness & FULLNESS_MASK); - page->mapping = (struct address_space *)m; -} - -static int get_size_class_index(int size) -{ - int idx = 0; - - if (likely(size > ZS_MIN_ALLOC_SIZE)) - idx = DIV_ROUND_UP(size - ZS_MIN_ALLOC_SIZE, - ZS_SIZE_CLASS_DELTA); - - return idx; -} - -static enum fullness_group get_fullness_group(struct page *page) -{ - int inuse, max_objects; - enum fullness_group fg; - BUG_ON(!is_first_page(page)); - - inuse = page->inuse; - max_objects = page->objects; - - if (inuse == 0) - fg = ZS_EMPTY; - else if (inuse == max_objects) - fg = ZS_FULL; - else if (inuse <= max_objects / fullness_threshold_frac) - fg = ZS_ALMOST_EMPTY; - else - fg = ZS_ALMOST_FULL; - - return fg; -} - -static void insert_zspage(struct page *page, struct size_class *class, - enum fullness_group fullness) -{ - struct page **head; - - BUG_ON(!is_first_page(page)); - - if (fullness >= _ZS_NR_FULLNESS_GROUPS) - return; - - head = &class->fullness_list[fullness]; - if (*head) - list_add_tail(&page->lru, &(*head)->lru); - - *head = page; -} - -static void remove_zspage(struct page *page, struct size_class *class, - enum fullness_group fullness) -{ - struct page **head; - - BUG_ON(!is_first_page(page)); - - if (fullness >= _ZS_NR_FULLNESS_GROUPS) - return; - - head = &class->fullness_list[fullness]; - BUG_ON(!*head); - if (list_empty(&(*head)->lru)) - *head = NULL; - else if (*head == page) - *head = (struct page *)list_entry((*head)->lru.next, - struct page, lru); - - list_del_init(&page->lru); -} - -static enum fullness_group fix_fullness_group(struct zs_pool *pool, - struct page *page) -{ - int class_idx; - struct size_class *class; - enum fullness_group currfg, newfg; - - BUG_ON(!is_first_page(page)); - - get_zspage_mapping(page, &class_idx, &currfg); - newfg = get_fullness_group(page); - if (newfg == currfg) - goto out; - - class = &pool->size_class[class_idx]; - remove_zspage(page, class, currfg); - insert_zspage(page, class, newfg); - set_zspage_mapping(page, class_idx, newfg); - -out: - return newfg; -} - -/* - * We have to decide on how many pages to link together - * to form a zspage for each size class. This is important - * to reduce wastage due to unusable space left at end of - * each zspage which is given as: - * wastage = Zp - Zp % size_class - * where Zp = zspage size = k * PAGE_SIZE where k = 1, 2, ... - * - * For example, for size class of 3/8 * PAGE_SIZE, we should - * link together 3 PAGE_SIZE sized pages to form a zspage - * since then we can perfectly fit in 8 such objects. - */ -static int get_pages_per_zspage(int class_size) -{ - int i, max_usedpc = 0; - /* zspage order which gives maximum used size per KB */ - int max_usedpc_order = 1; - - for (i = 1; i <= ZS_MAX_PAGES_PER_ZSPAGE; i++) { - int zspage_size; - int waste, usedpc; - - zspage_size = i * PAGE_SIZE; - waste = zspage_size % class_size; - usedpc = (zspage_size - waste) * 100 / zspage_size; - - if (usedpc > max_usedpc) { - max_usedpc = usedpc; - max_usedpc_order = i; - } - } - - return max_usedpc_order; -} - -/* - * A single 'zspage' is composed of many system pages which are - * linked together using fields in struct page. This function finds - * the first/head page, given any component page of a zspage. - */ -static struct page *get_first_page(struct page *page) -{ - if (is_first_page(page)) - return page; - else - return page->first_page; -} - -static struct page *get_next_page(struct page *page) -{ - struct page *next; - - if (is_last_page(page)) - next = NULL; - else if (is_first_page(page)) - next = (struct page *)page->private; - else - next = list_entry(page->lru.next, struct page, lru); - - return next; -} - -/* Encode <page, obj_idx> as a single handle value */ -static void *obj_location_to_handle(struct page *page, unsigned long obj_idx) -{ - unsigned long handle; - - if (!page) { - BUG_ON(obj_idx); - return NULL; - } - - handle = page_to_pfn(page) << OBJ_INDEX_BITS; - handle |= (obj_idx & OBJ_INDEX_MASK); - - return (void *)handle; -} - -/* Decode <page, obj_idx> pair from the given object handle */ -static void obj_handle_to_location(unsigned long handle, struct page **page, - unsigned long *obj_idx) -{ - *page = pfn_to_page(handle >> OBJ_INDEX_BITS); - *obj_idx = handle & OBJ_INDEX_MASK; -} - -static unsigned long obj_idx_to_offset(struct page *page, - unsigned long obj_idx, int class_size) -{ - unsigned long off = 0; - - if (!is_first_page(page)) - off = page->index; - - return off + obj_idx * class_size; -} - -static void reset_page(struct page *page) -{ - clear_bit(PG_private, &page->flags); - clear_bit(PG_private_2, &page->flags); - set_page_private(page, 0); - page->mapping = NULL; - page->freelist = NULL; - reset_page_mapcount(page); -} - -static void free_zspage(struct page *first_page) -{ - struct page *nextp, *tmp, *head_extra; - - BUG_ON(!is_first_page(first_page)); - BUG_ON(first_page->inuse); - - head_extra = (struct page *)page_private(first_page); - - reset_page(first_page); - __free_page(first_page); - - /* zspage with only 1 system page */ - if (!head_extra) - return; - - list_for_each_entry_safe(nextp, tmp, &head_extra->lru, lru) { - list_del(&nextp->lru); - reset_page(nextp); - __free_page(nextp); - } - reset_page(head_extra); - __free_page(head_extra); -} - -/* Initialize a newly allocated zspage */ -static void init_zspage(struct page *first_page, struct size_class *class) -{ - unsigned long off = 0; - struct page *page = first_page; - - BUG_ON(!is_first_page(first_page)); - while (page) { - struct page *next_page; - struct link_free *link; - unsigned int i, objs_on_page; - - /* - * page->index stores offset of first object starting - * in the page. For the first page, this is always 0, - * so we use first_page->index (aka ->freelist) to store - * head of corresponding zspage's freelist. - */ - if (page != first_page) - page->index = off; - - link = (struct link_free *)kmap_atomic(page) + - off / sizeof(*link); - objs_on_page = (PAGE_SIZE - off) / class->size; - - for (i = 1; i <= objs_on_page; i++) { - off += class->size; - if (off < PAGE_SIZE) { - link->next = obj_location_to_handle(page, i); - link += class->size / sizeof(*link); - } - } - - /* - * We now come to the last (full or partial) object on this - * page, which must point to the first object on the next - * page (if present) - */ - next_page = get_next_page(page); - link->next = obj_location_to_handle(next_page, 0); - kunmap_atomic(link); - page = next_page; - off = (off + class->size) % PAGE_SIZE; - } -} - -/* - * Allocate a zspage for the given size class - */ -static struct page *alloc_zspage(struct size_class *class, gfp_t flags) -{ - int i, error; - struct page *first_page = NULL, *uninitialized_var(prev_page); - - /* - * Allocate individual pages and link them together as: - * 1. first page->private = first sub-page - * 2. all sub-pages are linked together using page->lru - * 3. each sub-page is linked to the first page using page->first_page - * - * For each size class, First/Head pages are linked together using - * page->lru. Also, we set PG_private to identify the first page - * (i.e. no other sub-page has this flag set) and PG_private_2 to - * identify the last page. - */ - error = -ENOMEM; - for (i = 0; i < class->pages_per_zspage; i++) { - struct page *page; - - page = alloc_page(flags); - if (!page) - goto cleanup; - - INIT_LIST_HEAD(&page->lru); - if (i == 0) { /* first page */ - SetPagePrivate(page); - set_page_private(page, 0); - first_page = page; - first_page->inuse = 0; - } - if (i == 1) - first_page->private = (unsigned long)page; - if (i >= 1) - page->first_page = first_page; - if (i >= 2) - list_add(&page->lru, &prev_page->lru); - if (i == class->pages_per_zspage - 1) /* last page */ - SetPagePrivate2(page); - prev_page = page; - } - - init_zspage(first_page, class); - - first_page->freelist = obj_location_to_handle(first_page, 0); - /* Maximum number of objects we can store in this zspage */ - first_page->objects = class->pages_per_zspage * PAGE_SIZE / class->size; - - error = 0; /* Success */ - -cleanup: - if (unlikely(error) && first_page) { - free_zspage(first_page); - first_page = NULL; - } - - return first_page; -} - -static struct page *find_get_zspage(struct size_class *class) -{ - int i; - struct page *page; - - for (i = 0; i < _ZS_NR_FULLNESS_GROUPS; i++) { - page = class->fullness_list[i]; - if (page) - break; - } - - return page; -} - -#ifdef USE_PGTABLE_MAPPING -static inline int __zs_cpu_up(struct mapping_area *area) -{ - /* - * Make sure we don't leak memory if a cpu UP notification - * and zs_init() race and both call zs_cpu_up() on the same cpu - */ - if (area->vm) - return 0; - area->vm = alloc_vm_area(PAGE_SIZE * 2, NULL); - if (!area->vm) - return -ENOMEM; - return 0; -} - -static inline void __zs_cpu_down(struct mapping_area *area) -{ - if (area->vm) - free_vm_area(area->vm); - area->vm = NULL; -} - -static inline void *__zs_map_object(struct mapping_area *area, - struct page *pages[2], int off, int size) -{ - BUG_ON(map_vm_area(area->vm, PAGE_KERNEL, &pages)); - area->vm_addr = area->vm->addr; - return area->vm_addr + off; -} - -static inline void __zs_unmap_object(struct mapping_area *area, - struct page *pages[2], int off, int size) -{ - unsigned long addr = (unsigned long)area->vm_addr; - unsigned long end = addr + (PAGE_SIZE * 2); - - flush_cache_vunmap(addr, end); - unmap_kernel_range_noflush(addr, PAGE_SIZE * 2); - local_flush_tlb_kernel_range(addr, end); -} - -#else /* USE_PGTABLE_MAPPING */ - -static inline int __zs_cpu_up(struct mapping_area *area) -{ - /* - * Make sure we don't leak memory if a cpu UP notification - * and zs_init() race and both call zs_cpu_up() on the same cpu - */ - if (area->vm_buf) - return 0; - area->vm_buf = (char *)__get_free_page(GFP_KERNEL); - if (!area->vm_buf) - return -ENOMEM; - return 0; -} - -static inline void __zs_cpu_down(struct mapping_area *area) -{ - if (area->vm_buf) - free_page((unsigned long)area->vm_buf); - area->vm_buf = NULL; -} - -static void *__zs_map_object(struct mapping_area *area, - struct page *pages[2], int off, int size) -{ - int sizes[2]; - void *addr; - char *buf = area->vm_buf; - - /* disable page faults to match kmap_atomic() return conditions */ - pagefault_disable(); - - /* no read fastpath */ - if (area->vm_mm == ZS_MM_WO) - goto out; - - sizes[0] = PAGE_SIZE - off; - sizes[1] = size - sizes[0]; - - /* copy object to per-cpu buffer */ - addr = kmap_atomic(pages[0]); - memcpy(buf, addr + off, sizes[0]); - kunmap_atomic(addr); - addr = kmap_atomic(pages[1]); - memcpy(buf + sizes[0], addr, sizes[1]); - kunmap_atomic(addr); -out: - return area->vm_buf; -} - -static void __zs_unmap_object(struct mapping_area *area, - struct page *pages[2], int off, int size) -{ - int sizes[2]; - void *addr; - char *buf = area->vm_buf; - - /* no write fastpath */ - if (area->vm_mm == ZS_MM_RO) - goto out; - - sizes[0] = PAGE_SIZE - off; - sizes[1] = size - sizes[0]; - - /* copy per-cpu buffer to object */ - addr = kmap_atomic(pages[0]); - memcpy(addr + off, buf, sizes[0]); - kunmap_atomic(addr); - addr = kmap_atomic(pages[1]); - memcpy(addr, buf + sizes[0], sizes[1]); - kunmap_atomic(addr); - -out: - /* enable page faults to match kunmap_atomic() return conditions */ - pagefault_enable(); -} - -#endif /* USE_PGTABLE_MAPPING */ - -static int zs_cpu_notifier(struct notifier_block *nb, unsigned long action, - void *pcpu) -{ - int ret, cpu = (long)pcpu; - struct mapping_area *area; - - switch (action) { - case CPU_UP_PREPARE: - area = &per_cpu(zs_map_area, cpu); - ret = __zs_cpu_up(area); - if (ret) - return notifier_from_errno(ret); - break; - case CPU_DEAD: - case CPU_UP_CANCELED: - area = &per_cpu(zs_map_area, cpu); - __zs_cpu_down(area); - break; - } - - return NOTIFY_OK; -} - -static struct notifier_block zs_cpu_nb = { - .notifier_call = zs_cpu_notifier -}; - -static void zs_exit(void) -{ - int cpu; - - for_each_online_cpu(cpu) - zs_cpu_notifier(NULL, CPU_DEAD, (void *)(long)cpu); - unregister_cpu_notifier(&zs_cpu_nb); -} - -static int zs_init(void) -{ - int cpu, ret; - - register_cpu_notifier(&zs_cpu_nb); - for_each_online_cpu(cpu) { - ret = zs_cpu_notifier(NULL, CPU_UP_PREPARE, (void *)(long)cpu); - if (notifier_to_errno(ret)) - goto fail; - } - return 0; -fail: - zs_exit(); - return notifier_to_errno(ret); -} - -struct zs_pool *zs_create_pool(const char *name, gfp_t flags) -{ - int i, ovhd_size; - struct zs_pool *pool; - - if (!name) - return NULL; - - ovhd_size = roundup(sizeof(*pool), PAGE_SIZE); - pool = kzalloc(ovhd_size, GFP_KERNEL); - if (!pool) - return NULL; - - for (i = 0; i < ZS_SIZE_CLASSES; i++) { - int size; - struct size_class *class; - - size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA; - if (size > ZS_MAX_ALLOC_SIZE) - size = ZS_MAX_ALLOC_SIZE; - - class = &pool->size_class[i]; - class->size = size; - class->index = i; - spin_lock_init(&class->lock); - class->pages_per_zspage = get_pages_per_zspage(size); - - } - - pool->flags = flags; - pool->name = name; - - return pool; -} -EXPORT_SYMBOL_GPL(zs_create_pool); - -void zs_destroy_pool(struct zs_pool *pool) -{ - int i; - - for (i = 0; i < ZS_SIZE_CLASSES; i++) { - int fg; - struct size_class *class = &pool->size_class[i]; - - for (fg = 0; fg < _ZS_NR_FULLNESS_GROUPS; fg++) { - if (class->fullness_list[fg]) { - pr_info("Freeing non-empty class with size " - "%db, fullness group %d\n", - class->size, fg); - } - } - } - kfree(pool); -} -EXPORT_SYMBOL_GPL(zs_destroy_pool); - -/** - * zs_malloc - Allocate block of given size from pool. - * @pool: pool to allocate from - * @size: size of block to allocate - * - * On success, handle to the allocated object is returned, - * otherwise 0. - * Allocation requests with size > ZS_MAX_ALLOC_SIZE will fail. - */ -unsigned long zs_malloc(struct zs_pool *pool, size_t size) -{ - unsigned long obj; - struct link_free *link; - int class_idx; - struct size_class *class; - - struct page *first_page, *m_page; - unsigned long m_objidx, m_offset; - - if (unlikely(!size || size > ZS_MAX_ALLOC_SIZE)) - return 0; - - class_idx = get_size_class_index(size); - class = &pool->size_class[class_idx]; - BUG_ON(class_idx != class->index); - - spin_lock(&class->lock); - first_page = find_get_zspage(class); - - if (!first_page) { - spin_unlock(&class->lock); - first_page = alloc_zspage(class, pool->flags); - if (unlikely(!first_page)) - return 0; - - set_zspage_mapping(first_page, class->index, ZS_EMPTY); - spin_lock(&class->lock); - class->pages_allocated += class->pages_per_zspage; - } - - obj = (unsigned long)first_page->freelist; - obj_handle_to_location(obj, &m_page, &m_objidx); - m_offset = obj_idx_to_offset(m_page, m_objidx, class->size); - - link = (struct link_free *)kmap_atomic(m_page) + - m_offset / sizeof(*link); - first_page->freelist = link->next; - memset(link, POISON_INUSE, sizeof(*link)); - kunmap_atomic(link); - - first_page->inuse++; - /* Now move the zspage to another fullness group, if required */ - fix_fullness_group(pool, first_page); - spin_unlock(&class->lock); - - return obj; -} -EXPORT_SYMBOL_GPL(zs_malloc); - -void zs_free(struct zs_pool *pool, unsigned long obj) -{ - struct link_free *link; - struct page *first_page, *f_page; - unsigned long f_objidx, f_offset; - - int class_idx; - struct size_class *class; - enum fullness_group fullness; - - if (unlikely(!obj)) - return; - - obj_handle_to_location(obj, &f_page, &f_objidx); - first_page = get_first_page(f_page); - - get_zspage_mapping(first_page, &class_idx, &fullness); - class = &pool->size_class[class_idx]; - f_offset = obj_idx_to_offset(f_page, f_objidx, class->size); - - spin_lock(&class->lock); - - /* Insert this object in containing zspage's freelist */ - link = (struct link_free *)((unsigned char *)kmap_atomic(f_page) - + f_offset); - link->next = first_page->freelist; - kunmap_atomic(link); - first_page->freelist = (void *)obj; - - first_page->inuse--; - fullness = fix_fullness_group(pool, first_page); - - if (fullness == ZS_EMPTY) - class->pages_allocated -= class->pages_per_zspage; - - spin_unlock(&class->lock); - - if (fullness == ZS_EMPTY) - free_zspage(first_page); -} -EXPORT_SYMBOL_GPL(zs_free); - -/** - * zs_map_object - get address of allocated object from handle. - * @pool: pool from which the object was allocated - * @handle: handle returned from zs_malloc - * - * Before using an object allocated from zs_malloc, it must be mapped using - * this function. When done with the object, it must be unmapped using - * zs_unmap_object. - * - * Only one object can be mapped per cpu at a time. There is no protection - * against nested mappings. - * - * This function returns with preemption and page faults disabled. -*/ -void *zs_map_object(struct zs_pool *pool, unsigned long handle, - enum zs_mapmode mm) -{ - struct page *page; - unsigned long obj_idx, off; - - unsigned int class_idx; - enum fullness_group fg; - struct size_class *class; - struct mapping_area *area; - struct page *pages[2]; - - BUG_ON(!handle); - - /* - * Because we use per-cpu mapping areas shared among the - * pools/users, we can't allow mapping in interrupt context - * because it can corrupt another users mappings. - */ - BUG_ON(in_interrupt()); - - obj_handle_to_location(handle, &page, &obj_idx); - get_zspage_mapping(get_first_page(page), &class_idx, &fg); - class = &pool->size_class[class_idx]; - off = obj_idx_to_offset(page, obj_idx, class->size); - - area = &get_cpu_var(zs_map_area); - area->vm_mm = mm; - if (off + class->size <= PAGE_SIZE) { - /* this object is contained entirely within a page */ - area->vm_addr = kmap_atomic(page); - return area->vm_addr + off; - } - - /* this object spans two pages */ - pages[0] = page; - pages[1] = get_next_page(page); - BUG_ON(!pages[1]); - - return __zs_map_object(area, pages, off, class->size); -} -EXPORT_SYMBOL_GPL(zs_map_object); - -void zs_unmap_object(struct zs_pool *pool, unsigned long handle) -{ - struct page *page; - unsigned long obj_idx, off; - - unsigned int class_idx; - enum fullness_group fg; - struct size_class *class; - struct mapping_area *area; - - BUG_ON(!handle); - - obj_handle_to_location(handle, &page, &obj_idx); - get_zspage_mapping(get_first_page(page), &class_idx, &fg); - class = &pool->size_class[class_idx]; - off = obj_idx_to_offset(page, obj_idx, class->size); - - area = &__get_cpu_var(zs_map_area); - if (off + class->size <= PAGE_SIZE) - kunmap_atomic(area->vm_addr); - else { - struct page *pages[2]; - - pages[0] = page; - pages[1] = get_next_page(page); - BUG_ON(!pages[1]); - - __zs_unmap_object(area, pages, off, class->size); - } - put_cpu_var(zs_map_area); -} -EXPORT_SYMBOL_GPL(zs_unmap_object); - -u64 zs_get_total_size_bytes(struct zs_pool *pool) -{ - int i; - u64 npages = 0; - - for (i = 0; i < ZS_SIZE_CLASSES; i++) - npages += pool->size_class[i].pages_allocated; - - return npages << PAGE_SHIFT; -} -EXPORT_SYMBOL_GPL(zs_get_total_size_bytes); - -module_init(zs_init); -module_exit(zs_exit); - -MODULE_LICENSE("Dual BSD/GPL"); -MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); diff --git a/drivers/staging/zsmalloc/zsmalloc.h b/drivers/staging/zsmalloc/zsmalloc.h deleted file mode 100644 index de2e8bf..0000000 --- a/drivers/staging/zsmalloc/zsmalloc.h +++ /dev/null @@ -1,43 +0,0 @@ -/* - * zsmalloc memory allocator - * - * Copyright (C) 2011 Nitin Gupta - * - * This code is released using a dual license strategy: BSD/GPL - * You can choose the license that better fits your requirements. - * - * Released under the terms of 3-clause BSD License - * Released under the terms of GNU General Public License Version 2.0 - */ - -#ifndef _ZS_MALLOC_H_ -#define _ZS_MALLOC_H_ - -#include <linux/types.h> - -/* - * zsmalloc mapping modes - * - * NOTE: These only make a difference when a mapped object spans pages -*/ -enum zs_mapmode { - ZS_MM_RW, /* normal read-write mapping */ - ZS_MM_RO, /* read-only (no copy-out at unmap time) */ - ZS_MM_WO /* write-only (no copy-in at map time) */ -}; - -struct zs_pool; - -struct zs_pool *zs_create_pool(const char *name, gfp_t flags); -void zs_destroy_pool(struct zs_pool *pool); - -unsigned long zs_malloc(struct zs_pool *pool, size_t size); -void zs_free(struct zs_pool *pool, unsigned long obj); - -void *zs_map_object(struct zs_pool *pool, unsigned long handle, - enum zs_mapmode mm); -void zs_unmap_object(struct zs_pool *pool, unsigned long handle); - -u64 zs_get_total_size_bytes(struct zs_pool *pool); - -#endif diff --git a/include/linux/zsmalloc.h b/include/linux/zsmalloc.h new file mode 100644 index 0000000..de2e8bf --- /dev/null +++ b/include/linux/zsmalloc.h @@ -0,0 +1,43 @@ +/* + * zsmalloc memory allocator + * + * Copyright (C) 2011 Nitin Gupta + * + * This code is released using a dual license strategy: BSD/GPL + * You can choose the license that better fits your requirements. + * + * Released under the terms of 3-clause BSD License + * Released under the terms of GNU General Public License Version 2.0 + */ + +#ifndef _ZS_MALLOC_H_ +#define _ZS_MALLOC_H_ + +#include <linux/types.h> + +/* + * zsmalloc mapping modes + * + * NOTE: These only make a difference when a mapped object spans pages +*/ +enum zs_mapmode { + ZS_MM_RW, /* normal read-write mapping */ + ZS_MM_RO, /* read-only (no copy-out at unmap time) */ + ZS_MM_WO /* write-only (no copy-in at map time) */ +}; + +struct zs_pool; + +struct zs_pool *zs_create_pool(const char *name, gfp_t flags); +void zs_destroy_pool(struct zs_pool *pool); + +unsigned long zs_malloc(struct zs_pool *pool, size_t size); +void zs_free(struct zs_pool *pool, unsigned long obj); + +void *zs_map_object(struct zs_pool *pool, unsigned long handle, + enum zs_mapmode mm); +void zs_unmap_object(struct zs_pool *pool, unsigned long handle); + +u64 zs_get_total_size_bytes(struct zs_pool *pool); + +#endif diff --git a/lib/Kconfig b/lib/Kconfig index bb94c1b..d95da41 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -216,6 +216,8 @@ config DECOMPRESS_LZO config GENERIC_ALLOCATOR boolean +source "lib/zsmalloc/Kconfig" + # # reed solomon support is select'ed if needed # diff --git a/lib/Makefile b/lib/Makefile index 3128e35..dd26077 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -64,6 +64,7 @@ obj-$(CONFIG_CRC7) += crc7.o obj-$(CONFIG_LIBCRC32C) += libcrc32c.o obj-$(CONFIG_CRC8) += crc8.o obj-$(CONFIG_GENERIC_ALLOCATOR) += genalloc.o +obj-$(CONFIG_ZSMALLOC) += zsmalloc/ obj-$(CONFIG_ZLIB_INFLATE) += zlib_inflate/ obj-$(CONFIG_ZLIB_DEFLATE) += zlib_deflate/ diff --git a/lib/zsmalloc/Kconfig b/lib/zsmalloc/Kconfig new file mode 100644 index 0000000..b6abd31 --- /dev/null +++ b/lib/zsmalloc/Kconfig @@ -0,0 +1,18 @@ +config ZSMALLOC + tristate "Memory allocator for compressed pages" + default n + help + zsmalloc is a slab-based memory allocator designed to store + compressed RAM pages. zsmalloc uses a memory pool that combines + single pages into higher order pages by linking them together + using the fields of the struct page. Allocations are then + mapped through copy buffers or VM mapping, in order to reduce + memory pool fragmentation and increase allocation success rate under + memory pressure. + + This results in a non-standard allocator interface where + a handle, not a pointer, is returned by the allocation function. + This handle must be mapped in order to access the allocated space. + + If unsure, say N. + diff --git a/lib/zsmalloc/Makefile b/lib/zsmalloc/Makefile new file mode 100644 index 0000000..d02d3a5 --- /dev/null +++ b/lib/zsmalloc/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_ZSMALLOC) += zsmalloc.o diff --git a/lib/zsmalloc/zsmalloc.c b/lib/zsmalloc/zsmalloc.c new file mode 100644 index 0000000..2cde21e --- /dev/null +++ b/lib/zsmalloc/zsmalloc.c @@ -0,0 +1,1064 @@ +/* + * zsmalloc memory allocator + * + * Copyright (C) 2011 Nitin Gupta + * + * This code is released using a dual license strategy: BSD/GPL + * You can choose the license that better fits your requirements. + * + * Released under the terms of 3-clause BSD License + * Released under the terms of GNU General Public License Version 2.0 + */ + + +/* + * This allocator is designed for use with zcache and zram. Thus, the + * allocator is supposed to work well under low memory conditions. In + * particular, it never attempts higher order page allocation which is + * very likely to fail under memory pressure. On the other hand, if we + * just use single (0-order) pages, it would suffer from very high + * fragmentation -- any object of size PAGE_SIZE/2 or larger would occupy + * an entire page. This was one of the major issues with its predecessor + * (xvmalloc). + * + * To overcome these issues, zsmalloc allocates a bunch of 0-order pages + * and links them together using various 'struct page' fields. These linked + * pages act as a single higher-order page i.e. an object can span 0-order + * page boundaries. The code refers to these linked pages as a single entity + * called zspage. + * + * Following is how we use various fields and flags of underlying + * struct page(s) to form a zspage. + * + * Usage of struct page fields: + * page->first_page: points to the first component (0-order) page + * page->index (union with page->freelist): offset of the first object + * starting in this page. For the first page, this is + * always 0, so we use this field (aka freelist) to point + * to the first free object in zspage. + * page->lru: links together all component pages (except the first page) + * of a zspage + * + * For _first_ page only: + * + * page->private (union with page->first_page): refers to the + * component page after the first page + * page->freelist: points to the first free object in zspage. + * Free objects are linked together using in-place + * metadata. + * page->objects: maximum number of objects we can store in this + * zspage (class->zspage_order * PAGE_SIZE / class->size) + * page->lru: links together first pages of various zspages. + * Basically forming list of zspages in a fullness group. + * page->mapping: class index and fullness group of the zspage + * + * Usage of struct page flags: + * PG_private: identifies the first component page + * PG_private2: identifies the last component page + * + */ + +#ifdef CONFIG_ZSMALLOC_DEBUG +#define DEBUG +#endif + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/bitops.h> +#include <linux/errno.h> +#include <linux/highmem.h> +#include <linux/init.h> +#include <linux/string.h> +#include <linux/slab.h> +#include <asm/tlbflush.h> +#include <asm/pgtable.h> +#include <linux/cpumask.h> +#include <linux/cpu.h> +#include <linux/vmalloc.h> +#include <linux/hardirq.h> +#include <linux/spinlock.h> +#include <linux/types.h> + +#include <linux/zsmalloc.h> + +/* + * This must be power of 2 and greater than of equal to sizeof(link_free). + * These two conditions ensure that any 'struct link_free' itself doesn't + * span more than 1 page which avoids complex case of mapping 2 pages simply + * to restore link_free pointer values. + */ +#define ZS_ALIGN 8 + +/* + * A single 'zspage' is composed of up to 2^N discontiguous 0-order (single) + * pages. ZS_MAX_ZSPAGE_ORDER defines upper limit on N. + */ +#define ZS_MAX_ZSPAGE_ORDER 2 +#define ZS_MAX_PAGES_PER_ZSPAGE (_AC(1, UL) << ZS_MAX_ZSPAGE_ORDER) + +/* + * Object location (<PFN>, <obj_idx>) is encoded as + * as single (void *) handle value. + * + * Note that object index <obj_idx> is relative to system + * page <PFN> it is stored in, so for each sub-page belonging + * to a zspage, obj_idx starts with 0. + * + * This is made more complicated by various memory models and PAE. + */ + +#ifndef MAX_PHYSMEM_BITS +#ifdef CONFIG_HIGHMEM64G +#define MAX_PHYSMEM_BITS 36 +#else /* !CONFIG_HIGHMEM64G */ +/* + * If this definition of MAX_PHYSMEM_BITS is used, OBJ_INDEX_BITS will just + * be PAGE_SHIFT + */ +#define MAX_PHYSMEM_BITS BITS_PER_LONG +#endif +#endif +#define _PFN_BITS (MAX_PHYSMEM_BITS - PAGE_SHIFT) +#define OBJ_INDEX_BITS (BITS_PER_LONG - _PFN_BITS) +#define OBJ_INDEX_MASK ((_AC(1, UL) << OBJ_INDEX_BITS) - 1) + +#define MAX(a, b) ((a) >= (b) ? (a) : (b)) +/* ZS_MIN_ALLOC_SIZE must be multiple of ZS_ALIGN */ +#define ZS_MIN_ALLOC_SIZE \ + MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS)) +#define ZS_MAX_ALLOC_SIZE PAGE_SIZE + +/* + * On systems with 4K page size, this gives 254 size classes! There is a + * trader-off here: + * - Large number of size classes is potentially wasteful as free page are + * spread across these classes + * - Small number of size classes causes large internal fragmentation + * - Probably its better to use specific size classes (empirically + * determined). NOTE: all those class sizes must be set as multiple of + * ZS_ALIGN to make sure link_free itself never has to span 2 pages. + * + * ZS_MIN_ALLOC_SIZE and ZS_SIZE_CLASS_DELTA must be multiple of ZS_ALIGN + * (reason above) + */ +#define ZS_SIZE_CLASS_DELTA 16 +#define ZS_SIZE_CLASSES ((ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) / \ + ZS_SIZE_CLASS_DELTA + 1) + +/* + * We do not maintain any list for completely empty or full pages + */ +enum fullness_group { + ZS_ALMOST_FULL, + ZS_ALMOST_EMPTY, + _ZS_NR_FULLNESS_GROUPS, + + ZS_EMPTY, + ZS_FULL +}; + +/* + * We assign a page to ZS_ALMOST_EMPTY fullness group when: + * n <= N / f, where + * n = number of allocated objects + * N = total number of objects zspage can store + * f = 1/fullness_threshold_frac + * + * Similarly, we assign zspage to: + * ZS_ALMOST_FULL when n > N / f + * ZS_EMPTY when n == 0 + * ZS_FULL when n == N + * + * (see: fix_fullness_group()) + */ +static const int fullness_threshold_frac = 4; + +struct size_class { + /* + * Size of objects stored in this class. Must be multiple + * of ZS_ALIGN. + */ + int size; + unsigned int index; + + /* Number of PAGE_SIZE sized pages to combine to form a 'zspage' */ + int pages_per_zspage; + + spinlock_t lock; + + /* stats */ + u64 pages_allocated; + + struct page *fullness_list[_ZS_NR_FULLNESS_GROUPS]; +}; + +/* + * Placed within free objects to form a singly linked list. + * For every zspage, first_page->freelist gives head of this list. + * + * This must be power of 2 and less than or equal to ZS_ALIGN + */ +struct link_free { + /* Handle of next free chunk (encodes <PFN, obj_idx>) */ + void *next; +}; + +struct zs_pool { + struct size_class size_class[ZS_SIZE_CLASSES]; + + gfp_t flags; /* allocation flags used when growing pool */ + const char *name; +}; + +/* + * A zspage's class index and fullness group + * are encoded in its (first)page->mapping + */ +#define CLASS_IDX_BITS 28 +#define FULLNESS_BITS 4 +#define CLASS_IDX_MASK ((1 << CLASS_IDX_BITS) - 1) +#define FULLNESS_MASK ((1 << FULLNESS_BITS) - 1) + +/* + * By default, zsmalloc uses a copy-based object mapping method to access + * allocations that span two pages. However, if a particular architecture + * 1) Implements local_flush_tlb_kernel_range() and 2) Performs VM mapping + * faster than copying, then it should be added here so that + * USE_PGTABLE_MAPPING is defined. This causes zsmalloc to use page table + * mapping rather than copying + * for object mapping. +*/ +#if defined(CONFIG_ARM) +#define USE_PGTABLE_MAPPING +#endif + +struct mapping_area { +#ifdef USE_PGTABLE_MAPPING + struct vm_struct *vm; /* vm area for mapping object that span pages */ +#else + char *vm_buf; /* copy buffer for objects that span pages */ +#endif + char *vm_addr; /* address of kmap_atomic()'ed pages */ + enum zs_mapmode vm_mm; /* mapping mode */ +}; + + +/* per-cpu VM mapping areas for zspage accesses that cross page boundaries */ +static DEFINE_PER_CPU(struct mapping_area, zs_map_area); + +static int is_first_page(struct page *page) +{ + return PagePrivate(page); +} + +static int is_last_page(struct page *page) +{ + return PagePrivate2(page); +} + +static void get_zspage_mapping(struct page *page, unsigned int *class_idx, + enum fullness_group *fullness) +{ + unsigned long m; + BUG_ON(!is_first_page(page)); + + m = (unsigned long)page->mapping; + *fullness = m & FULLNESS_MASK; + *class_idx = (m >> FULLNESS_BITS) & CLASS_IDX_MASK; +} + +static void set_zspage_mapping(struct page *page, unsigned int class_idx, + enum fullness_group fullness) +{ + unsigned long m; + BUG_ON(!is_first_page(page)); + + m = ((class_idx & CLASS_IDX_MASK) << FULLNESS_BITS) | + (fullness & FULLNESS_MASK); + page->mapping = (struct address_space *)m; +} + +static int get_size_class_index(int size) +{ + int idx = 0; + + if (likely(size > ZS_MIN_ALLOC_SIZE)) + idx = DIV_ROUND_UP(size - ZS_MIN_ALLOC_SIZE, + ZS_SIZE_CLASS_DELTA); + + return idx; +} + +static enum fullness_group get_fullness_group(struct page *page) +{ + int inuse, max_objects; + enum fullness_group fg; + BUG_ON(!is_first_page(page)); + + inuse = page->inuse; + max_objects = page->objects; + + if (inuse == 0) + fg = ZS_EMPTY; + else if (inuse == max_objects) + fg = ZS_FULL; + else if (inuse <= max_objects / fullness_threshold_frac) + fg = ZS_ALMOST_EMPTY; + else + fg = ZS_ALMOST_FULL; + + return fg; +} + +static void insert_zspage(struct page *page, struct size_class *class, + enum fullness_group fullness) +{ + struct page **head; + + BUG_ON(!is_first_page(page)); + + if (fullness >= _ZS_NR_FULLNESS_GROUPS) + return; + + head = &class->fullness_list[fullness]; + if (*head) + list_add_tail(&page->lru, &(*head)->lru); + + *head = page; +} + +static void remove_zspage(struct page *page, struct size_class *class, + enum fullness_group fullness) +{ + struct page **head; + + BUG_ON(!is_first_page(page)); + + if (fullness >= _ZS_NR_FULLNESS_GROUPS) + return; + + head = &class->fullness_list[fullness]; + BUG_ON(!*head); + if (list_empty(&(*head)->lru)) + *head = NULL; + else if (*head == page) + *head = (struct page *)list_entry((*head)->lru.next, + struct page, lru); + + list_del_init(&page->lru); +} + +static enum fullness_group fix_fullness_group(struct zs_pool *pool, + struct page *page) +{ + int class_idx; + struct size_class *class; + enum fullness_group currfg, newfg; + + BUG_ON(!is_first_page(page)); + + get_zspage_mapping(page, &class_idx, &currfg); + newfg = get_fullness_group(page); + if (newfg == currfg) + goto out; + + class = &pool->size_class[class_idx]; + remove_zspage(page, class, currfg); + insert_zspage(page, class, newfg); + set_zspage_mapping(page, class_idx, newfg); + +out: + return newfg; +} + +/* + * We have to decide on how many pages to link together + * to form a zspage for each size class. This is important + * to reduce wastage due to unusable space left at end of + * each zspage which is given as: + * wastage = Zp - Zp % size_class + * where Zp = zspage size = k * PAGE_SIZE where k = 1, 2, ... + * + * For example, for size class of 3/8 * PAGE_SIZE, we should + * link together 3 PAGE_SIZE sized pages to form a zspage + * since then we can perfectly fit in 8 such objects. + */ +static int get_pages_per_zspage(int class_size) +{ + int i, max_usedpc = 0; + /* zspage order which gives maximum used size per KB */ + int max_usedpc_order = 1; + + for (i = 1; i <= ZS_MAX_PAGES_PER_ZSPAGE; i++) { + int zspage_size; + int waste, usedpc; + + zspage_size = i * PAGE_SIZE; + waste = zspage_size % class_size; + usedpc = (zspage_size - waste) * 100 / zspage_size; + + if (usedpc > max_usedpc) { + max_usedpc = usedpc; + max_usedpc_order = i; + } + } + + return max_usedpc_order; +} + +/* + * A single 'zspage' is composed of many system pages which are + * linked together using fields in struct page. This function finds + * the first/head page, given any component page of a zspage. + */ +static struct page *get_first_page(struct page *page) +{ + if (is_first_page(page)) + return page; + else + return page->first_page; +} + +static struct page *get_next_page(struct page *page) +{ + struct page *next; + + if (is_last_page(page)) + next = NULL; + else if (is_first_page(page)) + next = (struct page *)page->private; + else + next = list_entry(page->lru.next, struct page, lru); + + return next; +} + +/* Encode <page, obj_idx> as a single handle value */ +static void *obj_location_to_handle(struct page *page, unsigned long obj_idx) +{ + unsigned long handle; + + if (!page) { + BUG_ON(obj_idx); + return NULL; + } + + handle = page_to_pfn(page) << OBJ_INDEX_BITS; + handle |= (obj_idx & OBJ_INDEX_MASK); + + return (void *)handle; +} + +/* Decode <page, obj_idx> pair from the given object handle */ +static void obj_handle_to_location(unsigned long handle, struct page **page, + unsigned long *obj_idx) +{ + *page = pfn_to_page(handle >> OBJ_INDEX_BITS); + *obj_idx = handle & OBJ_INDEX_MASK; +} + +static unsigned long obj_idx_to_offset(struct page *page, + unsigned long obj_idx, int class_size) +{ + unsigned long off = 0; + + if (!is_first_page(page)) + off = page->index; + + return off + obj_idx * class_size; +} + +static void reset_page(struct page *page) +{ + clear_bit(PG_private, &page->flags); + clear_bit(PG_private_2, &page->flags); + set_page_private(page, 0); + page->mapping = NULL; + page->freelist = NULL; + reset_page_mapcount(page); +} + +static void free_zspage(struct page *first_page) +{ + struct page *nextp, *tmp, *head_extra; + + BUG_ON(!is_first_page(first_page)); + BUG_ON(first_page->inuse); + + head_extra = (struct page *)page_private(first_page); + + reset_page(first_page); + __free_page(first_page); + + /* zspage with only 1 system page */ + if (!head_extra) + return; + + list_for_each_entry_safe(nextp, tmp, &head_extra->lru, lru) { + list_del(&nextp->lru); + reset_page(nextp); + __free_page(nextp); + } + reset_page(head_extra); + __free_page(head_extra); +} + +/* Initialize a newly allocated zspage */ +static void init_zspage(struct page *first_page, struct size_class *class) +{ + unsigned long off = 0; + struct page *page = first_page; + + BUG_ON(!is_first_page(first_page)); + while (page) { + struct page *next_page; + struct link_free *link; + unsigned int i, objs_on_page; + + /* + * page->index stores offset of first object starting + * in the page. For the first page, this is always 0, + * so we use first_page->index (aka ->freelist) to store + * head of corresponding zspage's freelist. + */ + if (page != first_page) + page->index = off; + + link = (struct link_free *)kmap_atomic(page) + + off / sizeof(*link); + objs_on_page = (PAGE_SIZE - off) / class->size; + + for (i = 1; i <= objs_on_page; i++) { + off += class->size; + if (off < PAGE_SIZE) { + link->next = obj_location_to_handle(page, i); + link += class->size / sizeof(*link); + } + } + + /* + * We now come to the last (full or partial) object on this + * page, which must point to the first object on the next + * page (if present) + */ + next_page = get_next_page(page); + link->next = obj_location_to_handle(next_page, 0); + kunmap_atomic(link); + page = next_page; + off = (off + class->size) % PAGE_SIZE; + } +} + +/* + * Allocate a zspage for the given size class + */ +static struct page *alloc_zspage(struct size_class *class, gfp_t flags) +{ + int i, error; + struct page *first_page = NULL, *uninitialized_var(prev_page); + + /* + * Allocate individual pages and link them together as: + * 1. first page->private = first sub-page + * 2. all sub-pages are linked together using page->lru + * 3. each sub-page is linked to the first page using page->first_page + * + * For each size class, First/Head pages are linked together using + * page->lru. Also, we set PG_private to identify the first page + * (i.e. no other sub-page has this flag set) and PG_private_2 to + * identify the last page. + */ + error = -ENOMEM; + for (i = 0; i < class->pages_per_zspage; i++) { + struct page *page; + + page = alloc_page(flags); + if (!page) + goto cleanup; + + INIT_LIST_HEAD(&page->lru); + if (i == 0) { /* first page */ + SetPagePrivate(page); + set_page_private(page, 0); + first_page = page; + first_page->inuse = 0; + } + if (i == 1) + first_page->private = (unsigned long)page; + if (i >= 1) + page->first_page = first_page; + if (i >= 2) + list_add(&page->lru, &prev_page->lru); + if (i == class->pages_per_zspage - 1) /* last page */ + SetPagePrivate2(page); + prev_page = page; + } + + init_zspage(first_page, class); + + first_page->freelist = obj_location_to_handle(first_page, 0); + /* Maximum number of objects we can store in this zspage */ + first_page->objects = class->pages_per_zspage * PAGE_SIZE / class->size; + + error = 0; /* Success */ + +cleanup: + if (unlikely(error) && first_page) { + free_zspage(first_page); + first_page = NULL; + } + + return first_page; +} + +static struct page *find_get_zspage(struct size_class *class) +{ + int i; + struct page *page; + + for (i = 0; i < _ZS_NR_FULLNESS_GROUPS; i++) { + page = class->fullness_list[i]; + if (page) + break; + } + + return page; +} + +#ifdef USE_PGTABLE_MAPPING +static inline int __zs_cpu_up(struct mapping_area *area) +{ + /* + * Make sure we don't leak memory if a cpu UP notification + * and zs_init() race and both call zs_cpu_up() on the same cpu + */ + if (area->vm) + return 0; + area->vm = alloc_vm_area(PAGE_SIZE * 2, NULL); + if (!area->vm) + return -ENOMEM; + return 0; +} + +static inline void __zs_cpu_down(struct mapping_area *area) +{ + if (area->vm) + free_vm_area(area->vm); + area->vm = NULL; +} + +static inline void *__zs_map_object(struct mapping_area *area, + struct page *pages[2], int off, int size) +{ + BUG_ON(map_vm_area(area->vm, PAGE_KERNEL, &pages)); + area->vm_addr = area->vm->addr; + return area->vm_addr + off; +} + +static inline void __zs_unmap_object(struct mapping_area *area, + struct page *pages[2], int off, int size) +{ + unsigned long addr = (unsigned long)area->vm_addr; + unsigned long end = addr + (PAGE_SIZE * 2); + + flush_cache_vunmap(addr, end); + unmap_kernel_range_noflush(addr, PAGE_SIZE * 2); + local_flush_tlb_kernel_range(addr, end); +} + +#else /* USE_PGTABLE_MAPPING */ + +static inline int __zs_cpu_up(struct mapping_area *area) +{ + /* + * Make sure we don't leak memory if a cpu UP notification + * and zs_init() race and both call zs_cpu_up() on the same cpu + */ + if (area->vm_buf) + return 0; + area->vm_buf = (char *)__get_free_page(GFP_KERNEL); + if (!area->vm_buf) + return -ENOMEM; + return 0; +} + +static inline void __zs_cpu_down(struct mapping_area *area) +{ + if (area->vm_buf) + free_page((unsigned long)area->vm_buf); + area->vm_buf = NULL; +} + +static void *__zs_map_object(struct mapping_area *area, + struct page *pages[2], int off, int size) +{ + int sizes[2]; + void *addr; + char *buf = area->vm_buf; + + /* disable page faults to match kmap_atomic() return conditions */ + pagefault_disable(); + + /* no read fastpath */ + if (area->vm_mm == ZS_MM_WO) + goto out; + + sizes[0] = PAGE_SIZE - off; + sizes[1] = size - sizes[0]; + + /* copy object to per-cpu buffer */ + addr = kmap_atomic(pages[0]); + memcpy(buf, addr + off, sizes[0]); + kunmap_atomic(addr); + addr = kmap_atomic(pages[1]); + memcpy(buf + sizes[0], addr, sizes[1]); + kunmap_atomic(addr); +out: + return area->vm_buf; +} + +static void __zs_unmap_object(struct mapping_area *area, + struct page *pages[2], int off, int size) +{ + int sizes[2]; + void *addr; + char *buf = area->vm_buf; + + /* no write fastpath */ + if (area->vm_mm == ZS_MM_RO) + goto out; + + sizes[0] = PAGE_SIZE - off; + sizes[1] = size - sizes[0]; + + /* copy per-cpu buffer to object */ + addr = kmap_atomic(pages[0]); + memcpy(addr + off, buf, sizes[0]); + kunmap_atomic(addr); + addr = kmap_atomic(pages[1]); + memcpy(addr, buf + sizes[0], sizes[1]); + kunmap_atomic(addr); + +out: + /* enable page faults to match kunmap_atomic() return conditions */ + pagefault_enable(); +} + +#endif /* USE_PGTABLE_MAPPING */ + +static int zs_cpu_notifier(struct notifier_block *nb, unsigned long action, + void *pcpu) +{ + int ret, cpu = (long)pcpu; + struct mapping_area *area; + + switch (action) { + case CPU_UP_PREPARE: + area = &per_cpu(zs_map_area, cpu); + ret = __zs_cpu_up(area); + if (ret) + return notifier_from_errno(ret); + break; + case CPU_DEAD: + case CPU_UP_CANCELED: + area = &per_cpu(zs_map_area, cpu); + __zs_cpu_down(area); + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block zs_cpu_nb = { + .notifier_call = zs_cpu_notifier +}; + +static void zs_exit(void) +{ + int cpu; + + for_each_online_cpu(cpu) + zs_cpu_notifier(NULL, CPU_DEAD, (void *)(long)cpu); + unregister_cpu_notifier(&zs_cpu_nb); +} + +static int zs_init(void) +{ + int cpu, ret; + + register_cpu_notifier(&zs_cpu_nb); + for_each_online_cpu(cpu) { + ret = zs_cpu_notifier(NULL, CPU_UP_PREPARE, (void *)(long)cpu); + if (notifier_to_errno(ret)) + goto fail; + } + return 0; +fail: + zs_exit(); + return notifier_to_errno(ret); +} + +struct zs_pool *zs_create_pool(const char *name, gfp_t flags) +{ + int i, ovhd_size; + struct zs_pool *pool; + + if (!name) + return NULL; + + ovhd_size = roundup(sizeof(*pool), PAGE_SIZE); + pool = kzalloc(ovhd_size, GFP_KERNEL); + if (!pool) + return NULL; + + for (i = 0; i < ZS_SIZE_CLASSES; i++) { + int size; + struct size_class *class; + + size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA; + if (size > ZS_MAX_ALLOC_SIZE) + size = ZS_MAX_ALLOC_SIZE; + + class = &pool->size_class[i]; + class->size = size; + class->index = i; + spin_lock_init(&class->lock); + class->pages_per_zspage = get_pages_per_zspage(size); + + } + + pool->flags = flags; + pool->name = name; + + return pool; +} +EXPORT_SYMBOL_GPL(zs_create_pool); + +void zs_destroy_pool(struct zs_pool *pool) +{ + int i; + + for (i = 0; i < ZS_SIZE_CLASSES; i++) { + int fg; + struct size_class *class = &pool->size_class[i]; + + for (fg = 0; fg < _ZS_NR_FULLNESS_GROUPS; fg++) { + if (class->fullness_list[fg]) { + pr_info("Freeing non-empty class with size " + "%db, fullness group %d\n", + class->size, fg); + } + } + } + kfree(pool); +} +EXPORT_SYMBOL_GPL(zs_destroy_pool); + +/** + * zs_malloc - Allocate block of given size from pool. + * @pool: pool to allocate from + * @size: size of block to allocate + * + * On success, handle to the allocated object is returned, + * otherwise 0. + * Allocation requests with size > ZS_MAX_ALLOC_SIZE will fail. + */ +unsigned long zs_malloc(struct zs_pool *pool, size_t size) +{ + unsigned long obj; + struct link_free *link; + int class_idx; + struct size_class *class; + + struct page *first_page, *m_page; + unsigned long m_objidx, m_offset; + + if (unlikely(!size || size > ZS_MAX_ALLOC_SIZE)) + return 0; + + class_idx = get_size_class_index(size); + class = &pool->size_class[class_idx]; + BUG_ON(class_idx != class->index); + + spin_lock(&class->lock); + first_page = find_get_zspage(class); + + if (!first_page) { + spin_unlock(&class->lock); + first_page = alloc_zspage(class, pool->flags); + if (unlikely(!first_page)) + return 0; + + set_zspage_mapping(first_page, class->index, ZS_EMPTY); + spin_lock(&class->lock); + class->pages_allocated += class->pages_per_zspage; + } + + obj = (unsigned long)first_page->freelist; + obj_handle_to_location(obj, &m_page, &m_objidx); + m_offset = obj_idx_to_offset(m_page, m_objidx, class->size); + + link = (struct link_free *)kmap_atomic(m_page) + + m_offset / sizeof(*link); + first_page->freelist = link->next; + memset(link, POISON_INUSE, sizeof(*link)); + kunmap_atomic(link); + + first_page->inuse++; + /* Now move the zspage to another fullness group, if required */ + fix_fullness_group(pool, first_page); + spin_unlock(&class->lock); + + return obj; +} +EXPORT_SYMBOL_GPL(zs_malloc); + +void zs_free(struct zs_pool *pool, unsigned long obj) +{ + struct link_free *link; + struct page *first_page, *f_page; + unsigned long f_objidx, f_offset; + + int class_idx; + struct size_class *class; + enum fullness_group fullness; + + if (unlikely(!obj)) + return; + + obj_handle_to_location(obj, &f_page, &f_objidx); + first_page = get_first_page(f_page); + + get_zspage_mapping(first_page, &class_idx, &fullness); + class = &pool->size_class[class_idx]; + f_offset = obj_idx_to_offset(f_page, f_objidx, class->size); + + spin_lock(&class->lock); + + /* Insert this object in containing zspage's freelist */ + link = (struct link_free *)((unsigned char *)kmap_atomic(f_page) + + f_offset); + link->next = first_page->freelist; + kunmap_atomic(link); + first_page->freelist = (void *)obj; + + first_page->inuse--; + fullness = fix_fullness_group(pool, first_page); + + if (fullness == ZS_EMPTY) + class->pages_allocated -= class->pages_per_zspage; + + spin_unlock(&class->lock); + + if (fullness == ZS_EMPTY) + free_zspage(first_page); +} +EXPORT_SYMBOL_GPL(zs_free); + +/** + * zs_map_object - get address of allocated object from handle. + * @pool: pool from which the object was allocated + * @handle: handle returned from zs_malloc + * + * Before using an object allocated from zs_malloc, it must be mapped using + * this function. When done with the object, it must be unmapped using + * zs_unmap_object. + * + * Only one object can be mapped per cpu at a time. There is no protection + * against nested mappings. + * + * This function returns with preemption and page faults disabled. +*/ +void *zs_map_object(struct zs_pool *pool, unsigned long handle, + enum zs_mapmode mm) +{ + struct page *page; + unsigned long obj_idx, off; + + unsigned int class_idx; + enum fullness_group fg; + struct size_class *class; + struct mapping_area *area; + struct page *pages[2]; + + BUG_ON(!handle); + + /* + * Because we use per-cpu mapping areas shared among the + * pools/users, we can't allow mapping in interrupt context + * because it can corrupt another users mappings. + */ + BUG_ON(in_interrupt()); + + obj_handle_to_location(handle, &page, &obj_idx); + get_zspage_mapping(get_first_page(page), &class_idx, &fg); + class = &pool->size_class[class_idx]; + off = obj_idx_to_offset(page, obj_idx, class->size); + + area = &get_cpu_var(zs_map_area); + area->vm_mm = mm; + if (off + class->size <= PAGE_SIZE) { + /* this object is contained entirely within a page */ + area->vm_addr = kmap_atomic(page); + return area->vm_addr + off; + } + + /* this object spans two pages */ + pages[0] = page; + pages[1] = get_next_page(page); + BUG_ON(!pages[1]); + + return __zs_map_object(area, pages, off, class->size); +} +EXPORT_SYMBOL_GPL(zs_map_object); + +void zs_unmap_object(struct zs_pool *pool, unsigned long handle) +{ + struct page *page; + unsigned long obj_idx, off; + + unsigned int class_idx; + enum fullness_group fg; + struct size_class *class; + struct mapping_area *area; + + BUG_ON(!handle); + + obj_handle_to_location(handle, &page, &obj_idx); + get_zspage_mapping(get_first_page(page), &class_idx, &fg); + class = &pool->size_class[class_idx]; + off = obj_idx_to_offset(page, obj_idx, class->size); + + area = &__get_cpu_var(zs_map_area); + if (off + class->size <= PAGE_SIZE) + kunmap_atomic(area->vm_addr); + else { + struct page *pages[2]; + + pages[0] = page; + pages[1] = get_next_page(page); + BUG_ON(!pages[1]); + + __zs_unmap_object(area, pages, off, class->size); + } + put_cpu_var(zs_map_area); +} +EXPORT_SYMBOL_GPL(zs_unmap_object); + +u64 zs_get_total_size_bytes(struct zs_pool *pool) +{ + int i; + u64 npages = 0; + + for (i = 0; i < ZS_SIZE_CLASSES; i++) + npages += pool->size_class[i].pages_allocated; + + return npages << PAGE_SHIFT; +} +EXPORT_SYMBOL_GPL(zs_get_total_size_bytes); + +module_init(zs_init); +module_exit(zs_exit); + +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); -- 1.7.9.5 ^ permalink raw reply related [flat|nested] 30+ messages in thread
* Re: [PATCH 1/3] zsmalloc: promote to lib/ 2012-09-26 8:50 ` Minchan Kim @ 2012-09-26 9:42 ` Wanlong Gao -1 siblings, 0 replies; 30+ messages in thread From: Wanlong Gao @ 2012-09-26 9:42 UTC (permalink / raw) To: Minchan Kim Cc: Jens Axboe, Greg Kroah-Hartman, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel On 09/26/2012 04:50 PM, Minchan Kim wrote: > This patch promotes the slab-based zsmalloc memory allocator > from the staging tree to lib/ > > zcache/zram depends on this allocator for storing compressed RAM pages > in an efficient way under system wide memory pressure where > high-order (greater than 0) page allocation are very likely to > fail. > > For more information on zsmalloc and its internals, read the > documentation at the top of the zsmalloc.c file. > > Signed-off-by: Minchan Kim <minchan@kernel.org> > --- > drivers/staging/Kconfig | 2 - > drivers/staging/Makefile | 1 - > drivers/staging/zcache/zcache-main.c | 4 +- > drivers/staging/zram/zram_drv.h | 3 +- > drivers/staging/zsmalloc/Kconfig | 10 - > drivers/staging/zsmalloc/Makefile | 3 - > drivers/staging/zsmalloc/zsmalloc-main.c | 1064 ------------------------------ > drivers/staging/zsmalloc/zsmalloc.h | 43 -- > include/linux/zsmalloc.h | 43 ++ > lib/Kconfig | 2 + > lib/Makefile | 1 + > lib/zsmalloc/Kconfig | 18 + > lib/zsmalloc/Makefile | 1 + > lib/zsmalloc/zsmalloc.c | 1064 ++++++++++++++++++++++++++++++ > 14 files changed, 1132 insertions(+), 1127 deletions(-) > delete mode 100644 drivers/staging/zsmalloc/Kconfig > delete mode 100644 drivers/staging/zsmalloc/Makefile > delete mode 100644 drivers/staging/zsmalloc/zsmalloc-main.c > delete mode 100644 drivers/staging/zsmalloc/zsmalloc.h > create mode 100644 include/linux/zsmalloc.h > create mode 100644 lib/zsmalloc/Kconfig > create mode 100644 lib/zsmalloc/Makefile > create mode 100644 lib/zsmalloc/zsmalloc.c Since there's just one file here, why not just move to lib flatly without creating a new directory? Thanks, Wanlong Gao -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 1/3] zsmalloc: promote to lib/ @ 2012-09-26 9:42 ` Wanlong Gao 0 siblings, 0 replies; 30+ messages in thread From: Wanlong Gao @ 2012-09-26 9:42 UTC (permalink / raw) To: Minchan Kim Cc: Jens Axboe, Greg Kroah-Hartman, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel On 09/26/2012 04:50 PM, Minchan Kim wrote: > This patch promotes the slab-based zsmalloc memory allocator > from the staging tree to lib/ > > zcache/zram depends on this allocator for storing compressed RAM pages > in an efficient way under system wide memory pressure where > high-order (greater than 0) page allocation are very likely to > fail. > > For more information on zsmalloc and its internals, read the > documentation at the top of the zsmalloc.c file. > > Signed-off-by: Minchan Kim <minchan@kernel.org> > --- > drivers/staging/Kconfig | 2 - > drivers/staging/Makefile | 1 - > drivers/staging/zcache/zcache-main.c | 4 +- > drivers/staging/zram/zram_drv.h | 3 +- > drivers/staging/zsmalloc/Kconfig | 10 - > drivers/staging/zsmalloc/Makefile | 3 - > drivers/staging/zsmalloc/zsmalloc-main.c | 1064 ------------------------------ > drivers/staging/zsmalloc/zsmalloc.h | 43 -- > include/linux/zsmalloc.h | 43 ++ > lib/Kconfig | 2 + > lib/Makefile | 1 + > lib/zsmalloc/Kconfig | 18 + > lib/zsmalloc/Makefile | 1 + > lib/zsmalloc/zsmalloc.c | 1064 ++++++++++++++++++++++++++++++ > 14 files changed, 1132 insertions(+), 1127 deletions(-) > delete mode 100644 drivers/staging/zsmalloc/Kconfig > delete mode 100644 drivers/staging/zsmalloc/Makefile > delete mode 100644 drivers/staging/zsmalloc/zsmalloc-main.c > delete mode 100644 drivers/staging/zsmalloc/zsmalloc.h > create mode 100644 include/linux/zsmalloc.h > create mode 100644 lib/zsmalloc/Kconfig > create mode 100644 lib/zsmalloc/Makefile > create mode 100644 lib/zsmalloc/zsmalloc.c Since there's just one file here, why not just move to lib flatly without creating a new directory? Thanks, Wanlong Gao ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 1/3] zsmalloc: promote to lib/ 2012-09-26 8:50 ` Minchan Kim @ 2012-09-26 9:51 ` Pekka Enberg -1 siblings, 0 replies; 30+ messages in thread From: Pekka Enberg @ 2012-09-26 9:51 UTC (permalink / raw) To: Minchan Kim Cc: Jens Axboe, Greg Kroah-Hartman, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel, Andrew Morton On Wed, Sep 26, 2012 at 11:50 AM, Minchan Kim <minchan@kernel.org> wrote: > lib/Kconfig | 2 + > lib/Makefile | 1 + > lib/zsmalloc/Kconfig | 18 + > lib/zsmalloc/Makefile | 1 + > lib/zsmalloc/zsmalloc.c | 1064 ++++++++++++++++++++++++++++++ What's wrong with mm/zsmalloc.c? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 1/3] zsmalloc: promote to lib/ @ 2012-09-26 9:51 ` Pekka Enberg 0 siblings, 0 replies; 30+ messages in thread From: Pekka Enberg @ 2012-09-26 9:51 UTC (permalink / raw) To: Minchan Kim Cc: Jens Axboe, Greg Kroah-Hartman, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel, Andrew Morton On Wed, Sep 26, 2012 at 11:50 AM, Minchan Kim <minchan@kernel.org> wrote: > lib/Kconfig | 2 + > lib/Makefile | 1 + > lib/zsmalloc/Kconfig | 18 + > lib/zsmalloc/Makefile | 1 + > lib/zsmalloc/zsmalloc.c | 1064 ++++++++++++++++++++++++++++++ What's wrong with mm/zsmalloc.c? ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 1/3] zsmalloc: promote to lib/ 2012-09-26 9:51 ` Pekka Enberg @ 2012-09-26 17:06 ` Nitin Gupta -1 siblings, 0 replies; 30+ messages in thread From: Nitin Gupta @ 2012-09-26 17:06 UTC (permalink / raw) To: Pekka Enberg Cc: Minchan Kim, Jens Axboe, Greg Kroah-Hartman, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel, Andrew Morton 2012/9/26 Pekka Enberg <penberg@kernel.org>: > On Wed, Sep 26, 2012 at 11:50 AM, Minchan Kim <minchan@kernel.org> wrote: >> lib/Kconfig | 2 + >> lib/Makefile | 1 + >> lib/zsmalloc/Kconfig | 18 + >> lib/zsmalloc/Makefile | 1 + >> lib/zsmalloc/zsmalloc.c | 1064 ++++++++++++++++++++++++++++++ > > What's wrong with mm/zsmalloc.c? I think mm/ directory should only contain the code which is intended for global use such as the slab allocator, page reclaim code etc. zsmalloc is used by only one (or possibly two) drivers, so lib/ seems to be the right place. Thanks, Nitin -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 1/3] zsmalloc: promote to lib/ @ 2012-09-26 17:06 ` Nitin Gupta 0 siblings, 0 replies; 30+ messages in thread From: Nitin Gupta @ 2012-09-26 17:06 UTC (permalink / raw) To: Pekka Enberg Cc: Minchan Kim, Jens Axboe, Greg Kroah-Hartman, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel, Andrew Morton 2012/9/26 Pekka Enberg <penberg@kernel.org>: > On Wed, Sep 26, 2012 at 11:50 AM, Minchan Kim <minchan@kernel.org> wrote: >> lib/Kconfig | 2 + >> lib/Makefile | 1 + >> lib/zsmalloc/Kconfig | 18 + >> lib/zsmalloc/Makefile | 1 + >> lib/zsmalloc/zsmalloc.c | 1064 ++++++++++++++++++++++++++++++ > > What's wrong with mm/zsmalloc.c? I think mm/ directory should only contain the code which is intended for global use such as the slab allocator, page reclaim code etc. zsmalloc is used by only one (or possibly two) drivers, so lib/ seems to be the right place. Thanks, Nitin ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 1/3] zsmalloc: promote to lib/ 2012-09-26 9:51 ` Pekka Enberg @ 2012-09-27 1:39 ` Minchan Kim -1 siblings, 0 replies; 30+ messages in thread From: Minchan Kim @ 2012-09-27 1:39 UTC (permalink / raw) To: Pekka Enberg Cc: Jens Axboe, Greg Kroah-Hartman, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel, Andrew Morton Hi Pekka, On Wed, Sep 26, 2012 at 12:51:49PM +0300, Pekka Enberg wrote: > On Wed, Sep 26, 2012 at 11:50 AM, Minchan Kim <minchan@kernel.org> wrote: > > lib/Kconfig | 2 + > > lib/Makefile | 1 + > > lib/zsmalloc/Kconfig | 18 + > > lib/zsmalloc/Makefile | 1 + > > lib/zsmalloc/zsmalloc.c | 1064 ++++++++++++++++++++++++++++++ > > What's wrong with mm/zsmalloc.c? Why I put zsmalloc into under mm firstly is that Andrew had a concern about using strut page's some fields freely in zsmalloc so he wanted to maintain it in mm/ if I remember correctly. So I and Nitin tried to ask the opinion to akpm several times (at least 5 and even I sent such patch a few month ago) but didn't get any reply from him so I guess he doesn't have any concern about that any more. In point of view that it's an another slab-like allocator, it might be proper under mm but it's not popular as current mm's allocators(/SLUB/SLOB and page allocator). Frankly speaking, I'm okay whether we put it to mm/ or lib/. But it seems Nitin and Konrad like lib/ and Andrew is silent. That's why I am biased into lib/ now. If someone yell we should keep it to mm/ by logical claim, I can change my mind easily. But I've never heard abut that until now. > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 1/3] zsmalloc: promote to lib/ @ 2012-09-27 1:39 ` Minchan Kim 0 siblings, 0 replies; 30+ messages in thread From: Minchan Kim @ 2012-09-27 1:39 UTC (permalink / raw) To: Pekka Enberg Cc: Jens Axboe, Greg Kroah-Hartman, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel, Andrew Morton Hi Pekka, On Wed, Sep 26, 2012 at 12:51:49PM +0300, Pekka Enberg wrote: > On Wed, Sep 26, 2012 at 11:50 AM, Minchan Kim <minchan@kernel.org> wrote: > > lib/Kconfig | 2 + > > lib/Makefile | 1 + > > lib/zsmalloc/Kconfig | 18 + > > lib/zsmalloc/Makefile | 1 + > > lib/zsmalloc/zsmalloc.c | 1064 ++++++++++++++++++++++++++++++ > > What's wrong with mm/zsmalloc.c? Why I put zsmalloc into under mm firstly is that Andrew had a concern about using strut page's some fields freely in zsmalloc so he wanted to maintain it in mm/ if I remember correctly. So I and Nitin tried to ask the opinion to akpm several times (at least 5 and even I sent such patch a few month ago) but didn't get any reply from him so I guess he doesn't have any concern about that any more. In point of view that it's an another slab-like allocator, it might be proper under mm but it's not popular as current mm's allocators(/SLUB/SLOB and page allocator). Frankly speaking, I'm okay whether we put it to mm/ or lib/. But it seems Nitin and Konrad like lib/ and Andrew is silent. That's why I am biased into lib/ now. If someone yell we should keep it to mm/ by logical claim, I can change my mind easily. But I've never heard abut that until now. > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> -- Kind regards, Minchan Kim ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 1/3] zsmalloc: promote to lib/ 2012-09-27 1:39 ` Minchan Kim @ 2012-09-27 1:47 ` Andrew Morton -1 siblings, 0 replies; 30+ messages in thread From: Andrew Morton @ 2012-09-27 1:47 UTC (permalink / raw) To: Minchan Kim Cc: Pekka Enberg, Jens Axboe, Greg Kroah-Hartman, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel On Thu, 27 Sep 2012 10:39:12 +0900 Minchan Kim <minchan@kernel.org> wrote: > So I and Nitin tried to ask the opinion to akpm several times > (at least 5 and even I sent such patch a few month ago) but didn't get > any reply from him so I guess he doesn't have any concern about that > any more. I just haven't yet set aside a sufficiently large lump of time to work out what's going on here, sorry. Will try to get onto it next week. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 1/3] zsmalloc: promote to lib/ @ 2012-09-27 1:47 ` Andrew Morton 0 siblings, 0 replies; 30+ messages in thread From: Andrew Morton @ 2012-09-27 1:47 UTC (permalink / raw) To: Minchan Kim Cc: Pekka Enberg, Jens Axboe, Greg Kroah-Hartman, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel On Thu, 27 Sep 2012 10:39:12 +0900 Minchan Kim <minchan@kernel.org> wrote: > So I and Nitin tried to ask the opinion to akpm several times > (at least 5 and even I sent such patch a few month ago) but didn't get > any reply from him so I guess he doesn't have any concern about that > any more. I just haven't yet set aside a sufficiently large lump of time to work out what's going on here, sorry. Will try to get onto it next week. ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 1/3] zsmalloc: promote to lib/ 2012-09-27 1:47 ` Andrew Morton @ 2012-09-27 1:50 ` Minchan Kim -1 siblings, 0 replies; 30+ messages in thread From: Minchan Kim @ 2012-09-27 1:50 UTC (permalink / raw) To: Andrew Morton Cc: Pekka Enberg, Jens Axboe, Greg Kroah-Hartman, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel On Wed, Sep 26, 2012 at 06:47:43PM -0700, Andrew Morton wrote: > On Thu, 27 Sep 2012 10:39:12 +0900 Minchan Kim <minchan@kernel.org> wrote: > > > So I and Nitin tried to ask the opinion to akpm several times > > (at least 5 and even I sent such patch a few month ago) but didn't get > > any reply from him so I guess he doesn't have any concern about that > > any more. > > I just haven't yet set aside a sufficiently large lump of time to work > out what's going on here, sorry. Will try to get onto it next week. Okay. Thanks Andrew. I will wait your opinion. Of course, promotion would be stuck by next week. > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 1/3] zsmalloc: promote to lib/ @ 2012-09-27 1:50 ` Minchan Kim 0 siblings, 0 replies; 30+ messages in thread From: Minchan Kim @ 2012-09-27 1:50 UTC (permalink / raw) To: Andrew Morton Cc: Pekka Enberg, Jens Axboe, Greg Kroah-Hartman, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel On Wed, Sep 26, 2012 at 06:47:43PM -0700, Andrew Morton wrote: > On Thu, 27 Sep 2012 10:39:12 +0900 Minchan Kim <minchan@kernel.org> wrote: > > > So I and Nitin tried to ask the opinion to akpm several times > > (at least 5 and even I sent such patch a few month ago) but didn't get > > any reply from him so I guess he doesn't have any concern about that > > any more. > > I just haven't yet set aside a sufficiently large lump of time to work > out what's going on here, sorry. Will try to get onto it next week. Okay. Thanks Andrew. I will wait your opinion. Of course, promotion would be stuck by next week. > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> -- Kind regards, Minchan Kim ^ permalink raw reply [flat|nested] 30+ messages in thread
* [PATCH 2/3] zram: promote zram from staging 2012-09-26 8:50 ` Minchan Kim @ 2012-09-26 8:50 ` Minchan Kim -1 siblings, 0 replies; 30+ messages in thread From: Minchan Kim @ 2012-09-26 8:50 UTC (permalink / raw) To: Jens Axboe, Greg Kroah-Hartman Cc: Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel, Minchan Kim It's time to promote zram from staging because zram is in staging for a long time and is improved by many contributors so code is very clean. Most important issue, zram's dependency with x86 is solved by making zsmalloc portable. In addition, many embedded product uses zram in real practive so I think there is no reason to prevent promotion now. Cc: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: Minchan Kim <minchan@kernel.org> --- drivers/block/Kconfig | 1 + drivers/block/Makefile | 1 + drivers/block/zram/Kconfig | 25 ++ drivers/block/zram/Makefile | 3 + drivers/block/zram/zram.txt | 76 ++++ drivers/block/zram/zram_drv.c | 785 +++++++++++++++++++++++++++++++++++++ drivers/block/zram/zram_drv.h | 119 ++++++ drivers/block/zram/zram_sysfs.c | 225 +++++++++++ drivers/staging/Kconfig | 2 - drivers/staging/Makefile | 1 - drivers/staging/zram/Kconfig | 25 -- drivers/staging/zram/Makefile | 3 - drivers/staging/zram/zram.txt | 76 ---- drivers/staging/zram/zram_drv.c | 785 ------------------------------------- drivers/staging/zram/zram_drv.h | 119 ------ drivers/staging/zram/zram_sysfs.c | 225 ----------- 16 files changed, 1235 insertions(+), 1236 deletions(-) create mode 100644 drivers/block/zram/Kconfig create mode 100644 drivers/block/zram/Makefile create mode 100644 drivers/block/zram/zram.txt create mode 100644 drivers/block/zram/zram_drv.c create mode 100644 drivers/block/zram/zram_drv.h create mode 100644 drivers/block/zram/zram_sysfs.c delete mode 100644 drivers/staging/zram/Kconfig delete mode 100644 drivers/staging/zram/Makefile delete mode 100644 drivers/staging/zram/zram.txt delete mode 100644 drivers/staging/zram/zram_drv.c delete mode 100644 drivers/staging/zram/zram_drv.h delete mode 100644 drivers/staging/zram/zram_sysfs.c diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig index f7de322..3e3087e 100644 --- a/drivers/block/Kconfig +++ b/drivers/block/Kconfig @@ -290,6 +290,7 @@ config BLK_DEV_CRYPTOLOOP cryptoloop device. source "drivers/block/drbd/Kconfig" +source "drivers/block/zram/Kconfig" config BLK_DEV_NBD tristate "Network block device support" diff --git a/drivers/block/Makefile b/drivers/block/Makefile index 17e82df..0751c43 100644 --- a/drivers/block/Makefile +++ b/drivers/block/Makefile @@ -30,6 +30,7 @@ obj-$(CONFIG_BLK_DEV_UMEM) += umem.o obj-$(CONFIG_BLK_DEV_NBD) += nbd.o obj-$(CONFIG_BLK_DEV_CRYPTOLOOP) += cryptoloop.o obj-$(CONFIG_VIRTIO_BLK) += virtio_blk.o +obj-$(CONFIG_ZRAM) += zram/ obj-$(CONFIG_VIODASD) += viodasd.o obj-$(CONFIG_BLK_DEV_SX8) += sx8.o diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig new file mode 100644 index 0000000..be5abe8 --- /dev/null +++ b/drivers/block/zram/Kconfig @@ -0,0 +1,25 @@ +config ZRAM + tristate "Compressed RAM block device support" + depends on BLOCK && SYSFS && ZSMALLOC + select LZO_COMPRESS + select LZO_DECOMPRESS + default n + help + Creates virtual block devices called /dev/zramX (X = 0, 1, ...). + Pages written to these disks are compressed and stored in memory + itself. These disks allow very fast I/O and compression provides + good amounts of memory savings. + + It has several use cases, for example: /tmp storage, use as swap + disks and maybe many more. + + See zram.txt for more information. + Project home: http://compcache.googlecode.com/ + +config ZRAM_DEBUG + bool "Compressed RAM block device debug support" + depends on ZRAM + default n + help + This option adds additional debugging code to the compressed + RAM block device driver. diff --git a/drivers/block/zram/Makefile b/drivers/block/zram/Makefile new file mode 100644 index 0000000..7f4a301 --- /dev/null +++ b/drivers/block/zram/Makefile @@ -0,0 +1,3 @@ +zram-y := zram_drv.o zram_sysfs.o + +obj-$(CONFIG_ZRAM) += zram.o diff --git a/drivers/block/zram/zram.txt b/drivers/block/zram/zram.txt new file mode 100644 index 0000000..5f75d29 --- /dev/null +++ b/drivers/block/zram/zram.txt @@ -0,0 +1,76 @@ +zram: Compressed RAM based block devices +---------------------------------------- + +Project home: http://compcache.googlecode.com/ + +* Introduction + +The zram module creates RAM based block devices named /dev/zram<id> +(<id> = 0, 1, ...). Pages written to these disks are compressed and stored +in memory itself. These disks allow very fast I/O and compression provides +good amounts of memory savings. Some of the usecases include /tmp storage, +use as swap disks, various caches under /var and maybe many more :) + +Statistics for individual zram devices are exported through sysfs nodes at +/sys/block/zram<id>/ + +* Usage + +Following shows a typical sequence of steps for using zram. + +1) Load Module: + modprobe zram num_devices=4 + This creates 4 devices: /dev/zram{0,1,2,3} + (num_devices parameter is optional. Default: 1) + +2) Set Disksize (Optional): + Set disk size by writing the value to sysfs node 'disksize' + (in bytes). If disksize is not given, default value of 25% + of RAM is used. + + # Initialize /dev/zram0 with 50MB disksize + echo $((50*1024*1024)) > /sys/block/zram0/disksize + + NOTE: disksize cannot be changed if the disk contains any + data. So, for such a disk, you need to issue 'reset' (see below) + before you can change its disksize. + +3) Activate: + mkswap /dev/zram0 + swapon /dev/zram0 + + mkfs.ext4 /dev/zram1 + mount /dev/zram1 /tmp + +4) Stats: + Per-device statistics are exported as various nodes under + /sys/block/zram<id>/ + disksize + num_reads + num_writes + invalid_io + notify_free + discard + zero_pages + orig_data_size + compr_data_size + mem_used_total + +5) Deactivate: + swapoff /dev/zram0 + umount /dev/zram1 + +6) Reset: + Write any positive value to 'reset' sysfs node + echo 1 > /sys/block/zram0/reset + echo 1 > /sys/block/zram1/reset + + (This frees all the memory allocated for the given device). + + +Please report any problems at: + - Mailing list: linux-mm-cc at laptop dot org + - Issue tracker: http://code.google.com/p/compcache/issues/list + +Nitin Gupta +ngupta@vflare.org diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c new file mode 100644 index 0000000..653b074 --- /dev/null +++ b/drivers/block/zram/zram_drv.c @@ -0,0 +1,785 @@ +/* + * Compressed RAM block device + * + * Copyright (C) 2008, 2009, 2010 Nitin Gupta + * + * This code is released using a dual license strategy: BSD/GPL + * You can choose the licence that better fits your requirements. + * + * Released under the terms of 3-clause BSD License + * Released under the terms of GNU General Public License Version 2.0 + * + * Project home: http://compcache.googlecode.com + */ + +#define KMSG_COMPONENT "zram" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#ifdef CONFIG_ZRAM_DEBUG +#define DEBUG +#endif + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/bio.h> +#include <linux/bitops.h> +#include <linux/blkdev.h> +#include <linux/buffer_head.h> +#include <linux/device.h> +#include <linux/genhd.h> +#include <linux/highmem.h> +#include <linux/slab.h> +#include <linux/lzo.h> +#include <linux/string.h> +#include <linux/vmalloc.h> + +#include "zram_drv.h" + +/* Globals */ +static int zram_major; +struct zram *zram_devices; + +/* Module params (documentation at end) */ +static unsigned int num_devices; + +static void zram_stat_inc(u32 *v) +{ + *v = *v + 1; +} + +static void zram_stat_dec(u32 *v) +{ + *v = *v - 1; +} + +static void zram_stat64_add(struct zram *zram, u64 *v, u64 inc) +{ + spin_lock(&zram->stat64_lock); + *v = *v + inc; + spin_unlock(&zram->stat64_lock); +} + +static void zram_stat64_sub(struct zram *zram, u64 *v, u64 dec) +{ + spin_lock(&zram->stat64_lock); + *v = *v - dec; + spin_unlock(&zram->stat64_lock); +} + +static void zram_stat64_inc(struct zram *zram, u64 *v) +{ + zram_stat64_add(zram, v, 1); +} + +static int zram_test_flag(struct zram *zram, u32 index, + enum zram_pageflags flag) +{ + return zram->table[index].flags & BIT(flag); +} + +static void zram_set_flag(struct zram *zram, u32 index, + enum zram_pageflags flag) +{ + zram->table[index].flags |= BIT(flag); +} + +static void zram_clear_flag(struct zram *zram, u32 index, + enum zram_pageflags flag) +{ + zram->table[index].flags &= ~BIT(flag); +} + +static int page_zero_filled(void *ptr) +{ + unsigned int pos; + unsigned long *page; + + page = (unsigned long *)ptr; + + for (pos = 0; pos != PAGE_SIZE / sizeof(*page); pos++) { + if (page[pos]) + return 0; + } + + return 1; +} + +static void zram_set_disksize(struct zram *zram, size_t totalram_bytes) +{ + if (!zram->disksize) { + pr_info( + "disk size not provided. You can use disksize_kb module " + "param to specify size.\nUsing default: (%u%% of RAM).\n", + default_disksize_perc_ram + ); + zram->disksize = default_disksize_perc_ram * + (totalram_bytes / 100); + } + + if (zram->disksize > 2 * (totalram_bytes)) { + pr_info( + "There is little point creating a zram of greater than " + "twice the size of memory since we expect a 2:1 compression " + "ratio. Note that zram uses about 0.1%% of the size of " + "the disk when not in use so a huge zram is " + "wasteful.\n" + "\tMemory Size: %zu kB\n" + "\tSize you selected: %llu kB\n" + "Continuing anyway ...\n", + totalram_bytes >> 10, zram->disksize + ); + } + + zram->disksize &= PAGE_MASK; +} + +static void zram_free_page(struct zram *zram, size_t index) +{ + unsigned long handle = zram->table[index].handle; + u16 size = zram->table[index].size; + + if (unlikely(!handle)) { + /* + * No memory is allocated for zero filled pages. + * Simply clear zero page flag. + */ + if (zram_test_flag(zram, index, ZRAM_ZERO)) { + zram_clear_flag(zram, index, ZRAM_ZERO); + zram_stat_dec(&zram->stats.pages_zero); + } + return; + } + + if (unlikely(size > max_zpage_size)) + zram_stat_dec(&zram->stats.bad_compress); + + zs_free(zram->mem_pool, handle); + + if (size <= PAGE_SIZE / 2) + zram_stat_dec(&zram->stats.good_compress); + + zram_stat64_sub(zram, &zram->stats.compr_size, + zram->table[index].size); + zram_stat_dec(&zram->stats.pages_stored); + + zram->table[index].handle = 0; + zram->table[index].size = 0; +} + +static void handle_zero_page(struct bio_vec *bvec) +{ + struct page *page = bvec->bv_page; + void *user_mem; + + user_mem = kmap_atomic(page); + memset(user_mem + bvec->bv_offset, 0, bvec->bv_len); + kunmap_atomic(user_mem); + + flush_dcache_page(page); +} + +static inline int is_partial_io(struct bio_vec *bvec) +{ + return bvec->bv_len != PAGE_SIZE; +} + +static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, + u32 index, int offset, struct bio *bio) +{ + int ret; + size_t clen; + struct page *page; + unsigned char *user_mem, *cmem, *uncmem = NULL; + + page = bvec->bv_page; + + if (zram_test_flag(zram, index, ZRAM_ZERO)) { + handle_zero_page(bvec); + return 0; + } + + /* Requested page is not present in compressed area */ + if (unlikely(!zram->table[index].handle)) { + pr_debug("Read before write: sector=%lu, size=%u", + (ulong)(bio->bi_sector), bio->bi_size); + handle_zero_page(bvec); + return 0; + } + + if (is_partial_io(bvec)) { + /* Use a temporary buffer to decompress the page */ + uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!uncmem) { + pr_info("Error allocating temp memory!\n"); + return -ENOMEM; + } + } + + user_mem = kmap_atomic(page); + if (!is_partial_io(bvec)) + uncmem = user_mem; + clen = PAGE_SIZE; + + cmem = zs_map_object(zram->mem_pool, zram->table[index].handle, + ZS_MM_RO); + + ret = lzo1x_decompress_safe(cmem, zram->table[index].size, + uncmem, &clen); + + if (is_partial_io(bvec)) { + memcpy(user_mem + bvec->bv_offset, uncmem + offset, + bvec->bv_len); + kfree(uncmem); + } + + zs_unmap_object(zram->mem_pool, zram->table[index].handle); + kunmap_atomic(user_mem); + + /* Should NEVER happen. Return bio error if it does. */ + if (unlikely(ret != LZO_E_OK)) { + pr_err("Decompression failed! err=%d, page=%u\n", ret, index); + zram_stat64_inc(zram, &zram->stats.failed_reads); + return ret; + } + + flush_dcache_page(page); + + return 0; +} + +static int zram_read_before_write(struct zram *zram, char *mem, u32 index) +{ + int ret; + size_t clen = PAGE_SIZE; + unsigned char *cmem; + unsigned long handle = zram->table[index].handle; + + if (zram_test_flag(zram, index, ZRAM_ZERO) || !handle) { + memset(mem, 0, PAGE_SIZE); + return 0; + } + + cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_RO); + ret = lzo1x_decompress_safe(cmem, zram->table[index].size, + mem, &clen); + zs_unmap_object(zram->mem_pool, handle); + + /* Should NEVER happen. Return bio error if it does. */ + if (unlikely(ret != LZO_E_OK)) { + pr_err("Decompression failed! err=%d, page=%u\n", ret, index); + zram_stat64_inc(zram, &zram->stats.failed_reads); + return ret; + } + + return 0; +} + +static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, + int offset) +{ + int ret; + size_t clen; + unsigned long handle; + struct page *page; + unsigned char *user_mem, *cmem, *src, *uncmem = NULL; + + page = bvec->bv_page; + src = zram->compress_buffer; + + if (is_partial_io(bvec)) { + /* + * This is a partial IO. We need to read the full page + * before to write the changes. + */ + uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!uncmem) { + pr_info("Error allocating temp memory!\n"); + ret = -ENOMEM; + goto out; + } + ret = zram_read_before_write(zram, uncmem, index); + if (ret) { + kfree(uncmem); + goto out; + } + } + + /* + * System overwrites unused sectors. Free memory associated + * with this sector now. + */ + if (zram->table[index].handle || + zram_test_flag(zram, index, ZRAM_ZERO)) + zram_free_page(zram, index); + + user_mem = kmap_atomic(page); + + if (is_partial_io(bvec)) + memcpy(uncmem + offset, user_mem + bvec->bv_offset, + bvec->bv_len); + else + uncmem = user_mem; + + if (page_zero_filled(uncmem)) { + kunmap_atomic(user_mem); + if (is_partial_io(bvec)) + kfree(uncmem); + zram_stat_inc(&zram->stats.pages_zero); + zram_set_flag(zram, index, ZRAM_ZERO); + ret = 0; + goto out; + } + + ret = lzo1x_1_compress(uncmem, PAGE_SIZE, src, &clen, + zram->compress_workmem); + + kunmap_atomic(user_mem); + if (is_partial_io(bvec)) + kfree(uncmem); + + if (unlikely(ret != LZO_E_OK)) { + pr_err("Compression failed! err=%d\n", ret); + goto out; + } + + if (unlikely(clen > max_zpage_size)) + zram_stat_inc(&zram->stats.bad_compress); + + handle = zs_malloc(zram->mem_pool, clen); + if (!handle) { + pr_info("Error allocating memory for compressed " + "page: %u, size=%zu\n", index, clen); + ret = -ENOMEM; + goto out; + } + cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_WO); + + memcpy(cmem, src, clen); + + zs_unmap_object(zram->mem_pool, handle); + + zram->table[index].handle = handle; + zram->table[index].size = clen; + + /* Update stats */ + zram_stat64_add(zram, &zram->stats.compr_size, clen); + zram_stat_inc(&zram->stats.pages_stored); + if (clen <= PAGE_SIZE / 2) + zram_stat_inc(&zram->stats.good_compress); + + return 0; + +out: + if (ret) + zram_stat64_inc(zram, &zram->stats.failed_writes); + return ret; +} + +static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index, + int offset, struct bio *bio, int rw) +{ + int ret; + + if (rw == READ) { + down_read(&zram->lock); + ret = zram_bvec_read(zram, bvec, index, offset, bio); + up_read(&zram->lock); + } else { + down_write(&zram->lock); + ret = zram_bvec_write(zram, bvec, index, offset); + up_write(&zram->lock); + } + + return ret; +} + +static void update_position(u32 *index, int *offset, struct bio_vec *bvec) +{ + if (*offset + bvec->bv_len >= PAGE_SIZE) + (*index)++; + *offset = (*offset + bvec->bv_len) % PAGE_SIZE; +} + +static void __zram_make_request(struct zram *zram, struct bio *bio, int rw) +{ + int i, offset; + u32 index; + struct bio_vec *bvec; + + switch (rw) { + case READ: + zram_stat64_inc(zram, &zram->stats.num_reads); + break; + case WRITE: + zram_stat64_inc(zram, &zram->stats.num_writes); + break; + } + + index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT; + offset = (bio->bi_sector & (SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT; + + bio_for_each_segment(bvec, bio, i) { + int max_transfer_size = PAGE_SIZE - offset; + + if (bvec->bv_len > max_transfer_size) { + /* + * zram_bvec_rw() can only make operation on a single + * zram page. Split the bio vector. + */ + struct bio_vec bv; + + bv.bv_page = bvec->bv_page; + bv.bv_len = max_transfer_size; + bv.bv_offset = bvec->bv_offset; + + if (zram_bvec_rw(zram, &bv, index, offset, bio, rw) < 0) + goto out; + + bv.bv_len = bvec->bv_len - max_transfer_size; + bv.bv_offset += max_transfer_size; + if (zram_bvec_rw(zram, &bv, index+1, 0, bio, rw) < 0) + goto out; + } else + if (zram_bvec_rw(zram, bvec, index, offset, bio, rw) + < 0) + goto out; + + update_position(&index, &offset, bvec); + } + + set_bit(BIO_UPTODATE, &bio->bi_flags); + bio_endio(bio, 0); + return; + +out: + bio_io_error(bio); +} + +/* + * Check if request is within bounds and aligned on zram logical blocks. + */ +static inline int valid_io_request(struct zram *zram, struct bio *bio) +{ + if (unlikely( + (bio->bi_sector >= (zram->disksize >> SECTOR_SHIFT)) || + (bio->bi_sector & (ZRAM_SECTOR_PER_LOGICAL_BLOCK - 1)) || + (bio->bi_size & (ZRAM_LOGICAL_BLOCK_SIZE - 1)))) { + + return 0; + } + + /* I/O request is valid */ + return 1; +} + +/* + * Handler function for all zram I/O requests. + */ +static void zram_make_request(struct request_queue *queue, struct bio *bio) +{ + struct zram *zram = queue->queuedata; + + if (unlikely(!zram->init_done) && zram_init_device(zram)) + goto error; + + down_read(&zram->init_lock); + if (unlikely(!zram->init_done)) + goto error_unlock; + + if (!valid_io_request(zram, bio)) { + zram_stat64_inc(zram, &zram->stats.invalid_io); + goto error_unlock; + } + + __zram_make_request(zram, bio, bio_data_dir(bio)); + up_read(&zram->init_lock); + + return; + +error_unlock: + up_read(&zram->init_lock); +error: + bio_io_error(bio); +} + +void __zram_reset_device(struct zram *zram) +{ + size_t index; + + zram->init_done = 0; + + /* Free various per-device buffers */ + kfree(zram->compress_workmem); + free_pages((unsigned long)zram->compress_buffer, 1); + + zram->compress_workmem = NULL; + zram->compress_buffer = NULL; + + /* Free all pages that are still in this zram device */ + for (index = 0; index < zram->disksize >> PAGE_SHIFT; index++) { + unsigned long handle = zram->table[index].handle; + if (!handle) + continue; + + zs_free(zram->mem_pool, handle); + } + + vfree(zram->table); + zram->table = NULL; + + zs_destroy_pool(zram->mem_pool); + zram->mem_pool = NULL; + + /* Reset stats */ + memset(&zram->stats, 0, sizeof(zram->stats)); + + zram->disksize = 0; +} + +void zram_reset_device(struct zram *zram) +{ + down_write(&zram->init_lock); + __zram_reset_device(zram); + up_write(&zram->init_lock); +} + +int zram_init_device(struct zram *zram) +{ + int ret; + size_t num_pages; + + down_write(&zram->init_lock); + + if (zram->init_done) { + up_write(&zram->init_lock); + return 0; + } + + zram_set_disksize(zram, totalram_pages << PAGE_SHIFT); + + zram->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL); + if (!zram->compress_workmem) { + pr_err("Error allocating compressor working memory!\n"); + ret = -ENOMEM; + goto fail_no_table; + } + + zram->compress_buffer = + (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1); + if (!zram->compress_buffer) { + pr_err("Error allocating compressor buffer space\n"); + ret = -ENOMEM; + goto fail_no_table; + } + + num_pages = zram->disksize >> PAGE_SHIFT; + zram->table = vzalloc(num_pages * sizeof(*zram->table)); + if (!zram->table) { + pr_err("Error allocating zram address table\n"); + ret = -ENOMEM; + goto fail_no_table; + } + + set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); + + /* zram devices sort of resembles non-rotational disks */ + queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue); + + zram->mem_pool = zs_create_pool("zram", GFP_NOIO | __GFP_HIGHMEM); + if (!zram->mem_pool) { + pr_err("Error creating memory pool\n"); + ret = -ENOMEM; + goto fail; + } + + zram->init_done = 1; + up_write(&zram->init_lock); + + pr_debug("Initialization done!\n"); + return 0; + +fail_no_table: + /* To prevent accessing table entries during cleanup */ + zram->disksize = 0; +fail: + __zram_reset_device(zram); + up_write(&zram->init_lock); + pr_err("Initialization failed: err=%d\n", ret); + return ret; +} + +static void zram_slot_free_notify(struct block_device *bdev, + unsigned long index) +{ + struct zram *zram; + + zram = bdev->bd_disk->private_data; + zram_free_page(zram, index); + zram_stat64_inc(zram, &zram->stats.notify_free); +} + +static const struct block_device_operations zram_devops = { + .swap_slot_free_notify = zram_slot_free_notify, + .owner = THIS_MODULE +}; + +static int create_device(struct zram *zram, int device_id) +{ + int ret = 0; + + init_rwsem(&zram->lock); + init_rwsem(&zram->init_lock); + spin_lock_init(&zram->stat64_lock); + + zram->queue = blk_alloc_queue(GFP_KERNEL); + if (!zram->queue) { + pr_err("Error allocating disk queue for device %d\n", + device_id); + ret = -ENOMEM; + goto out; + } + + blk_queue_make_request(zram->queue, zram_make_request); + zram->queue->queuedata = zram; + + /* gendisk structure */ + zram->disk = alloc_disk(1); + if (!zram->disk) { + blk_cleanup_queue(zram->queue); + pr_warn("Error allocating disk structure for device %d\n", + device_id); + ret = -ENOMEM; + goto out; + } + + zram->disk->major = zram_major; + zram->disk->first_minor = device_id; + zram->disk->fops = &zram_devops; + zram->disk->queue = zram->queue; + zram->disk->private_data = zram; + snprintf(zram->disk->disk_name, 16, "zram%d", device_id); + + /* Actual capacity set using syfs (/sys/block/zram<id>/disksize */ + set_capacity(zram->disk, 0); + + /* + * To ensure that we always get PAGE_SIZE aligned + * and n*PAGE_SIZED sized I/O requests. + */ + blk_queue_physical_block_size(zram->disk->queue, PAGE_SIZE); + blk_queue_logical_block_size(zram->disk->queue, + ZRAM_LOGICAL_BLOCK_SIZE); + blk_queue_io_min(zram->disk->queue, PAGE_SIZE); + blk_queue_io_opt(zram->disk->queue, PAGE_SIZE); + + add_disk(zram->disk); + + ret = sysfs_create_group(&disk_to_dev(zram->disk)->kobj, + &zram_disk_attr_group); + if (ret < 0) { + pr_warn("Error creating sysfs group"); + goto out; + } + + zram->init_done = 0; + +out: + return ret; +} + +static void destroy_device(struct zram *zram) +{ + sysfs_remove_group(&disk_to_dev(zram->disk)->kobj, + &zram_disk_attr_group); + + if (zram->disk) { + del_gendisk(zram->disk); + put_disk(zram->disk); + } + + if (zram->queue) + blk_cleanup_queue(zram->queue); +} + +unsigned int zram_get_num_devices(void) +{ + return num_devices; +} + +static int __init zram_init(void) +{ + int ret, dev_id; + + if (num_devices > max_num_devices) { + pr_warn("Invalid value for num_devices: %u\n", + num_devices); + ret = -EINVAL; + goto out; + } + + zram_major = register_blkdev(0, "zram"); + if (zram_major <= 0) { + pr_warn("Unable to get major number\n"); + ret = -EBUSY; + goto out; + } + + if (!num_devices) { + pr_info("num_devices not specified. Using default: 1\n"); + num_devices = 1; + } + + /* Allocate the device array and initialize each one */ + pr_info("Creating %u devices ...\n", num_devices); + zram_devices = kzalloc(num_devices * sizeof(struct zram), GFP_KERNEL); + if (!zram_devices) { + ret = -ENOMEM; + goto unregister; + } + + for (dev_id = 0; dev_id < num_devices; dev_id++) { + ret = create_device(&zram_devices[dev_id], dev_id); + if (ret) + goto free_devices; + } + + return 0; + +free_devices: + while (dev_id) + destroy_device(&zram_devices[--dev_id]); + kfree(zram_devices); +unregister: + unregister_blkdev(zram_major, "zram"); +out: + return ret; +} + +static void __exit zram_exit(void) +{ + int i; + struct zram *zram; + + for (i = 0; i < num_devices; i++) { + zram = &zram_devices[i]; + + destroy_device(zram); + if (zram->init_done) + zram_reset_device(zram); + } + + unregister_blkdev(zram_major, "zram"); + + kfree(zram_devices); + pr_debug("Cleanup done!\n"); +} + +module_param(num_devices, uint, 0); +MODULE_PARM_DESC(num_devices, "Number of zram devices"); + +module_init(zram_init); +module_exit(zram_exit); + +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); +MODULE_DESCRIPTION("Compressed RAM Block Device"); diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h new file mode 100644 index 0000000..f6d0925 --- /dev/null +++ b/drivers/block/zram/zram_drv.h @@ -0,0 +1,119 @@ +/* + * Compressed RAM block device + * + * Copyright (C) 2008, 2009, 2010 Nitin Gupta + * + * This code is released using a dual license strategy: BSD/GPL + * You can choose the licence that better fits your requirements. + * + * Released under the terms of 3-clause BSD License + * Released under the terms of GNU General Public License Version 2.0 + * + * Project home: http://compcache.googlecode.com + */ + +#ifndef _ZRAM_DRV_H_ +#define _ZRAM_DRV_H_ + +#include <linux/spinlock.h> +#include <linux/mutex.h> +#include <linux/zsmalloc.h> + +/* + * Some arbitrary value. This is just to catch + * invalid value for num_devices module parameter. + */ +static const unsigned max_num_devices = 32; + +/*-- Configurable parameters */ + +/* Default zram disk size: 25% of total RAM */ +static const unsigned default_disksize_perc_ram = 25; + +/* + * Pages that compress to size greater than this are stored + * uncompressed in memory. + */ +static const size_t max_zpage_size = PAGE_SIZE / 4 * 3; + +/* + * NOTE: max_zpage_size must be less than or equal to: + * ZS_MAX_ALLOC_SIZE - sizeof(struct zobj_header) + * otherwise, xv_malloc() would always return failure. + */ + +/*-- End of configurable params */ + +#define SECTOR_SHIFT 9 +#define SECTOR_SIZE (1 << SECTOR_SHIFT) +#define SECTORS_PER_PAGE_SHIFT (PAGE_SHIFT - SECTOR_SHIFT) +#define SECTORS_PER_PAGE (1 << SECTORS_PER_PAGE_SHIFT) +#define ZRAM_LOGICAL_BLOCK_SHIFT 12 +#define ZRAM_LOGICAL_BLOCK_SIZE (1 << ZRAM_LOGICAL_BLOCK_SHIFT) +#define ZRAM_SECTOR_PER_LOGICAL_BLOCK \ + (1 << (ZRAM_LOGICAL_BLOCK_SHIFT - SECTOR_SHIFT)) + +/* Flags for zram pages (table[page_no].flags) */ +enum zram_pageflags { + /* Page consists entirely of zeros */ + ZRAM_ZERO, + + __NR_ZRAM_PAGEFLAGS, +}; + +/*-- Data structures */ + +/* Allocated for each disk page */ +struct table { + unsigned long handle; + u16 size; /* object size (excluding header) */ + u8 count; /* object ref count (not yet used) */ + u8 flags; +} __aligned(4); + +struct zram_stats { + u64 compr_size; /* compressed size of pages stored */ + u64 num_reads; /* failed + successful */ + u64 num_writes; /* --do-- */ + u64 failed_reads; /* should NEVER! happen */ + u64 failed_writes; /* can happen when memory is too low */ + u64 invalid_io; /* non-page-aligned I/O requests */ + u64 notify_free; /* no. of swap slot free notifications */ + u32 pages_zero; /* no. of zero filled pages */ + u32 pages_stored; /* no. of pages currently stored */ + u32 good_compress; /* % of pages with compression ratio<=50% */ + u32 bad_compress; /* % of pages with compression ratio>=75% */ +}; + +struct zram { + struct zs_pool *mem_pool; + void *compress_workmem; + void *compress_buffer; + struct table *table; + spinlock_t stat64_lock; /* protect 64-bit stats */ + struct rw_semaphore lock; /* protect compression buffers and table + * against concurrent read and writes */ + struct request_queue *queue; + struct gendisk *disk; + int init_done; + /* Prevent concurrent execution of device init, reset and R/W request */ + struct rw_semaphore init_lock; + /* + * This is the limit on amount of *uncompressed* worth of data + * we can store in a disk. + */ + u64 disksize; /* bytes */ + + struct zram_stats stats; +}; + +extern struct zram *zram_devices; +unsigned int zram_get_num_devices(void); +#ifdef CONFIG_SYSFS +extern struct attribute_group zram_disk_attr_group; +#endif + +extern int zram_init_device(struct zram *zram); +extern void __zram_reset_device(struct zram *zram); + +#endif diff --git a/drivers/block/zram/zram_sysfs.c b/drivers/block/zram/zram_sysfs.c new file mode 100644 index 0000000..edb0ed4 --- /dev/null +++ b/drivers/block/zram/zram_sysfs.c @@ -0,0 +1,225 @@ +/* + * Compressed RAM block device + * + * Copyright (C) 2008, 2009, 2010 Nitin Gupta + * + * This code is released using a dual license strategy: BSD/GPL + * You can choose the licence that better fits your requirements. + * + * Released under the terms of 3-clause BSD License + * Released under the terms of GNU General Public License Version 2.0 + * + * Project home: http://compcache.googlecode.com/ + */ + +#include <linux/device.h> +#include <linux/genhd.h> +#include <linux/mm.h> + +#include "zram_drv.h" + +static u64 zram_stat64_read(struct zram *zram, u64 *v) +{ + u64 val; + + spin_lock(&zram->stat64_lock); + val = *v; + spin_unlock(&zram->stat64_lock); + + return val; +} + +static struct zram *dev_to_zram(struct device *dev) +{ + int i; + struct zram *zram = NULL; + + for (i = 0; i < zram_get_num_devices(); i++) { + zram = &zram_devices[i]; + if (disk_to_dev(zram->disk) == dev) + break; + } + + return zram; +} + +static ssize_t disksize_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", zram->disksize); +} + +static ssize_t disksize_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + int ret; + u64 disksize; + struct zram *zram = dev_to_zram(dev); + + ret = kstrtoull(buf, 10, &disksize); + if (ret) + return ret; + + down_write(&zram->init_lock); + if (zram->init_done) { + up_write(&zram->init_lock); + pr_info("Cannot change disksize for initialized device\n"); + return -EBUSY; + } + + zram->disksize = PAGE_ALIGN(disksize); + set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); + up_write(&zram->init_lock); + + return len; +} + +static ssize_t initstate_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%u\n", zram->init_done); +} + +static ssize_t reset_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + int ret; + unsigned short do_reset; + struct zram *zram; + struct block_device *bdev; + + zram = dev_to_zram(dev); + bdev = bdget_disk(zram->disk, 0); + + /* Do not reset an active device! */ + if (bdev->bd_holders) + return -EBUSY; + + ret = kstrtou16(buf, 10, &do_reset); + if (ret) + return ret; + + if (!do_reset) + return -EINVAL; + + /* Make sure all pending I/O is finished */ + if (bdev) + fsync_bdev(bdev); + + down_write(&zram->init_lock); + if (zram->init_done) + __zram_reset_device(zram); + up_write(&zram->init_lock); + + return len; +} + +static ssize_t num_reads_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + zram_stat64_read(zram, &zram->stats.num_reads)); +} + +static ssize_t num_writes_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + zram_stat64_read(zram, &zram->stats.num_writes)); +} + +static ssize_t invalid_io_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + zram_stat64_read(zram, &zram->stats.invalid_io)); +} + +static ssize_t notify_free_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + zram_stat64_read(zram, &zram->stats.notify_free)); +} + +static ssize_t zero_pages_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%u\n", zram->stats.pages_zero); +} + +static ssize_t orig_data_size_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + (u64)(zram->stats.pages_stored) << PAGE_SHIFT); +} + +static ssize_t compr_data_size_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + zram_stat64_read(zram, &zram->stats.compr_size)); +} + +static ssize_t mem_used_total_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + u64 val = 0; + struct zram *zram = dev_to_zram(dev); + + if (zram->init_done) + val = zs_get_total_size_bytes(zram->mem_pool); + + return sprintf(buf, "%llu\n", val); +} + +static DEVICE_ATTR(disksize, S_IRUGO | S_IWUSR, + disksize_show, disksize_store); +static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL); +static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store); +static DEVICE_ATTR(num_reads, S_IRUGO, num_reads_show, NULL); +static DEVICE_ATTR(num_writes, S_IRUGO, num_writes_show, NULL); +static DEVICE_ATTR(invalid_io, S_IRUGO, invalid_io_show, NULL); +static DEVICE_ATTR(notify_free, S_IRUGO, notify_free_show, NULL); +static DEVICE_ATTR(zero_pages, S_IRUGO, zero_pages_show, NULL); +static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL); +static DEVICE_ATTR(compr_data_size, S_IRUGO, compr_data_size_show, NULL); +static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL); + +static struct attribute *zram_disk_attrs[] = { + &dev_attr_disksize.attr, + &dev_attr_initstate.attr, + &dev_attr_reset.attr, + &dev_attr_num_reads.attr, + &dev_attr_num_writes.attr, + &dev_attr_invalid_io.attr, + &dev_attr_notify_free.attr, + &dev_attr_zero_pages.attr, + &dev_attr_orig_data_size.attr, + &dev_attr_compr_data_size.attr, + &dev_attr_mem_used_total.attr, + NULL, +}; + +struct attribute_group zram_disk_attr_group = { + .attrs = zram_disk_attrs, +}; diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig index 4316ef5..9fc23d9 100644 --- a/drivers/staging/Kconfig +++ b/drivers/staging/Kconfig @@ -74,8 +74,6 @@ source "drivers/staging/sep/Kconfig" source "drivers/staging/iio/Kconfig" -source "drivers/staging/zram/Kconfig" - source "drivers/staging/zcache/Kconfig" source "drivers/staging/wlags49_h2/Kconfig" diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile index db18726..3aee49a 100644 --- a/drivers/staging/Makefile +++ b/drivers/staging/Makefile @@ -32,7 +32,6 @@ obj-$(CONFIG_VME_BUS) += vme/ obj-$(CONFIG_IPACK_BUS) += ipack/ obj-$(CONFIG_DX_SEP) += sep/ obj-$(CONFIG_IIO) += iio/ -obj-$(CONFIG_ZRAM) += zram/ obj-$(CONFIG_ZCACHE) += zcache/ obj-$(CONFIG_WLAGS49_H2) += wlags49_h2/ obj-$(CONFIG_WLAGS49_H25) += wlags49_h25/ diff --git a/drivers/staging/zram/Kconfig b/drivers/staging/zram/Kconfig deleted file mode 100644 index be5abe8..0000000 --- a/drivers/staging/zram/Kconfig +++ /dev/null @@ -1,25 +0,0 @@ -config ZRAM - tristate "Compressed RAM block device support" - depends on BLOCK && SYSFS && ZSMALLOC - select LZO_COMPRESS - select LZO_DECOMPRESS - default n - help - Creates virtual block devices called /dev/zramX (X = 0, 1, ...). - Pages written to these disks are compressed and stored in memory - itself. These disks allow very fast I/O and compression provides - good amounts of memory savings. - - It has several use cases, for example: /tmp storage, use as swap - disks and maybe many more. - - See zram.txt for more information. - Project home: http://compcache.googlecode.com/ - -config ZRAM_DEBUG - bool "Compressed RAM block device debug support" - depends on ZRAM - default n - help - This option adds additional debugging code to the compressed - RAM block device driver. diff --git a/drivers/staging/zram/Makefile b/drivers/staging/zram/Makefile deleted file mode 100644 index 7f4a301..0000000 --- a/drivers/staging/zram/Makefile +++ /dev/null @@ -1,3 +0,0 @@ -zram-y := zram_drv.o zram_sysfs.o - -obj-$(CONFIG_ZRAM) += zram.o diff --git a/drivers/staging/zram/zram.txt b/drivers/staging/zram/zram.txt deleted file mode 100644 index 5f75d29..0000000 --- a/drivers/staging/zram/zram.txt +++ /dev/null @@ -1,76 +0,0 @@ -zram: Compressed RAM based block devices ----------------------------------------- - -Project home: http://compcache.googlecode.com/ - -* Introduction - -The zram module creates RAM based block devices named /dev/zram<id> -(<id> = 0, 1, ...). Pages written to these disks are compressed and stored -in memory itself. These disks allow very fast I/O and compression provides -good amounts of memory savings. Some of the usecases include /tmp storage, -use as swap disks, various caches under /var and maybe many more :) - -Statistics for individual zram devices are exported through sysfs nodes at -/sys/block/zram<id>/ - -* Usage - -Following shows a typical sequence of steps for using zram. - -1) Load Module: - modprobe zram num_devices=4 - This creates 4 devices: /dev/zram{0,1,2,3} - (num_devices parameter is optional. Default: 1) - -2) Set Disksize (Optional): - Set disk size by writing the value to sysfs node 'disksize' - (in bytes). If disksize is not given, default value of 25% - of RAM is used. - - # Initialize /dev/zram0 with 50MB disksize - echo $((50*1024*1024)) > /sys/block/zram0/disksize - - NOTE: disksize cannot be changed if the disk contains any - data. So, for such a disk, you need to issue 'reset' (see below) - before you can change its disksize. - -3) Activate: - mkswap /dev/zram0 - swapon /dev/zram0 - - mkfs.ext4 /dev/zram1 - mount /dev/zram1 /tmp - -4) Stats: - Per-device statistics are exported as various nodes under - /sys/block/zram<id>/ - disksize - num_reads - num_writes - invalid_io - notify_free - discard - zero_pages - orig_data_size - compr_data_size - mem_used_total - -5) Deactivate: - swapoff /dev/zram0 - umount /dev/zram1 - -6) Reset: - Write any positive value to 'reset' sysfs node - echo 1 > /sys/block/zram0/reset - echo 1 > /sys/block/zram1/reset - - (This frees all the memory allocated for the given device). - - -Please report any problems at: - - Mailing list: linux-mm-cc at laptop dot org - - Issue tracker: http://code.google.com/p/compcache/issues/list - -Nitin Gupta -ngupta@vflare.org diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c deleted file mode 100644 index 653b074..0000000 --- a/drivers/staging/zram/zram_drv.c +++ /dev/null @@ -1,785 +0,0 @@ -/* - * Compressed RAM block device - * - * Copyright (C) 2008, 2009, 2010 Nitin Gupta - * - * This code is released using a dual license strategy: BSD/GPL - * You can choose the licence that better fits your requirements. - * - * Released under the terms of 3-clause BSD License - * Released under the terms of GNU General Public License Version 2.0 - * - * Project home: http://compcache.googlecode.com - */ - -#define KMSG_COMPONENT "zram" -#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt - -#ifdef CONFIG_ZRAM_DEBUG -#define DEBUG -#endif - -#include <linux/module.h> -#include <linux/kernel.h> -#include <linux/bio.h> -#include <linux/bitops.h> -#include <linux/blkdev.h> -#include <linux/buffer_head.h> -#include <linux/device.h> -#include <linux/genhd.h> -#include <linux/highmem.h> -#include <linux/slab.h> -#include <linux/lzo.h> -#include <linux/string.h> -#include <linux/vmalloc.h> - -#include "zram_drv.h" - -/* Globals */ -static int zram_major; -struct zram *zram_devices; - -/* Module params (documentation at end) */ -static unsigned int num_devices; - -static void zram_stat_inc(u32 *v) -{ - *v = *v + 1; -} - -static void zram_stat_dec(u32 *v) -{ - *v = *v - 1; -} - -static void zram_stat64_add(struct zram *zram, u64 *v, u64 inc) -{ - spin_lock(&zram->stat64_lock); - *v = *v + inc; - spin_unlock(&zram->stat64_lock); -} - -static void zram_stat64_sub(struct zram *zram, u64 *v, u64 dec) -{ - spin_lock(&zram->stat64_lock); - *v = *v - dec; - spin_unlock(&zram->stat64_lock); -} - -static void zram_stat64_inc(struct zram *zram, u64 *v) -{ - zram_stat64_add(zram, v, 1); -} - -static int zram_test_flag(struct zram *zram, u32 index, - enum zram_pageflags flag) -{ - return zram->table[index].flags & BIT(flag); -} - -static void zram_set_flag(struct zram *zram, u32 index, - enum zram_pageflags flag) -{ - zram->table[index].flags |= BIT(flag); -} - -static void zram_clear_flag(struct zram *zram, u32 index, - enum zram_pageflags flag) -{ - zram->table[index].flags &= ~BIT(flag); -} - -static int page_zero_filled(void *ptr) -{ - unsigned int pos; - unsigned long *page; - - page = (unsigned long *)ptr; - - for (pos = 0; pos != PAGE_SIZE / sizeof(*page); pos++) { - if (page[pos]) - return 0; - } - - return 1; -} - -static void zram_set_disksize(struct zram *zram, size_t totalram_bytes) -{ - if (!zram->disksize) { - pr_info( - "disk size not provided. You can use disksize_kb module " - "param to specify size.\nUsing default: (%u%% of RAM).\n", - default_disksize_perc_ram - ); - zram->disksize = default_disksize_perc_ram * - (totalram_bytes / 100); - } - - if (zram->disksize > 2 * (totalram_bytes)) { - pr_info( - "There is little point creating a zram of greater than " - "twice the size of memory since we expect a 2:1 compression " - "ratio. Note that zram uses about 0.1%% of the size of " - "the disk when not in use so a huge zram is " - "wasteful.\n" - "\tMemory Size: %zu kB\n" - "\tSize you selected: %llu kB\n" - "Continuing anyway ...\n", - totalram_bytes >> 10, zram->disksize - ); - } - - zram->disksize &= PAGE_MASK; -} - -static void zram_free_page(struct zram *zram, size_t index) -{ - unsigned long handle = zram->table[index].handle; - u16 size = zram->table[index].size; - - if (unlikely(!handle)) { - /* - * No memory is allocated for zero filled pages. - * Simply clear zero page flag. - */ - if (zram_test_flag(zram, index, ZRAM_ZERO)) { - zram_clear_flag(zram, index, ZRAM_ZERO); - zram_stat_dec(&zram->stats.pages_zero); - } - return; - } - - if (unlikely(size > max_zpage_size)) - zram_stat_dec(&zram->stats.bad_compress); - - zs_free(zram->mem_pool, handle); - - if (size <= PAGE_SIZE / 2) - zram_stat_dec(&zram->stats.good_compress); - - zram_stat64_sub(zram, &zram->stats.compr_size, - zram->table[index].size); - zram_stat_dec(&zram->stats.pages_stored); - - zram->table[index].handle = 0; - zram->table[index].size = 0; -} - -static void handle_zero_page(struct bio_vec *bvec) -{ - struct page *page = bvec->bv_page; - void *user_mem; - - user_mem = kmap_atomic(page); - memset(user_mem + bvec->bv_offset, 0, bvec->bv_len); - kunmap_atomic(user_mem); - - flush_dcache_page(page); -} - -static inline int is_partial_io(struct bio_vec *bvec) -{ - return bvec->bv_len != PAGE_SIZE; -} - -static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, - u32 index, int offset, struct bio *bio) -{ - int ret; - size_t clen; - struct page *page; - unsigned char *user_mem, *cmem, *uncmem = NULL; - - page = bvec->bv_page; - - if (zram_test_flag(zram, index, ZRAM_ZERO)) { - handle_zero_page(bvec); - return 0; - } - - /* Requested page is not present in compressed area */ - if (unlikely(!zram->table[index].handle)) { - pr_debug("Read before write: sector=%lu, size=%u", - (ulong)(bio->bi_sector), bio->bi_size); - handle_zero_page(bvec); - return 0; - } - - if (is_partial_io(bvec)) { - /* Use a temporary buffer to decompress the page */ - uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!uncmem) { - pr_info("Error allocating temp memory!\n"); - return -ENOMEM; - } - } - - user_mem = kmap_atomic(page); - if (!is_partial_io(bvec)) - uncmem = user_mem; - clen = PAGE_SIZE; - - cmem = zs_map_object(zram->mem_pool, zram->table[index].handle, - ZS_MM_RO); - - ret = lzo1x_decompress_safe(cmem, zram->table[index].size, - uncmem, &clen); - - if (is_partial_io(bvec)) { - memcpy(user_mem + bvec->bv_offset, uncmem + offset, - bvec->bv_len); - kfree(uncmem); - } - - zs_unmap_object(zram->mem_pool, zram->table[index].handle); - kunmap_atomic(user_mem); - - /* Should NEVER happen. Return bio error if it does. */ - if (unlikely(ret != LZO_E_OK)) { - pr_err("Decompression failed! err=%d, page=%u\n", ret, index); - zram_stat64_inc(zram, &zram->stats.failed_reads); - return ret; - } - - flush_dcache_page(page); - - return 0; -} - -static int zram_read_before_write(struct zram *zram, char *mem, u32 index) -{ - int ret; - size_t clen = PAGE_SIZE; - unsigned char *cmem; - unsigned long handle = zram->table[index].handle; - - if (zram_test_flag(zram, index, ZRAM_ZERO) || !handle) { - memset(mem, 0, PAGE_SIZE); - return 0; - } - - cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_RO); - ret = lzo1x_decompress_safe(cmem, zram->table[index].size, - mem, &clen); - zs_unmap_object(zram->mem_pool, handle); - - /* Should NEVER happen. Return bio error if it does. */ - if (unlikely(ret != LZO_E_OK)) { - pr_err("Decompression failed! err=%d, page=%u\n", ret, index); - zram_stat64_inc(zram, &zram->stats.failed_reads); - return ret; - } - - return 0; -} - -static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, - int offset) -{ - int ret; - size_t clen; - unsigned long handle; - struct page *page; - unsigned char *user_mem, *cmem, *src, *uncmem = NULL; - - page = bvec->bv_page; - src = zram->compress_buffer; - - if (is_partial_io(bvec)) { - /* - * This is a partial IO. We need to read the full page - * before to write the changes. - */ - uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!uncmem) { - pr_info("Error allocating temp memory!\n"); - ret = -ENOMEM; - goto out; - } - ret = zram_read_before_write(zram, uncmem, index); - if (ret) { - kfree(uncmem); - goto out; - } - } - - /* - * System overwrites unused sectors. Free memory associated - * with this sector now. - */ - if (zram->table[index].handle || - zram_test_flag(zram, index, ZRAM_ZERO)) - zram_free_page(zram, index); - - user_mem = kmap_atomic(page); - - if (is_partial_io(bvec)) - memcpy(uncmem + offset, user_mem + bvec->bv_offset, - bvec->bv_len); - else - uncmem = user_mem; - - if (page_zero_filled(uncmem)) { - kunmap_atomic(user_mem); - if (is_partial_io(bvec)) - kfree(uncmem); - zram_stat_inc(&zram->stats.pages_zero); - zram_set_flag(zram, index, ZRAM_ZERO); - ret = 0; - goto out; - } - - ret = lzo1x_1_compress(uncmem, PAGE_SIZE, src, &clen, - zram->compress_workmem); - - kunmap_atomic(user_mem); - if (is_partial_io(bvec)) - kfree(uncmem); - - if (unlikely(ret != LZO_E_OK)) { - pr_err("Compression failed! err=%d\n", ret); - goto out; - } - - if (unlikely(clen > max_zpage_size)) - zram_stat_inc(&zram->stats.bad_compress); - - handle = zs_malloc(zram->mem_pool, clen); - if (!handle) { - pr_info("Error allocating memory for compressed " - "page: %u, size=%zu\n", index, clen); - ret = -ENOMEM; - goto out; - } - cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_WO); - - memcpy(cmem, src, clen); - - zs_unmap_object(zram->mem_pool, handle); - - zram->table[index].handle = handle; - zram->table[index].size = clen; - - /* Update stats */ - zram_stat64_add(zram, &zram->stats.compr_size, clen); - zram_stat_inc(&zram->stats.pages_stored); - if (clen <= PAGE_SIZE / 2) - zram_stat_inc(&zram->stats.good_compress); - - return 0; - -out: - if (ret) - zram_stat64_inc(zram, &zram->stats.failed_writes); - return ret; -} - -static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index, - int offset, struct bio *bio, int rw) -{ - int ret; - - if (rw == READ) { - down_read(&zram->lock); - ret = zram_bvec_read(zram, bvec, index, offset, bio); - up_read(&zram->lock); - } else { - down_write(&zram->lock); - ret = zram_bvec_write(zram, bvec, index, offset); - up_write(&zram->lock); - } - - return ret; -} - -static void update_position(u32 *index, int *offset, struct bio_vec *bvec) -{ - if (*offset + bvec->bv_len >= PAGE_SIZE) - (*index)++; - *offset = (*offset + bvec->bv_len) % PAGE_SIZE; -} - -static void __zram_make_request(struct zram *zram, struct bio *bio, int rw) -{ - int i, offset; - u32 index; - struct bio_vec *bvec; - - switch (rw) { - case READ: - zram_stat64_inc(zram, &zram->stats.num_reads); - break; - case WRITE: - zram_stat64_inc(zram, &zram->stats.num_writes); - break; - } - - index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT; - offset = (bio->bi_sector & (SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT; - - bio_for_each_segment(bvec, bio, i) { - int max_transfer_size = PAGE_SIZE - offset; - - if (bvec->bv_len > max_transfer_size) { - /* - * zram_bvec_rw() can only make operation on a single - * zram page. Split the bio vector. - */ - struct bio_vec bv; - - bv.bv_page = bvec->bv_page; - bv.bv_len = max_transfer_size; - bv.bv_offset = bvec->bv_offset; - - if (zram_bvec_rw(zram, &bv, index, offset, bio, rw) < 0) - goto out; - - bv.bv_len = bvec->bv_len - max_transfer_size; - bv.bv_offset += max_transfer_size; - if (zram_bvec_rw(zram, &bv, index+1, 0, bio, rw) < 0) - goto out; - } else - if (zram_bvec_rw(zram, bvec, index, offset, bio, rw) - < 0) - goto out; - - update_position(&index, &offset, bvec); - } - - set_bit(BIO_UPTODATE, &bio->bi_flags); - bio_endio(bio, 0); - return; - -out: - bio_io_error(bio); -} - -/* - * Check if request is within bounds and aligned on zram logical blocks. - */ -static inline int valid_io_request(struct zram *zram, struct bio *bio) -{ - if (unlikely( - (bio->bi_sector >= (zram->disksize >> SECTOR_SHIFT)) || - (bio->bi_sector & (ZRAM_SECTOR_PER_LOGICAL_BLOCK - 1)) || - (bio->bi_size & (ZRAM_LOGICAL_BLOCK_SIZE - 1)))) { - - return 0; - } - - /* I/O request is valid */ - return 1; -} - -/* - * Handler function for all zram I/O requests. - */ -static void zram_make_request(struct request_queue *queue, struct bio *bio) -{ - struct zram *zram = queue->queuedata; - - if (unlikely(!zram->init_done) && zram_init_device(zram)) - goto error; - - down_read(&zram->init_lock); - if (unlikely(!zram->init_done)) - goto error_unlock; - - if (!valid_io_request(zram, bio)) { - zram_stat64_inc(zram, &zram->stats.invalid_io); - goto error_unlock; - } - - __zram_make_request(zram, bio, bio_data_dir(bio)); - up_read(&zram->init_lock); - - return; - -error_unlock: - up_read(&zram->init_lock); -error: - bio_io_error(bio); -} - -void __zram_reset_device(struct zram *zram) -{ - size_t index; - - zram->init_done = 0; - - /* Free various per-device buffers */ - kfree(zram->compress_workmem); - free_pages((unsigned long)zram->compress_buffer, 1); - - zram->compress_workmem = NULL; - zram->compress_buffer = NULL; - - /* Free all pages that are still in this zram device */ - for (index = 0; index < zram->disksize >> PAGE_SHIFT; index++) { - unsigned long handle = zram->table[index].handle; - if (!handle) - continue; - - zs_free(zram->mem_pool, handle); - } - - vfree(zram->table); - zram->table = NULL; - - zs_destroy_pool(zram->mem_pool); - zram->mem_pool = NULL; - - /* Reset stats */ - memset(&zram->stats, 0, sizeof(zram->stats)); - - zram->disksize = 0; -} - -void zram_reset_device(struct zram *zram) -{ - down_write(&zram->init_lock); - __zram_reset_device(zram); - up_write(&zram->init_lock); -} - -int zram_init_device(struct zram *zram) -{ - int ret; - size_t num_pages; - - down_write(&zram->init_lock); - - if (zram->init_done) { - up_write(&zram->init_lock); - return 0; - } - - zram_set_disksize(zram, totalram_pages << PAGE_SHIFT); - - zram->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL); - if (!zram->compress_workmem) { - pr_err("Error allocating compressor working memory!\n"); - ret = -ENOMEM; - goto fail_no_table; - } - - zram->compress_buffer = - (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1); - if (!zram->compress_buffer) { - pr_err("Error allocating compressor buffer space\n"); - ret = -ENOMEM; - goto fail_no_table; - } - - num_pages = zram->disksize >> PAGE_SHIFT; - zram->table = vzalloc(num_pages * sizeof(*zram->table)); - if (!zram->table) { - pr_err("Error allocating zram address table\n"); - ret = -ENOMEM; - goto fail_no_table; - } - - set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); - - /* zram devices sort of resembles non-rotational disks */ - queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue); - - zram->mem_pool = zs_create_pool("zram", GFP_NOIO | __GFP_HIGHMEM); - if (!zram->mem_pool) { - pr_err("Error creating memory pool\n"); - ret = -ENOMEM; - goto fail; - } - - zram->init_done = 1; - up_write(&zram->init_lock); - - pr_debug("Initialization done!\n"); - return 0; - -fail_no_table: - /* To prevent accessing table entries during cleanup */ - zram->disksize = 0; -fail: - __zram_reset_device(zram); - up_write(&zram->init_lock); - pr_err("Initialization failed: err=%d\n", ret); - return ret; -} - -static void zram_slot_free_notify(struct block_device *bdev, - unsigned long index) -{ - struct zram *zram; - - zram = bdev->bd_disk->private_data; - zram_free_page(zram, index); - zram_stat64_inc(zram, &zram->stats.notify_free); -} - -static const struct block_device_operations zram_devops = { - .swap_slot_free_notify = zram_slot_free_notify, - .owner = THIS_MODULE -}; - -static int create_device(struct zram *zram, int device_id) -{ - int ret = 0; - - init_rwsem(&zram->lock); - init_rwsem(&zram->init_lock); - spin_lock_init(&zram->stat64_lock); - - zram->queue = blk_alloc_queue(GFP_KERNEL); - if (!zram->queue) { - pr_err("Error allocating disk queue for device %d\n", - device_id); - ret = -ENOMEM; - goto out; - } - - blk_queue_make_request(zram->queue, zram_make_request); - zram->queue->queuedata = zram; - - /* gendisk structure */ - zram->disk = alloc_disk(1); - if (!zram->disk) { - blk_cleanup_queue(zram->queue); - pr_warn("Error allocating disk structure for device %d\n", - device_id); - ret = -ENOMEM; - goto out; - } - - zram->disk->major = zram_major; - zram->disk->first_minor = device_id; - zram->disk->fops = &zram_devops; - zram->disk->queue = zram->queue; - zram->disk->private_data = zram; - snprintf(zram->disk->disk_name, 16, "zram%d", device_id); - - /* Actual capacity set using syfs (/sys/block/zram<id>/disksize */ - set_capacity(zram->disk, 0); - - /* - * To ensure that we always get PAGE_SIZE aligned - * and n*PAGE_SIZED sized I/O requests. - */ - blk_queue_physical_block_size(zram->disk->queue, PAGE_SIZE); - blk_queue_logical_block_size(zram->disk->queue, - ZRAM_LOGICAL_BLOCK_SIZE); - blk_queue_io_min(zram->disk->queue, PAGE_SIZE); - blk_queue_io_opt(zram->disk->queue, PAGE_SIZE); - - add_disk(zram->disk); - - ret = sysfs_create_group(&disk_to_dev(zram->disk)->kobj, - &zram_disk_attr_group); - if (ret < 0) { - pr_warn("Error creating sysfs group"); - goto out; - } - - zram->init_done = 0; - -out: - return ret; -} - -static void destroy_device(struct zram *zram) -{ - sysfs_remove_group(&disk_to_dev(zram->disk)->kobj, - &zram_disk_attr_group); - - if (zram->disk) { - del_gendisk(zram->disk); - put_disk(zram->disk); - } - - if (zram->queue) - blk_cleanup_queue(zram->queue); -} - -unsigned int zram_get_num_devices(void) -{ - return num_devices; -} - -static int __init zram_init(void) -{ - int ret, dev_id; - - if (num_devices > max_num_devices) { - pr_warn("Invalid value for num_devices: %u\n", - num_devices); - ret = -EINVAL; - goto out; - } - - zram_major = register_blkdev(0, "zram"); - if (zram_major <= 0) { - pr_warn("Unable to get major number\n"); - ret = -EBUSY; - goto out; - } - - if (!num_devices) { - pr_info("num_devices not specified. Using default: 1\n"); - num_devices = 1; - } - - /* Allocate the device array and initialize each one */ - pr_info("Creating %u devices ...\n", num_devices); - zram_devices = kzalloc(num_devices * sizeof(struct zram), GFP_KERNEL); - if (!zram_devices) { - ret = -ENOMEM; - goto unregister; - } - - for (dev_id = 0; dev_id < num_devices; dev_id++) { - ret = create_device(&zram_devices[dev_id], dev_id); - if (ret) - goto free_devices; - } - - return 0; - -free_devices: - while (dev_id) - destroy_device(&zram_devices[--dev_id]); - kfree(zram_devices); -unregister: - unregister_blkdev(zram_major, "zram"); -out: - return ret; -} - -static void __exit zram_exit(void) -{ - int i; - struct zram *zram; - - for (i = 0; i < num_devices; i++) { - zram = &zram_devices[i]; - - destroy_device(zram); - if (zram->init_done) - zram_reset_device(zram); - } - - unregister_blkdev(zram_major, "zram"); - - kfree(zram_devices); - pr_debug("Cleanup done!\n"); -} - -module_param(num_devices, uint, 0); -MODULE_PARM_DESC(num_devices, "Number of zram devices"); - -module_init(zram_init); -module_exit(zram_exit); - -MODULE_LICENSE("Dual BSD/GPL"); -MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); -MODULE_DESCRIPTION("Compressed RAM Block Device"); diff --git a/drivers/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h deleted file mode 100644 index f6d0925..0000000 --- a/drivers/staging/zram/zram_drv.h +++ /dev/null @@ -1,119 +0,0 @@ -/* - * Compressed RAM block device - * - * Copyright (C) 2008, 2009, 2010 Nitin Gupta - * - * This code is released using a dual license strategy: BSD/GPL - * You can choose the licence that better fits your requirements. - * - * Released under the terms of 3-clause BSD License - * Released under the terms of GNU General Public License Version 2.0 - * - * Project home: http://compcache.googlecode.com - */ - -#ifndef _ZRAM_DRV_H_ -#define _ZRAM_DRV_H_ - -#include <linux/spinlock.h> -#include <linux/mutex.h> -#include <linux/zsmalloc.h> - -/* - * Some arbitrary value. This is just to catch - * invalid value for num_devices module parameter. - */ -static const unsigned max_num_devices = 32; - -/*-- Configurable parameters */ - -/* Default zram disk size: 25% of total RAM */ -static const unsigned default_disksize_perc_ram = 25; - -/* - * Pages that compress to size greater than this are stored - * uncompressed in memory. - */ -static const size_t max_zpage_size = PAGE_SIZE / 4 * 3; - -/* - * NOTE: max_zpage_size must be less than or equal to: - * ZS_MAX_ALLOC_SIZE - sizeof(struct zobj_header) - * otherwise, xv_malloc() would always return failure. - */ - -/*-- End of configurable params */ - -#define SECTOR_SHIFT 9 -#define SECTOR_SIZE (1 << SECTOR_SHIFT) -#define SECTORS_PER_PAGE_SHIFT (PAGE_SHIFT - SECTOR_SHIFT) -#define SECTORS_PER_PAGE (1 << SECTORS_PER_PAGE_SHIFT) -#define ZRAM_LOGICAL_BLOCK_SHIFT 12 -#define ZRAM_LOGICAL_BLOCK_SIZE (1 << ZRAM_LOGICAL_BLOCK_SHIFT) -#define ZRAM_SECTOR_PER_LOGICAL_BLOCK \ - (1 << (ZRAM_LOGICAL_BLOCK_SHIFT - SECTOR_SHIFT)) - -/* Flags for zram pages (table[page_no].flags) */ -enum zram_pageflags { - /* Page consists entirely of zeros */ - ZRAM_ZERO, - - __NR_ZRAM_PAGEFLAGS, -}; - -/*-- Data structures */ - -/* Allocated for each disk page */ -struct table { - unsigned long handle; - u16 size; /* object size (excluding header) */ - u8 count; /* object ref count (not yet used) */ - u8 flags; -} __aligned(4); - -struct zram_stats { - u64 compr_size; /* compressed size of pages stored */ - u64 num_reads; /* failed + successful */ - u64 num_writes; /* --do-- */ - u64 failed_reads; /* should NEVER! happen */ - u64 failed_writes; /* can happen when memory is too low */ - u64 invalid_io; /* non-page-aligned I/O requests */ - u64 notify_free; /* no. of swap slot free notifications */ - u32 pages_zero; /* no. of zero filled pages */ - u32 pages_stored; /* no. of pages currently stored */ - u32 good_compress; /* % of pages with compression ratio<=50% */ - u32 bad_compress; /* % of pages with compression ratio>=75% */ -}; - -struct zram { - struct zs_pool *mem_pool; - void *compress_workmem; - void *compress_buffer; - struct table *table; - spinlock_t stat64_lock; /* protect 64-bit stats */ - struct rw_semaphore lock; /* protect compression buffers and table - * against concurrent read and writes */ - struct request_queue *queue; - struct gendisk *disk; - int init_done; - /* Prevent concurrent execution of device init, reset and R/W request */ - struct rw_semaphore init_lock; - /* - * This is the limit on amount of *uncompressed* worth of data - * we can store in a disk. - */ - u64 disksize; /* bytes */ - - struct zram_stats stats; -}; - -extern struct zram *zram_devices; -unsigned int zram_get_num_devices(void); -#ifdef CONFIG_SYSFS -extern struct attribute_group zram_disk_attr_group; -#endif - -extern int zram_init_device(struct zram *zram); -extern void __zram_reset_device(struct zram *zram); - -#endif diff --git a/drivers/staging/zram/zram_sysfs.c b/drivers/staging/zram/zram_sysfs.c deleted file mode 100644 index edb0ed4..0000000 --- a/drivers/staging/zram/zram_sysfs.c +++ /dev/null @@ -1,225 +0,0 @@ -/* - * Compressed RAM block device - * - * Copyright (C) 2008, 2009, 2010 Nitin Gupta - * - * This code is released using a dual license strategy: BSD/GPL - * You can choose the licence that better fits your requirements. - * - * Released under the terms of 3-clause BSD License - * Released under the terms of GNU General Public License Version 2.0 - * - * Project home: http://compcache.googlecode.com/ - */ - -#include <linux/device.h> -#include <linux/genhd.h> -#include <linux/mm.h> - -#include "zram_drv.h" - -static u64 zram_stat64_read(struct zram *zram, u64 *v) -{ - u64 val; - - spin_lock(&zram->stat64_lock); - val = *v; - spin_unlock(&zram->stat64_lock); - - return val; -} - -static struct zram *dev_to_zram(struct device *dev) -{ - int i; - struct zram *zram = NULL; - - for (i = 0; i < zram_get_num_devices(); i++) { - zram = &zram_devices[i]; - if (disk_to_dev(zram->disk) == dev) - break; - } - - return zram; -} - -static ssize_t disksize_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%llu\n", zram->disksize); -} - -static ssize_t disksize_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) -{ - int ret; - u64 disksize; - struct zram *zram = dev_to_zram(dev); - - ret = kstrtoull(buf, 10, &disksize); - if (ret) - return ret; - - down_write(&zram->init_lock); - if (zram->init_done) { - up_write(&zram->init_lock); - pr_info("Cannot change disksize for initialized device\n"); - return -EBUSY; - } - - zram->disksize = PAGE_ALIGN(disksize); - set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); - up_write(&zram->init_lock); - - return len; -} - -static ssize_t initstate_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%u\n", zram->init_done); -} - -static ssize_t reset_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) -{ - int ret; - unsigned short do_reset; - struct zram *zram; - struct block_device *bdev; - - zram = dev_to_zram(dev); - bdev = bdget_disk(zram->disk, 0); - - /* Do not reset an active device! */ - if (bdev->bd_holders) - return -EBUSY; - - ret = kstrtou16(buf, 10, &do_reset); - if (ret) - return ret; - - if (!do_reset) - return -EINVAL; - - /* Make sure all pending I/O is finished */ - if (bdev) - fsync_bdev(bdev); - - down_write(&zram->init_lock); - if (zram->init_done) - __zram_reset_device(zram); - up_write(&zram->init_lock); - - return len; -} - -static ssize_t num_reads_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%llu\n", - zram_stat64_read(zram, &zram->stats.num_reads)); -} - -static ssize_t num_writes_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%llu\n", - zram_stat64_read(zram, &zram->stats.num_writes)); -} - -static ssize_t invalid_io_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%llu\n", - zram_stat64_read(zram, &zram->stats.invalid_io)); -} - -static ssize_t notify_free_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%llu\n", - zram_stat64_read(zram, &zram->stats.notify_free)); -} - -static ssize_t zero_pages_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%u\n", zram->stats.pages_zero); -} - -static ssize_t orig_data_size_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%llu\n", - (u64)(zram->stats.pages_stored) << PAGE_SHIFT); -} - -static ssize_t compr_data_size_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%llu\n", - zram_stat64_read(zram, &zram->stats.compr_size)); -} - -static ssize_t mem_used_total_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - u64 val = 0; - struct zram *zram = dev_to_zram(dev); - - if (zram->init_done) - val = zs_get_total_size_bytes(zram->mem_pool); - - return sprintf(buf, "%llu\n", val); -} - -static DEVICE_ATTR(disksize, S_IRUGO | S_IWUSR, - disksize_show, disksize_store); -static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL); -static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store); -static DEVICE_ATTR(num_reads, S_IRUGO, num_reads_show, NULL); -static DEVICE_ATTR(num_writes, S_IRUGO, num_writes_show, NULL); -static DEVICE_ATTR(invalid_io, S_IRUGO, invalid_io_show, NULL); -static DEVICE_ATTR(notify_free, S_IRUGO, notify_free_show, NULL); -static DEVICE_ATTR(zero_pages, S_IRUGO, zero_pages_show, NULL); -static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL); -static DEVICE_ATTR(compr_data_size, S_IRUGO, compr_data_size_show, NULL); -static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL); - -static struct attribute *zram_disk_attrs[] = { - &dev_attr_disksize.attr, - &dev_attr_initstate.attr, - &dev_attr_reset.attr, - &dev_attr_num_reads.attr, - &dev_attr_num_writes.attr, - &dev_attr_invalid_io.attr, - &dev_attr_notify_free.attr, - &dev_attr_zero_pages.attr, - &dev_attr_orig_data_size.attr, - &dev_attr_compr_data_size.attr, - &dev_attr_mem_used_total.attr, - NULL, -}; - -struct attribute_group zram_disk_attr_group = { - .attrs = zram_disk_attrs, -}; -- 1.7.9.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 30+ messages in thread
* [PATCH 2/3] zram: promote zram from staging @ 2012-09-26 8:50 ` Minchan Kim 0 siblings, 0 replies; 30+ messages in thread From: Minchan Kim @ 2012-09-26 8:50 UTC (permalink / raw) To: Jens Axboe, Greg Kroah-Hartman Cc: Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel, Minchan Kim It's time to promote zram from staging because zram is in staging for a long time and is improved by many contributors so code is very clean. Most important issue, zram's dependency with x86 is solved by making zsmalloc portable. In addition, many embedded product uses zram in real practive so I think there is no reason to prevent promotion now. Cc: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: Minchan Kim <minchan@kernel.org> --- drivers/block/Kconfig | 1 + drivers/block/Makefile | 1 + drivers/block/zram/Kconfig | 25 ++ drivers/block/zram/Makefile | 3 + drivers/block/zram/zram.txt | 76 ++++ drivers/block/zram/zram_drv.c | 785 +++++++++++++++++++++++++++++++++++++ drivers/block/zram/zram_drv.h | 119 ++++++ drivers/block/zram/zram_sysfs.c | 225 +++++++++++ drivers/staging/Kconfig | 2 - drivers/staging/Makefile | 1 - drivers/staging/zram/Kconfig | 25 -- drivers/staging/zram/Makefile | 3 - drivers/staging/zram/zram.txt | 76 ---- drivers/staging/zram/zram_drv.c | 785 ------------------------------------- drivers/staging/zram/zram_drv.h | 119 ------ drivers/staging/zram/zram_sysfs.c | 225 ----------- 16 files changed, 1235 insertions(+), 1236 deletions(-) create mode 100644 drivers/block/zram/Kconfig create mode 100644 drivers/block/zram/Makefile create mode 100644 drivers/block/zram/zram.txt create mode 100644 drivers/block/zram/zram_drv.c create mode 100644 drivers/block/zram/zram_drv.h create mode 100644 drivers/block/zram/zram_sysfs.c delete mode 100644 drivers/staging/zram/Kconfig delete mode 100644 drivers/staging/zram/Makefile delete mode 100644 drivers/staging/zram/zram.txt delete mode 100644 drivers/staging/zram/zram_drv.c delete mode 100644 drivers/staging/zram/zram_drv.h delete mode 100644 drivers/staging/zram/zram_sysfs.c diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig index f7de322..3e3087e 100644 --- a/drivers/block/Kconfig +++ b/drivers/block/Kconfig @@ -290,6 +290,7 @@ config BLK_DEV_CRYPTOLOOP cryptoloop device. source "drivers/block/drbd/Kconfig" +source "drivers/block/zram/Kconfig" config BLK_DEV_NBD tristate "Network block device support" diff --git a/drivers/block/Makefile b/drivers/block/Makefile index 17e82df..0751c43 100644 --- a/drivers/block/Makefile +++ b/drivers/block/Makefile @@ -30,6 +30,7 @@ obj-$(CONFIG_BLK_DEV_UMEM) += umem.o obj-$(CONFIG_BLK_DEV_NBD) += nbd.o obj-$(CONFIG_BLK_DEV_CRYPTOLOOP) += cryptoloop.o obj-$(CONFIG_VIRTIO_BLK) += virtio_blk.o +obj-$(CONFIG_ZRAM) += zram/ obj-$(CONFIG_VIODASD) += viodasd.o obj-$(CONFIG_BLK_DEV_SX8) += sx8.o diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig new file mode 100644 index 0000000..be5abe8 --- /dev/null +++ b/drivers/block/zram/Kconfig @@ -0,0 +1,25 @@ +config ZRAM + tristate "Compressed RAM block device support" + depends on BLOCK && SYSFS && ZSMALLOC + select LZO_COMPRESS + select LZO_DECOMPRESS + default n + help + Creates virtual block devices called /dev/zramX (X = 0, 1, ...). + Pages written to these disks are compressed and stored in memory + itself. These disks allow very fast I/O and compression provides + good amounts of memory savings. + + It has several use cases, for example: /tmp storage, use as swap + disks and maybe many more. + + See zram.txt for more information. + Project home: http://compcache.googlecode.com/ + +config ZRAM_DEBUG + bool "Compressed RAM block device debug support" + depends on ZRAM + default n + help + This option adds additional debugging code to the compressed + RAM block device driver. diff --git a/drivers/block/zram/Makefile b/drivers/block/zram/Makefile new file mode 100644 index 0000000..7f4a301 --- /dev/null +++ b/drivers/block/zram/Makefile @@ -0,0 +1,3 @@ +zram-y := zram_drv.o zram_sysfs.o + +obj-$(CONFIG_ZRAM) += zram.o diff --git a/drivers/block/zram/zram.txt b/drivers/block/zram/zram.txt new file mode 100644 index 0000000..5f75d29 --- /dev/null +++ b/drivers/block/zram/zram.txt @@ -0,0 +1,76 @@ +zram: Compressed RAM based block devices +---------------------------------------- + +Project home: http://compcache.googlecode.com/ + +* Introduction + +The zram module creates RAM based block devices named /dev/zram<id> +(<id> = 0, 1, ...). Pages written to these disks are compressed and stored +in memory itself. These disks allow very fast I/O and compression provides +good amounts of memory savings. Some of the usecases include /tmp storage, +use as swap disks, various caches under /var and maybe many more :) + +Statistics for individual zram devices are exported through sysfs nodes at +/sys/block/zram<id>/ + +* Usage + +Following shows a typical sequence of steps for using zram. + +1) Load Module: + modprobe zram num_devices=4 + This creates 4 devices: /dev/zram{0,1,2,3} + (num_devices parameter is optional. Default: 1) + +2) Set Disksize (Optional): + Set disk size by writing the value to sysfs node 'disksize' + (in bytes). If disksize is not given, default value of 25% + of RAM is used. + + # Initialize /dev/zram0 with 50MB disksize + echo $((50*1024*1024)) > /sys/block/zram0/disksize + + NOTE: disksize cannot be changed if the disk contains any + data. So, for such a disk, you need to issue 'reset' (see below) + before you can change its disksize. + +3) Activate: + mkswap /dev/zram0 + swapon /dev/zram0 + + mkfs.ext4 /dev/zram1 + mount /dev/zram1 /tmp + +4) Stats: + Per-device statistics are exported as various nodes under + /sys/block/zram<id>/ + disksize + num_reads + num_writes + invalid_io + notify_free + discard + zero_pages + orig_data_size + compr_data_size + mem_used_total + +5) Deactivate: + swapoff /dev/zram0 + umount /dev/zram1 + +6) Reset: + Write any positive value to 'reset' sysfs node + echo 1 > /sys/block/zram0/reset + echo 1 > /sys/block/zram1/reset + + (This frees all the memory allocated for the given device). + + +Please report any problems at: + - Mailing list: linux-mm-cc at laptop dot org + - Issue tracker: http://code.google.com/p/compcache/issues/list + +Nitin Gupta +ngupta@vflare.org diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c new file mode 100644 index 0000000..653b074 --- /dev/null +++ b/drivers/block/zram/zram_drv.c @@ -0,0 +1,785 @@ +/* + * Compressed RAM block device + * + * Copyright (C) 2008, 2009, 2010 Nitin Gupta + * + * This code is released using a dual license strategy: BSD/GPL + * You can choose the licence that better fits your requirements. + * + * Released under the terms of 3-clause BSD License + * Released under the terms of GNU General Public License Version 2.0 + * + * Project home: http://compcache.googlecode.com + */ + +#define KMSG_COMPONENT "zram" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#ifdef CONFIG_ZRAM_DEBUG +#define DEBUG +#endif + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/bio.h> +#include <linux/bitops.h> +#include <linux/blkdev.h> +#include <linux/buffer_head.h> +#include <linux/device.h> +#include <linux/genhd.h> +#include <linux/highmem.h> +#include <linux/slab.h> +#include <linux/lzo.h> +#include <linux/string.h> +#include <linux/vmalloc.h> + +#include "zram_drv.h" + +/* Globals */ +static int zram_major; +struct zram *zram_devices; + +/* Module params (documentation at end) */ +static unsigned int num_devices; + +static void zram_stat_inc(u32 *v) +{ + *v = *v + 1; +} + +static void zram_stat_dec(u32 *v) +{ + *v = *v - 1; +} + +static void zram_stat64_add(struct zram *zram, u64 *v, u64 inc) +{ + spin_lock(&zram->stat64_lock); + *v = *v + inc; + spin_unlock(&zram->stat64_lock); +} + +static void zram_stat64_sub(struct zram *zram, u64 *v, u64 dec) +{ + spin_lock(&zram->stat64_lock); + *v = *v - dec; + spin_unlock(&zram->stat64_lock); +} + +static void zram_stat64_inc(struct zram *zram, u64 *v) +{ + zram_stat64_add(zram, v, 1); +} + +static int zram_test_flag(struct zram *zram, u32 index, + enum zram_pageflags flag) +{ + return zram->table[index].flags & BIT(flag); +} + +static void zram_set_flag(struct zram *zram, u32 index, + enum zram_pageflags flag) +{ + zram->table[index].flags |= BIT(flag); +} + +static void zram_clear_flag(struct zram *zram, u32 index, + enum zram_pageflags flag) +{ + zram->table[index].flags &= ~BIT(flag); +} + +static int page_zero_filled(void *ptr) +{ + unsigned int pos; + unsigned long *page; + + page = (unsigned long *)ptr; + + for (pos = 0; pos != PAGE_SIZE / sizeof(*page); pos++) { + if (page[pos]) + return 0; + } + + return 1; +} + +static void zram_set_disksize(struct zram *zram, size_t totalram_bytes) +{ + if (!zram->disksize) { + pr_info( + "disk size not provided. You can use disksize_kb module " + "param to specify size.\nUsing default: (%u%% of RAM).\n", + default_disksize_perc_ram + ); + zram->disksize = default_disksize_perc_ram * + (totalram_bytes / 100); + } + + if (zram->disksize > 2 * (totalram_bytes)) { + pr_info( + "There is little point creating a zram of greater than " + "twice the size of memory since we expect a 2:1 compression " + "ratio. Note that zram uses about 0.1%% of the size of " + "the disk when not in use so a huge zram is " + "wasteful.\n" + "\tMemory Size: %zu kB\n" + "\tSize you selected: %llu kB\n" + "Continuing anyway ...\n", + totalram_bytes >> 10, zram->disksize + ); + } + + zram->disksize &= PAGE_MASK; +} + +static void zram_free_page(struct zram *zram, size_t index) +{ + unsigned long handle = zram->table[index].handle; + u16 size = zram->table[index].size; + + if (unlikely(!handle)) { + /* + * No memory is allocated for zero filled pages. + * Simply clear zero page flag. + */ + if (zram_test_flag(zram, index, ZRAM_ZERO)) { + zram_clear_flag(zram, index, ZRAM_ZERO); + zram_stat_dec(&zram->stats.pages_zero); + } + return; + } + + if (unlikely(size > max_zpage_size)) + zram_stat_dec(&zram->stats.bad_compress); + + zs_free(zram->mem_pool, handle); + + if (size <= PAGE_SIZE / 2) + zram_stat_dec(&zram->stats.good_compress); + + zram_stat64_sub(zram, &zram->stats.compr_size, + zram->table[index].size); + zram_stat_dec(&zram->stats.pages_stored); + + zram->table[index].handle = 0; + zram->table[index].size = 0; +} + +static void handle_zero_page(struct bio_vec *bvec) +{ + struct page *page = bvec->bv_page; + void *user_mem; + + user_mem = kmap_atomic(page); + memset(user_mem + bvec->bv_offset, 0, bvec->bv_len); + kunmap_atomic(user_mem); + + flush_dcache_page(page); +} + +static inline int is_partial_io(struct bio_vec *bvec) +{ + return bvec->bv_len != PAGE_SIZE; +} + +static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, + u32 index, int offset, struct bio *bio) +{ + int ret; + size_t clen; + struct page *page; + unsigned char *user_mem, *cmem, *uncmem = NULL; + + page = bvec->bv_page; + + if (zram_test_flag(zram, index, ZRAM_ZERO)) { + handle_zero_page(bvec); + return 0; + } + + /* Requested page is not present in compressed area */ + if (unlikely(!zram->table[index].handle)) { + pr_debug("Read before write: sector=%lu, size=%u", + (ulong)(bio->bi_sector), bio->bi_size); + handle_zero_page(bvec); + return 0; + } + + if (is_partial_io(bvec)) { + /* Use a temporary buffer to decompress the page */ + uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!uncmem) { + pr_info("Error allocating temp memory!\n"); + return -ENOMEM; + } + } + + user_mem = kmap_atomic(page); + if (!is_partial_io(bvec)) + uncmem = user_mem; + clen = PAGE_SIZE; + + cmem = zs_map_object(zram->mem_pool, zram->table[index].handle, + ZS_MM_RO); + + ret = lzo1x_decompress_safe(cmem, zram->table[index].size, + uncmem, &clen); + + if (is_partial_io(bvec)) { + memcpy(user_mem + bvec->bv_offset, uncmem + offset, + bvec->bv_len); + kfree(uncmem); + } + + zs_unmap_object(zram->mem_pool, zram->table[index].handle); + kunmap_atomic(user_mem); + + /* Should NEVER happen. Return bio error if it does. */ + if (unlikely(ret != LZO_E_OK)) { + pr_err("Decompression failed! err=%d, page=%u\n", ret, index); + zram_stat64_inc(zram, &zram->stats.failed_reads); + return ret; + } + + flush_dcache_page(page); + + return 0; +} + +static int zram_read_before_write(struct zram *zram, char *mem, u32 index) +{ + int ret; + size_t clen = PAGE_SIZE; + unsigned char *cmem; + unsigned long handle = zram->table[index].handle; + + if (zram_test_flag(zram, index, ZRAM_ZERO) || !handle) { + memset(mem, 0, PAGE_SIZE); + return 0; + } + + cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_RO); + ret = lzo1x_decompress_safe(cmem, zram->table[index].size, + mem, &clen); + zs_unmap_object(zram->mem_pool, handle); + + /* Should NEVER happen. Return bio error if it does. */ + if (unlikely(ret != LZO_E_OK)) { + pr_err("Decompression failed! err=%d, page=%u\n", ret, index); + zram_stat64_inc(zram, &zram->stats.failed_reads); + return ret; + } + + return 0; +} + +static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, + int offset) +{ + int ret; + size_t clen; + unsigned long handle; + struct page *page; + unsigned char *user_mem, *cmem, *src, *uncmem = NULL; + + page = bvec->bv_page; + src = zram->compress_buffer; + + if (is_partial_io(bvec)) { + /* + * This is a partial IO. We need to read the full page + * before to write the changes. + */ + uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!uncmem) { + pr_info("Error allocating temp memory!\n"); + ret = -ENOMEM; + goto out; + } + ret = zram_read_before_write(zram, uncmem, index); + if (ret) { + kfree(uncmem); + goto out; + } + } + + /* + * System overwrites unused sectors. Free memory associated + * with this sector now. + */ + if (zram->table[index].handle || + zram_test_flag(zram, index, ZRAM_ZERO)) + zram_free_page(zram, index); + + user_mem = kmap_atomic(page); + + if (is_partial_io(bvec)) + memcpy(uncmem + offset, user_mem + bvec->bv_offset, + bvec->bv_len); + else + uncmem = user_mem; + + if (page_zero_filled(uncmem)) { + kunmap_atomic(user_mem); + if (is_partial_io(bvec)) + kfree(uncmem); + zram_stat_inc(&zram->stats.pages_zero); + zram_set_flag(zram, index, ZRAM_ZERO); + ret = 0; + goto out; + } + + ret = lzo1x_1_compress(uncmem, PAGE_SIZE, src, &clen, + zram->compress_workmem); + + kunmap_atomic(user_mem); + if (is_partial_io(bvec)) + kfree(uncmem); + + if (unlikely(ret != LZO_E_OK)) { + pr_err("Compression failed! err=%d\n", ret); + goto out; + } + + if (unlikely(clen > max_zpage_size)) + zram_stat_inc(&zram->stats.bad_compress); + + handle = zs_malloc(zram->mem_pool, clen); + if (!handle) { + pr_info("Error allocating memory for compressed " + "page: %u, size=%zu\n", index, clen); + ret = -ENOMEM; + goto out; + } + cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_WO); + + memcpy(cmem, src, clen); + + zs_unmap_object(zram->mem_pool, handle); + + zram->table[index].handle = handle; + zram->table[index].size = clen; + + /* Update stats */ + zram_stat64_add(zram, &zram->stats.compr_size, clen); + zram_stat_inc(&zram->stats.pages_stored); + if (clen <= PAGE_SIZE / 2) + zram_stat_inc(&zram->stats.good_compress); + + return 0; + +out: + if (ret) + zram_stat64_inc(zram, &zram->stats.failed_writes); + return ret; +} + +static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index, + int offset, struct bio *bio, int rw) +{ + int ret; + + if (rw == READ) { + down_read(&zram->lock); + ret = zram_bvec_read(zram, bvec, index, offset, bio); + up_read(&zram->lock); + } else { + down_write(&zram->lock); + ret = zram_bvec_write(zram, bvec, index, offset); + up_write(&zram->lock); + } + + return ret; +} + +static void update_position(u32 *index, int *offset, struct bio_vec *bvec) +{ + if (*offset + bvec->bv_len >= PAGE_SIZE) + (*index)++; + *offset = (*offset + bvec->bv_len) % PAGE_SIZE; +} + +static void __zram_make_request(struct zram *zram, struct bio *bio, int rw) +{ + int i, offset; + u32 index; + struct bio_vec *bvec; + + switch (rw) { + case READ: + zram_stat64_inc(zram, &zram->stats.num_reads); + break; + case WRITE: + zram_stat64_inc(zram, &zram->stats.num_writes); + break; + } + + index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT; + offset = (bio->bi_sector & (SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT; + + bio_for_each_segment(bvec, bio, i) { + int max_transfer_size = PAGE_SIZE - offset; + + if (bvec->bv_len > max_transfer_size) { + /* + * zram_bvec_rw() can only make operation on a single + * zram page. Split the bio vector. + */ + struct bio_vec bv; + + bv.bv_page = bvec->bv_page; + bv.bv_len = max_transfer_size; + bv.bv_offset = bvec->bv_offset; + + if (zram_bvec_rw(zram, &bv, index, offset, bio, rw) < 0) + goto out; + + bv.bv_len = bvec->bv_len - max_transfer_size; + bv.bv_offset += max_transfer_size; + if (zram_bvec_rw(zram, &bv, index+1, 0, bio, rw) < 0) + goto out; + } else + if (zram_bvec_rw(zram, bvec, index, offset, bio, rw) + < 0) + goto out; + + update_position(&index, &offset, bvec); + } + + set_bit(BIO_UPTODATE, &bio->bi_flags); + bio_endio(bio, 0); + return; + +out: + bio_io_error(bio); +} + +/* + * Check if request is within bounds and aligned on zram logical blocks. + */ +static inline int valid_io_request(struct zram *zram, struct bio *bio) +{ + if (unlikely( + (bio->bi_sector >= (zram->disksize >> SECTOR_SHIFT)) || + (bio->bi_sector & (ZRAM_SECTOR_PER_LOGICAL_BLOCK - 1)) || + (bio->bi_size & (ZRAM_LOGICAL_BLOCK_SIZE - 1)))) { + + return 0; + } + + /* I/O request is valid */ + return 1; +} + +/* + * Handler function for all zram I/O requests. + */ +static void zram_make_request(struct request_queue *queue, struct bio *bio) +{ + struct zram *zram = queue->queuedata; + + if (unlikely(!zram->init_done) && zram_init_device(zram)) + goto error; + + down_read(&zram->init_lock); + if (unlikely(!zram->init_done)) + goto error_unlock; + + if (!valid_io_request(zram, bio)) { + zram_stat64_inc(zram, &zram->stats.invalid_io); + goto error_unlock; + } + + __zram_make_request(zram, bio, bio_data_dir(bio)); + up_read(&zram->init_lock); + + return; + +error_unlock: + up_read(&zram->init_lock); +error: + bio_io_error(bio); +} + +void __zram_reset_device(struct zram *zram) +{ + size_t index; + + zram->init_done = 0; + + /* Free various per-device buffers */ + kfree(zram->compress_workmem); + free_pages((unsigned long)zram->compress_buffer, 1); + + zram->compress_workmem = NULL; + zram->compress_buffer = NULL; + + /* Free all pages that are still in this zram device */ + for (index = 0; index < zram->disksize >> PAGE_SHIFT; index++) { + unsigned long handle = zram->table[index].handle; + if (!handle) + continue; + + zs_free(zram->mem_pool, handle); + } + + vfree(zram->table); + zram->table = NULL; + + zs_destroy_pool(zram->mem_pool); + zram->mem_pool = NULL; + + /* Reset stats */ + memset(&zram->stats, 0, sizeof(zram->stats)); + + zram->disksize = 0; +} + +void zram_reset_device(struct zram *zram) +{ + down_write(&zram->init_lock); + __zram_reset_device(zram); + up_write(&zram->init_lock); +} + +int zram_init_device(struct zram *zram) +{ + int ret; + size_t num_pages; + + down_write(&zram->init_lock); + + if (zram->init_done) { + up_write(&zram->init_lock); + return 0; + } + + zram_set_disksize(zram, totalram_pages << PAGE_SHIFT); + + zram->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL); + if (!zram->compress_workmem) { + pr_err("Error allocating compressor working memory!\n"); + ret = -ENOMEM; + goto fail_no_table; + } + + zram->compress_buffer = + (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1); + if (!zram->compress_buffer) { + pr_err("Error allocating compressor buffer space\n"); + ret = -ENOMEM; + goto fail_no_table; + } + + num_pages = zram->disksize >> PAGE_SHIFT; + zram->table = vzalloc(num_pages * sizeof(*zram->table)); + if (!zram->table) { + pr_err("Error allocating zram address table\n"); + ret = -ENOMEM; + goto fail_no_table; + } + + set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); + + /* zram devices sort of resembles non-rotational disks */ + queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue); + + zram->mem_pool = zs_create_pool("zram", GFP_NOIO | __GFP_HIGHMEM); + if (!zram->mem_pool) { + pr_err("Error creating memory pool\n"); + ret = -ENOMEM; + goto fail; + } + + zram->init_done = 1; + up_write(&zram->init_lock); + + pr_debug("Initialization done!\n"); + return 0; + +fail_no_table: + /* To prevent accessing table entries during cleanup */ + zram->disksize = 0; +fail: + __zram_reset_device(zram); + up_write(&zram->init_lock); + pr_err("Initialization failed: err=%d\n", ret); + return ret; +} + +static void zram_slot_free_notify(struct block_device *bdev, + unsigned long index) +{ + struct zram *zram; + + zram = bdev->bd_disk->private_data; + zram_free_page(zram, index); + zram_stat64_inc(zram, &zram->stats.notify_free); +} + +static const struct block_device_operations zram_devops = { + .swap_slot_free_notify = zram_slot_free_notify, + .owner = THIS_MODULE +}; + +static int create_device(struct zram *zram, int device_id) +{ + int ret = 0; + + init_rwsem(&zram->lock); + init_rwsem(&zram->init_lock); + spin_lock_init(&zram->stat64_lock); + + zram->queue = blk_alloc_queue(GFP_KERNEL); + if (!zram->queue) { + pr_err("Error allocating disk queue for device %d\n", + device_id); + ret = -ENOMEM; + goto out; + } + + blk_queue_make_request(zram->queue, zram_make_request); + zram->queue->queuedata = zram; + + /* gendisk structure */ + zram->disk = alloc_disk(1); + if (!zram->disk) { + blk_cleanup_queue(zram->queue); + pr_warn("Error allocating disk structure for device %d\n", + device_id); + ret = -ENOMEM; + goto out; + } + + zram->disk->major = zram_major; + zram->disk->first_minor = device_id; + zram->disk->fops = &zram_devops; + zram->disk->queue = zram->queue; + zram->disk->private_data = zram; + snprintf(zram->disk->disk_name, 16, "zram%d", device_id); + + /* Actual capacity set using syfs (/sys/block/zram<id>/disksize */ + set_capacity(zram->disk, 0); + + /* + * To ensure that we always get PAGE_SIZE aligned + * and n*PAGE_SIZED sized I/O requests. + */ + blk_queue_physical_block_size(zram->disk->queue, PAGE_SIZE); + blk_queue_logical_block_size(zram->disk->queue, + ZRAM_LOGICAL_BLOCK_SIZE); + blk_queue_io_min(zram->disk->queue, PAGE_SIZE); + blk_queue_io_opt(zram->disk->queue, PAGE_SIZE); + + add_disk(zram->disk); + + ret = sysfs_create_group(&disk_to_dev(zram->disk)->kobj, + &zram_disk_attr_group); + if (ret < 0) { + pr_warn("Error creating sysfs group"); + goto out; + } + + zram->init_done = 0; + +out: + return ret; +} + +static void destroy_device(struct zram *zram) +{ + sysfs_remove_group(&disk_to_dev(zram->disk)->kobj, + &zram_disk_attr_group); + + if (zram->disk) { + del_gendisk(zram->disk); + put_disk(zram->disk); + } + + if (zram->queue) + blk_cleanup_queue(zram->queue); +} + +unsigned int zram_get_num_devices(void) +{ + return num_devices; +} + +static int __init zram_init(void) +{ + int ret, dev_id; + + if (num_devices > max_num_devices) { + pr_warn("Invalid value for num_devices: %u\n", + num_devices); + ret = -EINVAL; + goto out; + } + + zram_major = register_blkdev(0, "zram"); + if (zram_major <= 0) { + pr_warn("Unable to get major number\n"); + ret = -EBUSY; + goto out; + } + + if (!num_devices) { + pr_info("num_devices not specified. Using default: 1\n"); + num_devices = 1; + } + + /* Allocate the device array and initialize each one */ + pr_info("Creating %u devices ...\n", num_devices); + zram_devices = kzalloc(num_devices * sizeof(struct zram), GFP_KERNEL); + if (!zram_devices) { + ret = -ENOMEM; + goto unregister; + } + + for (dev_id = 0; dev_id < num_devices; dev_id++) { + ret = create_device(&zram_devices[dev_id], dev_id); + if (ret) + goto free_devices; + } + + return 0; + +free_devices: + while (dev_id) + destroy_device(&zram_devices[--dev_id]); + kfree(zram_devices); +unregister: + unregister_blkdev(zram_major, "zram"); +out: + return ret; +} + +static void __exit zram_exit(void) +{ + int i; + struct zram *zram; + + for (i = 0; i < num_devices; i++) { + zram = &zram_devices[i]; + + destroy_device(zram); + if (zram->init_done) + zram_reset_device(zram); + } + + unregister_blkdev(zram_major, "zram"); + + kfree(zram_devices); + pr_debug("Cleanup done!\n"); +} + +module_param(num_devices, uint, 0); +MODULE_PARM_DESC(num_devices, "Number of zram devices"); + +module_init(zram_init); +module_exit(zram_exit); + +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); +MODULE_DESCRIPTION("Compressed RAM Block Device"); diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h new file mode 100644 index 0000000..f6d0925 --- /dev/null +++ b/drivers/block/zram/zram_drv.h @@ -0,0 +1,119 @@ +/* + * Compressed RAM block device + * + * Copyright (C) 2008, 2009, 2010 Nitin Gupta + * + * This code is released using a dual license strategy: BSD/GPL + * You can choose the licence that better fits your requirements. + * + * Released under the terms of 3-clause BSD License + * Released under the terms of GNU General Public License Version 2.0 + * + * Project home: http://compcache.googlecode.com + */ + +#ifndef _ZRAM_DRV_H_ +#define _ZRAM_DRV_H_ + +#include <linux/spinlock.h> +#include <linux/mutex.h> +#include <linux/zsmalloc.h> + +/* + * Some arbitrary value. This is just to catch + * invalid value for num_devices module parameter. + */ +static const unsigned max_num_devices = 32; + +/*-- Configurable parameters */ + +/* Default zram disk size: 25% of total RAM */ +static const unsigned default_disksize_perc_ram = 25; + +/* + * Pages that compress to size greater than this are stored + * uncompressed in memory. + */ +static const size_t max_zpage_size = PAGE_SIZE / 4 * 3; + +/* + * NOTE: max_zpage_size must be less than or equal to: + * ZS_MAX_ALLOC_SIZE - sizeof(struct zobj_header) + * otherwise, xv_malloc() would always return failure. + */ + +/*-- End of configurable params */ + +#define SECTOR_SHIFT 9 +#define SECTOR_SIZE (1 << SECTOR_SHIFT) +#define SECTORS_PER_PAGE_SHIFT (PAGE_SHIFT - SECTOR_SHIFT) +#define SECTORS_PER_PAGE (1 << SECTORS_PER_PAGE_SHIFT) +#define ZRAM_LOGICAL_BLOCK_SHIFT 12 +#define ZRAM_LOGICAL_BLOCK_SIZE (1 << ZRAM_LOGICAL_BLOCK_SHIFT) +#define ZRAM_SECTOR_PER_LOGICAL_BLOCK \ + (1 << (ZRAM_LOGICAL_BLOCK_SHIFT - SECTOR_SHIFT)) + +/* Flags for zram pages (table[page_no].flags) */ +enum zram_pageflags { + /* Page consists entirely of zeros */ + ZRAM_ZERO, + + __NR_ZRAM_PAGEFLAGS, +}; + +/*-- Data structures */ + +/* Allocated for each disk page */ +struct table { + unsigned long handle; + u16 size; /* object size (excluding header) */ + u8 count; /* object ref count (not yet used) */ + u8 flags; +} __aligned(4); + +struct zram_stats { + u64 compr_size; /* compressed size of pages stored */ + u64 num_reads; /* failed + successful */ + u64 num_writes; /* --do-- */ + u64 failed_reads; /* should NEVER! happen */ + u64 failed_writes; /* can happen when memory is too low */ + u64 invalid_io; /* non-page-aligned I/O requests */ + u64 notify_free; /* no. of swap slot free notifications */ + u32 pages_zero; /* no. of zero filled pages */ + u32 pages_stored; /* no. of pages currently stored */ + u32 good_compress; /* % of pages with compression ratio<=50% */ + u32 bad_compress; /* % of pages with compression ratio>=75% */ +}; + +struct zram { + struct zs_pool *mem_pool; + void *compress_workmem; + void *compress_buffer; + struct table *table; + spinlock_t stat64_lock; /* protect 64-bit stats */ + struct rw_semaphore lock; /* protect compression buffers and table + * against concurrent read and writes */ + struct request_queue *queue; + struct gendisk *disk; + int init_done; + /* Prevent concurrent execution of device init, reset and R/W request */ + struct rw_semaphore init_lock; + /* + * This is the limit on amount of *uncompressed* worth of data + * we can store in a disk. + */ + u64 disksize; /* bytes */ + + struct zram_stats stats; +}; + +extern struct zram *zram_devices; +unsigned int zram_get_num_devices(void); +#ifdef CONFIG_SYSFS +extern struct attribute_group zram_disk_attr_group; +#endif + +extern int zram_init_device(struct zram *zram); +extern void __zram_reset_device(struct zram *zram); + +#endif diff --git a/drivers/block/zram/zram_sysfs.c b/drivers/block/zram/zram_sysfs.c new file mode 100644 index 0000000..edb0ed4 --- /dev/null +++ b/drivers/block/zram/zram_sysfs.c @@ -0,0 +1,225 @@ +/* + * Compressed RAM block device + * + * Copyright (C) 2008, 2009, 2010 Nitin Gupta + * + * This code is released using a dual license strategy: BSD/GPL + * You can choose the licence that better fits your requirements. + * + * Released under the terms of 3-clause BSD License + * Released under the terms of GNU General Public License Version 2.0 + * + * Project home: http://compcache.googlecode.com/ + */ + +#include <linux/device.h> +#include <linux/genhd.h> +#include <linux/mm.h> + +#include "zram_drv.h" + +static u64 zram_stat64_read(struct zram *zram, u64 *v) +{ + u64 val; + + spin_lock(&zram->stat64_lock); + val = *v; + spin_unlock(&zram->stat64_lock); + + return val; +} + +static struct zram *dev_to_zram(struct device *dev) +{ + int i; + struct zram *zram = NULL; + + for (i = 0; i < zram_get_num_devices(); i++) { + zram = &zram_devices[i]; + if (disk_to_dev(zram->disk) == dev) + break; + } + + return zram; +} + +static ssize_t disksize_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", zram->disksize); +} + +static ssize_t disksize_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + int ret; + u64 disksize; + struct zram *zram = dev_to_zram(dev); + + ret = kstrtoull(buf, 10, &disksize); + if (ret) + return ret; + + down_write(&zram->init_lock); + if (zram->init_done) { + up_write(&zram->init_lock); + pr_info("Cannot change disksize for initialized device\n"); + return -EBUSY; + } + + zram->disksize = PAGE_ALIGN(disksize); + set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); + up_write(&zram->init_lock); + + return len; +} + +static ssize_t initstate_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%u\n", zram->init_done); +} + +static ssize_t reset_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + int ret; + unsigned short do_reset; + struct zram *zram; + struct block_device *bdev; + + zram = dev_to_zram(dev); + bdev = bdget_disk(zram->disk, 0); + + /* Do not reset an active device! */ + if (bdev->bd_holders) + return -EBUSY; + + ret = kstrtou16(buf, 10, &do_reset); + if (ret) + return ret; + + if (!do_reset) + return -EINVAL; + + /* Make sure all pending I/O is finished */ + if (bdev) + fsync_bdev(bdev); + + down_write(&zram->init_lock); + if (zram->init_done) + __zram_reset_device(zram); + up_write(&zram->init_lock); + + return len; +} + +static ssize_t num_reads_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + zram_stat64_read(zram, &zram->stats.num_reads)); +} + +static ssize_t num_writes_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + zram_stat64_read(zram, &zram->stats.num_writes)); +} + +static ssize_t invalid_io_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + zram_stat64_read(zram, &zram->stats.invalid_io)); +} + +static ssize_t notify_free_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + zram_stat64_read(zram, &zram->stats.notify_free)); +} + +static ssize_t zero_pages_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%u\n", zram->stats.pages_zero); +} + +static ssize_t orig_data_size_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + (u64)(zram->stats.pages_stored) << PAGE_SHIFT); +} + +static ssize_t compr_data_size_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + zram_stat64_read(zram, &zram->stats.compr_size)); +} + +static ssize_t mem_used_total_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + u64 val = 0; + struct zram *zram = dev_to_zram(dev); + + if (zram->init_done) + val = zs_get_total_size_bytes(zram->mem_pool); + + return sprintf(buf, "%llu\n", val); +} + +static DEVICE_ATTR(disksize, S_IRUGO | S_IWUSR, + disksize_show, disksize_store); +static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL); +static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store); +static DEVICE_ATTR(num_reads, S_IRUGO, num_reads_show, NULL); +static DEVICE_ATTR(num_writes, S_IRUGO, num_writes_show, NULL); +static DEVICE_ATTR(invalid_io, S_IRUGO, invalid_io_show, NULL); +static DEVICE_ATTR(notify_free, S_IRUGO, notify_free_show, NULL); +static DEVICE_ATTR(zero_pages, S_IRUGO, zero_pages_show, NULL); +static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL); +static DEVICE_ATTR(compr_data_size, S_IRUGO, compr_data_size_show, NULL); +static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL); + +static struct attribute *zram_disk_attrs[] = { + &dev_attr_disksize.attr, + &dev_attr_initstate.attr, + &dev_attr_reset.attr, + &dev_attr_num_reads.attr, + &dev_attr_num_writes.attr, + &dev_attr_invalid_io.attr, + &dev_attr_notify_free.attr, + &dev_attr_zero_pages.attr, + &dev_attr_orig_data_size.attr, + &dev_attr_compr_data_size.attr, + &dev_attr_mem_used_total.attr, + NULL, +}; + +struct attribute_group zram_disk_attr_group = { + .attrs = zram_disk_attrs, +}; diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig index 4316ef5..9fc23d9 100644 --- a/drivers/staging/Kconfig +++ b/drivers/staging/Kconfig @@ -74,8 +74,6 @@ source "drivers/staging/sep/Kconfig" source "drivers/staging/iio/Kconfig" -source "drivers/staging/zram/Kconfig" - source "drivers/staging/zcache/Kconfig" source "drivers/staging/wlags49_h2/Kconfig" diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile index db18726..3aee49a 100644 --- a/drivers/staging/Makefile +++ b/drivers/staging/Makefile @@ -32,7 +32,6 @@ obj-$(CONFIG_VME_BUS) += vme/ obj-$(CONFIG_IPACK_BUS) += ipack/ obj-$(CONFIG_DX_SEP) += sep/ obj-$(CONFIG_IIO) += iio/ -obj-$(CONFIG_ZRAM) += zram/ obj-$(CONFIG_ZCACHE) += zcache/ obj-$(CONFIG_WLAGS49_H2) += wlags49_h2/ obj-$(CONFIG_WLAGS49_H25) += wlags49_h25/ diff --git a/drivers/staging/zram/Kconfig b/drivers/staging/zram/Kconfig deleted file mode 100644 index be5abe8..0000000 --- a/drivers/staging/zram/Kconfig +++ /dev/null @@ -1,25 +0,0 @@ -config ZRAM - tristate "Compressed RAM block device support" - depends on BLOCK && SYSFS && ZSMALLOC - select LZO_COMPRESS - select LZO_DECOMPRESS - default n - help - Creates virtual block devices called /dev/zramX (X = 0, 1, ...). - Pages written to these disks are compressed and stored in memory - itself. These disks allow very fast I/O and compression provides - good amounts of memory savings. - - It has several use cases, for example: /tmp storage, use as swap - disks and maybe many more. - - See zram.txt for more information. - Project home: http://compcache.googlecode.com/ - -config ZRAM_DEBUG - bool "Compressed RAM block device debug support" - depends on ZRAM - default n - help - This option adds additional debugging code to the compressed - RAM block device driver. diff --git a/drivers/staging/zram/Makefile b/drivers/staging/zram/Makefile deleted file mode 100644 index 7f4a301..0000000 --- a/drivers/staging/zram/Makefile +++ /dev/null @@ -1,3 +0,0 @@ -zram-y := zram_drv.o zram_sysfs.o - -obj-$(CONFIG_ZRAM) += zram.o diff --git a/drivers/staging/zram/zram.txt b/drivers/staging/zram/zram.txt deleted file mode 100644 index 5f75d29..0000000 --- a/drivers/staging/zram/zram.txt +++ /dev/null @@ -1,76 +0,0 @@ -zram: Compressed RAM based block devices ----------------------------------------- - -Project home: http://compcache.googlecode.com/ - -* Introduction - -The zram module creates RAM based block devices named /dev/zram<id> -(<id> = 0, 1, ...). Pages written to these disks are compressed and stored -in memory itself. These disks allow very fast I/O and compression provides -good amounts of memory savings. Some of the usecases include /tmp storage, -use as swap disks, various caches under /var and maybe many more :) - -Statistics for individual zram devices are exported through sysfs nodes at -/sys/block/zram<id>/ - -* Usage - -Following shows a typical sequence of steps for using zram. - -1) Load Module: - modprobe zram num_devices=4 - This creates 4 devices: /dev/zram{0,1,2,3} - (num_devices parameter is optional. Default: 1) - -2) Set Disksize (Optional): - Set disk size by writing the value to sysfs node 'disksize' - (in bytes). If disksize is not given, default value of 25% - of RAM is used. - - # Initialize /dev/zram0 with 50MB disksize - echo $((50*1024*1024)) > /sys/block/zram0/disksize - - NOTE: disksize cannot be changed if the disk contains any - data. So, for such a disk, you need to issue 'reset' (see below) - before you can change its disksize. - -3) Activate: - mkswap /dev/zram0 - swapon /dev/zram0 - - mkfs.ext4 /dev/zram1 - mount /dev/zram1 /tmp - -4) Stats: - Per-device statistics are exported as various nodes under - /sys/block/zram<id>/ - disksize - num_reads - num_writes - invalid_io - notify_free - discard - zero_pages - orig_data_size - compr_data_size - mem_used_total - -5) Deactivate: - swapoff /dev/zram0 - umount /dev/zram1 - -6) Reset: - Write any positive value to 'reset' sysfs node - echo 1 > /sys/block/zram0/reset - echo 1 > /sys/block/zram1/reset - - (This frees all the memory allocated for the given device). - - -Please report any problems at: - - Mailing list: linux-mm-cc at laptop dot org - - Issue tracker: http://code.google.com/p/compcache/issues/list - -Nitin Gupta -ngupta@vflare.org diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c deleted file mode 100644 index 653b074..0000000 --- a/drivers/staging/zram/zram_drv.c +++ /dev/null @@ -1,785 +0,0 @@ -/* - * Compressed RAM block device - * - * Copyright (C) 2008, 2009, 2010 Nitin Gupta - * - * This code is released using a dual license strategy: BSD/GPL - * You can choose the licence that better fits your requirements. - * - * Released under the terms of 3-clause BSD License - * Released under the terms of GNU General Public License Version 2.0 - * - * Project home: http://compcache.googlecode.com - */ - -#define KMSG_COMPONENT "zram" -#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt - -#ifdef CONFIG_ZRAM_DEBUG -#define DEBUG -#endif - -#include <linux/module.h> -#include <linux/kernel.h> -#include <linux/bio.h> -#include <linux/bitops.h> -#include <linux/blkdev.h> -#include <linux/buffer_head.h> -#include <linux/device.h> -#include <linux/genhd.h> -#include <linux/highmem.h> -#include <linux/slab.h> -#include <linux/lzo.h> -#include <linux/string.h> -#include <linux/vmalloc.h> - -#include "zram_drv.h" - -/* Globals */ -static int zram_major; -struct zram *zram_devices; - -/* Module params (documentation at end) */ -static unsigned int num_devices; - -static void zram_stat_inc(u32 *v) -{ - *v = *v + 1; -} - -static void zram_stat_dec(u32 *v) -{ - *v = *v - 1; -} - -static void zram_stat64_add(struct zram *zram, u64 *v, u64 inc) -{ - spin_lock(&zram->stat64_lock); - *v = *v + inc; - spin_unlock(&zram->stat64_lock); -} - -static void zram_stat64_sub(struct zram *zram, u64 *v, u64 dec) -{ - spin_lock(&zram->stat64_lock); - *v = *v - dec; - spin_unlock(&zram->stat64_lock); -} - -static void zram_stat64_inc(struct zram *zram, u64 *v) -{ - zram_stat64_add(zram, v, 1); -} - -static int zram_test_flag(struct zram *zram, u32 index, - enum zram_pageflags flag) -{ - return zram->table[index].flags & BIT(flag); -} - -static void zram_set_flag(struct zram *zram, u32 index, - enum zram_pageflags flag) -{ - zram->table[index].flags |= BIT(flag); -} - -static void zram_clear_flag(struct zram *zram, u32 index, - enum zram_pageflags flag) -{ - zram->table[index].flags &= ~BIT(flag); -} - -static int page_zero_filled(void *ptr) -{ - unsigned int pos; - unsigned long *page; - - page = (unsigned long *)ptr; - - for (pos = 0; pos != PAGE_SIZE / sizeof(*page); pos++) { - if (page[pos]) - return 0; - } - - return 1; -} - -static void zram_set_disksize(struct zram *zram, size_t totalram_bytes) -{ - if (!zram->disksize) { - pr_info( - "disk size not provided. You can use disksize_kb module " - "param to specify size.\nUsing default: (%u%% of RAM).\n", - default_disksize_perc_ram - ); - zram->disksize = default_disksize_perc_ram * - (totalram_bytes / 100); - } - - if (zram->disksize > 2 * (totalram_bytes)) { - pr_info( - "There is little point creating a zram of greater than " - "twice the size of memory since we expect a 2:1 compression " - "ratio. Note that zram uses about 0.1%% of the size of " - "the disk when not in use so a huge zram is " - "wasteful.\n" - "\tMemory Size: %zu kB\n" - "\tSize you selected: %llu kB\n" - "Continuing anyway ...\n", - totalram_bytes >> 10, zram->disksize - ); - } - - zram->disksize &= PAGE_MASK; -} - -static void zram_free_page(struct zram *zram, size_t index) -{ - unsigned long handle = zram->table[index].handle; - u16 size = zram->table[index].size; - - if (unlikely(!handle)) { - /* - * No memory is allocated for zero filled pages. - * Simply clear zero page flag. - */ - if (zram_test_flag(zram, index, ZRAM_ZERO)) { - zram_clear_flag(zram, index, ZRAM_ZERO); - zram_stat_dec(&zram->stats.pages_zero); - } - return; - } - - if (unlikely(size > max_zpage_size)) - zram_stat_dec(&zram->stats.bad_compress); - - zs_free(zram->mem_pool, handle); - - if (size <= PAGE_SIZE / 2) - zram_stat_dec(&zram->stats.good_compress); - - zram_stat64_sub(zram, &zram->stats.compr_size, - zram->table[index].size); - zram_stat_dec(&zram->stats.pages_stored); - - zram->table[index].handle = 0; - zram->table[index].size = 0; -} - -static void handle_zero_page(struct bio_vec *bvec) -{ - struct page *page = bvec->bv_page; - void *user_mem; - - user_mem = kmap_atomic(page); - memset(user_mem + bvec->bv_offset, 0, bvec->bv_len); - kunmap_atomic(user_mem); - - flush_dcache_page(page); -} - -static inline int is_partial_io(struct bio_vec *bvec) -{ - return bvec->bv_len != PAGE_SIZE; -} - -static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, - u32 index, int offset, struct bio *bio) -{ - int ret; - size_t clen; - struct page *page; - unsigned char *user_mem, *cmem, *uncmem = NULL; - - page = bvec->bv_page; - - if (zram_test_flag(zram, index, ZRAM_ZERO)) { - handle_zero_page(bvec); - return 0; - } - - /* Requested page is not present in compressed area */ - if (unlikely(!zram->table[index].handle)) { - pr_debug("Read before write: sector=%lu, size=%u", - (ulong)(bio->bi_sector), bio->bi_size); - handle_zero_page(bvec); - return 0; - } - - if (is_partial_io(bvec)) { - /* Use a temporary buffer to decompress the page */ - uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!uncmem) { - pr_info("Error allocating temp memory!\n"); - return -ENOMEM; - } - } - - user_mem = kmap_atomic(page); - if (!is_partial_io(bvec)) - uncmem = user_mem; - clen = PAGE_SIZE; - - cmem = zs_map_object(zram->mem_pool, zram->table[index].handle, - ZS_MM_RO); - - ret = lzo1x_decompress_safe(cmem, zram->table[index].size, - uncmem, &clen); - - if (is_partial_io(bvec)) { - memcpy(user_mem + bvec->bv_offset, uncmem + offset, - bvec->bv_len); - kfree(uncmem); - } - - zs_unmap_object(zram->mem_pool, zram->table[index].handle); - kunmap_atomic(user_mem); - - /* Should NEVER happen. Return bio error if it does. */ - if (unlikely(ret != LZO_E_OK)) { - pr_err("Decompression failed! err=%d, page=%u\n", ret, index); - zram_stat64_inc(zram, &zram->stats.failed_reads); - return ret; - } - - flush_dcache_page(page); - - return 0; -} - -static int zram_read_before_write(struct zram *zram, char *mem, u32 index) -{ - int ret; - size_t clen = PAGE_SIZE; - unsigned char *cmem; - unsigned long handle = zram->table[index].handle; - - if (zram_test_flag(zram, index, ZRAM_ZERO) || !handle) { - memset(mem, 0, PAGE_SIZE); - return 0; - } - - cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_RO); - ret = lzo1x_decompress_safe(cmem, zram->table[index].size, - mem, &clen); - zs_unmap_object(zram->mem_pool, handle); - - /* Should NEVER happen. Return bio error if it does. */ - if (unlikely(ret != LZO_E_OK)) { - pr_err("Decompression failed! err=%d, page=%u\n", ret, index); - zram_stat64_inc(zram, &zram->stats.failed_reads); - return ret; - } - - return 0; -} - -static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, - int offset) -{ - int ret; - size_t clen; - unsigned long handle; - struct page *page; - unsigned char *user_mem, *cmem, *src, *uncmem = NULL; - - page = bvec->bv_page; - src = zram->compress_buffer; - - if (is_partial_io(bvec)) { - /* - * This is a partial IO. We need to read the full page - * before to write the changes. - */ - uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!uncmem) { - pr_info("Error allocating temp memory!\n"); - ret = -ENOMEM; - goto out; - } - ret = zram_read_before_write(zram, uncmem, index); - if (ret) { - kfree(uncmem); - goto out; - } - } - - /* - * System overwrites unused sectors. Free memory associated - * with this sector now. - */ - if (zram->table[index].handle || - zram_test_flag(zram, index, ZRAM_ZERO)) - zram_free_page(zram, index); - - user_mem = kmap_atomic(page); - - if (is_partial_io(bvec)) - memcpy(uncmem + offset, user_mem + bvec->bv_offset, - bvec->bv_len); - else - uncmem = user_mem; - - if (page_zero_filled(uncmem)) { - kunmap_atomic(user_mem); - if (is_partial_io(bvec)) - kfree(uncmem); - zram_stat_inc(&zram->stats.pages_zero); - zram_set_flag(zram, index, ZRAM_ZERO); - ret = 0; - goto out; - } - - ret = lzo1x_1_compress(uncmem, PAGE_SIZE, src, &clen, - zram->compress_workmem); - - kunmap_atomic(user_mem); - if (is_partial_io(bvec)) - kfree(uncmem); - - if (unlikely(ret != LZO_E_OK)) { - pr_err("Compression failed! err=%d\n", ret); - goto out; - } - - if (unlikely(clen > max_zpage_size)) - zram_stat_inc(&zram->stats.bad_compress); - - handle = zs_malloc(zram->mem_pool, clen); - if (!handle) { - pr_info("Error allocating memory for compressed " - "page: %u, size=%zu\n", index, clen); - ret = -ENOMEM; - goto out; - } - cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_WO); - - memcpy(cmem, src, clen); - - zs_unmap_object(zram->mem_pool, handle); - - zram->table[index].handle = handle; - zram->table[index].size = clen; - - /* Update stats */ - zram_stat64_add(zram, &zram->stats.compr_size, clen); - zram_stat_inc(&zram->stats.pages_stored); - if (clen <= PAGE_SIZE / 2) - zram_stat_inc(&zram->stats.good_compress); - - return 0; - -out: - if (ret) - zram_stat64_inc(zram, &zram->stats.failed_writes); - return ret; -} - -static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index, - int offset, struct bio *bio, int rw) -{ - int ret; - - if (rw == READ) { - down_read(&zram->lock); - ret = zram_bvec_read(zram, bvec, index, offset, bio); - up_read(&zram->lock); - } else { - down_write(&zram->lock); - ret = zram_bvec_write(zram, bvec, index, offset); - up_write(&zram->lock); - } - - return ret; -} - -static void update_position(u32 *index, int *offset, struct bio_vec *bvec) -{ - if (*offset + bvec->bv_len >= PAGE_SIZE) - (*index)++; - *offset = (*offset + bvec->bv_len) % PAGE_SIZE; -} - -static void __zram_make_request(struct zram *zram, struct bio *bio, int rw) -{ - int i, offset; - u32 index; - struct bio_vec *bvec; - - switch (rw) { - case READ: - zram_stat64_inc(zram, &zram->stats.num_reads); - break; - case WRITE: - zram_stat64_inc(zram, &zram->stats.num_writes); - break; - } - - index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT; - offset = (bio->bi_sector & (SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT; - - bio_for_each_segment(bvec, bio, i) { - int max_transfer_size = PAGE_SIZE - offset; - - if (bvec->bv_len > max_transfer_size) { - /* - * zram_bvec_rw() can only make operation on a single - * zram page. Split the bio vector. - */ - struct bio_vec bv; - - bv.bv_page = bvec->bv_page; - bv.bv_len = max_transfer_size; - bv.bv_offset = bvec->bv_offset; - - if (zram_bvec_rw(zram, &bv, index, offset, bio, rw) < 0) - goto out; - - bv.bv_len = bvec->bv_len - max_transfer_size; - bv.bv_offset += max_transfer_size; - if (zram_bvec_rw(zram, &bv, index+1, 0, bio, rw) < 0) - goto out; - } else - if (zram_bvec_rw(zram, bvec, index, offset, bio, rw) - < 0) - goto out; - - update_position(&index, &offset, bvec); - } - - set_bit(BIO_UPTODATE, &bio->bi_flags); - bio_endio(bio, 0); - return; - -out: - bio_io_error(bio); -} - -/* - * Check if request is within bounds and aligned on zram logical blocks. - */ -static inline int valid_io_request(struct zram *zram, struct bio *bio) -{ - if (unlikely( - (bio->bi_sector >= (zram->disksize >> SECTOR_SHIFT)) || - (bio->bi_sector & (ZRAM_SECTOR_PER_LOGICAL_BLOCK - 1)) || - (bio->bi_size & (ZRAM_LOGICAL_BLOCK_SIZE - 1)))) { - - return 0; - } - - /* I/O request is valid */ - return 1; -} - -/* - * Handler function for all zram I/O requests. - */ -static void zram_make_request(struct request_queue *queue, struct bio *bio) -{ - struct zram *zram = queue->queuedata; - - if (unlikely(!zram->init_done) && zram_init_device(zram)) - goto error; - - down_read(&zram->init_lock); - if (unlikely(!zram->init_done)) - goto error_unlock; - - if (!valid_io_request(zram, bio)) { - zram_stat64_inc(zram, &zram->stats.invalid_io); - goto error_unlock; - } - - __zram_make_request(zram, bio, bio_data_dir(bio)); - up_read(&zram->init_lock); - - return; - -error_unlock: - up_read(&zram->init_lock); -error: - bio_io_error(bio); -} - -void __zram_reset_device(struct zram *zram) -{ - size_t index; - - zram->init_done = 0; - - /* Free various per-device buffers */ - kfree(zram->compress_workmem); - free_pages((unsigned long)zram->compress_buffer, 1); - - zram->compress_workmem = NULL; - zram->compress_buffer = NULL; - - /* Free all pages that are still in this zram device */ - for (index = 0; index < zram->disksize >> PAGE_SHIFT; index++) { - unsigned long handle = zram->table[index].handle; - if (!handle) - continue; - - zs_free(zram->mem_pool, handle); - } - - vfree(zram->table); - zram->table = NULL; - - zs_destroy_pool(zram->mem_pool); - zram->mem_pool = NULL; - - /* Reset stats */ - memset(&zram->stats, 0, sizeof(zram->stats)); - - zram->disksize = 0; -} - -void zram_reset_device(struct zram *zram) -{ - down_write(&zram->init_lock); - __zram_reset_device(zram); - up_write(&zram->init_lock); -} - -int zram_init_device(struct zram *zram) -{ - int ret; - size_t num_pages; - - down_write(&zram->init_lock); - - if (zram->init_done) { - up_write(&zram->init_lock); - return 0; - } - - zram_set_disksize(zram, totalram_pages << PAGE_SHIFT); - - zram->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL); - if (!zram->compress_workmem) { - pr_err("Error allocating compressor working memory!\n"); - ret = -ENOMEM; - goto fail_no_table; - } - - zram->compress_buffer = - (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1); - if (!zram->compress_buffer) { - pr_err("Error allocating compressor buffer space\n"); - ret = -ENOMEM; - goto fail_no_table; - } - - num_pages = zram->disksize >> PAGE_SHIFT; - zram->table = vzalloc(num_pages * sizeof(*zram->table)); - if (!zram->table) { - pr_err("Error allocating zram address table\n"); - ret = -ENOMEM; - goto fail_no_table; - } - - set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); - - /* zram devices sort of resembles non-rotational disks */ - queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue); - - zram->mem_pool = zs_create_pool("zram", GFP_NOIO | __GFP_HIGHMEM); - if (!zram->mem_pool) { - pr_err("Error creating memory pool\n"); - ret = -ENOMEM; - goto fail; - } - - zram->init_done = 1; - up_write(&zram->init_lock); - - pr_debug("Initialization done!\n"); - return 0; - -fail_no_table: - /* To prevent accessing table entries during cleanup */ - zram->disksize = 0; -fail: - __zram_reset_device(zram); - up_write(&zram->init_lock); - pr_err("Initialization failed: err=%d\n", ret); - return ret; -} - -static void zram_slot_free_notify(struct block_device *bdev, - unsigned long index) -{ - struct zram *zram; - - zram = bdev->bd_disk->private_data; - zram_free_page(zram, index); - zram_stat64_inc(zram, &zram->stats.notify_free); -} - -static const struct block_device_operations zram_devops = { - .swap_slot_free_notify = zram_slot_free_notify, - .owner = THIS_MODULE -}; - -static int create_device(struct zram *zram, int device_id) -{ - int ret = 0; - - init_rwsem(&zram->lock); - init_rwsem(&zram->init_lock); - spin_lock_init(&zram->stat64_lock); - - zram->queue = blk_alloc_queue(GFP_KERNEL); - if (!zram->queue) { - pr_err("Error allocating disk queue for device %d\n", - device_id); - ret = -ENOMEM; - goto out; - } - - blk_queue_make_request(zram->queue, zram_make_request); - zram->queue->queuedata = zram; - - /* gendisk structure */ - zram->disk = alloc_disk(1); - if (!zram->disk) { - blk_cleanup_queue(zram->queue); - pr_warn("Error allocating disk structure for device %d\n", - device_id); - ret = -ENOMEM; - goto out; - } - - zram->disk->major = zram_major; - zram->disk->first_minor = device_id; - zram->disk->fops = &zram_devops; - zram->disk->queue = zram->queue; - zram->disk->private_data = zram; - snprintf(zram->disk->disk_name, 16, "zram%d", device_id); - - /* Actual capacity set using syfs (/sys/block/zram<id>/disksize */ - set_capacity(zram->disk, 0); - - /* - * To ensure that we always get PAGE_SIZE aligned - * and n*PAGE_SIZED sized I/O requests. - */ - blk_queue_physical_block_size(zram->disk->queue, PAGE_SIZE); - blk_queue_logical_block_size(zram->disk->queue, - ZRAM_LOGICAL_BLOCK_SIZE); - blk_queue_io_min(zram->disk->queue, PAGE_SIZE); - blk_queue_io_opt(zram->disk->queue, PAGE_SIZE); - - add_disk(zram->disk); - - ret = sysfs_create_group(&disk_to_dev(zram->disk)->kobj, - &zram_disk_attr_group); - if (ret < 0) { - pr_warn("Error creating sysfs group"); - goto out; - } - - zram->init_done = 0; - -out: - return ret; -} - -static void destroy_device(struct zram *zram) -{ - sysfs_remove_group(&disk_to_dev(zram->disk)->kobj, - &zram_disk_attr_group); - - if (zram->disk) { - del_gendisk(zram->disk); - put_disk(zram->disk); - } - - if (zram->queue) - blk_cleanup_queue(zram->queue); -} - -unsigned int zram_get_num_devices(void) -{ - return num_devices; -} - -static int __init zram_init(void) -{ - int ret, dev_id; - - if (num_devices > max_num_devices) { - pr_warn("Invalid value for num_devices: %u\n", - num_devices); - ret = -EINVAL; - goto out; - } - - zram_major = register_blkdev(0, "zram"); - if (zram_major <= 0) { - pr_warn("Unable to get major number\n"); - ret = -EBUSY; - goto out; - } - - if (!num_devices) { - pr_info("num_devices not specified. Using default: 1\n"); - num_devices = 1; - } - - /* Allocate the device array and initialize each one */ - pr_info("Creating %u devices ...\n", num_devices); - zram_devices = kzalloc(num_devices * sizeof(struct zram), GFP_KERNEL); - if (!zram_devices) { - ret = -ENOMEM; - goto unregister; - } - - for (dev_id = 0; dev_id < num_devices; dev_id++) { - ret = create_device(&zram_devices[dev_id], dev_id); - if (ret) - goto free_devices; - } - - return 0; - -free_devices: - while (dev_id) - destroy_device(&zram_devices[--dev_id]); - kfree(zram_devices); -unregister: - unregister_blkdev(zram_major, "zram"); -out: - return ret; -} - -static void __exit zram_exit(void) -{ - int i; - struct zram *zram; - - for (i = 0; i < num_devices; i++) { - zram = &zram_devices[i]; - - destroy_device(zram); - if (zram->init_done) - zram_reset_device(zram); - } - - unregister_blkdev(zram_major, "zram"); - - kfree(zram_devices); - pr_debug("Cleanup done!\n"); -} - -module_param(num_devices, uint, 0); -MODULE_PARM_DESC(num_devices, "Number of zram devices"); - -module_init(zram_init); -module_exit(zram_exit); - -MODULE_LICENSE("Dual BSD/GPL"); -MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); -MODULE_DESCRIPTION("Compressed RAM Block Device"); diff --git a/drivers/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h deleted file mode 100644 index f6d0925..0000000 --- a/drivers/staging/zram/zram_drv.h +++ /dev/null @@ -1,119 +0,0 @@ -/* - * Compressed RAM block device - * - * Copyright (C) 2008, 2009, 2010 Nitin Gupta - * - * This code is released using a dual license strategy: BSD/GPL - * You can choose the licence that better fits your requirements. - * - * Released under the terms of 3-clause BSD License - * Released under the terms of GNU General Public License Version 2.0 - * - * Project home: http://compcache.googlecode.com - */ - -#ifndef _ZRAM_DRV_H_ -#define _ZRAM_DRV_H_ - -#include <linux/spinlock.h> -#include <linux/mutex.h> -#include <linux/zsmalloc.h> - -/* - * Some arbitrary value. This is just to catch - * invalid value for num_devices module parameter. - */ -static const unsigned max_num_devices = 32; - -/*-- Configurable parameters */ - -/* Default zram disk size: 25% of total RAM */ -static const unsigned default_disksize_perc_ram = 25; - -/* - * Pages that compress to size greater than this are stored - * uncompressed in memory. - */ -static const size_t max_zpage_size = PAGE_SIZE / 4 * 3; - -/* - * NOTE: max_zpage_size must be less than or equal to: - * ZS_MAX_ALLOC_SIZE - sizeof(struct zobj_header) - * otherwise, xv_malloc() would always return failure. - */ - -/*-- End of configurable params */ - -#define SECTOR_SHIFT 9 -#define SECTOR_SIZE (1 << SECTOR_SHIFT) -#define SECTORS_PER_PAGE_SHIFT (PAGE_SHIFT - SECTOR_SHIFT) -#define SECTORS_PER_PAGE (1 << SECTORS_PER_PAGE_SHIFT) -#define ZRAM_LOGICAL_BLOCK_SHIFT 12 -#define ZRAM_LOGICAL_BLOCK_SIZE (1 << ZRAM_LOGICAL_BLOCK_SHIFT) -#define ZRAM_SECTOR_PER_LOGICAL_BLOCK \ - (1 << (ZRAM_LOGICAL_BLOCK_SHIFT - SECTOR_SHIFT)) - -/* Flags for zram pages (table[page_no].flags) */ -enum zram_pageflags { - /* Page consists entirely of zeros */ - ZRAM_ZERO, - - __NR_ZRAM_PAGEFLAGS, -}; - -/*-- Data structures */ - -/* Allocated for each disk page */ -struct table { - unsigned long handle; - u16 size; /* object size (excluding header) */ - u8 count; /* object ref count (not yet used) */ - u8 flags; -} __aligned(4); - -struct zram_stats { - u64 compr_size; /* compressed size of pages stored */ - u64 num_reads; /* failed + successful */ - u64 num_writes; /* --do-- */ - u64 failed_reads; /* should NEVER! happen */ - u64 failed_writes; /* can happen when memory is too low */ - u64 invalid_io; /* non-page-aligned I/O requests */ - u64 notify_free; /* no. of swap slot free notifications */ - u32 pages_zero; /* no. of zero filled pages */ - u32 pages_stored; /* no. of pages currently stored */ - u32 good_compress; /* % of pages with compression ratio<=50% */ - u32 bad_compress; /* % of pages with compression ratio>=75% */ -}; - -struct zram { - struct zs_pool *mem_pool; - void *compress_workmem; - void *compress_buffer; - struct table *table; - spinlock_t stat64_lock; /* protect 64-bit stats */ - struct rw_semaphore lock; /* protect compression buffers and table - * against concurrent read and writes */ - struct request_queue *queue; - struct gendisk *disk; - int init_done; - /* Prevent concurrent execution of device init, reset and R/W request */ - struct rw_semaphore init_lock; - /* - * This is the limit on amount of *uncompressed* worth of data - * we can store in a disk. - */ - u64 disksize; /* bytes */ - - struct zram_stats stats; -}; - -extern struct zram *zram_devices; -unsigned int zram_get_num_devices(void); -#ifdef CONFIG_SYSFS -extern struct attribute_group zram_disk_attr_group; -#endif - -extern int zram_init_device(struct zram *zram); -extern void __zram_reset_device(struct zram *zram); - -#endif diff --git a/drivers/staging/zram/zram_sysfs.c b/drivers/staging/zram/zram_sysfs.c deleted file mode 100644 index edb0ed4..0000000 --- a/drivers/staging/zram/zram_sysfs.c +++ /dev/null @@ -1,225 +0,0 @@ -/* - * Compressed RAM block device - * - * Copyright (C) 2008, 2009, 2010 Nitin Gupta - * - * This code is released using a dual license strategy: BSD/GPL - * You can choose the licence that better fits your requirements. - * - * Released under the terms of 3-clause BSD License - * Released under the terms of GNU General Public License Version 2.0 - * - * Project home: http://compcache.googlecode.com/ - */ - -#include <linux/device.h> -#include <linux/genhd.h> -#include <linux/mm.h> - -#include "zram_drv.h" - -static u64 zram_stat64_read(struct zram *zram, u64 *v) -{ - u64 val; - - spin_lock(&zram->stat64_lock); - val = *v; - spin_unlock(&zram->stat64_lock); - - return val; -} - -static struct zram *dev_to_zram(struct device *dev) -{ - int i; - struct zram *zram = NULL; - - for (i = 0; i < zram_get_num_devices(); i++) { - zram = &zram_devices[i]; - if (disk_to_dev(zram->disk) == dev) - break; - } - - return zram; -} - -static ssize_t disksize_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%llu\n", zram->disksize); -} - -static ssize_t disksize_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) -{ - int ret; - u64 disksize; - struct zram *zram = dev_to_zram(dev); - - ret = kstrtoull(buf, 10, &disksize); - if (ret) - return ret; - - down_write(&zram->init_lock); - if (zram->init_done) { - up_write(&zram->init_lock); - pr_info("Cannot change disksize for initialized device\n"); - return -EBUSY; - } - - zram->disksize = PAGE_ALIGN(disksize); - set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); - up_write(&zram->init_lock); - - return len; -} - -static ssize_t initstate_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%u\n", zram->init_done); -} - -static ssize_t reset_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) -{ - int ret; - unsigned short do_reset; - struct zram *zram; - struct block_device *bdev; - - zram = dev_to_zram(dev); - bdev = bdget_disk(zram->disk, 0); - - /* Do not reset an active device! */ - if (bdev->bd_holders) - return -EBUSY; - - ret = kstrtou16(buf, 10, &do_reset); - if (ret) - return ret; - - if (!do_reset) - return -EINVAL; - - /* Make sure all pending I/O is finished */ - if (bdev) - fsync_bdev(bdev); - - down_write(&zram->init_lock); - if (zram->init_done) - __zram_reset_device(zram); - up_write(&zram->init_lock); - - return len; -} - -static ssize_t num_reads_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%llu\n", - zram_stat64_read(zram, &zram->stats.num_reads)); -} - -static ssize_t num_writes_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%llu\n", - zram_stat64_read(zram, &zram->stats.num_writes)); -} - -static ssize_t invalid_io_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%llu\n", - zram_stat64_read(zram, &zram->stats.invalid_io)); -} - -static ssize_t notify_free_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%llu\n", - zram_stat64_read(zram, &zram->stats.notify_free)); -} - -static ssize_t zero_pages_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%u\n", zram->stats.pages_zero); -} - -static ssize_t orig_data_size_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%llu\n", - (u64)(zram->stats.pages_stored) << PAGE_SHIFT); -} - -static ssize_t compr_data_size_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct zram *zram = dev_to_zram(dev); - - return sprintf(buf, "%llu\n", - zram_stat64_read(zram, &zram->stats.compr_size)); -} - -static ssize_t mem_used_total_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - u64 val = 0; - struct zram *zram = dev_to_zram(dev); - - if (zram->init_done) - val = zs_get_total_size_bytes(zram->mem_pool); - - return sprintf(buf, "%llu\n", val); -} - -static DEVICE_ATTR(disksize, S_IRUGO | S_IWUSR, - disksize_show, disksize_store); -static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL); -static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store); -static DEVICE_ATTR(num_reads, S_IRUGO, num_reads_show, NULL); -static DEVICE_ATTR(num_writes, S_IRUGO, num_writes_show, NULL); -static DEVICE_ATTR(invalid_io, S_IRUGO, invalid_io_show, NULL); -static DEVICE_ATTR(notify_free, S_IRUGO, notify_free_show, NULL); -static DEVICE_ATTR(zero_pages, S_IRUGO, zero_pages_show, NULL); -static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL); -static DEVICE_ATTR(compr_data_size, S_IRUGO, compr_data_size_show, NULL); -static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL); - -static struct attribute *zram_disk_attrs[] = { - &dev_attr_disksize.attr, - &dev_attr_initstate.attr, - &dev_attr_reset.attr, - &dev_attr_num_reads.attr, - &dev_attr_num_writes.attr, - &dev_attr_invalid_io.attr, - &dev_attr_notify_free.attr, - &dev_attr_zero_pages.attr, - &dev_attr_orig_data_size.attr, - &dev_attr_compr_data_size.attr, - &dev_attr_mem_used_total.attr, - NULL, -}; - -struct attribute_group zram_disk_attr_group = { - .attrs = zram_disk_attrs, -}; -- 1.7.9.5 ^ permalink raw reply related [flat|nested] 30+ messages in thread
* Re: [PATCH 2/3] zram: promote zram from staging 2012-09-26 8:50 ` Minchan Kim @ 2012-09-26 9:54 ` Pekka Enberg -1 siblings, 0 replies; 30+ messages in thread From: Pekka Enberg @ 2012-09-26 9:54 UTC (permalink / raw) To: Minchan Kim Cc: Jens Axboe, Greg Kroah-Hartman, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel On Wed, Sep 26, 2012 at 11:50 AM, Minchan Kim <minchan@kernel.org> wrote: > It's time to promote zram from staging because zram is in staging > for a long time and is improved by many contributors so code is > very clean. Most important issue, zram's dependency with x86 is > solved by making zsmalloc portable. In addition, many embedded > product uses zram in real practive so I think there is no reason > to prevent promotion now. > > Cc: Seth Jennings <sjenning@linux.vnet.ibm.com> > Cc: Nitin Gupta <ngupta@vflare.org> > Signed-off-by: Minchan Kim <minchan@kernel.org> FWIW, Acked-by: Pekka Enberg <penberg@kernel.org> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 2/3] zram: promote zram from staging @ 2012-09-26 9:54 ` Pekka Enberg 0 siblings, 0 replies; 30+ messages in thread From: Pekka Enberg @ 2012-09-26 9:54 UTC (permalink / raw) To: Minchan Kim Cc: Jens Axboe, Greg Kroah-Hartman, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel On Wed, Sep 26, 2012 at 11:50 AM, Minchan Kim <minchan@kernel.org> wrote: > It's time to promote zram from staging because zram is in staging > for a long time and is improved by many contributors so code is > very clean. Most important issue, zram's dependency with x86 is > solved by making zsmalloc portable. In addition, many embedded > product uses zram in real practive so I think there is no reason > to prevent promotion now. > > Cc: Seth Jennings <sjenning@linux.vnet.ibm.com> > Cc: Nitin Gupta <ngupta@vflare.org> > Signed-off-by: Minchan Kim <minchan@kernel.org> FWIW, Acked-by: Pekka Enberg <penberg@kernel.org> ^ permalink raw reply [flat|nested] 30+ messages in thread
* [PATCH 3/3] zram: select ZSMALLOC when ZRAM is configured 2012-09-26 8:50 ` Minchan Kim @ 2012-09-26 8:50 ` Minchan Kim -1 siblings, 0 replies; 30+ messages in thread From: Minchan Kim @ 2012-09-26 8:50 UTC (permalink / raw) To: Jens Axboe, Greg Kroah-Hartman Cc: Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel, Minchan Kim At the monent, we can configure zram in driver/block once zsmalloc in /lib menu is configured firstly. It's not convenient. User can configure zram in driver/block regardless of zsmalloc enabling by this patch. Signed-off-by: Minchan Kim <minchan@kernel.org> --- drivers/block/zram/Kconfig | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig index be5abe8..ee23a86 100644 --- a/drivers/block/zram/Kconfig +++ b/drivers/block/zram/Kconfig @@ -1,6 +1,7 @@ config ZRAM tristate "Compressed RAM block device support" - depends on BLOCK && SYSFS && ZSMALLOC + depends on BLOCK && SYSFS + select ZSMALLOC select LZO_COMPRESS select LZO_DECOMPRESS default n -- 1.7.9.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 30+ messages in thread
* [PATCH 3/3] zram: select ZSMALLOC when ZRAM is configured @ 2012-09-26 8:50 ` Minchan Kim 0 siblings, 0 replies; 30+ messages in thread From: Minchan Kim @ 2012-09-26 8:50 UTC (permalink / raw) To: Jens Axboe, Greg Kroah-Hartman Cc: Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel, Minchan Kim At the monent, we can configure zram in driver/block once zsmalloc in /lib menu is configured firstly. It's not convenient. User can configure zram in driver/block regardless of zsmalloc enabling by this patch. Signed-off-by: Minchan Kim <minchan@kernel.org> --- drivers/block/zram/Kconfig | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig index be5abe8..ee23a86 100644 --- a/drivers/block/zram/Kconfig +++ b/drivers/block/zram/Kconfig @@ -1,6 +1,7 @@ config ZRAM tristate "Compressed RAM block device support" - depends on BLOCK && SYSFS && ZSMALLOC + depends on BLOCK && SYSFS + select ZSMALLOC select LZO_COMPRESS select LZO_DECOMPRESS default n -- 1.7.9.5 ^ permalink raw reply related [flat|nested] 30+ messages in thread
* Re: [PATCH 3/3] zram: select ZSMALLOC when ZRAM is configured 2012-09-26 8:50 ` Minchan Kim @ 2012-09-26 16:15 ` Greg Kroah-Hartman -1 siblings, 0 replies; 30+ messages in thread From: Greg Kroah-Hartman @ 2012-09-26 16:15 UTC (permalink / raw) To: Minchan Kim Cc: Jens Axboe, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel On Wed, Sep 26, 2012 at 05:50:19PM +0900, Minchan Kim wrote: > At the monent, we can configure zram in driver/block once zsmalloc > in /lib menu is configured firstly. It's not convenient. > > User can configure zram in driver/block regardless of zsmalloc enabling > by this patch. > > Signed-off-by: Minchan Kim <minchan@kernel.org> > --- > drivers/block/zram/Kconfig | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig > index be5abe8..ee23a86 100644 > --- a/drivers/block/zram/Kconfig > +++ b/drivers/block/zram/Kconfig > @@ -1,6 +1,7 @@ > config ZRAM > tristate "Compressed RAM block device support" > - depends on BLOCK && SYSFS && ZSMALLOC > + depends on BLOCK && SYSFS > + select ZSMALLOC As ZSMALLOC is dependant on CONFIG_STAGING, this isn't going to work at all, sorry. If your code depends on staging code, we need to get the staging code out of staging first, before this code can be moved out. So please work to get zsmalloc cleaned up and merged out first please, as it is, this patch series is not ok. greg k-h -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 3/3] zram: select ZSMALLOC when ZRAM is configured @ 2012-09-26 16:15 ` Greg Kroah-Hartman 0 siblings, 0 replies; 30+ messages in thread From: Greg Kroah-Hartman @ 2012-09-26 16:15 UTC (permalink / raw) To: Minchan Kim Cc: Jens Axboe, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel On Wed, Sep 26, 2012 at 05:50:19PM +0900, Minchan Kim wrote: > At the monent, we can configure zram in driver/block once zsmalloc > in /lib menu is configured firstly. It's not convenient. > > User can configure zram in driver/block regardless of zsmalloc enabling > by this patch. > > Signed-off-by: Minchan Kim <minchan@kernel.org> > --- > drivers/block/zram/Kconfig | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig > index be5abe8..ee23a86 100644 > --- a/drivers/block/zram/Kconfig > +++ b/drivers/block/zram/Kconfig > @@ -1,6 +1,7 @@ > config ZRAM > tristate "Compressed RAM block device support" > - depends on BLOCK && SYSFS && ZSMALLOC > + depends on BLOCK && SYSFS > + select ZSMALLOC As ZSMALLOC is dependant on CONFIG_STAGING, this isn't going to work at all, sorry. If your code depends on staging code, we need to get the staging code out of staging first, before this code can be moved out. So please work to get zsmalloc cleaned up and merged out first please, as it is, this patch series is not ok. greg k-h ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 3/3] zram: select ZSMALLOC when ZRAM is configured 2012-09-26 16:15 ` Greg Kroah-Hartman @ 2012-09-26 16:23 ` Calvin Walton -1 siblings, 0 replies; 30+ messages in thread From: Calvin Walton @ 2012-09-26 16:23 UTC (permalink / raw) To: Greg Kroah-Hartman Cc: Minchan Kim, Jens Axboe, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel On Wed, 2012-09-26 at 09:15 -0700, Greg Kroah-Hartman wrote: > On Wed, Sep 26, 2012 at 05:50:19PM +0900, Minchan Kim wrote: > > At the monent, we can configure zram in driver/block once zsmalloc > > in /lib menu is configured firstly. It's not convenient. > > > > User can configure zram in driver/block regardless of zsmalloc enabling > > by this patch. > > > > Signed-off-by: Minchan Kim <minchan@kernel.org> > > --- > > drivers/block/zram/Kconfig | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig > > index be5abe8..ee23a86 100644 > > --- a/drivers/block/zram/Kconfig > > +++ b/drivers/block/zram/Kconfig > > @@ -1,6 +1,7 @@ > > config ZRAM > > tristate "Compressed RAM block device support" > > - depends on BLOCK && SYSFS && ZSMALLOC > > + depends on BLOCK && SYSFS > > + select ZSMALLOC > > As ZSMALLOC is dependant on CONFIG_STAGING, this isn't going to work at > all, sorry. Perhaps you missed [PATCH 1/3] zsmalloc: promote to lib/ ? The first patch in this series moves zsmalloc out of the staging directory, and removes the dependency on CONFIG_STAGING. -- Calvin Walton <calvin.walton@kepstin.ca> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 3/3] zram: select ZSMALLOC when ZRAM is configured @ 2012-09-26 16:23 ` Calvin Walton 0 siblings, 0 replies; 30+ messages in thread From: Calvin Walton @ 2012-09-26 16:23 UTC (permalink / raw) To: Greg Kroah-Hartman Cc: Minchan Kim, Jens Axboe, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel On Wed, 2012-09-26 at 09:15 -0700, Greg Kroah-Hartman wrote: > On Wed, Sep 26, 2012 at 05:50:19PM +0900, Minchan Kim wrote: > > At the monent, we can configure zram in driver/block once zsmalloc > > in /lib menu is configured firstly. It's not convenient. > > > > User can configure zram in driver/block regardless of zsmalloc enabling > > by this patch. > > > > Signed-off-by: Minchan Kim <minchan@kernel.org> > > --- > > drivers/block/zram/Kconfig | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig > > index be5abe8..ee23a86 100644 > > --- a/drivers/block/zram/Kconfig > > +++ b/drivers/block/zram/Kconfig > > @@ -1,6 +1,7 @@ > > config ZRAM > > tristate "Compressed RAM block device support" > > - depends on BLOCK && SYSFS && ZSMALLOC > > + depends on BLOCK && SYSFS > > + select ZSMALLOC > > As ZSMALLOC is dependant on CONFIG_STAGING, this isn't going to work at > all, sorry. Perhaps you missed [PATCH 1/3] zsmalloc: promote to lib/ ? The first patch in this series moves zsmalloc out of the staging directory, and removes the dependency on CONFIG_STAGING. -- Calvin Walton <calvin.walton@kepstin.ca> ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 3/3] zram: select ZSMALLOC when ZRAM is configured 2012-09-26 16:23 ` Calvin Walton @ 2012-09-26 16:29 ` Greg Kroah-Hartman -1 siblings, 0 replies; 30+ messages in thread From: Greg Kroah-Hartman @ 2012-09-26 16:29 UTC (permalink / raw) To: Calvin Walton Cc: Minchan Kim, Jens Axboe, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel On Wed, Sep 26, 2012 at 12:23:35PM -0400, Calvin Walton wrote: > On Wed, 2012-09-26 at 09:15 -0700, Greg Kroah-Hartman wrote: > > On Wed, Sep 26, 2012 at 05:50:19PM +0900, Minchan Kim wrote: > > > At the monent, we can configure zram in driver/block once zsmalloc > > > in /lib menu is configured firstly. It's not convenient. > > > > > > User can configure zram in driver/block regardless of zsmalloc enabling > > > by this patch. > > > > > > Signed-off-by: Minchan Kim <minchan@kernel.org> > > > --- > > > drivers/block/zram/Kconfig | 3 ++- > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig > > > index be5abe8..ee23a86 100644 > > > --- a/drivers/block/zram/Kconfig > > > +++ b/drivers/block/zram/Kconfig > > > @@ -1,6 +1,7 @@ > > > config ZRAM > > > tristate "Compressed RAM block device support" > > > - depends on BLOCK && SYSFS && ZSMALLOC > > > + depends on BLOCK && SYSFS > > > + select ZSMALLOC > > > > As ZSMALLOC is dependant on CONFIG_STAGING, this isn't going to work at > > all, sorry. > > Perhaps you missed [PATCH 1/3] zsmalloc: promote to lib/ ? The first > patch in this series moves zsmalloc out of the staging directory, and > removes the dependency on CONFIG_STAGING. Ah, I did, thanks. For 3.7, it's too late to be moving stuff out of staging to the "real" part of the kernel as 3.6 is about to be released. Possibly, if everyone agrees with this, after 3.7 is out we can do this for 3.8, ok? thanks, greg k-h -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 3/3] zram: select ZSMALLOC when ZRAM is configured @ 2012-09-26 16:29 ` Greg Kroah-Hartman 0 siblings, 0 replies; 30+ messages in thread From: Greg Kroah-Hartman @ 2012-09-26 16:29 UTC (permalink / raw) To: Calvin Walton Cc: Minchan Kim, Jens Axboe, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel On Wed, Sep 26, 2012 at 12:23:35PM -0400, Calvin Walton wrote: > On Wed, 2012-09-26 at 09:15 -0700, Greg Kroah-Hartman wrote: > > On Wed, Sep 26, 2012 at 05:50:19PM +0900, Minchan Kim wrote: > > > At the monent, we can configure zram in driver/block once zsmalloc > > > in /lib menu is configured firstly. It's not convenient. > > > > > > User can configure zram in driver/block regardless of zsmalloc enabling > > > by this patch. > > > > > > Signed-off-by: Minchan Kim <minchan@kernel.org> > > > --- > > > drivers/block/zram/Kconfig | 3 ++- > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig > > > index be5abe8..ee23a86 100644 > > > --- a/drivers/block/zram/Kconfig > > > +++ b/drivers/block/zram/Kconfig > > > @@ -1,6 +1,7 @@ > > > config ZRAM > > > tristate "Compressed RAM block device support" > > > - depends on BLOCK && SYSFS && ZSMALLOC > > > + depends on BLOCK && SYSFS > > > + select ZSMALLOC > > > > As ZSMALLOC is dependant on CONFIG_STAGING, this isn't going to work at > > all, sorry. > > Perhaps you missed [PATCH 1/3] zsmalloc: promote to lib/ ? The first > patch in this series moves zsmalloc out of the staging directory, and > removes the dependency on CONFIG_STAGING. Ah, I did, thanks. For 3.7, it's too late to be moving stuff out of staging to the "real" part of the kernel as 3.6 is about to be released. Possibly, if everyone agrees with this, after 3.7 is out we can do this for 3.8, ok? thanks, greg k-h ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 3/3] zram: select ZSMALLOC when ZRAM is configured 2012-09-26 16:29 ` Greg Kroah-Hartman @ 2012-09-27 1:53 ` Minchan Kim -1 siblings, 0 replies; 30+ messages in thread From: Minchan Kim @ 2012-09-27 1:53 UTC (permalink / raw) To: Greg Kroah-Hartman Cc: Calvin Walton, Jens Axboe, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel On Wed, Sep 26, 2012 at 09:29:41AM -0700, Greg Kroah-Hartman wrote: > On Wed, Sep 26, 2012 at 12:23:35PM -0400, Calvin Walton wrote: > > On Wed, 2012-09-26 at 09:15 -0700, Greg Kroah-Hartman wrote: > > > On Wed, Sep 26, 2012 at 05:50:19PM +0900, Minchan Kim wrote: > > > > At the monent, we can configure zram in driver/block once zsmalloc > > > > in /lib menu is configured firstly. It's not convenient. > > > > > > > > User can configure zram in driver/block regardless of zsmalloc enabling > > > > by this patch. > > > > > > > > Signed-off-by: Minchan Kim <minchan@kernel.org> > > > > --- > > > > drivers/block/zram/Kconfig | 3 ++- > > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig > > > > index be5abe8..ee23a86 100644 > > > > --- a/drivers/block/zram/Kconfig > > > > +++ b/drivers/block/zram/Kconfig > > > > @@ -1,6 +1,7 @@ > > > > config ZRAM > > > > tristate "Compressed RAM block device support" > > > > - depends on BLOCK && SYSFS && ZSMALLOC > > > > + depends on BLOCK && SYSFS > > > > + select ZSMALLOC > > > > > > As ZSMALLOC is dependant on CONFIG_STAGING, this isn't going to work at > > > all, sorry. > > > > Perhaps you missed [PATCH 1/3] zsmalloc: promote to lib/ ? The first > > patch in this series moves zsmalloc out of the staging directory, and > > removes the dependency on CONFIG_STAGING. > > Ah, I did, thanks. > > For 3.7, it's too late to be moving stuff out of staging to the "real" > part of the kernel as 3.6 is about to be released. > > Possibly, if everyone agrees with this, after 3.7 is out we can do this > for 3.8, ok? For me, no problem. I will send the patchset after listening akpm's opinion about zsmalloc's location. Maybe nextweek. Thanks, Greg. > > thanks, > > greg k-h > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 30+ messages in thread
* Re: [PATCH 3/3] zram: select ZSMALLOC when ZRAM is configured @ 2012-09-27 1:53 ` Minchan Kim 0 siblings, 0 replies; 30+ messages in thread From: Minchan Kim @ 2012-09-27 1:53 UTC (permalink / raw) To: Greg Kroah-Hartman Cc: Calvin Walton, Jens Axboe, Nitin Gupta, Konrad Rzeszutek Wilk, Seth Jennings, Dan Magenheimer, linux-mm, linux-kernel On Wed, Sep 26, 2012 at 09:29:41AM -0700, Greg Kroah-Hartman wrote: > On Wed, Sep 26, 2012 at 12:23:35PM -0400, Calvin Walton wrote: > > On Wed, 2012-09-26 at 09:15 -0700, Greg Kroah-Hartman wrote: > > > On Wed, Sep 26, 2012 at 05:50:19PM +0900, Minchan Kim wrote: > > > > At the monent, we can configure zram in driver/block once zsmalloc > > > > in /lib menu is configured firstly. It's not convenient. > > > > > > > > User can configure zram in driver/block regardless of zsmalloc enabling > > > > by this patch. > > > > > > > > Signed-off-by: Minchan Kim <minchan@kernel.org> > > > > --- > > > > drivers/block/zram/Kconfig | 3 ++- > > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig > > > > index be5abe8..ee23a86 100644 > > > > --- a/drivers/block/zram/Kconfig > > > > +++ b/drivers/block/zram/Kconfig > > > > @@ -1,6 +1,7 @@ > > > > config ZRAM > > > > tristate "Compressed RAM block device support" > > > > - depends on BLOCK && SYSFS && ZSMALLOC > > > > + depends on BLOCK && SYSFS > > > > + select ZSMALLOC > > > > > > As ZSMALLOC is dependant on CONFIG_STAGING, this isn't going to work at > > > all, sorry. > > > > Perhaps you missed [PATCH 1/3] zsmalloc: promote to lib/ ? The first > > patch in this series moves zsmalloc out of the staging directory, and > > removes the dependency on CONFIG_STAGING. > > Ah, I did, thanks. > > For 3.7, it's too late to be moving stuff out of staging to the "real" > part of the kernel as 3.6 is about to be released. > > Possibly, if everyone agrees with this, after 3.7 is out we can do this > for 3.8, ok? For me, no problem. I will send the patchset after listening akpm's opinion about zsmalloc's location. Maybe nextweek. Thanks, Greg. > > thanks, > > greg k-h > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> -- Kind regards, Minchan Kim ^ permalink raw reply [flat|nested] 30+ messages in thread
end of thread, other threads:[~2012-09-27 1:51 UTC | newest] Thread overview: 30+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2012-09-26 8:50 [PATCH 0/3] zram/zsmalloc promotion Minchan Kim 2012-09-26 8:50 ` Minchan Kim 2012-09-26 8:50 ` [PATCH 1/3] zsmalloc: promote to lib/ Minchan Kim 2012-09-26 8:50 ` Minchan Kim 2012-09-26 9:42 ` Wanlong Gao 2012-09-26 9:42 ` Wanlong Gao 2012-09-26 9:51 ` Pekka Enberg 2012-09-26 9:51 ` Pekka Enberg 2012-09-26 17:06 ` Nitin Gupta 2012-09-26 17:06 ` Nitin Gupta 2012-09-27 1:39 ` Minchan Kim 2012-09-27 1:39 ` Minchan Kim 2012-09-27 1:47 ` Andrew Morton 2012-09-27 1:47 ` Andrew Morton 2012-09-27 1:50 ` Minchan Kim 2012-09-27 1:50 ` Minchan Kim 2012-09-26 8:50 ` [PATCH 2/3] zram: promote zram from staging Minchan Kim 2012-09-26 8:50 ` Minchan Kim 2012-09-26 9:54 ` Pekka Enberg 2012-09-26 9:54 ` Pekka Enberg 2012-09-26 8:50 ` [PATCH 3/3] zram: select ZSMALLOC when ZRAM is configured Minchan Kim 2012-09-26 8:50 ` Minchan Kim 2012-09-26 16:15 ` Greg Kroah-Hartman 2012-09-26 16:15 ` Greg Kroah-Hartman 2012-09-26 16:23 ` Calvin Walton 2012-09-26 16:23 ` Calvin Walton 2012-09-26 16:29 ` Greg Kroah-Hartman 2012-09-26 16:29 ` Greg Kroah-Hartman 2012-09-27 1:53 ` Minchan Kim 2012-09-27 1:53 ` Minchan Kim
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