[PATCH 3/3] zram: use common zpool interface

Vitaly Wool
2015-09-14T13:55:31Z

Update zram driver to use common zpool API instead of calling
zsmalloc functions directly. This patch also adds a parameter
that allows for changing underlying compressor storage to zbud.

Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
---
drivers/block/zram/Kconfig | 3 ++-
drivers/block/zram/zram_drv.c | 44 ++++++++++++++++++++++++-------------------
drivers/block/zram/zram_drv.h | 4 ++--
3 files changed, 29 insertions(+), 22 deletions(-)

diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig
index 386ba3d..4831d0a 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 ZPOOL
select LZO_COMPRESS
select LZO_DECOMPRESS
default n
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 49d5a65..2829c3d 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -44,6 +44,9 @@ static const char *default_compressor = "lzo";
static unsigned int num_devices = 1;
static size_t max_zpage_size = PAGE_SIZE / 4 * 3;

+#define ZRAM_ZPOOL_DEFAULT "zsmalloc"
+static char *pool_type = ZRAM_ZPOOL_DEFAULT;
+
static inline void deprecated_attr_warn(const char *name)
{
pr_warn_once("%d (%s) Attribute %s (and others) will be removed. %s\n",
@@ -229,11 +232,11 @@ static ssize_t mem_used_total_show(struct device *dev,
down_read(&zram->init_lock);
if (init_done(zram)) {
struct zram_meta *meta = zram->meta;
- val = zs_get_total_pages(meta->mem_pool);
+ val = zpool_get_total_size(meta->mem_pool);
}
up_read(&zram->init_lock);

- return scnprintf(buf, PAGE_SIZE, "%llu\n", val << PAGE_SHIFT);
+ return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
}

static ssize_t mem_limit_show(struct device *dev,
@@ -298,7 +301,7 @@ static ssize_t mem_used_max_store(struct device *dev,
if (init_done(zram)) {
struct zram_meta *meta = zram->meta;
atomic_long_set(&zram->stats.max_used_pages,
- zs_get_total_pages(meta->mem_pool));
+ zpool_get_total_size(meta->mem_pool) >> PAGE_SHIFT);
}
up_read(&zram->init_lock);

@@ -399,7 +402,7 @@ static ssize_t compact_store(struct device *dev,
}

meta = zram->meta;
- zs_compact(meta->mem_pool);
+ zpool_compact(meta->mem_pool, NULL);
up_read(&zram->init_lock);

return len;
@@ -436,8 +439,8 @@ static ssize_t mm_stat_show(struct device *dev,

down_read(&zram->init_lock);
if (init_done(zram)) {
- mem_used = zs_get_total_pages(zram->meta->mem_pool);
- zs_pool_stats(zram->meta->mem_pool, &pool_stats);
+ mem_used = zpool_get_total_size(zram->meta->mem_pool);
+ zpool_stats(zram->meta->mem_pool, &pool_stats);
}

orig_size = atomic64_read(&zram->stats.pages_stored);
@@ -447,7 +450,7 @@ static ssize_t mm_stat_show(struct device *dev,
"%8llu %8llu %8llu %8lu %8ld %8llu %8lu\n",
orig_size << PAGE_SHIFT,
(u64)atomic64_read(&zram->stats.compr_data_size),
- mem_used << PAGE_SHIFT,
+ mem_used,
zram->limit_pages << PAGE_SHIFT,
max_used << PAGE_SHIFT,
(u64)atomic64_read(&zram->stats.zero_pages),
@@ -492,10 +495,10 @@ static void zram_meta_free(struct zram_meta *meta, u64 disksize)
if (!handle)
continue;

- zs_free(meta->mem_pool, handle);
+ zpool_free(meta->mem_pool, handle);
}

- zs_destroy_pool(meta->mem_pool);
+ zpool_destroy_pool(meta->mem_pool);
vfree(meta->table);
kfree(meta);
}
@@ -515,7 +518,8 @@ static struct zram_meta *zram_meta_alloc(char *pool_name, u64 disksize)
goto out_error;
}

- meta->mem_pool = zs_create_pool(pool_name, GFP_NOIO | __GFP_HIGHMEM);
+ meta->mem_pool = zpool_create_pool(pool_type, pool_name,
+ GFP_NOIO | __GFP_HIGHMEM, NULL);
if (!meta->mem_pool) {
pr_err("Error creating memory pool\n");
goto out_error;
@@ -551,7 +555,7 @@ static void zram_free_page(struct zram *zram, size_t index)
return;
}

- zs_free(meta->mem_pool, handle);
+ zpool_free(meta->mem_pool, handle);

atomic64_sub(zram_get_obj_size(meta, index),
&zram->stats.compr_data_size);
@@ -579,12 +583,12 @@ static int zram_decompress_page(struct zram *zram, char *mem, u32 index)
return 0;
}

- cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_RO);
+ cmem = zpool_map_handle(meta->mem_pool, handle, ZPOOL_MM_RO);
if (size == PAGE_SIZE)
copy_page(mem, cmem);
else
ret = zcomp_decompress(zram->comp, cmem, size, mem);
- zs_unmap_object(meta->mem_pool, handle);
+ zpool_unmap_handle(meta->mem_pool, handle);
bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value);

/* Should NEVER happen. Return bio error if it does. */
@@ -718,24 +722,24 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
src = uncmem;
}

- handle = zs_malloc(meta->mem_pool, clen);
- if (!handle) {
+ if (zpool_malloc(meta->mem_pool, clen, __GFP_IO | __GFP_NOWARN,
+ &handle) != 0) {
pr_err("Error allocating memory for compressed page: %u, size=%zu\n",
index, clen);
ret = -ENOMEM;
goto out;
}

- alloced_pages = zs_get_total_pages(meta->mem_pool);
+ alloced_pages = zpool_get_total_size(meta->mem_pool) >> PAGE_SHIFT;
if (zram->limit_pages && alloced_pages > zram->limit_pages) {
- zs_free(meta->mem_pool, handle);
+ zpool_free(meta->mem_pool, handle);
ret = -ENOMEM;
goto out;
}

update_used_max(zram, alloced_pages);

- cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_WO);
+ cmem = zpool_map_handle(meta->mem_pool, handle, ZPOOL_MM_WO);

if ((clen == PAGE_SIZE) && !is_partial_io(bvec)) {
src = kmap_atomic(page);
@@ -747,7 +751,7 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,

zcomp_strm_release(zram->comp, zstrm);
zstrm = NULL;
- zs_unmap_object(meta->mem_pool, handle);
+ zpool_unmap_handle(meta->mem_pool, handle);

/*
* Free memory associated with this sector
@@ -1457,6 +1461,8 @@ module_param(num_devices, uint, 0);
MODULE_PARM_DESC(num_devices, "Number of pre-created zram devices");
module_param(max_zpage_size, ulong, 0);
MODULE_PARM_DESC(max_zpage_size, "Threshold for storing compressed pages");
+module_param_named(zpool_type, pool_type, charp, 0444);
+MODULE_PARM_DESC(zpool_type, "zpool implementation selection (zsmalloc vs zbud)");

MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>");
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index 3a29c33..9a64b94 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -16,7 +16,7 @@
#define _ZRAM_DRV_H_

#include <linux/spinlock.h>
-#include <linux/zsmalloc.h>
+#include <linux/zpool.h>

#include "zcomp.h"

@@ -73,7 +73,7 @@ struct zram_stats {

struct zram_meta {
struct zram_table_entry *table;
- struct zs_pool *mem_pool;
+ struct zpool *mem_pool;
};

struct zram {
--
1.9.1