[PATCHv3 2/6] zsmalloc: promote to lib/

Seth Jennings
2013-01-28T21:55:53Z

This patch promotes the slab-based zsmalloc memory allocator
from the staging tree to lib/

zswap 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: Seth Jennings <sjenning@linux.vnet.ibm.com>
--
This patch is similar to a patch Minchan has on out on the list
to promote for use in zram.
---
drivers/staging/Kconfig | 2 --
drivers/staging/Makefile | 1 -
drivers/staging/zcache/zcache-main.c | 3 +--
drivers/staging/zram/zram_drv.h | 3 +--
drivers/staging/zsmalloc/Kconfig | 10 ----------
drivers/staging/zsmalloc/Makefile | 3 ---
.../staging/zsmalloc => include/linux}/zsmalloc.h | 0
lib/Kconfig | 18 ++++++++++++++++++
lib/Makefile | 1 +
.../zsmalloc/zsmalloc-main.c => lib/zsmalloc.c | 3 +--
10 files changed, 22 insertions(+), 22 deletions(-)
delete mode 100644 drivers/staging/zsmalloc/Kconfig
delete mode 100644 drivers/staging/zsmalloc/Makefile
rename {drivers/staging/zsmalloc => include/linux}/zsmalloc.h (100%)
rename drivers/staging/zsmalloc/zsmalloc-main.c => lib/zsmalloc.c (99%)

diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig
index 329bdb4..c0a7918 100644
--- a/drivers/staging/Kconfig
+++ b/drivers/staging/Kconfig
@@ -76,8 +76,6 @@ 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 c7ec486..1572fe5 100644
--- a/drivers/staging/Makefile
+++ b/drivers/staging/Makefile
@@ -32,7 +32,6 @@ 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..75c08c5 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -32,10 +32,9 @@
#include <linux/crypto.h>
#include <linux/string.h>
#include <linux/idr.h>
+#include <linux/zsmalloc.h>
#include "tmem.h"

-#include "../zsmalloc/zsmalloc.h"
-
#ifdef CONFIG_CLEANCACHE
#include <linux/cleancache.h>
#endif
diff --git a/drivers/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h
index df2eec4..1e72965 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.h b/include/linux/zsmalloc.h
similarity index 100%
rename from drivers/staging/zsmalloc/zsmalloc.h
rename to include/linux/zsmalloc.h
diff --git a/lib/Kconfig b/lib/Kconfig
index 75cdb77..fdab273 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -219,6 +219,24 @@ config DECOMPRESS_LZO
config GENERIC_ALLOCATOR
boolean

+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.
+
#
# reed solomon support is select'ed if needed
#
diff --git a/lib/Makefile b/lib/Makefile
index 02ed6c0..70b0892 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -65,6 +65,7 @@ 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.o

obj-$(CONFIG_ZLIB_INFLATE) += zlib_inflate/
obj-$(CONFIG_ZLIB_DEFLATE) += zlib_deflate/
diff --git a/drivers/staging/zsmalloc/zsmalloc-main.c b/lib/zsmalloc.c
similarity index 99%
rename from drivers/staging/zsmalloc/zsmalloc-main.c
rename to lib/zsmalloc.c
index 13018b7..d5146c7 100644
--- a/drivers/staging/zsmalloc/zsmalloc-main.c
+++ b/lib/zsmalloc.c
@@ -78,8 +78,7 @@
#include <linux/hardirq.h>
#include <linux/spinlock.h>
#include <linux/types.h>
-
-#include "zsmalloc.h"
+#include <linux/zsmalloc.h>

/*
* This must be power of 2 and greater than of equal to sizeof(link_free).
--
1.7.9.5