zsmalloc: expand class bit
Now 64K page system, zsamlloc has 257 classes so 8 class bit is not
enough. With that, it corrupts the system when zsmalloc stores
65536byte data(ie, index number 256) so that this patch increases class
bit for simple fix for stable backport. We should clean up this mess
soon.
index size
0 32
1 288
..
..
204 52256
256 65536
Fixes: 3783689a1 ("zsmalloc: introduce zspage structure")
Link: http://lkml.kernel.org/r/1492042622-12074-3-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index b7ee9c3..d41edd2 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -276,7 +276,7 @@
struct zspage {
struct {
unsigned int fullness:FULLNESS_BITS;
- unsigned int class:CLASS_BITS;
+ unsigned int class:CLASS_BITS + 1;
unsigned int isolated:ISOLATED_BITS;
unsigned int magic:MAGIC_VAL_BITS;
};