Rokudo Yan 2395928158 zsmalloc: account the number of compacted pages correctly ... There exists multiple path may do zram compaction concurrently. 1. auto-compaction triggered during memory reclaim 2. userspace utils write zram<id>/compaction node So, multiple threads may call zs_shrinker_scan/zs_compact concurrently. But pages_compacted is a per zsmalloc pool variable and modification of the variable is not serialized(through under class->lock). There are two issues here: 1. the pages_compacted may not equal to total number of pages freed(due to concurrently add). 2. zs_shrinker_scan may not return the correct number of pages freed(issued by current shrinker). The fix is simple: 1. account the number of pages freed in zs_compact locally. 2. use actomic variable pages_compacted to accumulate total number. Link: https://lkml.kernel.org/r/20210202122235.26885-1-wu-yan@tcl.com Fixes: 860c707dca ("zsmalloc: account the number of compacted pages") Signed-off-by: Rokudo Yan <wu-yan@tcl.com> Cc: 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>		2021-02-26 09:41:01 -08:00
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Kconfig	zram: break the strict dependency from lzo	2020-12-15 12:13:47 -08:00
Makefile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
zcomp.c	zram: break the strict dependency from lzo	2020-12-15 12:13:47 -08:00
zcomp.h	zram: Use local lock to protect per-CPU data	2020-05-28 10:31:10 +02:00
zram_drv.c	zsmalloc: account the number of compacted pages correctly	2021-02-26 09:41:01 -08:00
zram_drv.h	for-5.11/block-2020-12-14	2020-12-16 12:57:51 -08:00