Rokudo Yan 02f768edb9 zsmalloc: account the number of compacted pages correctly ... commit 2395928158059b8f9858365fce7713ce7fef62e4 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-03-07 12:34:15 +01:00
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Kconfig	docs: blockdev: add it to the admin-guide	2019-07-15 11:03:01 -03:00
Makefile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
zcomp.c	zcomp: Use ARRAY_SIZE() for backends list	2020-06-04 19:06:24 -07:00
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	2021-03-07 12:34:15 +01:00
zram_drv.h	zram: idle writeback fixes and cleanup	2019-01-08 17:15:10 -08:00