Revision 2395928158059b8f9858365fce7713ce7fef62e4 authored by Rokudo Yan on 26 February 2021, 01:18:31 UTC, committed by Linus Torvalds on 26 February 2021, 17:41:01 UTC
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: 860c707dca155a56 ("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>
1 parent f023130
.gitignore
# SPDX-License-Identifier: GPL-2.0-only
#
# NOTE! Don't add files that are generated in specific
# subdirectories here. Add them in the ".gitignore" file
# in that subdirectory instead.
#
# NOTE! Please use 'git ls-files -i --exclude-standard'
# command after changing this file, to see if there are
# any tracked files which get ignored after the change.
#
# Normal rules (sorted alphabetically)
#
.*
*.a
*.asn1.[ch]
*.bin
*.bz2
*.c.[012]*.*
*.dt.yaml
*.dtb
*.dtbo
*.dtb.S
*.dwo
*.elf
*.gcno
*.gz
*.i
*.ko
*.lex.c
*.ll
*.lst
*.lz4
*.lzma
*.lzo
*.mod
*.mod.c
*.o
*.o.*
*.patch
*.s
*.so
*.so.dbg
*.su
*.symtypes
*.symversions
*.tab.[ch]
*.tar
*.xz
*.zst
Module.symvers
modules.builtin
modules.order
#
# Top-level generic files
#
/tags
/TAGS
/linux
/vmlinux
/vmlinux.32
/vmlinux.symvers
/vmlinux-gdb.py
/vmlinuz
/System.map
/Module.markers
/modules.builtin.modinfo
/modules.nsdeps
#
# RPM spec file (make rpm-pkg)
#
/*.spec
#
# Debian directory (make deb-pkg)
#
/debian/
#
# Snap directory (make snap-pkg)
#
/snap/
#
# tar directory (make tar*-pkg)
#
/tar-install/
#
# We don't want to ignore the following even if they are dot-files
#
!.clang-format
!.cocciconfig
!.get_maintainer.ignore
!.gitattributes
!.gitignore
!.mailmap
#
# Generated include files
#
/include/config/
/include/generated/
/include/ksym/
/arch/*/include/generated/
# stgit generated dirs
patches-*
# quilt's files
patches
series
# cscope files
cscope.*
ncscope.*
# gnu global files
GPATH
GRTAGS
GSYMS
GTAGS
# id-utils files
ID
*.orig
*~
\#*#
#
# Leavings from module signing
#
extra_certificates
signing_key.pem
signing_key.priv
signing_key.x509
x509.genkey
# Kconfig presets
/all.config
/alldef.config
/allmod.config
/allno.config
/allrandom.config
/allyes.config
# Kconfig savedefconfig output
/defconfig
# Kdevelop4
*.kdev4
# Clang's compilation database file
/compile_commands.json
# Documentation toolchain
sphinx_*/
Computing file changes ...
