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Yosry Ahmed 9fad9aee1f memcg: sleep during flushing stats in safe contexts
Currently, all contexts that flush memcg stats do so with sleeping not
allowed.  Some of these contexts are perfectly safe to sleep in, such as
reading cgroup files from userspace or the background periodic flusher. 
Flushing is an expensive operation that scales with the number of cpus and
the number of cgroups in the system, so avoid doing it atomically where
possible.

Refactor the code to make mem_cgroup_flush_stats() non-atomic (aka
sleepable), and provide a separate atomic version.  The atomic version is
used in reclaim, refault, writeback, and in mem_cgroup_usage().  All other
code paths are left to use the non-atomic version.  This includes
callbacks for userspace reads and the periodic flusher.

Since refault is the only caller of mem_cgroup_flush_stats_ratelimited(),
change it to mem_cgroup_flush_stats_atomic_ratelimited().  Reclaim and
refault code paths are modified to do non-atomic flushing in separate
later patches -- so it will eventually be changed back to
mem_cgroup_flush_stats_ratelimited().

Link: https://lkml.kernel.org/r/20230330191801.1967435-6-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vasily Averin <vasily.averin@linux.dev>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:29:50 -07:00
arch xtensa: reword ARCH_FORCE_MAX_ORDER prompt and help text 2023-04-18 16:29:46 -07:00
block block: remove obsolete config BLOCK_COMPAT 2023-03-16 09:35:44 -06:00
certs Kbuild updates for v6.3 2023-02-26 11:53:25 -08:00
crypto asymmetric_keys: log on fatal failures in PE/pkcs7 2023-03-21 16:23:56 +00:00
Documentation sync mm-stable with mm-hotfixes-stable to pick up depended-upon upstream changes 2023-04-16 12:31:58 -07:00
drivers drm/ttm: remove comment referencing now-removed vmf_insert_mixed_prot() 2023-04-05 19:42:56 -07:00
fs sync mm-stable with mm-hotfixes-stable to pick up depended-upon upstream changes 2023-04-18 14:53:49 -07:00
include memcg: sleep during flushing stats in safe contexts 2023-04-18 16:29:50 -07:00
init init,mm: fold late call to page_ext_init() to page_alloc_init_late() 2023-04-05 19:42:54 -07:00
io_uring block-6.3-2023-03-24 2023-03-24 14:10:39 -07:00
ipc Merge branch 'work.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2023-02-24 19:20:07 -08:00
kernel cgroup: rename cgroup_rstat_flush_"irqsafe" to "atomic" 2023-04-18 16:29:49 -07:00
lib lib/test_vmalloc.c: add vm_map_ram()/vm_unmap_ram() test case 2023-04-18 16:29:47 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm memcg: sleep during flushing stats in safe contexts 2023-04-18 16:29:50 -07:00
net mm, treewide: redefine MAX_ORDER sanely 2023-04-05 19:42:46 -07:00
rust Rust fixes for 6.3-rc1 2023-03-03 14:51:15 -08:00
samples kmemleak-test: fix kmemleak_test.c build logic 2023-04-18 16:29:47 -07:00
scripts kasan: remove hwasan-kernel-mem-intrinsic-prefix=1 for clang-14 2023-04-18 16:29:43 -07:00
security mm, treewide: redefine MAX_ORDER sanely 2023-04-05 19:42:46 -07:00
sound ALSA: hda/ca0132: fixup buffer overrun at tuning_ctl_set() 2023-03-14 17:04:53 +01:00
tools sync mm-stable with mm-hotfixes-stable to pick up depended-upon upstream changes 2023-04-18 14:53:49 -07:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt KVM/riscv changes for 6.3 2023-02-15 12:33:28 -05:00
.clang-format cpumask: re-introduce constant-sized cpumask optimizations 2023-03-05 14:30:34 -08:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for *.dtso files 2023-02-26 15:28:23 +09:00
.gitignore kbuild: rpm-pkg: move source components to rpmbuild/SOURCES 2023-03-16 22:45:56 +09:00
.mailmap mailmap: update jtoppins' entry to reference correct email 2023-04-16 10:41:25 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS There is no particular theme here - mainly quick hits all over the tree. 2023-02-23 17:55:40 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: extend memblock entry to include MM initialization 2023-04-05 19:42:55 -07:00
Makefile Linux 6.3-rc4 2023-03-26 14:40:20 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.