kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-10-22 19:14:51 +00:00
Code Issues Releases Packages Activity
No description
1,318,234 commits 117 branches 5,803 tags 5.7 GiB
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Breno Leitao 314bf771cb memcg: always call cond_resched() after fn() 
commit 06717a7b6c upstream.

I am seeing soft lockup on certain machine types when a cgroup OOMs.  This
is happening because killing the process in certain machine might be very
slow, which causes the soft lockup and RCU stalls.  This happens usually
when the cgroup has MANY processes and memory.oom.group is set.

Example I am seeing in real production:

       [462012.244552] Memory cgroup out of memory: Killed process 3370438 (crosvm) ....
       ....
       [462037.318059] Memory cgroup out of memory: Killed process 4171372 (adb) ....
       [462037.348314] watchdog: BUG: soft lockup - CPU#64 stuck for 26s! [stat_manager-ag:1618982]
       ....

Quick look at why this is so slow, it seems to be related to serial flush
for certain machine types.  For all the crashes I saw, the target CPU was
at console_flush_all().

In the case above, there are thousands of processes in the cgroup, and it
is soft locking up before it reaches the 1024 limit in the code (which
would call the cond_resched()).  So, cond_resched() in 1024 blocks is not
sufficient.

Remove the counter-based conditional rescheduling logic and call
cond_resched() unconditionally after each task iteration, after fn() is
called.  This avoids the lockup independently of how slow fn() is.

Link: https://lkml.kernel.org/r/20250523-memcg_fix-v1-1-ad3eafb60477@debian.org
Fixes: ade81479c7 ("memcg: fix soft lockup in the OOM process")
Signed-off-by: Breno Leitao <leitao@debian.org>
Suggested-by: Rik van Riel <riel@surriel.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Michael van der Westhuizen <rmikey@meta.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: Chen Ridong <chenridong@huawei.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2025-05-29 11:03:22 +02:00
arch arm64: dts: marvell: uDPU: define pinctrl state for alarm LEDs 2025-05-29 11:03:22 +02:00
block block: only update request sector if needed 2025-05-29 11:03:12 +02:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: algif_hash - fix double free in hash_accept 2025-05-29 11:03:18 +02:00
Documentation serial: mctrl_gpio: split disable_ms into sync and no_sync APIs 2025-05-29 11:02:45 +02:00
drivers Input: xpad - add more controllers 2025-05-29 11:03:22 +02:00
fs smb: client: Reset all search buffer pointers when releasing buffer 2025-05-29 11:03:22 +02:00
include highmem: add folio_test_partial_kmap() 2025-05-29 11:03:22 +02:00
init rust: clean Rust 1.88.0's unnecessary_transmutes lint 2025-05-18 08:24:51 +02:00
io_uring io_uring: fix overflow resched cqe reordering 2025-05-29 11:03:17 +02:00
ipc ipc: fix memleak if msg_init_ns failed in create_ipc_ns 2024-12-05 14:03:02 +01:00
kernel padata: do not leak refcount in reorder_work 2025-05-29 11:03:19 +02:00
lib crypto: lzo - Fix compression buffer overrun 2025-05-29 11:02:25 +02:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm memcg: always call cond_resched() after fn() 2025-05-29 11:03:22 +02:00
net net: dsa: microchip: linearize skb for tail-tagging switches 2025-05-29 11:03:20 +02:00
rust rust: clean Rust 1.88.0's clippy::uninlined_format_args lint 2025-05-18 08:24:57 +02:00
samples samples/bpf: Fix compilation failure for samples/bpf on LoongArch Fedora 2025-05-29 11:02:01 +02:00
scripts kconfig: do not clear SYMBOL_VALID when reading include/config/auto.conf 2025-05-29 11:02:17 +02:00
security smack: Revert "smackfs: Added check catlen" 2025-05-29 11:02:48 +02:00
sound ALSA: hda/realtek: Add quirk for Lenovo Yoga Pro 7 14ASP10 2025-05-29 11:03:20 +02:00
tools tools: ynl-gen: validate 0 len strings from kernel 2025-05-29 11:03:12 +02:00
usr kbuild: hdrcheck: fix cross build with clang 2025-03-13 13:02:18 +01:00
virt KVM: Add member to struct kvm_gfn_range to indicate private/shared 2025-05-22 14:29:36 +02:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-18 08:24:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore rust: introduce .clippy.toml 2025-03-13 13:01:42 +01:00
.mailmap mailmap: add entry for Thorsten Blum 2024-11-07 14:14:59 -08:00
.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 MAINTAINERS: Remove self from DSA entry 2024-11-03 12:52:38 -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: Update Alexey Makhalov's email address 2025-05-22 14:29:46 +02:00
Makefile Linux 6.12.30 2025-05-22 14:29:54 +02:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

README 

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 reStructuredText 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.