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zhongjinji 59d4d36158 mm/oom_kill: thaw the entire OOM victim process
Patch series "Improvements to Victim Process Thawing and OOM Reaper
Traversal Order", v10.

This patch series focuses on optimizing victim process thawing and
refining the traversal order of the OOM reaper.  Since __thaw_task() is
used to thaw a single thread of the victim, thawing only one thread cannot
guarantee the exit of the OOM victim when it is frozen.  Patch 1 thaw the
entire process of the OOM victim to ensure that OOM victims are able to
terminate themselves.  Even if the oom_reaper is delayed, patch 2 is still
beneficial for reaping processes with a large address space footprint, and
it also greatly improves process_mrelease.


This patch (of 10):

OOM killer is a mechanism that selects and kills processes when the system
runs out of memory to reclaim resources and keep the system stable.  But
the oom victim cannot terminate on its own when it is frozen, even if the
OOM victim task is thawed through __thaw_task().  This is because
__thaw_task() can only thaw a single OOM victim thread, and cannot thaw
the entire OOM victim process.

In addition, freezing_slow_path() determines whether a task is an OOM
victim by checking the task's TIF_MEMDIE flag.  When a task is identified
as an OOM victim, the freezer bypasses both PM freezing and cgroup
freezing states to thaw it.

Historically, TIF_MEMDIE was a "this is the oom victim & it has access to
memory reserves" flag in the past.  It has that thread vs.  process
problems and tsk_is_oom_victim was introduced later to get rid of them and
other issues as well as the guarantee that we can identify the oom
victim's mm reliably for other oom_reaper.

Therefore, thaw_process() is introduced to unfreeze all threads within the
OOM victim process, ensuring that every thread is properly thawed.  The
freezer now uses tsk_is_oom_victim() to determine OOM victim status,
allowing all victim threads to be unfrozen as necessary.

With this change, the entire OOM victim process will be thawed when an OOM
event occurs, ensuring that the victim can terminate on its own.

Link: https://lkml.kernel.org/r/20250915162946.5515-1-zhongjinji@honor.com
Link: https://lkml.kernel.org/r/20250915162946.5515-2-zhongjinji@honor.com
Signed-off-by: zhongjinji <zhongjinji@honor.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
History 2025-09-21 14:22:35 -07:00
arch ptdesc: remove ptdesc_to_virt() 2025-09-21 14:22:27 -07:00
block block: use largest_zero_folio in __blkdev_issue_zero_pages() 2025-09-13 16:54:54 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: remove nth_page() usage within SG entry 2025-09-21 14:22:09 -07:00
Documentation docs/mm: add document for swap table 2025-09-21 14:22:22 -07:00
drivers mm: make folio page count functions return unsigned 2025-09-21 14:22:31 -07:00
fs mm/hwpoison: decouple hwpoison_filter from mm/memory-failure.c 2025-09-21 14:22:21 -07:00
include mm/oom_kill: thaw the entire OOM victim process 2025-09-21 14:22:35 -07:00
init init/main.c: fix boot time tracing crash 2025-09-03 17:10:36 -07:00
io_uring io_uring/zcrx: remove nth_page() usage within folio 2025-09-21 14:22:05 -07:00
ipc vfs-6.17-rc1.mmap_prepare 2025-07-28 13:43:25 -07:00
kernel mm/oom_kill: thaw the entire OOM victim process 2025-09-21 14:22:35 -07:00
lib alloc_tag: prevent enabling memory profiling if it was shut down 2025-09-21 14:22:30 -07:00
LICENSES LICENSES: Replace the obsolete address of the FSF in the GFDL-1.2 2025-07-24 11:15:39 +02:00
mm mm/oom_kill: thaw the entire OOM victim process 2025-09-21 14:22:35 -07:00
net net: ipv4: fix regression in local-broadcast routes 2025-08-28 10:52:30 +02:00
rust rust: maple_tree: add MapleTreeAlloc 2025-09-21 14:22:19 -07:00
samples samples/cgroup: rm unused MEMCG_EVENTS macro 2025-09-21 14:22:26 -07:00
scripts scripts/decode_stacktrace.sh: code: preserve alignment 2025-09-21 14:22:28 -07:00
security + Features 2025-08-04 08:17:28 -07:00
sound ALSA: hda/hdmi: Add pin fix for another HP EliteDesk 800 G4 model 2025-09-01 13:51:57 +02:00
tools selftests/mm: protection_keys: fix dead code 2025-09-21 14:22:34 -07:00
usr usr/include: openrisc: don't HDRTEST bpf_perf_event.h 2025-05-12 15:03:17 +09:00
virt Merge tag 'kvm-x86-no_assignment-6.17' of https://github.com/kvm-x86/linux into HEAD 2025-07-29 08:36:42 -04:00
.clang-format Linux 6.15-rc5 2025-05-06 16:39:25 +10:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-07 00:11:47 +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 MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore gitignore: allow .pylintrc to be tracked 2025-07-02 17:10:04 -06:00
.mailmap .mailmap: add entry for Easwar Hariharan 2025-08-19 16:35:55 -07:00
.pylintrc docs: add a .pylintrc file with sys path for docs scripts 2025-04-09 12:10:33 -06:00
.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: retire Boris from TLS maintainers 2025-08-26 17:36:01 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS mm, swap: use the swap table for the swap cache and switch API 2025-09-21 14:22:24 -07:00
Makefile Linux 6.17-rc4 2025-08-31 15:33:07 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -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 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.