The patch titled
Subject: mm: oom: terminate the oom_evaluate_task() loop early
has been added to the -mm mm-unstable branch. Its filename is
mm-oom-terminate-the-oom_evaluate_task-loop-early.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-oom-terminate-the-oom_evaluate_task-loop-early.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: ZhangPeng <zhangpeng362@xxxxxxxxxx>
Subject: mm: oom: terminate the oom_evaluate_task() loop early
Date: Mon, 14 Aug 2023 14:34:28 +0800
If task is allocating a lot of memory and has been marked to be killed
first, then it gets the highest score (LONG_MAX). Therefore, there is no
need to continue to calculate the points of other tasks. Just terminate
the oom_evaluate_task() loop early, when the task with the highest score
is found. By doing this, we can get some performance gains in
select_bad_process().
To implement it, the return value of oom_evaluate_task() is modified.
When the task with the highest score is found (points == LONG_MAX),
oom_evaluate_task() will return 1 and the loop will terminate early.
Link: https://lkml.kernel.org/r/20230814063428.4111206-3-zhangpeng362@xxxxxxxxxx
Signed-off-by: ZhangPeng <zhangpeng362@xxxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Nanyong Sun <sunnanyong@xxxxxxxxxx>
Cc: Shakeel Butt <shakeelb@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/oom_kill.c | 2 ++
1 file changed, 2 insertions(+)
--- a/mm/oom_kill.c~mm-oom-terminate-the-oom_evaluate_task-loop-early
+++ a/mm/oom_kill.c
@@ -346,6 +346,8 @@ static int oom_evaluate_task(struct task
get_task_struct(task);
oc->chosen = task;
oc->chosen_points = points;
+ if (points == LONG_MAX)
+ return 1;
next:
return 0;
abort:
_
Patches currently in -mm which might be from zhangpeng362@xxxxxxxxxx are
mm-kmsan-use-helper-function-page_size.patch
mm-kmsan-use-helper-macro-offset_in_page.patch
mm-kmsan-use-helper-macros-page_align-and-page_align_down.patch
mm-remove-redundant-k-macro-definition.patch
mm-swapfilec-use-helper-macro-k.patch
mm-swap_statec-use-helper-macro-k.patch
mm-shmemc-use-helper-macro-k.patch
mm-nommuc-use-helper-macro-k.patch
mm-mmapc-use-helper-macro-k.patch
mm-hugetlbc-use-helper-macro-k.patch
mm-page_alloc-remove-unused-parameter-from-reserve_highatomic_pageblock.patch
mm-oom-remove-unnecessary-goto-in-oom_evaluate_task.patch
mm-oom-terminate-the-oom_evaluate_task-loop-early.patch
