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| author | Arkadiusz Miśkiewicz | 2019-02-07 14:55:52 (GMT) |
|---|---|---|
| committer | Arkadiusz Miśkiewicz | 2019-02-07 14:55:52 (GMT) |
| commit | a95548fd21b8b36dc19b0a5922af2be3a0017233 (patch) | |
| tree | 31af1ec332a2b14a511e67c4f2043c5f9d46b050 /kernel-small_fixes.patch | |
| parent | 0ebff2b6d3172df1ecfc057cac0f52f8dc29134f (diff) | |
| download | kernel-a95548fd21b8b36dc19b0a5922af2be3a0017233.zip kernel-a95548fd21b8b36dc19b0a5922af2be3a0017233.tar.gz | |
- up to 4.20.7
Diffstat (limited to 'kernel-small_fixes.patch')
| -rw-r--r-- | kernel-small_fixes.patch | 61 |
1 files changed, 0 insertions, 61 deletions
diff --git a/kernel-small_fixes.patch b/kernel-small_fixes.patch index eb20ac4..1398e42 100644 --- a/kernel-small_fixes.patch +++ b/kernel-small_fixes.patch @@ -162,65 +162,4 @@ index 76c92e31afc0..abb5d382f64d 100644 -- cgit 1.2-0.3.lf.el7 -From 9c9e935fc038342c48461aabca666f1b544e32b1 Mon Sep 17 00:00:00 2001 -From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> -Date: Sun, 27 Jan 2019 23:51:37 +0900 -Subject: [PATCH v3] oom, oom_reaper: do not enqueue same task twice - -Arkadiusz reported that enabling memcg's group oom killing causes -strange memcg statistics where there is no task in a memcg despite -the number of tasks in that memcg is not 0. It turned out that there -is a bug in wake_oom_reaper() which allows enqueuing same task twice -which makes impossible to decrease the number of tasks in that memcg -due to a refcount leak. - -This bug existed since the OOM reaper became invokable from -task_will_free_mem(current) path in out_of_memory() in Linux 4.7, -but memcg's group oom killing made it easier to trigger this bug by -calling wake_oom_reaper() on the same task from one out_of_memory() -request. - -Fix this bug using an approach used by commit 855b018325737f76 -("oom, oom_reaper: disable oom_reaper for oom_kill_allocating_task"). -As a side effect of this patch, this patch also avoids enqueuing -multiple threads sharing memory via task_will_free_mem(current) path. - -Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> -Reported-by: Arkadiusz Miśkiewicz <arekm@maven.pl> -Tested-by: Arkadiusz Miśkiewicz <arekm@maven.pl> -Fixes: af8e15cc85a25315 ("oom, oom_reaper: do not enqueue task if it is on the oom_reaper_list head") ---- - include/linux/sched/coredump.h | 1 + - mm/oom_kill.c | 4 ++-- - 2 files changed, 3 insertions(+), 2 deletions(-) - -diff --git a/include/linux/sched/coredump.h b/include/linux/sched/coredump.h -index ec912d0..ecdc654 100644 ---- a/include/linux/sched/coredump.h -+++ b/include/linux/sched/coredump.h -@@ -71,6 +71,7 @@ static inline int get_dumpable(struct mm_struct *mm) - #define MMF_HUGE_ZERO_PAGE 23 /* mm has ever used the global huge zero page */ - #define MMF_DISABLE_THP 24 /* disable THP for all VMAs */ - #define MMF_OOM_VICTIM 25 /* mm is the oom victim */ -+#define MMF_OOM_REAP_QUEUED 26 /* mm was queued for oom_reaper */ - #define MMF_DISABLE_THP_MASK (1 << MMF_DISABLE_THP) - - #define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\ -diff --git a/mm/oom_kill.c b/mm/oom_kill.c -index f0e8cd9..059e617 100644 ---- a/mm/oom_kill.c -+++ b/mm/oom_kill.c -@@ -647,8 +647,8 @@ static int oom_reaper(void *unused) - - static void wake_oom_reaper(struct task_struct *tsk) - { -- /* tsk is already queued? */ -- if (tsk == oom_reaper_list || tsk->oom_reaper_list) -+ /* mm is already queued? */ -+ if (test_and_set_bit(MMF_OOM_REAP_QUEUED, &tsk->signal->oom_mm->flags)) - return; - - get_task_struct(tsk); --- -1.8.3.1 |