From bb29902a7515208846114b3b36a4281a9bbf766a Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Fri, 25 Mar 2016 14:20:44 -0700
Subject: [PATCH] oom, oom_reaper: protect oom_reaper_list using simpler way
"oom, oom_reaper: disable oom_reaper for oom_kill_allocating_task" tried
to protect oom_reaper_list using MMF_OOM_KILLED flag. But we can do it
by simply checking tsk->oom_reaper_list != NULL.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
include/linux/sched.h | 2 --
mm/oom_kill.c | 8 ++------
2 files changed, 2 insertions(+), 8 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 49b1febcf7c31..60bba7e032dc3 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -512,8 +512,6 @@ static inline int get_dumpable(struct mm_struct *mm)
#define MMF_HAS_UPROBES 19 /* has uprobes */
#define MMF_RECALC_UPROBES 20 /* MMF_HAS_UPROBES can be wrong */
-#define MMF_OOM_KILLED 21 /* OOM killer has chosen this mm */
-
#define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
struct sighand_struct {
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 8cc55f0f0e5cd..b34d279a7ee6c 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -547,7 +547,7 @@ static int oom_reaper(void *unused)
static void wake_oom_reaper(struct task_struct *tsk)
{
- if (!oom_reaper_th)
+ if (!oom_reaper_th || tsk->oom_reaper_list)
return;
get_task_struct(tsk);
@@ -681,7 +681,7 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p,
unsigned int victim_points = 0;
static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL,
DEFAULT_RATELIMIT_BURST);
- bool can_oom_reap;
+ bool can_oom_reap = true;
/*
* If the task is already exiting, don't alarm the sysadmin or kill
@@ -743,10 +743,6 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p,
/* Get a reference to safely compare mm after task_unlock(victim) */
mm = victim->mm;
atomic_inc(&mm->mm_count);
-
- /* Make sure we do not try to oom reap the mm multiple times */
- can_oom_reap = !test_and_set_bit(MMF_OOM_KILLED, &mm->flags);
-
/*
* We should send SIGKILL before setting TIF_MEMDIE in order to prevent
* the OOM victim from depleting the memory reserves from the user
--
GitLab