Commit bb29902a authored by Tetsuo Handa's avatar Tetsuo Handa Committed by Linus Torvalds
Browse files

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: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: default avatarMichal Hocko <mhocko@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e2679606

include/linux/sched.h

+0 −2
Original line number Diff line number Diff line
@@ -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 {

mm/oom_kill.c

+2 −6
Original line number Diff line number Diff line
@@ -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

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