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>
This commit is contained in:
Tetsuo Handa 2016-03-25 14:20:44 -07:00 committed by Linus Torvalds
parent e26796066f
commit bb29902a75
2 changed files with 2 additions and 8 deletions

View File

@ -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 {

View File

@ -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