2022-05-16 08:28:11

by Suren Baghdasaryan

Subject: [PATCH v2 2/2] mm: delete unused MMF_OOM_VICTIM flag

With the last usage of MMF_OOM_VICTIM in exit_mmap gone, this flag is
now unused and can be removed.

Signed-off-by: Suren Baghdasaryan <[email protected]>
Acked-by: Michal Hocko <[email protected]>
---
include/linux/oom.h | 9 ---------
include/linux/sched/coredump.h | 7 +++----
mm/oom_kill.c | 4 +---
3 files changed, 4 insertions(+), 16 deletions(-)

diff --git a/include/linux/oom.h b/include/linux/oom.h
index 6cdf0772dbae..25990e9d9e15 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -77,15 +77,6 @@ static inline bool tsk_is_oom_victim(struct task_struct * tsk)
return tsk->signal->oom_mm;
}

-/*
- * Use this helper if tsk->mm != mm and the victim mm needs a special
- * handling. This is guaranteed to stay true after once set.
- */
-static inline bool mm_is_oom_victim(struct mm_struct *mm)
-{
- return test_bit(MMF_OOM_VICTIM, &mm->flags);
-}
-
/*
* Checks whether a page fault on the given mm is still reliable.
* This is no longer true if the oom reaper started to reap the
diff --git a/include/linux/sched/coredump.h b/include/linux/sched/coredump.h
index 4d9e3a656875..5318c791ad39 100644
--- a/include/linux/sched/coredump.h
+++ b/include/linux/sched/coredump.h
@@ -70,9 +70,8 @@ static inline int get_dumpable(struct mm_struct *mm)
#define MMF_UNSTABLE 22 /* mm is unstable for copy_from_user */
#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_MULTIPROCESS 27 /* mm is shared between processes */
+#define MMF_OOM_REAP_QUEUED 25 /* mm was queued for oom_reaper */
+#define MMF_MULTIPROCESS 26 /* mm is shared between processes */
/*
* MMF_HAS_PINNED: Whether this mm has pinned any pages. This can be either
* replaced in the future by mm.pinned_vm when it becomes stable, or grow into
@@ -80,7 +79,7 @@ static inline int get_dumpable(struct mm_struct *mm)
* pinned pages were unpinned later on, we'll still keep this bit set for the
* lifecycle of this mm, just for simplicity.
*/
-#define MMF_HAS_PINNED 28 /* FOLL_PIN has run, never cleared */
+#define MMF_HAS_PINNED 27 /* FOLL_PIN has run, never cleared */
#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 36355b162727..11291b99599f 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -732,10 +732,8 @@ static void mark_oom_victim(struct task_struct *tsk)
return;

/* oom_mm is bound to the signal struct life time. */
- if (!cmpxchg(&tsk->signal->oom_mm, NULL, mm)) {
+ if (!cmpxchg(&tsk->signal->oom_mm, NULL, mm))
mmgrab(tsk->signal->oom_mm);
- set_bit(MMF_OOM_VICTIM, &mm->flags);
- }

/*
* Make sure that the task is woken up from uninterruptible sleep
--
2.36.0.550.gb090851708-goog

2022-05-17 09:40:43

by Shuah Khan

Subject: Re: [PATCH v2 2/2] mm: delete unused MMF_OOM_VICTIM flag

On 5/16/22 1:56 AM, Suren Baghdasaryan wrote:
> With the last usage of MMF_OOM_VICTIM in exit_mmap gone, this flag is
> now unused and can be removed.
>
> Signed-off-by: Suren Baghdasaryan <[email protected]>
> Acked-by: Michal Hocko <[email protected]>
> ---
> include/linux/oom.h | 9 ---------
> include/linux/sched/coredump.h | 7 +++----
> mm/oom_kill.c | 4 +---
> 3 files changed, 4 insertions(+), 16 deletions(-)
>
Looks good to me.

Reviewed-by: Shuah Khan <[email protected]>

thanks,
-- Shuah