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.

[akpm@linux-foundation.org: remove comment about now-removed mm_is_oom_victim()]
Link: https://lkml.kernel.org/r/20220531223100.510392-2-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christian Brauner (Microsoft) <brauner@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/oom.h b/include/linux/oom.h
index 6cdde62b078b5efe361ed7c289e153b3aa7682b1..7d0c9c48a0c54e7265e2dc872d7f81c60463788a 100644 (file)
--- 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 4d0a5be28b70f11ef5e17acf8eb6033fac9606d4..8270ad7ae14c2ab8f70c9d1b1687476dd8e06d56 100644 (file)
--- a/include/linux/sched/coredump.h
+++ b/include/linux/sched/coredump.h
@@ -71,9 +71,8 @@ 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
@@ -81,7 +80,7 @@ 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/mmap.c b/mm/mmap.c
index be111bbe807547b48a26dbfdd4ee05c005fc6d23..2a62d589d3c27d2937e4f19f160e9b5ffc9ea72e 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -3105,8 +3105,7 @@ void exit_mmap(struct mm_struct *mm)
 
        /*
         * Set MMF_OOM_SKIP to hide this task from the oom killer/reaper
-        * because the memory has been already freed. Do not bother checking
-        * mm_is_oom_victim because setting a bit unconditionally is cheaper.
+        * because the memory has been already freed.
         */
        set_bit(MMF_OOM_SKIP, &mm->flags);
        mmap_write_lock(mm);

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index decb21474c6c5da7aafac65572456cace4fc9240..35ec75cdfee21ee8f1d79acbe8d19bc383893610 100644 (file)
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -765,10 +765,8 @@ 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