From: Michal Hocko <mhocko@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>,
Mel Gorman <mgorman@suse.de>,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
Oleg Nesterov <oleg@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Hugh Dickins <hughd@google.com>,
Andrea Argangeli <andrea@kernel.org>,
Rik van Riel <riel@redhat.com>, <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Michal Hocko <mhocko@suse.com>
Subject: [PATCH 2/5] oom reaper: handle mlocked pages
Date: Wed, 3 Feb 2016 14:13:57 +0100 [thread overview]
Message-ID: <1454505240-23446-3-git-send-email-mhocko@kernel.org> (raw)
In-Reply-To: <1454505240-23446-1-git-send-email-mhocko@kernel.org>
From: Michal Hocko <mhocko@suse.com>
__oom_reap_vmas current skips over all mlocked vmas because they need a
special treatment before they are unmapped. This is primarily done for
simplicity. There is no reason to skip over them and reduce the amount
of reclaimed memory. This is safe from the semantic point of view
because try_to_unmap_one during rmap walk would keep tell the reclaim
to cull the page back and mlock it again.
munlock_vma_pages_all is also safe to be called from the oom reaper
context because it doesn't sit on any locks but mmap_sem (for read).
Signed-off-by: Michal Hocko <mhocko@suse.com>
---
mm/oom_kill.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 9a0e4e5f50b4..840e03986497 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -443,13 +443,6 @@ static bool __oom_reap_vmas(struct mm_struct *mm)
continue;
/*
- * mlocked VMAs require explicit munlocking before unmap.
- * Let's keep it simple here and skip such VMAs.
- */
- if (vma->vm_flags & VM_LOCKED)
- continue;
-
- /*
* Only anonymous pages have a good chance to be dropped
* without additional steps which we cannot afford as we
* are OOM already.
@@ -459,9 +452,12 @@ static bool __oom_reap_vmas(struct mm_struct *mm)
* we do not want to block exit_mmap by keeping mm ref
* count elevated without a good reason.
*/
- if (vma_is_anonymous(vma) || !(vma->vm_flags & VM_SHARED))
+ if (vma_is_anonymous(vma) || !(vma->vm_flags & VM_SHARED)) {
+ if (vma->vm_flags & VM_LOCKED)
+ munlock_vma_pages_all(vma);
unmap_page_range(&tlb, vma, vma->vm_start, vma->vm_end,
&details);
+ }
}
tlb_finish_mmu(&tlb, 0, -1);
up_read(&mm->mmap_sem);
--
2.7.0
next prev parent reply other threads:[~2016-02-03 13:15 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-03 13:13 [PATCH 0/5] oom reaper v5 Michal Hocko
2016-02-03 13:13 ` [PATCH 1/5] mm, oom: introduce oom reaper Michal Hocko
2016-02-03 23:48 ` David Rientjes
2016-02-04 6:41 ` Michal Hocko
2016-02-06 13:22 ` Tetsuo Handa
2016-02-15 20:50 ` Michal Hocko
2016-02-03 13:13 ` Michal Hocko [this message]
2016-02-03 23:57 ` [PATCH 2/5] oom reaper: handle mlocked pages David Rientjes
2016-02-23 1:36 ` David Rientjes
2016-02-23 13:21 ` Michal Hocko
2016-02-29 3:19 ` Hugh Dickins
2016-02-29 13:41 ` Michal Hocko
2016-03-08 13:40 ` Michal Hocko
2016-03-08 20:07 ` Hugh Dickins
2016-03-09 8:26 ` Michal Hocko
2016-02-03 13:13 ` [PATCH 3/5] oom: clear TIF_MEMDIE after oom_reaper managed to unmap the address space Michal Hocko
2016-02-04 14:22 ` Tetsuo Handa
2016-02-04 14:43 ` Michal Hocko
2016-02-04 15:08 ` Tetsuo Handa
2016-02-04 16:31 ` Michal Hocko
2016-02-05 11:14 ` Tetsuo Handa
2016-02-06 8:30 ` Michal Hocko
2016-02-06 11:23 ` Tetsuo Handa
2016-02-15 20:47 ` Michal Hocko
2016-02-06 6:45 ` Michal Hocko
2016-02-06 14:33 ` Tetsuo Handa
2016-02-15 20:40 ` [PATCH 3.1/5] oom: make oom_reaper freezable Michal Hocko
2016-02-03 13:13 ` [PATCH 4/5] mm, oom_reaper: report success/failure Michal Hocko
2016-02-03 23:10 ` David Rientjes
2016-02-04 6:46 ` Michal Hocko
2016-02-04 22:31 ` David Rientjes
2016-02-05 9:26 ` Michal Hocko
2016-02-06 6:34 ` Michal Hocko
2016-02-03 13:14 ` [PATCH 5/5] mm, oom_reaper: implement OOM victims queuing Michal Hocko
2016-02-04 10:49 ` Tetsuo Handa
2016-02-04 14:53 ` Michal Hocko
2016-02-06 5:54 ` Tetsuo Handa
2016-02-06 8:37 ` Michal Hocko
2016-02-06 15:33 ` Tetsuo Handa
2016-02-15 20:15 ` Michal Hocko
2016-02-16 11:11 ` Tetsuo Handa
2016-02-16 15:53 ` Michal Hocko
2016-02-17 9:48 ` [PATCH 6/5] oom, oom_reaper: disable oom_reaper for Michal Hocko
2016-02-17 10:41 ` Tetsuo Handa
2016-02-17 11:33 ` Michal Hocko
2016-02-19 18:34 ` Michal Hocko
2016-02-20 2:32 ` [PATCH 6/5] oom, oom_reaper: disable oom_reaper for oom_kill_allocating_task Tetsuo Handa
2016-02-22 9:41 ` Michal Hocko
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