Re: [PATCH 2/3] oom, oom_reaper: Try to reap tasks which skip regular OOM killer path

[Michal Hocko <mhocko@kernel.org>]

Andrew, could you fold this in?
---
>From 9645b0518c20da67decfd2a94b1cc99ef1b4218a Mon Sep 17 00:00:00 2001
From: Michal Hocko <mhocko@suse.com>
Date: Fri, 8 Apr 2016 15:11:59 +0200
Subject: [PATCH] mm, oom_reaper: Try to reap tasks which skip regular memcg
 OOM killer path

no reason to include memcg oom killed tasks as well.

Suggested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Michal Hocko <mhocko@suse.com>
---
 include/linux/oom.h | 8 ++++++++
 mm/memcontrol.c     | 1 +
 mm/oom_kill.c       | 2 +-
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/include/linux/oom.h b/include/linux/oom.h
index 628a43242a34..83b9c39bd8b7 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -72,6 +72,14 @@ static inline bool oom_task_origin(const struct task_struct *p)
 
 extern void mark_oom_victim(struct task_struct *tsk);
 
+#ifdef CONFIG_MMU
+extern void try_oom_reaper(struct task_struct *tsk);
+#else
+static inline void try_oom_reaper(struct task_struct *tsk)
+{
+}
+#endif
+
 extern unsigned long oom_badness(struct task_struct *p,
 		struct mem_cgroup *memcg, const nodemask_t *nodemask,
 		unsigned long totalpages);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 17a847c96618..6d2f699e4d3d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1256,6 +1256,7 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
 	 */
 	if (fatal_signal_pending(current) || task_will_free_mem(current)) {
 		mark_oom_victim(current);
+		try_oom_reaper(current);
 		goto unlock;
 	}
 
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 74c38f5fffef..e656ee2c0be4 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -585,7 +585,7 @@ static void wake_oom_reaper(struct task_struct *tsk)
 /* Check if we can reap the given task. This has to be called with stable
  * tsk->mm
  */
-static void try_oom_reaper(struct task_struct *tsk)
+void try_oom_reaper(struct task_struct *tsk)
 {
 	struct mm_struct *mm = tsk->mm;
 	struct task_struct *p;
-- 
2.8.0.rc3

-- 
Michal Hocko
SUSE Labs