From bc448e897b6d24aae32701763b8a1fe15d29fa26 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Fri, 25 Mar 2016 14:20:30 -0700 Subject: [PATCH] mm, oom_reaper: report success/failure Inform about the successful/failed oom_reaper attempts and dump all the held locks to tell us more who is blocking the progress. [akpm@linux-foundation.org: fix CONFIG_MMU=n build] Signed-off-by: Michal Hocko Cc: Andrea Argangeli Cc: David Rientjes Cc: Hugh Dickins Cc: Johannes Weiner Cc: Mel Gorman Cc: Oleg Nesterov Cc: Rik van Riel Cc: Tetsuo Handa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/oom_kill.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 2830b1c6483e..30a60991173a 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -410,6 +410,8 @@ static DECLARE_WAIT_QUEUE_HEAD(oom_victims_wait); bool oom_killer_disabled __read_mostly; +#define K(x) ((x) << (PAGE_SHIFT-10)) + #ifdef CONFIG_MMU /* * OOM Reaper kernel thread which tries to reap the memory used by the OOM @@ -479,6 +481,11 @@ static bool __oom_reap_task(struct task_struct *tsk) &details); } tlb_finish_mmu(&tlb, 0, -1); + pr_info("oom_reaper: reaped process %d (%s), now anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB\n", + task_pid_nr(tsk), tsk->comm, + K(get_mm_counter(mm, MM_ANONPAGES)), + K(get_mm_counter(mm, MM_FILEPAGES)), + K(get_mm_counter(mm, MM_SHMEMPAGES))); up_read(&mm->mmap_sem); /* @@ -495,14 +502,21 @@ out: return ret; } +#define MAX_OOM_REAP_RETRIES 10 static void oom_reap_task(struct task_struct *tsk) { int attempts = 0; /* Retry the down_read_trylock(mmap_sem) a few times */ - while (attempts++ < 10 && !__oom_reap_task(tsk)) + while (attempts++ < MAX_OOM_REAP_RETRIES && !__oom_reap_task(tsk)) schedule_timeout_idle(HZ/10); + if (attempts > MAX_OOM_REAP_RETRIES) { + pr_info("oom_reaper: unable to reap pid:%d (%s)\n", + task_pid_nr(tsk), tsk->comm); + debug_show_all_locks(); + } + /* Drop a reference taken by wake_oom_reaper */ put_task_struct(tsk); } @@ -649,7 +663,6 @@ static bool process_shares_mm(struct task_struct *p, struct mm_struct *mm) return false; } -#define K(x) ((x) << (PAGE_SHIFT-10)) /* * Must be called while holding a reference to p, which will be released upon * returning. -- 2.20.1