From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f70.google.com (mail-it0-f70.google.com [209.85.214.70]) by kanga.kvack.org (Postfix) with ESMTP id C649F6B0253 for ; Thu, 7 Jul 2016 12:01:46 -0400 (EDT) Received: by mail-it0-f70.google.com with SMTP id j185so57545619ith.0 for ; Thu, 07 Jul 2016 09:01:46 -0700 (PDT) Received: from www262.sakura.ne.jp (www262.sakura.ne.jp. [2001:e42:101:1:202:181:97:72]) by mx.google.com with ESMTPS id l204si2623044oig.178.2016.07.07.09.01.45 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 07 Jul 2016 09:01:46 -0700 (PDT) Subject: [PATCH 2/6] mm,oom_reaper: Do not attempt to reap a task twice. From: Tetsuo Handa References: <201607080058.BFI87504.JtFOOFQFVHSLOM@I-love.SAKURA.ne.jp> In-Reply-To: <201607080058.BFI87504.JtFOOFQFVHSLOM@I-love.SAKURA.ne.jp> Message-Id: <201607080101.CCE57351.tQFOOVOFJSHMLF@I-love.SAKURA.ne.jp> Date: Fri, 8 Jul 2016 01:01:36 +0900 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: akpm@linux-foundation.org, oleg@redhat.com, rientjes@google.com, vdavydov@parallels.com, mst@redhat.com, mhocko@suse.com, mhocko@kernel.org >>From 50b3a862b136c783be6ce25e0f22446f15a0ab03 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Fri, 8 Jul 2016 00:28:50 +0900 Subject: [PATCH 2/6] mm,oom_reaper: Do not attempt to reap a task twice. "mm, oom_reaper: do not attempt to reap a task twice" tried to give OOM reaper one more chance to retry. But since OOM killer or one of threads sharing that mm will queue that mm immediately, retrying MMF_OOM_NOT_REAPABLE mm is unlikely helpful. Let's always set MMF_OOM_REAPED. Signed-off-by: Tetsuo Handa --- include/linux/sched.h | 1 - mm/oom_kill.c | 15 +++------------ 2 files changed, 3 insertions(+), 13 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 553af29..c0efd80 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -523,7 +523,6 @@ static inline int get_dumpable(struct mm_struct *mm) #define MMF_HAS_UPROBES 19 /* has uprobes */ #define MMF_RECALC_UPROBES 20 /* MMF_HAS_UPROBES can be wrong */ #define MMF_OOM_REAPED 21 /* mm has been already reaped */ -#define MMF_OOM_NOT_REAPABLE 22 /* mm couldn't be reaped */ #define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 951eb1b..9f0022e 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -567,20 +567,11 @@ static void oom_reap_task(struct task_struct *tsk) if (attempts <= MAX_OOM_REAP_RETRIES) goto done; + /* Ignore this mm because somebody can't call up_write(mmap_sem). */ + set_bit(MMF_OOM_REAPED, &mm->flags); + pr_info("oom_reaper: unable to reap pid:%d (%s)\n", task_pid_nr(tsk), tsk->comm); - - /* - * If we've already tried to reap this task in the past and - * failed it probably doesn't make much sense to try yet again - * so hide the mm from the oom killer so that it can move on - * to another task with a different mm struct. - */ - if (test_and_set_bit(MMF_OOM_NOT_REAPABLE, &mm->flags)) { - pr_info("oom_reaper: giving up pid:%d (%s)\n", - task_pid_nr(tsk), tsk->comm); - set_bit(MMF_OOM_REAPED, &mm->flags); - } debug_show_all_locks(); done: -- 1.8.3.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org