From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 67DF1C67863 for ; Mon, 22 Oct 2018 08:48:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1C49E20658 for ; Mon, 22 Oct 2018 08:48:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C49E20658 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728200AbeJVRGT (ORCPT ); Mon, 22 Oct 2018 13:06:19 -0400 Received: from mx2.suse.de ([195.135.220.15]:33126 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727388AbeJVRGS (ORCPT ); Mon, 22 Oct 2018 13:06:18 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 418E4AE10; Mon, 22 Oct 2018 08:48:43 +0000 (UTC) Date: Mon, 22 Oct 2018 10:48:42 +0200 From: Michal Hocko To: Tetsuo Handa Cc: linux-mm@kvack.org, Johannes Weiner , David Rientjes , Andrew Morton , LKML Subject: Re: [RFC PATCH 1/2] mm, oom: marks all killed tasks as oom victims Message-ID: <20181022084842.GW18839@dhcp22.suse.cz> References: <20181022071323.9550-1-mhocko@kernel.org> <20181022071323.9550-2-mhocko@kernel.org> <201810220758.w9M7wojE016890@www262.sakura.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201810220758.w9M7wojE016890@www262.sakura.ne.jp> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 22-10-18 16:58:50, Tetsuo Handa wrote: > Michal Hocko wrote: > > --- a/mm/oom_kill.c > > +++ b/mm/oom_kill.c > > @@ -898,6 +898,7 @@ static void __oom_kill_process(struct task_struct *victim) > > if (unlikely(p->flags & PF_KTHREAD)) > > continue; > > do_send_sig_info(SIGKILL, SEND_SIG_FORCED, p, PIDTYPE_TGID); > > + mark_oom_victim(p); > > } > > rcu_read_unlock(); > > > > -- > > Wrong. Either You are right. The mm might go away between process_shares_mm and here. While your find_lock_task_mm would be correct I believe we can do better by using the existing mm that we already have. I will make it a separate patch to clarity. Thanks for pointing this out. diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 188ae490cf3e..4c205061ed67 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -663,6 +663,7 @@ static inline void wake_oom_reaper(struct task_struct *tsk) /** * mark_oom_victim - mark the given task as OOM victim * @tsk: task to mark + * @mm: mm associated with the task * * Has to be called with oom_lock held and never after * oom has been disabled already. @@ -670,10 +671,8 @@ static inline void wake_oom_reaper(struct task_struct *tsk) * tsk->mm has to be non NULL and caller has to guarantee it is stable (either * under task_lock or operate on the current). */ -static void mark_oom_victim(struct task_struct *tsk) +static void mark_oom_victim(struct task_struct *tsk, struct mm_struct *mm) { - struct mm_struct *mm = tsk->mm; - WARN_ON(oom_killer_disabled); /* OOM killer might race with memcg OOM */ if (test_and_set_tsk_thread_flag(tsk, TIF_MEMDIE)) @@ -860,7 +859,7 @@ static void __oom_kill_process(struct task_struct *victim) * reserves from the user space under its control. */ do_send_sig_info(SIGKILL, SEND_SIG_FORCED, victim, PIDTYPE_TGID); - mark_oom_victim(victim); + mark_oom_victim(victim, mm); pr_err("Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB\n", task_pid_nr(victim), victim->comm, K(victim->mm->total_vm), K(get_mm_counter(victim->mm, MM_ANONPAGES)), @@ -898,7 +897,7 @@ static void __oom_kill_process(struct task_struct *victim) if (unlikely(p->flags & PF_KTHREAD)) continue; do_send_sig_info(SIGKILL, SEND_SIG_FORCED, p, PIDTYPE_TGID); - mark_oom_victim(p); + mark_oom_victim(p, mm); } rcu_read_unlock(); @@ -942,7 +941,7 @@ static void oom_kill_process(struct oom_control *oc, const char *message) */ task_lock(p); if (task_will_free_mem(p)) { - mark_oom_victim(p); + mark_oom_victim(p, p->mm); wake_oom_reaper(p); task_unlock(p); put_task_struct(p); @@ -1072,7 +1071,7 @@ bool out_of_memory(struct oom_control *oc) * quickly exit and free its memory. */ if (task_will_free_mem(current)) { - mark_oom_victim(current); + mark_oom_victim(current, current->mm); wake_oom_reaper(current); return true; } -- Michal Hocko SUSE Labs