From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qg0-f72.google.com (mail-qg0-f72.google.com [209.85.192.72]) by kanga.kvack.org (Postfix) with ESMTP id 2528C6B007E for ; Mon, 30 May 2016 14:18:21 -0400 (EDT) Received: by mail-qg0-f72.google.com with SMTP id e93so323498444qgf.3 for ; Mon, 30 May 2016 11:18:21 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id z35si509019qge.18.2016.05.30.11.18.20 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 30 May 2016 11:18:20 -0700 (PDT) Date: Mon, 30 May 2016 20:18:16 +0200 From: Oleg Nesterov Subject: Re: [PATCH 5/6] mm, oom: kill all tasks sharing the mm Message-ID: <20160530181816.GA25480@redhat.com> References: <1464613556-16708-1-git-send-email-mhocko@kernel.org> <1464613556-16708-6-git-send-email-mhocko@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1464613556-16708-6-git-send-email-mhocko@kernel.org> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-mm@kvack.org, Tetsuo Handa , David Rientjes , Vladimir Davydov , Andrew Morton , LKML , Michal Hocko On 05/30, Michal Hocko wrote: > > @@ -852,8 +852,7 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p, > continue; > if (same_thread_group(p, victim)) > continue; > - if (unlikely(p->flags & PF_KTHREAD) || is_global_init(p) || > - p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) { > + if (unlikely(p->flags & PF_KTHREAD) || is_global_init(p)) { > /* > * We cannot use oom_reaper for the mm shared by this > * process because it wouldn't get killed and so the > @@ -862,6 +861,11 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p, > can_oom_reap = false; > continue; > } > + if (p->signal->oom_score_adj == OOM_ADJUST_MIN) > + pr_warn("%s pid=%d shares mm with oom disabled %s pid=%d. Seems like misconfiguration, killing anyway!" > + " Report at linux-mm@kvack.org\n", > + victim->comm, task_pid_nr(victim), > + p->comm, task_pid_nr(p)); Oh, yes, I personally do agree ;) perhaps the is_global_init() == T case needs a warning too? the previous changes take care about vfork() from /sbin/init, so the only reason we can see it true is that /sbin/init shares the memory with a memory hog... Nevermind, forget. This is a bit off-topic, but perhaps we can also change the PF_KTHREAD check later. Of course we should not try to kill this kthread, but can_oom_reap can be true in this case. A kernel thread which does use_mm() should handle the errors correctly if (say) get_user() fails because we unmap the memory. Oleg. -- 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