From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: Re: [v10 3/6] mm, oom: cgroup-aware OOM killer Date: Wed, 4 Oct 2017 16:31:38 -0400 Message-ID: <20171004203138.GA2632@cmpxchg.org> References: <20171004154638.710-1-guro@fb.com> <20171004154638.710-4-guro@fb.com> <20171004192720.GC1501@cmpxchg.org> <20171004195110.GA18900@castle> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=cmpxchg.org ; s=x; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID:Subject: Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=zlU+4zrDwluanoDTAx04ucNWn+inRvYa5zpwEYt8784=; b=B2VAqKl7UK6/xmeBxDKCTJayFq 6vwGiPIze2ja1HGAxyiclWPhXTKJ4vOBZiprXONuQxXSJwxnDGO3Y/8W6fKcvvK/cTAEVNKJu5FSg j7nn6gsY3uAxMjtHzw2OlhBvfM+PI5hnakt+jmeDl9ehklNLiKYPvborm9ZRJPuOExrw=; Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Rientjes Cc: Roman Gushchin , linux-mm@kvack.org, Michal Hocko , Vladimir Davydov , Tetsuo Handa , Andrew Morton , Tejun Heo , kernel-team@fb.com, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org On Wed, Oct 04, 2017 at 01:17:14PM -0700, David Rientjes wrote: > On Wed, 4 Oct 2017, Roman Gushchin wrote: > > > > > @@ -828,6 +828,12 @@ static void __oom_kill_process(struct task_struct *victim) > > > > struct mm_struct *mm; > > > > bool can_oom_reap = true; > > > > > > > > + if (is_global_init(victim) || (victim->flags & PF_KTHREAD) || > > > > + victim->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) { > > > > + put_task_struct(victim); > > > > + return; > > > > + } > > > > + > > > > p = find_lock_task_mm(victim); > > > > if (!p) { > > > > put_task_struct(victim); > > > > > > Is this necessary? The callers of this function use oom_badness() to > > > find a victim, and that filters init, kthread, OOM_SCORE_ADJ_MIN. > > > > It is. __oom_kill_process() is used to kill all processes belonging > > to the selected memory cgroup, so we should perform these checks > > to avoid killing unkillable processes. > > > > That's only true after the next patch in the series which uses the > oom_kill_memcg_member() callback to kill processes for oom_group, correct? > Would it be possible to move this check to that patch so it's more > obvious? Yup, I realized it when reviewing the next patch. Moving this hunk to the next patch would probably make sense. Although, us reviewers have been made aware of this now, so I don't feel strongly about it. Won't make much of a difference once the patches are merged. -- 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