Date: Wed, 13 Sep 2017 14:59:57 -0700
From: Roman Gushchin <guro@fb.com>
To: David Rientjes <rientjes@google.com>
CC: <linux-mm@kvack.org>, Michal Hocko <mhocko@kernel.org>,
        Vladimir Davydov <vdavydov.dev@gmail.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
        Andrew Morton <akpm@linux-foundation.org>, Tejun Heo <tj@kernel.org>,
        <kernel-team@fb.com>, <cgroups@vger.kernel.org>,
        <linux-doc@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [v8 2/4] mm, oom: cgroup-aware OOM killer
Message-ID: <20170913215957.GB19259@castle>
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On Wed, Sep 13, 2017 at 01:46:51PM -0700, David Rientjes wrote:
> On Mon, 11 Sep 2017, Roman Gushchin wrote:
> 
> > diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> > index 15af3da5af02..da2b12ea4667 100644
> > --- a/mm/memcontrol.c
> > +++ b/mm/memcontrol.c
> > @@ -2661,6 +2661,231 @@ static inline bool memcg_has_children(struct mem_cgroup *memcg)
> >  	return ret;
> >  }
> >  
> > +static long memcg_oom_badness(struct mem_cgroup *memcg,
> > +			      const nodemask_t *nodemask,
> > +			      unsigned long totalpages)
> > +{
> > +	long points = 0;
> > +	int nid;
> > +	pg_data_t *pgdat;
> > +
> > +	/*
> > +	 * We don't have necessary stats for the root memcg,
> > +	 * so we define it's oom_score as the maximum oom_score
> > +	 * of the belonging tasks.
> > +	 */
> > +	if (memcg == root_mem_cgroup) {
> > +		struct css_task_iter it;
> > +		struct task_struct *task;
> > +		long score, max_score = 0;
> > +
> > +		css_task_iter_start(&memcg->css, 0, &it);
> > +		while ((task = css_task_iter_next(&it))) {
> > +			score = oom_badness(task, memcg, nodemask,
> > +					    totalpages);
> > +			if (max_score > score)
> 
> score > max_score

Ups. Fixed. Thanks!