From: Johannes Weiner <hannes@cmpxchg.org>
To: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] memcg: put soft limit reclaim out of way if the excess tree is empty
Date: Mon, 1 Aug 2016 13:17:17 -0400 [thread overview]
Message-ID: <20160801171717.GB8724@cmpxchg.org> (raw)
In-Reply-To: <20160801152454.GK13544@dhcp22.suse.cz>
On Mon, Aug 01, 2016 at 05:24:54PM +0200, Michal Hocko wrote:
> @@ -2564,7 +2559,13 @@ unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
> return 0;
>
> mctz = soft_limit_tree_node(pgdat->node_id);
> - if (soft_limit_tree_empty(mctz))
> +
> + /*
> + * Do not even bother to check the largest node if the node
root
> + * is empty. Do it lockless to prevent lock bouncing. Races
> + * are acceptable as soft limit is best effort anyway.
> + */
> + if (RB_EMPTY_ROOT(&mctz->rb_root))
> return 0;
Other than that, looks good. Please retain my
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
in version 2.
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next prev parent reply other threads:[~2016-08-01 17:17 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-01 10:00 Michal Hocko
2016-08-01 13:57 ` Vladimir Davydov
2016-08-01 14:12 ` Michal Hocko
2016-08-01 14:26 ` Vladimir Davydov
2016-08-01 15:03 ` Johannes Weiner
2016-08-01 15:24 ` Michal Hocko
2016-08-01 17:17 ` Johannes Weiner [this message]
2016-08-01 17:39 ` Michal Hocko
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