From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f69.google.com (mail-wm0-f69.google.com [74.125.82.69]) by kanga.kvack.org (Postfix) with ESMTP id 54B986B02B4 for ; Wed, 30 Aug 2017 08:55:46 -0400 (EDT) Received: by mail-wm0-f69.google.com with SMTP id v2so2201812wmd.11 for ; Wed, 30 Aug 2017 05:55:46 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id u4si4465977wre.276.2017.08.30.05.55.45 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 30 Aug 2017 05:55:45 -0700 (PDT) Date: Wed, 30 Aug 2017 14:55:43 +0200 From: Michal Hocko Subject: Re: [PATCH] mm: memcontrol: use per-cpu stocks for socket memory uncharging Message-ID: <20170830125543.um72yjhzps4lbj4t@dhcp22.suse.cz> References: <20170829100150.4580-1-guro@fb.com> <20170830123655.6kce7yfkrhrhwubu@dhcp22.suse.cz> <20170830124459.GA10438@castle.DHCP.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170830124459.GA10438@castle.DHCP.thefacebook.com> Sender: owner-linux-mm@kvack.org List-ID: To: Roman Gushchin Cc: linux-mm@kvack.org, Johannes Weiner , Vladimir Davydov , cgroups@vger.kernel.org, kernel-team@fb.com, linux-kernel@vger.kernel.org On Wed 30-08-17 13:44:59, Roman Gushchin wrote: > On Wed, Aug 30, 2017 at 02:36:55PM +0200, Michal Hocko wrote: > > On Tue 29-08-17 11:01:50, Roman Gushchin wrote: > > [...] > > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > > > index b9cf3cf4a3d0..a69d23082abf 100644 > > > --- a/mm/memcontrol.c > > > +++ b/mm/memcontrol.c > > > @@ -1792,6 +1792,9 @@ static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) > > > } > > > stock->nr_pages += nr_pages; > > > > > > + if (stock->nr_pages > CHARGE_BATCH) > > > + drain_stock(stock); > > > + > > > local_irq_restore(flags); > > > } > > > > Why do we need this? In other words, why cannot we rely on draining we > > already do? > > The existing draining depends on memory pressure, so to keep > the accounting (which we expose to a user) reasonable accurate > even without memory pressure, we need to limit the size of per-cpu stocks. Why don't we need this for regular page charges? Or maybe we do but that sounds like a seprate and an unrealted fix to me. -- Michal Hocko SUSE Labs -- 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