Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755782Ab2FTN2I (ORCPT ); Wed, 20 Jun 2012 09:28:08 -0400 Received: from cantor2.suse.de ([195.135.220.15]:49060 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751290Ab2FTN2G (ORCPT ); Wed, 20 Jun 2012 09:28:06 -0400 Date: Wed, 20 Jun 2012 15:28:04 +0200 From: Michal Hocko To: Glauber Costa Cc: linux-mm@kvack.org, Pekka Enberg , Cristoph Lameter , David Rientjes , cgroups@vger.kernel.org, devel@openvz.org, kamezawa.hiroyu@jp.fujitsu.com, linux-kernel@vger.kernel.org, Frederic Weisbecker , Suleiman Souhlal Subject: Re: [PATCH v4 06/25] memcg: Make it possible to use the stock for more than one page. Message-ID: <20120620132804.GF5541@tiehlicka.suse.cz> References: <1340015298-14133-1-git-send-email-glommer@parallels.com> <1340015298-14133-7-git-send-email-glommer@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1340015298-14133-7-git-send-email-glommer@parallels.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3059 Lines: 91 On Mon 18-06-12 14:27:59, Glauber Costa wrote: > From: Suleiman Souhlal > > Signed-off-by: Suleiman Souhlal > Signed-off-by: Glauber Costa > Acked-by: Kamezawa Hiroyuki I am not sure the patch is good to merge on its own without the rest. One comment bellow. > --- > mm/memcontrol.c | 18 +++++++++--------- > 1 file changed, 9 insertions(+), 9 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index ce15be4..00b9f1e 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -1998,19 +1998,19 @@ static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); > static DEFINE_MUTEX(percpu_charge_mutex); > > /* > - * Try to consume stocked charge on this cpu. If success, one page is consumed > - * from local stock and true is returned. If the stock is 0 or charges from a > - * cgroup which is not current target, returns false. This stock will be > - * refilled. > + * Try to consume stocked charge on this cpu. If success, nr_pages pages are > + * consumed from local stock and true is returned. If the stock is 0 or > + * charges from a cgroup which is not current target, returns false. > + * This stock will be refilled. > */ > -static bool consume_stock(struct mem_cgroup *memcg) > +static bool consume_stock(struct mem_cgroup *memcg, int nr_pages) > { > struct memcg_stock_pcp *stock; > bool ret = true; I guess you want: if (nr_pages > CHARGE_BATCH) return false; because you don't want to try to use stock for THP pages. > > stock = &get_cpu_var(memcg_stock); > - if (memcg == stock->cached && stock->nr_pages) > - stock->nr_pages--; > + if (memcg == stock->cached && stock->nr_pages >= nr_pages) > + stock->nr_pages -= nr_pages; > else /* need to call res_counter_charge */ > ret = false; > put_cpu_var(memcg_stock); > @@ -2309,7 +2309,7 @@ again: > VM_BUG_ON(css_is_removed(&memcg->css)); > if (mem_cgroup_is_root(memcg)) > goto done; > - if (nr_pages == 1 && consume_stock(memcg)) > + if (consume_stock(memcg, nr_pages)) > goto done; > css_get(&memcg->css); > } else { > @@ -2334,7 +2334,7 @@ again: > rcu_read_unlock(); > goto done; > } > - if (nr_pages == 1 && consume_stock(memcg)) { > + if (consume_stock(memcg, nr_pages)) { > /* > * It seems dagerous to access memcg without css_get(). > * But considering how consume_stok works, it's not > -- > 1.7.10.2 > > -- > 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 -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/