Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757940Ab2FTTjY (ORCPT ); Wed, 20 Jun 2012 15:39:24 -0400 Received: from mx2.parallels.com ([64.131.90.16]:49405 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752414Ab2FTTjX (ORCPT ); Wed, 20 Jun 2012 15:39:23 -0400 Message-ID: <4FE2264F.4070805@parallels.com> Date: Wed, 20 Jun 2012 23:36:47 +0400 From: Glauber Costa User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120605 Thunderbird/13.0 MIME-Version: 1.0 To: Michal Hocko CC: , Pekka Enberg , Cristoph Lameter , David Rientjes , , , , , Frederic Weisbecker , Suleiman Souhlal Subject: Re: [PATCH v4 06/25] memcg: Make it possible to use the stock for more than one page. References: <1340015298-14133-1-git-send-email-glommer@parallels.com> <1340015298-14133-7-git-send-email-glommer@parallels.com> <20120620132804.GF5541@tiehlicka.suse.cz> In-Reply-To: <20120620132804.GF5541@tiehlicka.suse.cz> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [109.173.9.3] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2106 Lines: 56 On 06/20/2012 05:28 PM, Michal Hocko wrote: > 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. The code reads: + if (memcg == stock->cached && stock->nr_pages >= nr_pages) + stock->nr_pages -= nr_pages; Isn't stock->nr_pages always <= CHARGE_BATCH by definition? -- 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/