From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754111Ab2CUEtB (ORCPT ); Wed, 21 Mar 2012 00:49:01 -0400 Received: from e28smtp01.in.ibm.com ([122.248.162.1]:49840 "EHLO e28smtp01.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753438Ab2CUEs7 (ORCPT ); Wed, 21 Mar 2012 00:48:59 -0400 From: "Aneesh Kumar K.V" To: Glauber Costa , KAMEZAWA Hiroyuki Cc: linux-mm@kvack.org, mgorman@suse.de, dhillf@gmail.com, aarcange@redhat.com, mhocko@suse.cz, akpm@linux-foundation.org, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Subject: Re: [PATCH -V4 04/10] memcg: Add HugeTLB extension In-Reply-To: <4F671AE6.5020204@parallels.com> References: <1331919570-2264-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1331919570-2264-5-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <4F669C2E.1010502@jp.fujitsu.com> <874ntlkrp6.fsf@linux.vnet.ibm.com> <4F66D993.2080100@jp.fujitsu.com> <4F671AE6.5020204@parallels.com>User-Agent: Notmuch/0.11.1+346~g13d19c3 (http://notmuchmail.org) Emacs/23.3.1 (x86_64-pc-linux-gnu) Date: Wed, 21 Mar 2012 10:18:43 +0530 Message-ID: <87obrqsgno.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii x-cbid: 12032104-4790-0000-0000-000001E228CF Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Glauber Costa writes: > On 03/19/2012 11:00 AM, KAMEZAWA Hiroyuki wrote: >> (2012/03/19 15:52), Aneesh Kumar K.V wrote: >> >>> >>>>> +#ifdef CONFIG_MEM_RES_CTLR_HUGETLB >>>>> +static bool mem_cgroup_have_hugetlb_usage(struct mem_cgroup *memcg) >>>>> +{ >>>>> + int idx; >>>>> + for (idx = 0; idx< hugetlb_max_hstate; idx++) { >>>>> + if (memcg->hugepage[idx].usage> 0) >>>>> + return 1; >>>>> + } >>>>> + return 0; >>>>> +} >>>> >>>> >>>> Please use res_counter_read_u64() rather than reading the value directly. >>>> >>> >>> The open-coded variant is mostly derived from mem_cgroup_force_empty. I >>> have updated the patch to use res_counter_read_u64. >>> >> >> Ah, ok. it's(maybe) my bad. I'll schedule a fix. >> > Kame, > > I actually have it ready here. I can submit it if you want. > > This one has bitten me as well when I was trying to experiment with the > res_counter performance... Do we really need memcg.res.usage to be accurate in that while loop ? If we miss a zero update because we encountered a partial update; in the next loop we will find it zero right ? -aneesh