From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with ESMTP id 572246B00B4 for ; Tue, 9 Mar 2010 22:56:38 -0500 (EST) Received: from d23relay05.au.ibm.com (d23relay05.au.ibm.com [202.81.31.247]) by e23smtp09.au.ibm.com (8.14.3/8.13.1) with ESMTP id o2A3uQq4027766 for ; Wed, 10 Mar 2010 14:56:26 +1100 Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay05.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o2A3oebh1560596 for ; Wed, 10 Mar 2010 14:50:40 +1100 Received: from d23av03.au.ibm.com (loopback [127.0.0.1]) by d23av03.au.ibm.com (8.14.3/8.13.1/NCO v10.0 AVout) with ESMTP id o2A3uPjb016483 for ; Wed, 10 Mar 2010 14:56:26 +1100 Date: Wed, 10 Mar 2010 09:26:24 +0530 From: Balbir Singh Subject: Re: [PATCH mmotm 2.5/4] memcg: disable irq at page cgroup lock (Re: [PATCH -mmotm 3/4] memcg: dirty pages accounting and limiting infrastructure) Message-ID: <20100310035624.GP3073@balbir.in.ibm.com> Reply-To: balbir@linux.vnet.ibm.com References: <20100308105641.e2e714f4.kamezawa.hiroyu@jp.fujitsu.com> <20100308111724.3e48aee3.nishimura@mxp.nes.nec.co.jp> <20100308113711.d7a249da.kamezawa.hiroyu@jp.fujitsu.com> <20100308170711.4d8b02f0.nishimura@mxp.nes.nec.co.jp> <20100308173100.b5997fd4.kamezawa.hiroyu@jp.fujitsu.com> <20100309001252.GB13490@linux> <20100309091914.4b5f6661.kamezawa.hiroyu@jp.fujitsu.com> <20100309102928.9f36d2bb.nishimura@mxp.nes.nec.co.jp> <20100309045058.GX3073@balbir.in.ibm.com> <20100310104309.c5f9c9a9.nishimura@mxp.nes.nec.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20100310104309.c5f9c9a9.nishimura@mxp.nes.nec.co.jp> Sender: owner-linux-mm@kvack.org To: Daisuke Nishimura Cc: linux-mm@kvack.org, Andrea Righi , linux-kernel@vger.kernel.org, Trond Myklebust , Suleiman Souhlal , Andrew Morton , containers@lists.linux-foundation.org, Vivek Goyal List-ID: * nishimura@mxp.nes.nec.co.jp [2010-03-10 10:43:09]: > > Please please measure the performance overhead of this change. > > > > here. > > > > > > > > I made a patch below and measured the time(average of 10 times) of kernel build > > > > > > > on tmpfs(make -j8 on 8 CPU machine with 2.6.33 defconfig). > > > > > > > > > > > > > > > > > > > > > - root cgroup: 190.47 sec > > > > > > > - child cgroup: 192.81 sec > > > > > > > > > > > > > > > > > > > > > - root cgroup: 191.06 sec > > > > > > > - child cgroup: 193.06 sec > > > > > > > > > > - root cgroup: 191.42 sec > - child cgroup: 193.55 sec > > hmm, I think it's in error range, but I can see a tendency by testing several times > that it's getting slower as I add additional codes. Using local_irq_disable()/enable() > except in mem_cgroup_update_file_mapped(it can be the only candidate to be called > with irq disabled in future) might be the choice. > Error range would depend on things like standard deviation and repetition. It might be good to keep update_file_mapped and see the impact. My concern is with large systems, the difference might be larger. -- Three Cheers, Balbir -- 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