From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id 0EC1B6200FA for ; Mon, 2 Aug 2010 23:18:01 -0400 (EDT) Received: from d03relay01.boulder.ibm.com (d03relay01.boulder.ibm.com [9.17.195.226]) by e37.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id o733KRoM018565 for ; Mon, 2 Aug 2010 21:20:27 -0600 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay01.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o733MLmL151102 for ; Mon, 2 Aug 2010 21:22:21 -0600 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id o733MKnF005949 for ; Mon, 2 Aug 2010 21:22:20 -0600 Date: Tue, 3 Aug 2010 08:52:16 +0530 From: Balbir Singh Subject: Re: [PATCH -mm 1/5] quick lookup memcg by ID Message-ID: <20100803032216.GC3863@balbir.in.ibm.com> Reply-To: balbir@linux.vnet.ibm.com References: <20100802191113.05c982e4.kamezawa.hiroyu@jp.fujitsu.com> <20100802191304.8e520808.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20100802191304.8e520808.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: linux-mm@kvack.org, "nishimura@mxp.nes.nec.co.jp" , vgoyal@redhat.com, m-ikeda@ds.jp.nec.com, gthelen@google.com, "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" List-ID: * KAMEZAWA Hiroyuki [2010-08-02 19:13:04]: > From: KAMEZAWA Hiroyuki > > Now, memory cgroup has an ID per cgroup and make use of it at > - hierarchy walk, > - swap recording. > > This patch is for making more use of it. The final purpose is > to replace page_cgroup->mem_cgroup's pointer to an unsigned short. > > This patch caches a pointer of memcg in an array. By this, we > don't have to call css_lookup() which requires radix-hash walk. > This saves some amount of memory footprint at lookup memcg via id. > It is a memory versus speed tradeoff, but if the number of created cgroups is low, it might not be all that slow, besides we do that for swap_cgroup anyway - no? -- 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