From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751978AbZHaMJ4 (ORCPT ); Mon, 31 Aug 2009 08:09:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751360AbZHaMJ4 (ORCPT ); Mon, 31 Aug 2009 08:09:56 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:56714 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751273AbZHaMJz (ORCPT ); Mon, 31 Aug 2009 08:09:55 -0400 Message-ID: <360d07ecdf467c2e15231f420375ffee.squirrel@webmail-b.css.fujitsu.com> In-Reply-To: <20090831111146.GJ4770@balbir.in.ibm.com> References: <20090828132015.10a42e40.kamezawa.hiroyu@jp.fujitsu.com> <20090828132809.ad7cfebc.kamezawa.hiroyu@jp.fujitsu.com> <20090831111146.GJ4770@balbir.in.ibm.com> Date: Mon, 31 Aug 2009 21:09:55 +0900 (JST) Subject: Re: [RFC][PATCH 5/5] memcg: drain per cpu stock From: "KAMEZAWA Hiroyuki" To: balbir@linux.vnet.ibm.com Cc: "KAMEZAWA Hiroyuki" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "nishimura@mxp.nes.nec.co.jp" User-Agent: SquirrelMail/1.4.16 MIME-Version: 1.0 Content-Type: text/plain;charset=iso-2022-jp Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) Importance: Normal Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Balbir Singh さんは書きました： > * KAMEZAWA Hiroyuki [2009-08-28 > 13:28:09]: > >> >> Add function for dropping per-cpu stock of charges. >> This is called when >> - cpu is unplugged. >> - force_empty >> - recalim seems to be not easy. >> >> Signed-off-by: KAMEZAWA Hiroyuki > > The complexity of this patch and additional code make percpu_counter > more attractive. Why not work on percpu_counter if that is not as good > as we expect it to be and in turn help other exploiters as well. - percpu counter is slow. - percpu counter is "counter". we use res_counter not as counter but as accounting for "limit". This "borrow" charges is core of this patch. - Adding "flush" ops for percpu counter will be much more mess. - This implementation handles mem->res and mem->memsw at the same time. This reduces much overhead. Thanks, -Kame