From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752094AbZH1PM2 (ORCPT ); Fri, 28 Aug 2009 11:12:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751737AbZH1PM2 (ORCPT ); Fri, 28 Aug 2009 11:12:28 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:49281 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751618AbZH1PM1 (ORCPT ); Fri, 28 Aug 2009 11:12:27 -0400 Message-ID: <25afd2b84c65e7c2c8f2edde31c914f7.squirrel@webmail-b.css.fujitsu.com> In-Reply-To: <20090828150829.GR4889@balbir.in.ibm.com> References: <20090828132015.10a42e40.kamezawa.hiroyu@jp.fujitsu.com> <20090828132321.e4a497bb.kamezawa.hiroyu@jp.fujitsu.com> <20090828072007.GH4889@balbir.in.ibm.com> <20090828163523.e51678be.kamezawa.hiroyu@jp.fujitsu.com> <20090828132643.GM4889@balbir.in.ibm.com> <712c0209222358d9c7d1e33f93e21c30.squirrel@webmail-b.css.fujitsu.com> <20090828144648.GO4889@balbir.in.ibm.com> <20090828150829.GR4889@balbir.in.ibm.com> Date: Sat, 29 Aug 2009 00:12:26 +0900 (JST) Subject: Re: [RFC][PATCH 1/5] memcg: change for softlimit. 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: 8bit 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 wrote: > * KAMEZAWA Hiroyuki [2009-08-29 > 00:06:23]: > >> Balbir Singh wrote: >> > * KAMEZAWA Hiroyuki [2009-08-28 >> > 23:40:56]: >> > >> >> KAMEZAWA Hiroyuki wrote: >> >> > Balbir Singh wrote: >> >> >> But Bob and Mike might need to set soft limits between themselves. >> if >> >> >> soft limit of gold is 1G and bob needs to be close to 750M and >> mike >> >> >> 250M, how do we do it without supporting what we have today? >> >> >> >> >> > Don't use hierarchy or don't use softlimit. >> >> > (I never think fine-grain soft limit can be useful.) >> >> > >> >> > Anyway, I have to modify unnecessary hacks for res_counter of >> >> softlimit. >> >> > plz allow modification. that's bad. >> >> > I postpone RB-tree breakage problem, plz explain it or fix it by >> >> yourself. >> >> > >> >> I changed my mind....per-zone RB-tree is also broken ;) >> >> >> >> Why I don't like broken system is a function which a user can't >> >> know/calculate how-it-works is of no use in mission critical systems. >> >> >> >> I'd like to think how-to-fix it with better algorithm. Maybe RB-tree >> >> is not a choice. >> >> >> > >> > Soft limits are not meant for mission critical work :-) Soft limits is >> > best effort and not a guaranteed resource allocation mechanism. I've >> > mentioned in previous emails how we recover if we find the data is >> > stale >> > >> yes. but can you explain how selection will be done to users ? >> I can't. >> > > From a user point, we get what we set, but the timelines can be a > little longer. > I'll drop this patch, anyway. But will modify res_counter. We have to reduce ops under lock after we see spinlock can explode system time. Thanks, -Kame