From mboxrd@z Thu Jan 1 00:00:00 1970 From: Balbir Singh Subject: Re: [RFC][PATCH 1/5] memcg: change for softlimit. Date: Fri, 28 Aug 2009 20:16:48 +0530 Message-ID: <20090828144648.GO4889@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> Reply-To: balbir@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Return-path: Content-Disposition: inline In-Reply-To: <712c0209222358d9c7d1e33f93e21c30.squirrel@webmail-b.css.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "nishimura@mxp.nes.nec.co.jp" List-Id: linux-mm.kvack.org * 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 -- Balbir