From mboxrd@z Thu Jan 1 00:00:00 1970 From: Balbir Singh Subject: Re: [RFC][PATCH 2/5] memcg: uncharge in batched manner Date: Mon, 31 Aug 2009 17:53:16 +0530 Message-ID: <20090831122316.GM4770@balbir.in.ibm.com> References: <20090828132015.10a42e40.kamezawa.hiroyu@jp.fujitsu.com> <20090828132438.b33828bc.kamezawa.hiroyu@jp.fujitsu.com> <20090831110204.GG4770@balbir.in.ibm.com> <119e8331d1210b1f56d0f6416863bfbc.squirrel@webmail-b.css.fujitsu.com> <20090831121008.GL4770@balbir.in.ibm.com> <48d928bed22f20fc495e9ca1758dc7ed.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: <48d928bed22f20fc495e9ca1758dc7ed.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 [2009-08-31 21:14:10]: > Balbir Singh wrote: > >> > Does this effect deleting of a group and delay it by a large amount? > >> > > >> plz see what cgroup_release_and_xxxx fixed. This is not for delay > >> but for race-condition, which makes rmdir sleep permanently. > >> > > > > I've seen those patches, where rmdir() can hang. My conern was time > > elapsed since we do css_get() and do a cgroup_release_and_wake_rmdir() > > > plz read unmap() and truncate() code. > The number of pages handled without cond_resched() is limited. > > I understand that part, I was referring to tasks stuck doing rmdir() while we do batched uncharge, will it be very visible to the end user? cond_resched() is bad in this case.. since it means we'll stay longer before we release the cgroup. -- Balbir