From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 20 Jun 2008 09:13:16 +0900 From: KAMEZAWA Hiroyuki Subject: Re: Question : memrlimit cgroup's task_move (2.6.26-rc5-mm3) Message-Id: <20080620091316.80771d14.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20080619182556.GA10461@balbir.in.ibm.com> References: <20080619121435.f868c110.kamezawa.hiroyu@jp.fujitsu.com> <20080619182556.GA10461@balbir.in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: balbir@linux.vnet.ibm.com Cc: "linux-mm@kvack.org" , "menage@google.com" , "containers@lists.osdl.org" List-ID: On Thu, 19 Jun 2008 23:55:56 +0530 Balbir Singh wrote: > * KAMEZAWA Hiroyuki [2008-06-19 12:14:35]: > > > I used memrlimit cgroup at the first time. > > > > May I ask a question about memrlimit cgroup ? > > > > Hi, Kamezawa-San, > > Could you please review/test the patch below to see if it solves your > problem? If it does, I'll push it up to Andrew > At quick glance, > + /* > + * NOTE: Even though we do the necessary checks in can_attach(), > + * by the time we come here, there is a chance that we still > + * fail (the memrlimit cgroup has grown its usage, and the > + * addition of total_vm will no longer fit into its limit) > + */ I don't like this kind of holes. Considering tests which are usually done by developpers, the problem seems not to be mentioned as "rare".. It seems we can easily cause Warning. right ? Even if you don't want to handle this case now, please mention as "TBD" rather than as "NOTE". > + > +/* > + * Add the value val to the resource counter and check if we are > + * still under the limit. > + */ > +static inline bool res_counter_add_check(struct res_counter *cnt, > + unsigned long val) > +{ > + bool ret = false; > + unsigned long flags; > + > + spin_lock_irqsave(&cnt->lock, flags); > + if (cnt->usage + val < cnt->limit) > + ret = true; cnt->usage + val <= cnt->limit. Thanks, -Kame -- 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