From mboxrd@z Thu Jan 1 00:00:00 1970 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH 3/7] memcg: move charges to root at rmdir() Date: Wed, 18 Apr 2012 16:02:27 +0900 Message-ID: <4F8E6703.70101@jp.fujitsu.com> References: <4F86B9BE.8000105@jp.fujitsu.com> <4F86BB02.2060607@jp.fujitsu.com> <20120416223012.GD12421@google.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120416223012.GD12421@google.com> Sender: owner-linux-mm@kvack.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Tejun Heo Cc: "linux-mm@kvack.org" , "cgroups@vger.kernel.org" , Michal Hocko , Johannes Weiner , Glauber Costa , Hugh Dickins , Andrew Morton (2012/04/17 7:30), Tejun Heo wrote: > Hello, > > On Thu, Apr 12, 2012 at 08:22:42PM +0900, KAMEZAWA Hiroyuki wrote: >> As recently discussed, Tejun Heo, the cgroup maintainer, tries to >> remove ->pre_destroy() and cgroup will never return -EBUSY at rmdir(). > > I'm not trying to remove ->pre_destory() per-se. I want to remove css > ref draining and ->pre_destroy() vetoing cgroup removal. Probably > better wording would be "tries to simplify removal path such that > removal always succeeds". > Ok. >> To do that, in memcg, handling case of use_hierarchy==false is a problem. >> >> We move memcg's charges to its parent at rmdir(). If use_hierarchy==true, >> it's already accounted in the parent, no problem. If use_hierarchy==false, >> we cannot guarantee we can move all charges to the parent. >> >> This patch changes the behavior to move all charges to root_mem_cgroup >> if use_hierarchy=false. It seems this matches semantics of use_hierarchy==false,which means parent and child has no hierarchical relationship. > > Maybe better to break the above line? > yes, I'll fix it. 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org