From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta8.messagelabs.com (mail6.bemta8.messagelabs.com [216.82.243.55]) by kanga.kvack.org (Postfix) with ESMTP id 28B9C9000BD for ; Mon, 26 Sep 2011 06:53:05 -0400 (EDT) Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 80A5F3EE0BB for ; Mon, 26 Sep 2011 19:53:01 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 60C7945DE90 for ; Mon, 26 Sep 2011 19:53:01 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 327CA45DE92 for ; Mon, 26 Sep 2011 19:53:01 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 2122D1DB803F for ; Mon, 26 Sep 2011 19:53:01 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.240.81.133]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id D4C781DB803E for ; Mon, 26 Sep 2011 19:53:00 +0900 (JST) Date: Mon, 26 Sep 2011 19:52:13 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH v3 2/7] socket: initial cgroup code. Message-Id: <20110926195213.12da87b4.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <4E7DECF0.9050804@parallels.com> References: <1316393805-3005-1-git-send-email-glommer@parallels.com> <1316393805-3005-3-git-send-email-glommer@parallels.com> <4E7A342B.5040608@parallels.com> <4E7DECF0.9050804@parallels.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Glauber Costa Cc: Balbir Singh , Greg Thelen , linux-kernel@vger.kernel.org, paul@paulmenage.org, lizf@cn.fujitsu.com, ebiederm@xmission.com, davem@davemloft.net, netdev@vger.kernel.org, linux-mm@kvack.org, kirill@shutemov.name On Sat, 24 Sep 2011 11:45:04 -0300 Glauber Costa wrote: > On 09/22/2011 12:09 PM, Balbir Singh wrote: > > On Thu, Sep 22, 2011 at 11:30 AM, Greg Thelen wrote: > >> On Wed, Sep 21, 2011 at 11:59 AM, Glauber Costa wrote: > >>> Right now I am working under the assumption that tasks are long lived inside > >>> the cgroup. Migration potentially introduces some nasty locking problems in > >>> the mem_schedule path. > >>> > >>> Also, unless I am missing something, the memcg already has the policy of > >>> not carrying charges around, probably because of this very same complexity. > >>> > >>> True that at least it won't EBUSY you... But I think this is at least a way > >>> to guarantee that the cgroup under our nose won't disappear in the middle of > >>> our allocations. > >> > >> Here's the memcg user page behavior using the same pattern: > >> > >> 1. user page P is allocate by task T in memcg M1 > >> 2. T is moved to memcg M2. The P charge is left behind still charged > >> to M1 if memory.move_charge_at_immigrate=0; or the charge is moved to > >> M2 if memory.move_charge_at_immigrate=1. > >> 3. rmdir M1 will try to reclaim P (if P was left in M1). If unable to > >> reclaim, then P is recharged to parent(M1). > >> > > > > We also have some magic in page_referenced() to remove pages > > referenced from different containers. What we do is try not to > > penalize a cgroup if another cgroup is referencing this page and the > > page under consideration is being reclaimed from the cgroup that > > touched it. > > > > Balbir Singh > Do you guys see it as a showstopper for this series to be merged, or can > we just TODO it ? > In my experience, 'I can't rmdir cgroup.' is always an important/difficult problem. The users cannot know where the accouting is leaking other than kmem.usage_in_bytes or memory.usage_in_bytes. and can't fix the issue. please add EXPERIMENTAL to Kconfig until this is fixed. > I can push a proposal for it, but it would be done in a separate patch > anyway. Also, we may be in better conditions to fix this when the slab > part is merged - since it will likely have the same problems... > Yes. considering sockets which can be shared between tasks(cgroups) you'll finally need - owner task of socket - account moving callback Or disallow task moving once accounted. 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