From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with ESMTP id 1FC9F9000BD for ; Sat, 24 Sep 2011 09:35:04 -0400 (EDT) Message-ID: <4E7DDC3A.1060100@parallels.com> Date: Sat, 24 Sep 2011 10:33:46 -0300 From: Glauber Costa MIME-Version: 1.0 Subject: Re: [PATCH v3 2/7] socket: initial cgroup code. References: <1316393805-3005-1-git-send-email-glommer@parallels.com> <1316393805-3005-3-git-send-email-glommer@parallels.com> <4E7A342B.5040608@parallels.com> In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Balbir Singh Cc: Greg Thelen , linux-kernel@vger.kernel.org, paul@paulmenage.org, lizf@cn.fujitsu.com, kamezawa.hiroyu@jp.fujitsu.com, ebiederm@xmission.com, davem@davemloft.net, netdev@vger.kernel.org, linux-mm@kvack.org, kirill@shutemov.name 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 humm... Then we need to keep pointers to: 1) Which allocations comes from each socket, and 2) Which sockets comes from each task. 2 is pretty easy, 1 may get expensive. I will investigate it now. -- 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