From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752180Ab2JAIcF (ORCPT ); Mon, 1 Oct 2012 04:32:05 -0400 Received: from mx2.parallels.com ([64.131.90.16]:51909 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751829Ab2JAIcC (ORCPT ); Mon, 1 Oct 2012 04:32:02 -0400 Message-ID: <5069542C.2020103@parallels.com> Date: Mon, 1 Oct 2012 12:28:28 +0400 From: Glauber Costa User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120911 Thunderbird/15.0.1 MIME-Version: 1.0 To: Tejun Heo CC: Michal Hocko , , , , , , Suleiman Souhlal , Frederic Weisbecker , Mel Gorman , David Rientjes , Christoph Lameter , Pekka Enberg , Johannes Weiner Subject: Re: [PATCH v3 06/13] memcg: kmem controller infrastructure References: <1347977050-29476-1-git-send-email-glommer@parallels.com> <1347977050-29476-7-git-send-email-glommer@parallels.com> <20120926155108.GE15801@dhcp22.suse.cz> <5064392D.5040707@parallels.com> <20120927134432.GE29104@dhcp22.suse.cz> <50658B3B.9020303@parallels.com> <20120930082542.GH10383@mtj.dyndns.org> In-Reply-To: <20120930082542.GH10383@mtj.dyndns.org> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/30/2012 12:25 PM, Tejun Heo wrote: > On Fri, Sep 28, 2012 at 03:34:19PM +0400, Glauber Costa wrote: >> On 09/27/2012 05:44 PM, Michal Hocko wrote: >>> Anyway, I have just noticed that __mem_cgroup_try_charge does >>> VM_BUG_ON(css_is_removed(&memcg->css)) on a given memcg so you should >>> keep css ref count up as well. >> >> IIRC, css_get will prevent the cgroup directory from being removed. >> Because some allocations are expected to outlive the cgroup, we >> specifically don't want that. > > That synchronous ref draining is going away. Maybe we can do that > before kmemcg? Michal, do you have some timeframe on mind? > Since you said yourself in other points in this thread that you are fine with some page references outliving the cgroup in the case of slab, this is a situation that comes with the code, not a situation that was incidentally there, and we're making use of. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Glauber Costa Subject: Re: [PATCH v3 06/13] memcg: kmem controller infrastructure Date: Mon, 1 Oct 2012 12:28:28 +0400 Message-ID: <5069542C.2020103@parallels.com> References: <1347977050-29476-1-git-send-email-glommer@parallels.com> <1347977050-29476-7-git-send-email-glommer@parallels.com> <20120926155108.GE15801@dhcp22.suse.cz> <5064392D.5040707@parallels.com> <20120927134432.GE29104@dhcp22.suse.cz> <50658B3B.9020303@parallels.com> <20120930082542.GH10383@mtj.dyndns.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120930082542.GH10383@mtj.dyndns.org> Sender: owner-linux-mm@kvack.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Tejun Heo Cc: Michal Hocko , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, kamezawa.hiroyu@jp.fujitsu.com, devel@openvz.org, linux-mm@kvack.org, Suleiman Souhlal , Frederic Weisbecker , Mel Gorman , David Rientjes , Christoph Lameter , Pekka Enberg , Johannes Weiner On 09/30/2012 12:25 PM, Tejun Heo wrote: > On Fri, Sep 28, 2012 at 03:34:19PM +0400, Glauber Costa wrote: >> On 09/27/2012 05:44 PM, Michal Hocko wrote: >>> Anyway, I have just noticed that __mem_cgroup_try_charge does >>> VM_BUG_ON(css_is_removed(&memcg->css)) on a given memcg so you should >>> keep css ref count up as well. >> >> IIRC, css_get will prevent the cgroup directory from being removed. >> Because some allocations are expected to outlive the cgroup, we >> specifically don't want that. > > That synchronous ref draining is going away. Maybe we can do that > before kmemcg? Michal, do you have some timeframe on mind? > Since you said yourself in other points in this thread that you are fine with some page references outliving the cgroup in the case of slab, this is a situation that comes with the code, not a situation that was incidentally there, and we're making use of. -- 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