From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758952Ab2GLJMp (ORCPT ); Thu, 12 Jul 2012 05:12:45 -0400 Received: from zene.cmpxchg.org ([85.214.230.12]:53955 "EHLO zene.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753247Ab2GLJMo (ORCPT ); Thu, 12 Jul 2012 05:12:44 -0400 Date: Thu, 12 Jul 2012 11:12:27 +0200 From: Johannes Weiner To: Wanpeng Li Cc: Andrew Morton , KAMEZAWA Hiroyuki , Michal Hocko , Hugh Dickins , David Rientjes , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [patch 01/10] mm: memcg: fix compaction/migration failing due to memcg limits Message-ID: <20120712091227.GA1239@cmpxchg.org> References: <1342026142-7284-1-git-send-email-hannes@cmpxchg.org> <1342026142-7284-2-git-send-email-hannes@cmpxchg.org> <20120712085354.GA3181@kernel> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120712085354.GA3181@kernel> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 12, 2012 at 04:54:07PM +0800, Wanpeng Li wrote: > On Wed, Jul 11, 2012 at 07:02:13PM +0200, Johannes Weiner wrote: > >Compaction (and page migration in general) can currently be hindered > >through pages being owned by memory cgroups that are at their limits > >and unreclaimable. > > > >The reason is that the replacement page is being charged against the > >limit while the page being replaced is also still charged. But this > >seems unnecessary, given that only one of the two pages will still be > >in use after migration finishes. > > > >This patch changes the memcg migration sequence so that the > >replacement page is not charged. Whatever page is still in use after > >successful or failed migration gets to keep the charge of the page > >that was going to be replaced. > > > >The replacement page will still show up temporarily in the rss/cache > >statistics, this can be fixed in a later patch as it's less urgent. > > So I want to know after this patch be merged if mem_cgroup_wait_acct_move > still make sense, if the answer is no, I will send a patch to remove it. This change is about migrating a charge from one physical page to another, account moving is about migrating charges between groups. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: Re: [patch 01/10] mm: memcg: fix compaction/migration failing due to memcg limits Date: Thu, 12 Jul 2012 11:12:27 +0200 Message-ID: <20120712091227.GA1239@cmpxchg.org> References: <1342026142-7284-1-git-send-email-hannes@cmpxchg.org> <1342026142-7284-2-git-send-email-hannes@cmpxchg.org> <20120712085354.GA3181@kernel> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20120712085354.GA3181@kernel> Sender: owner-linux-mm@kvack.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Wanpeng Li Cc: Andrew Morton , KAMEZAWA Hiroyuki , Michal Hocko , Hugh Dickins , David Rientjes , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org On Thu, Jul 12, 2012 at 04:54:07PM +0800, Wanpeng Li wrote: > On Wed, Jul 11, 2012 at 07:02:13PM +0200, Johannes Weiner wrote: > >Compaction (and page migration in general) can currently be hindered > >through pages being owned by memory cgroups that are at their limits > >and unreclaimable. > > > >The reason is that the replacement page is being charged against the > >limit while the page being replaced is also still charged. But this > >seems unnecessary, given that only one of the two pages will still be > >in use after migration finishes. > > > >This patch changes the memcg migration sequence so that the > >replacement page is not charged. Whatever page is still in use after > >successful or failed migration gets to keep the charge of the page > >that was going to be replaced. > > > >The replacement page will still show up temporarily in the rss/cache > >statistics, this can be fixed in a later patch as it's less urgent. > > So I want to know after this patch be merged if mem_cgroup_wait_acct_move > still make sense, if the answer is no, I will send a patch to remove it. This change is about migrating a charge from one physical page to another, account moving is about migrating charges between groups. -- 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