From mboxrd@z Thu Jan 1 00:00:00 1970 From: Glauber Costa Subject: Re: [PATCH v2 04/11] kmem accounting basic infrastructure Date: Wed, 15 Aug 2012 19:11:49 +0400 Message-ID: <502BBC35.809@parallels.com> References: <1344517279-30646-1-git-send-email-glommer@parallels.com> <1344517279-30646-5-git-send-email-glommer@parallels.com> <20120814162144.GC6905@dhcp22.suse.cz> <502B6D03.1080804@parallels.com> <20120815123931.GF23985@dhcp22.suse.cz> <000001392ac15404-43a3fd2c-a6d3-4985-b173-74bb586ad47c-000000@email.amazonses.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <000001392ac15404-43a3fd2c-a6d3-4985-b173-74bb586ad47c-000000-p/GC64/jrecnJqMo6gzdpkEOCMrvLtNR@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Christoph Lameter Cc: Michal Hocko , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devel-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org, Johannes Weiner , Andrew Morton , kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org, David Rientjes , Pekka Enberg On 08/15/2012 06:47 PM, Christoph Lameter wrote: > On Wed, 15 Aug 2012, Michal Hocko wrote: > >>> That is not what the kernel does, in general. We assume that if he wants >>> that memory and we can serve it, we should. Also, not all kernel memory >>> is unreclaimable. We can shrink the slabs, for instance. Ying Han >>> claims she has patches for that already... >> >> Are those patches somewhere around? > > You can already shrink the reclaimable slabs (dentries / inodes) via > calls to the subsystem specific shrinkers. Did Ying Han do anything to > go beyond that? > That is not enough for us. We would like to make sure that the objects being discarded belong to the memcg which is under pressure. We don't need to be perfect here, and an occasional slip is totally fine. But if in general, shrinking from memcg A will mostly wipe out objects from memcg B, we harmed the system in return for nothing good. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx150.postini.com [74.125.245.150]) by kanga.kvack.org (Postfix) with SMTP id 787796B005D for ; Wed, 15 Aug 2012 11:15:01 -0400 (EDT) Message-ID: <502BBC35.809@parallels.com> Date: Wed, 15 Aug 2012 19:11:49 +0400 From: Glauber Costa MIME-Version: 1.0 Subject: Re: [PATCH v2 04/11] kmem accounting basic infrastructure References: <1344517279-30646-1-git-send-email-glommer@parallels.com> <1344517279-30646-5-git-send-email-glommer@parallels.com> <20120814162144.GC6905@dhcp22.suse.cz> <502B6D03.1080804@parallels.com> <20120815123931.GF23985@dhcp22.suse.cz> <000001392ac15404-43a3fd2c-a6d3-4985-b173-74bb586ad47c-000000@email.amazonses.com> In-Reply-To: <000001392ac15404-43a3fd2c-a6d3-4985-b173-74bb586ad47c-000000@email.amazonses.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: Michal Hocko , linux-kernel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, devel@openvz.org, Johannes Weiner , Andrew Morton , kamezawa.hiroyu@jp.fujitsu.com, David Rientjes , Pekka Enberg On 08/15/2012 06:47 PM, Christoph Lameter wrote: > On Wed, 15 Aug 2012, Michal Hocko wrote: > >>> That is not what the kernel does, in general. We assume that if he wants >>> that memory and we can serve it, we should. Also, not all kernel memory >>> is unreclaimable. We can shrink the slabs, for instance. Ying Han >>> claims she has patches for that already... >> >> Are those patches somewhere around? > > You can already shrink the reclaimable slabs (dentries / inodes) via > calls to the subsystem specific shrinkers. Did Ying Han do anything to > go beyond that? > That is not enough for us. We would like to make sure that the objects being discarded belong to the memcg which is under pressure. We don't need to be perfect here, and an occasional slip is totally fine. But if in general, shrinking from memcg A will mostly wipe out objects from memcg B, we harmed the system in return for nothing good. -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751567Ab2HOPPD (ORCPT ); Wed, 15 Aug 2012 11:15:03 -0400 Received: from mx2.parallels.com ([64.131.90.16]:56068 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750781Ab2HOPPB (ORCPT ); Wed, 15 Aug 2012 11:15:01 -0400 Message-ID: <502BBC35.809@parallels.com> Date: Wed, 15 Aug 2012 19:11:49 +0400 From: Glauber Costa User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120717 Thunderbird/14.0 MIME-Version: 1.0 To: Christoph Lameter CC: Michal Hocko , , , , , "Johannes Weiner" , Andrew Morton , , David Rientjes , "Pekka Enberg" Subject: Re: [PATCH v2 04/11] kmem accounting basic infrastructure References: <1344517279-30646-1-git-send-email-glommer@parallels.com> <1344517279-30646-5-git-send-email-glommer@parallels.com> <20120814162144.GC6905@dhcp22.suse.cz> <502B6D03.1080804@parallels.com> <20120815123931.GF23985@dhcp22.suse.cz> <000001392ac15404-43a3fd2c-a6d3-4985-b173-74bb586ad47c-000000@email.amazonses.com> In-Reply-To: <000001392ac15404-43a3fd2c-a6d3-4985-b173-74bb586ad47c-000000@email.amazonses.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [109.173.1.99] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/15/2012 06:47 PM, Christoph Lameter wrote: > On Wed, 15 Aug 2012, Michal Hocko wrote: > >>> That is not what the kernel does, in general. We assume that if he wants >>> that memory and we can serve it, we should. Also, not all kernel memory >>> is unreclaimable. We can shrink the slabs, for instance. Ying Han >>> claims she has patches for that already... >> >> Are those patches somewhere around? > > You can already shrink the reclaimable slabs (dentries / inodes) via > calls to the subsystem specific shrinkers. Did Ying Han do anything to > go beyond that? > That is not enough for us. We would like to make sure that the objects being discarded belong to the memcg which is under pressure. We don't need to be perfect here, and an occasional slip is totally fine. But if in general, shrinking from memcg A will mostly wipe out objects from memcg B, we harmed the system in return for nothing good.