Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933650Ab0KQBDq (ORCPT ); Tue, 16 Nov 2010 20:03:46 -0500 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:34426 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932835Ab0KQBDo (ORCPT ); Tue, 16 Nov 2010 20:03:44 -0500 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Wed, 17 Nov 2010 09:57:59 +0900 From: KAMEZAWA Hiroyuki To: Daisuke Nishimura Cc: Andrew Morton , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org, balbir@linux.vnet.ibm.com, stable@kernel.org Subject: Re: [PATCH] Make swap accounting default behavior configurable Message-Id: <20101117095759.738de832.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20101117092339.1b7c2d6d.nishimura@mxp.nes.nec.co.jp> References: <20101116101726.GA21296@tiehlicka.suse.cz> <20101116124615.978ed940.akpm@linux-foundation.org> <20101117092339.1b7c2d6d.nishimura@mxp.nes.nec.co.jp> Organization: FUJITSU Co. 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X-Mailer: Sylpheed 3.0.3 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4254 Lines: 104 On Wed, 17 Nov 2010 09:23:39 +0900 Daisuke Nishimura wrote: > On Tue, 16 Nov 2010 12:46:15 -0800 > Andrew Morton wrote: > > > On Tue, 16 Nov 2010 11:17:26 +0100 > > Michal Hocko wrote: > > > > > Hi Andrew, > > > could you consider the following patch for the Linus tree, please? > > > The discussion took place in this email thread > > > http://lkml.org/lkml/2010/11/10/114. > > > The patch is based on top of 151f52f09c572 commit in the Linus tree. > > > > > > Please let me know if there I should route this patch through somebody > > > else. > > > > > > Thanks! > > > > > > --- > > > >From 30238aaec758988493af793939f14b0ba83dc4b3 Mon Sep 17 00:00:00 2001 > > > From: Michal Hocko > > > Date: Wed, 10 Nov 2010 13:30:04 +0100 > > > Subject: [PATCH] Make swap accounting default behavior configurable > > > > > > Swap accounting can be configured by CONFIG_CGROUP_MEM_RES_CTLR_SWAP > > > configuration option and then it is turned on by default. There is > > > a boot option (noswapaccount) which can disable this feature. > > > > > > This makes it hard for distributors to enable the configuration option > > > as this feature leads to a bigger memory consumption and this is a no-go > > > for general purpose distribution kernel. On the other hand swap > > > accounting may be very usuful for some workloads. > > > > This patch is needed by distros, and distros use the -stable tree, I > > assume. Do you see reasons why this patch should be backported into > > -stable, so distros don't need to patch it themselves? If so, any > > particular kernel versions? 2.6.37? > > > > > This patch adds a new configuration option which controls the default > > > behavior (CGROUP_MEM_RES_CTLR_SWAP_ENABLED). If the option is selected > > > then the feature is turned on by default. > > > > > > It also adds a new boot parameter swapaccount which (contrary to > > > noswapaccount) enables the feature. (I would consider swapaccount=yes|no > > > semantic with removed noswapaccount parameter much better but this > > > parameter is kind of API which might be in use and unexpected breakage > > > is no-go.) > > > > > > The default behavior is unchanged (if CONFIG_CGROUP_MEM_RES_CTLR_SWAP is > > > enabled then CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED is enabled as well) > > > > > > Signed-off-by: Michal Hocko > > > Acked-by: Daisuke Nishimura > > > --- > > > Documentation/kernel-parameters.txt | 3 +++ > > > init/Kconfig | 13 +++++++++++++ > > > mm/memcontrol.c | 15 ++++++++++++++- > > > 3 files changed, 30 insertions(+), 1 deletions(-) > > > > > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > > > index ed45e98..14eafa5 100644 > > > --- a/Documentation/kernel-parameters.txt > > > +++ b/Documentation/kernel-parameters.txt > > > @@ -2385,6 +2385,9 @@ and is between 256 and 4096 characters. It is defined in the file > > > improve throughput, but will also increase the > > > amount of memory reserved for use by the client. > > > > > > + swapaccount [KNL] Enable accounting of swap in memory resource > > > + controller. (See Documentation/cgroups/memory.txt) > > > > So we have swapaccount and noswapaccount. Ho hum, "swapaccount=[1|0]" > > would have been better. > > > I suggested to keep "noswapaccount" for compatibility. > If you and other guys don't like having two parameters, I don't stick to > the old parameter. > I don't think "noswapaccount" is important if "enable is default" when proper configuration is used ....because it's rarelly used. BTW, memory usage of swap_cgroup is really important ? It consumes 1 Mbytes per 2G of swap. Off topic. I wonder I'll be happy if we can have default config template for all others as recent "Add Kconfig option for default swappiness" discuss. Thanks, -Kame Thanks, -Kame -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/