From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id 839F98D0001 for ; Fri, 12 Nov 2010 03:31:07 -0500 (EST) Date: Fri, 12 Nov 2010 09:31:03 +0100 From: Michal Hocko Subject: Re: [RFC PATCH] Make swap accounting default behavior configurable v2 Message-ID: <20101112083103.GB7285@tiehlicka.suse.cz> References: <20101110125154.GC5867@tiehlicka.suse.cz> <20101111094613.eab2ec0b.nishimura@mxp.nes.nec.co.jp> <20101111093155.GA20630@tiehlicka.suse.cz> <20101112094118.b02b669f.nishimura@mxp.nes.nec.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101112094118.b02b669f.nishimura@mxp.nes.nec.co.jp> Sender: owner-linux-mm@kvack.org To: Daisuke Nishimura Cc: linux-mm@kvack.org, KAMEZAWA Hiroyuki , linux-kernel@vger.kernel.org List-ID: On Fri 12-11-10 09:41:18, Daisuke Nishimura wrote: > On Thu, 11 Nov 2010 10:31:55 +0100 > Michal Hocko wrote: > > > On Thu 11-11-10 09:46:13, Daisuke Nishimura wrote: > > > On Wed, 10 Nov 2010 13:51:54 +0100 > > > Michal Hocko wrote: > > > > > > > Hi, > > > > could you consider the patch bellow? It basically changes the default > > > > swap accounting behavior (when it is turned on in configuration) to be > > > > configurable as well. > > > > > > > > The rationale is described in the patch but in short it makes it much > > > > more easier to enable this feature in distribution kernels as the > > > > functionality can be provided in the general purpose kernel (with the > > > > option disabled) without any drawbacks and interested users can enable > > > > it. This is not possible currently. > > > > > > > > I am aware that boot command line parameter name change is not ideal but > > > > the original semantic wasn't good enough and I don't like > > > > noswapaccount=yes|no very much. > > > > > > > > If we really have to stick to it I can rework the patch to keep the name > > > > and just add the yes|no logic, though. Or we can keep the original one > > > > and add swapaccount paramete which would mean the oposite as the other > > > > one. > > > > > > > hmm, I agree that current parameter name(noswapaccount) is not desirable > > > for yes|no, but IMHO changing the user interface(iow, making what worked before > > > unusable) is worse. > > > > > > Although I'm not sure how many people are using this parameter, I vote for > > > using "noswapaccount[=(yes|no)]". > > > > Isn't a new swapaccount parameter better than that? I know we don't want > > to have too many parameters but having a something with a clear meaning > > is better IMO (noswapaccount=no doesn't sound very intuitive to me). > > > Fair enough. It's just an trade-off between compatibility and understandability. > > > > And you should update Documentation/kernel-parameters.txt too. > > > > Yes, I am aware of that and will do that once there is an agreement on > > the patch itself. At this stage, I just wanted to have a feadback about > > the change. > > > I'll ack your patch when it's been released with documentation update. Changes since v1: * do not remove noswapaccount parameter and add swapaccount parameter instead * Documentation/kernel-parameters.txt updated ---