From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: <482C2631.1030600@mxp.nes.nec.co.jp> Date: Thu, 15 May 2008 21:01:53 +0900 From: Daisuke Nishimura MIME-Version: 1.0 Subject: Re: [RFC][PATCH] another swap controller for cgroup References: <6599ad830805150019v5ba23fe1xe5a6e8b80bc194f5@mail.gmail.com> <20080515085606.7239D5A07@siro.lan> In-Reply-To: <20080515085606.7239D5A07@siro.lan> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: YAMAMOTO Takashi Cc: menage@google.com, minoura@valinux.co.jp, linux-mm@kvack.org, containers@lists.osdl.org, hugh@veritas.com, balbir@linux.vnet.ibm.com, kamezawa.hiroyu@jp.fujitsu.com, "IKEDA, Munehiro" List-ID: On 2008/05/15 17:56 +0900, YAMAMOTO Takashi wrote: >>> > If so, why is this better >>> > than charging for actual swap usage? >>> >>> its behaviour is more determinstic and it uses less memory. >>> (than nishimura-san's one, which charges for actual swap usage.) >>> Consuming more memory cannot be helped for my controller... >> Using less memory is good, but maybe not worth it if the result isn't so useful. >> >> I'd say that it's less deterministic than nishimura-san's controller - >> with his you just need to know how much swap is in use (which you can >> tell by observing the app on a real system) but with yours you also >> have to know whether there are any processes sharing anon pages (but >> not mms). > > deterministic in the sense that, even when two or more processes > from different cgroups are sharing a page, both of them, rather than > only unlucky one, are always charged. > I'm not sure whether this behavior itself is good or bad, but I think it's not good idea to make memory controller, which charges only one process for a shared page, and swap controller behave differently. I think it will be confusing for users. At least, I would feel it strange. > another related advantage is that it's possible to move charges > quite precisely when moving a task among cgroups. > Moving charges is one of future todo of my controller. But, as you say, it won't be so precise as yours. Thanks, Daisuke Nishimura. -- 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