Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755367AbYFZGhm (ORCPT ); Thu, 26 Jun 2008 02:37:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752854AbYFZGhe (ORCPT ); Thu, 26 Jun 2008 02:37:34 -0400 Received: from an-out-0708.google.com ([209.85.132.242]:38620 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751467AbYFZGhd (ORCPT ); Thu, 26 Jun 2008 02:37:33 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=aECvzDrbIouJlUS7Ms+yfGJkQeRguF11KydIUSrDFpIahbAA7jwQdxc5jQrnxaajq/ Qw4yVjBEiE74mop7wdjAeO9cD9EFYDgW8ykx28K5wfiVZmhrAOtgc+bDxb9CtmlfvO6y ESe5dVwS82tpxK8VCz+//HPqHHlByDOdUuR4A= Message-ID: <28c262360806252337o3ef22ddl7331ecc79d49e72b@mail.gmail.com> Date: Thu, 26 Jun 2008 15:37:32 +0900 From: "MinChan Kim" To: "Takenori Nagano" Subject: Re: [RFC][PATCH] prevent incorrect oom under split_lru Cc: "Peter Zijlstra" , "KOSAKI Motohiro" , "Rik van Riel" , linux-mm , LKML , "Lee Schermerhorn" , akpm@linux-foundation.org In-Reply-To: <486327F9.6030004@ah.jp.nec.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080624092824.4f0440ca@bree.surriel.com> <28c262360806242259k3ac308c4n7cee29b72456e95b@mail.gmail.com> <20080625150141.D845.KOSAKI.MOTOHIRO@jp.fujitsu.com> <28c262360806242356n3f7e02abwfee1f6acf0fd2c61@mail.gmail.com> <1214395885.15232.17.camel@twins> <28c262360806250605le31ba48ma8bb16f996783142@mail.gmail.com> <4862F5BB.9030200@ah.jp.nec.com> <28c262360806252137j78a90480n6c3973cd489c1ef2@mail.gmail.com> <486327F9.6030004@ah.jp.nec.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2229 Lines: 68 On Thu, Jun 26, 2008 at 2:24 PM, Takenori Nagano wrote: > MinChan Kim wrote: >> On Thu, Jun 26, 2008 at 10:49 AM, Takenori Nagano >> wrote: >>> MinChan Kim wrote: >>>> Hi peter, >>>> >>>> I agree with you. but if application's virtual address space is big, >>>> we have a hard problem with mlockall since memory pressure might be a >>>> big. >>>> Of course, It will be a RT application design problem. >>>> >>>>> The much more important case is desktop usage - that is where we run non >>>>> real-time code, but do expect 'low' latency due to user-interaction. >>>>> >>>>> >From hitting swap on my 512M laptop (rather frequent occurance) I know >>>>> we can do better here,.. >>>>> >>>> Absolutely. It is another example. So, I suggest following patch. >>>> It's based on idea of Takenori Nagano's memory reclaim more efficiently. >>> Hi Kim-san, >>> >>> Thank you for agreeing with me. >>> >>> I have one question. >>> My patch don't mind priority. Why do you need "priority == 0"? >> >> Hi, Takenori-san. >> >> Now, Kosaiki-san's patch didn't consider application latency. >> That patch scan all lru[x] pages when memory pressure is very high. >> (ie, priority == 0) >> It will cause application latency to high as peter and me notice that. >> We need a idea which prevent big scanning overhead >> I modified your idea to prevent big scanning overhead only when memory >> pressure is very big. > > Hi, Kim-san. > > Thank you for your explanation. > I understand your opinion. > > But...your patch is not enough for me. :-( > Our Xeon box has 128GB memory, application latency will be very large if > priority goes to be zero. > So, I would like to use "cut off" on every priority. I am not sure it will be a regression. We don't have any enough data. My intention is just to prevent kosaki-san's patch's corner case. > I would like to delete "priority == 0", Can you? > > Thanks, > Takenori > -- Kinds regards, MinChan Kim -- 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/