From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756202AbZBFKGo (ORCPT ); Fri, 6 Feb 2009 05:06:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752937AbZBFKGg (ORCPT ); Fri, 6 Feb 2009 05:06:36 -0500 Received: from el-out-1112.google.com ([209.85.162.180]:35961 "EHLO el-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751180AbZBFKGf (ORCPT ); Fri, 6 Feb 2009 05:06:35 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=IHrRL4OWjcMureVACdH+Odd3iEQHQr89rJIW6T18kIc95QPJ8noCQy0JAYJpKxx0XI +LHPiZfzrb7Xxu/kPfewOoxXlrWR59Q5fuVCzvLaC0eWVRZvt93JVfsz67m4me5DAgNF PcQPbeSBS8jfe8l1Yzb6Qk/+up2VgX5tlFmic= MIME-Version: 1.0 In-Reply-To: <20090206080354.GA6516@barrios-desktop> References: <20090206031125.693559239@cmpxchg.org> <20090206031324.004715023@cmpxchg.org> <20090206080354.GA6516@barrios-desktop> Date: Fri, 6 Feb 2009 19:06:34 +0900 Message-ID: <28c262360902060206h78c15a1dsf52b481c5cc1bc74@mail.gmail.com> Subject: Re: [PATCH 3/3][RFC] swsusp: shrink file cache first From: MinChan Kim To: Johannes Weiner Cc: Andrew Morton , "Rafael J. Wysocki" , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 6, 2009 at 5:03 PM, MinChan Kim wrote: > Hi, Johannes. > I have some questions. > Just out of curiosity. :) > > On Fri, Feb 06, 2009 at 04:11:28AM +0100, Johannes Weiner wrote: >> File cache pages are saved to disk either through normal writeback by >> reclaim or by including them in the suspend image written to a >> swapfile. >> >> Writing them either way should take the same amount of time but doing >> normal writeback and unmap changes the fault behaviour on resume from >> prefault to on-demand paging, smoothening out resume and giving > > What do you mean "unmap"? > Why normal writeback and unmap chnages the fault behavior on resume ? Please, Ignore poor first my question. :( I agree with your opinion. >> previously cached pages the chance to stay out of memory completely if >> they are not used anymore. >> >> Another reason for preferring file page eviction is that the locality >> principle is visible in fault patterns and swap might perform really >> bad with subsequent faulting of contiguously mapped pages. > > Why do you think that swap might perform bad with subsequent faulting > of contiguusly mapped page ? > You mean normal file system is faster than swap due to readahead and > smart block of allocation ? But, I still can't understand this issue. what mean "page eviction" ? Is it reclaim or swap out ? > > -- > Kinds Regards > MinChan Kim > > -- Kinds regards, MinChan Kim