Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755696AbZCMJRU (ORCPT ); Fri, 13 Mar 2009 05:17:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752478AbZCMJRJ (ORCPT ); Fri, 13 Mar 2009 05:17:09 -0400 Received: from rv-out-0506.google.com ([209.85.198.235]:39344 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751517AbZCMJRH convert rfc822-to-8bit (ORCPT ); Fri, 13 Mar 2009 05:17:07 -0400 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=dMifB/WZXohAmsL57J4ms6peIJY4HB/Wt9G+YsJtbt82NXE90HUmogBIsVRjQX6lLD iJtY4SwJTxSEwA0fu/aXks+E+HvLyy70XXYmnoIPl9jRYbihdeDyBv0CeeesCQlJ8cux qCXo5K//oBHwydv/JeFP1q8B6WckMGqzirj+o= MIME-Version: 1.0 In-Reply-To: <1236930985.5188.77.camel@laptop> References: <20090311153034.9389.19938.stgit@warthog.procyon.org.uk> <20090311170840.2f136849.akpm@linux-foundation.org> <5DC5324CE00E4D4494EE5F031E354E9501CE9C0F@BUDMLVEM03.e2k.ad.ge.com> <20090312112953.GD6995@shareable.org> <1236858608.22914.3689.camel@twins> <20090313082051.5eaa11a3.minchan.kim@barrios-desktop> <1236930985.5188.77.camel@laptop> Date: Fri, 13 Mar 2009 18:17:05 +0900 Message-ID: <28c262360903130217u4ebbc80ct6d857acd768f2eda@mail.gmail.com> Subject: Re: [uClinux-dev] RE: [PATCH] NOMMU: Pages allocated to a ramfs inode's pagecache may get wrongly discarded From: Minchan Kim To: Peter Zijlstra Cc: Jamie Lokier , uClinux development list , Andrew Morton , David Howells , torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, KOSAKI Motohiro Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1477 Lines: 37 On Fri, Mar 13, 2009 at 4:56 PM, Peter Zijlstra wrote: > On Fri, 2009-03-13 at 08:20 +0900, Minchan Kim wrote: > >> > > Does the vm pageout logic include or skip these "dirty" pages looking >> > > for candidates to flush to storage?  What about with MMU? >> > >> > Includes them, regular pageout will try to do the writeout to clean them >> > and then discard them. >> > >> > The ramfs stuff is rather icky in that it adds the pages to the aging >> > list, marks them dirty, but does not provide a writeout method. >> > >> > This will make the paging code scan over them (continuously) trying to >> > clean them, failing that (lack of writeout method) and putting them back >> > on the list. >> >> It ins't true any more. >> UNEVICTABLE_LRU will move ramfs's page from LRU to unevictable list. >> Couldn't we solve this problem if NOMMU can support CONFIG_UNEVICTABLE_LRU ? > > That's more of a band-aid than a solution, no? They should never have > been on the list to begin with. > I agree as Andrew pointed out. It may be workaround but can be a good solution in current status. And then, we have to improve it for removal of ramfs pages from lru list in future, I think. -- 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/