Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965680AbXAYHve (ORCPT ); Thu, 25 Jan 2007 02:51:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965681AbXAYHve (ORCPT ); Thu, 25 Jan 2007 02:51:34 -0500 Received: from ausmtp04.au.ibm.com ([202.81.18.152]:41704 "EHLO ausmtp04.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965680AbXAYHvd (ORCPT ); Thu, 25 Jan 2007 02:51:33 -0500 Message-ID: <45B86120.1020201@linux.vnet.ibm.com> Date: Thu, 25 Jan 2007 13:19:52 +0530 From: Vaidyanathan Srinivasan Organization: IBM User-Agent: Thunderbird 1.5.0.5 (X11/20060728) MIME-Version: 1.0 To: Aubrey Li CC: Christoph Lameter , Nick Piggin , Robin Getz , "Hennerich, Michael" , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFC] Limit the size of the pagecache References: <45B75208.90208@linux.vnet.ibm.com> <45B82F41.9040705@linux.vnet.ibm.com> <6d6a94c50701242235m48013856kb5a947c489d9da37@mail.gmail.com> In-Reply-To: <6d6a94c50701242235m48013856kb5a947c489d9da37@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2146 Lines: 52 Aubrey Li wrote: > On 1/25/07, Vaidyanathan Srinivasan wrote: >> >> Christoph Lameter wrote: >>> On Wed, 24 Jan 2007, Vaidyanathan Srinivasan wrote: >>> >>>> With your patch, MMAP of a file that will cross the pagecache limit hangs the >>>> system. As I mentioned in my previous mail, without subtracting the >>>> NR_FILE_MAPPED, the reclaim will infinitely try and fail. >>> Well mapped pages are still pagecache pages. >>> >> Yes, but they can be classified under a process RSS pages. Whether it >> is an anon page or shared mem or mmap of pagecache, it would show up >> under RSS. Those pages can be limited by RSS limiter similar to the >> one we are discussing in pagecache limiter. In my opinion, once a >> file page is mapped by the process, then it should be treated at par >> with anon pages. Application programs generally do not mmap a file >> page if the reuse for the content is very low. >> > > I agree, we shouldn't take mmapped page into account. > But Vaidy - even with your patch, we are still using the existing > reclaimer, that means we dont ensure that only page cache is > reclaimed/limited. mapped pages will be hit also. > I think we still need to add a new scancontrol field to lock mmaped > pages and remove unmapped pagecache pages only. I have tried to add scan control to Roy's patch at http://lkml.org/lkml/2007/01/17/96 In that patch, we search and remove only pages that are not mapped. We also remove referenced and hot pagecache pages which the normal reclaimer is not expected to consider. I will try to fit that logic in Christoph's patch and test. --Vaidy > -Aubrey > - > 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/ > - 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/