From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sd0208e0.au.ibm.com (d23rh904.au.ibm.com [202.81.18.202]) by ausmtp04.au.ibm.com (8.13.8/8.13.8) with ESMTP id l0P85sve303318 for ; Thu, 25 Jan 2007 19:05:54 +1100 Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.250.237]) by sd0208e0.au.ibm.com (8.13.8/8.13.8/NCO v8.2) with ESMTP id l0P7rUir064554 for ; Thu, 25 Jan 2007 18:53:32 +1100 Received: from d23av04.au.ibm.com (loopback [127.0.0.1]) by d23av04.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l0P7o0ns006356 for ; Thu, 25 Jan 2007 18:50:00 +1100 Message-ID: <45B86120.1020201@linux.vnet.ibm.com> Date: Thu, 25 Jan 2007 13:19:52 +0530 From: Vaidyanathan Srinivasan MIME-Version: 1.0 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: owner-linux-mm@kvack.org Return-Path: To: Aubrey Li Cc: Christoph Lameter , Nick Piggin , Robin Getz , "Hennerich, Michael" , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: 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, 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