From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by wx-out-0506.google.com with SMTP id s8so377254wxc for ; Wed, 24 Jan 2007 22:35:29 -0800 (PST) Message-ID: <6d6a94c50701242235m48013856kb5a947c489d9da37@mail.gmail.com> Date: Thu, 25 Jan 2007 14:35:29 +0800 From: "Aubrey Li" Subject: Re: [RFC] Limit the size of the pagecache In-Reply-To: <45B82F41.9040705@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <45B75208.90208@linux.vnet.ibm.com> <45B82F41.9040705@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org Return-Path: To: Vaidyanathan Srinivasan Cc: Christoph Lameter , Nick Piggin , Robin Getz , "Hennerich, Michael" , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: 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. -Aubrey -- 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