Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934287Ab3CHP0t (ORCPT ); Fri, 8 Mar 2013 10:26:49 -0500 Received: from exprod7og107.obsmtp.com ([64.18.2.167]:53973 "EHLO exprod7og107.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932262Ab3CHP0s (ORCPT ); Fri, 8 Mar 2013 10:26:48 -0500 Message-ID: <513A02FC.4070208@genband.com> Date: Fri, 08 Mar 2013 09:25:48 -0600 From: Chris Friesen User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.24) Gecko/20111108 Fedora/3.1.16-1.fc14 Lightning/1.0b3pre Thunderbird/3.1.16 MIME-Version: 1.0 To: Howard Chu CC: "Kirill A. Shutemov" , Johannes Weiner , Jan Kara , linux-kernel , linux-mm@kvack.org Subject: Re: mmap vs fs cache References: <5136320E.8030109@symas.com> <20130307154312.GG6723@quack.suse.cz> <20130308020854.GC23767@cmpxchg.org> <5139975F.9070509@symas.com> <20130308084246.GA4411@shutemov.name> <5139B214.3040303@symas.com> <5139FA13.8090305@genband.com> <5139FD27.1030208@symas.com> In-Reply-To: <5139FD27.1030208@symas.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 08 Mar 2013 15:25:50.0043 (UTC) FILETIME=[36D762B0:01CE1C11] X-TM-AS-Product-Ver: SMEX-8.0.0.4160-6.500.1024-19698.004 X-TM-AS-Result: No--12.365600-8.000000-31 X-TM-AS-User-Approved-Sender: No X-TM-AS-User-Blocked-Sender: No Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1178 Lines: 25 On 03/08/2013 09:00 AM, Howard Chu wrote: > First obvious conclusion - kswapd is being too aggressive. When free > memory hits the low watermark, the reclaim shrinks slapd down from 25GB > to 18-19GB, while the page cache still contains ~7GB of unmapped pages. > Ideally I'd like a tuning knob so I can say to keep no more than 2GB of > unmapped pages in the cache. (And the desired effect of that would be to > allow user processes to grow to 30GB total, in this case.) > > I mentioned this "unmapped page cache control" post already > http://lwn.net/Articles/436010/ but it seems that the idea was > ultimately rejected. Is there anything else similar in current kernels? Sorry, I'm not aware of anything. I'm not a filesystem/vm guy though, so maybe there's something I don't know about. I would have expected both posix_madvise(..POSIX_MADV_RANDOM) and swappiness to help, but it doesn't sound like they're working. Chris -- 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/