From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx200.postini.com [74.125.245.200]) by kanga.kvack.org (Postfix) with SMTP id 3513A6B0006 for ; Fri, 8 Mar 2013 10:26:02 -0500 (EST) Message-ID: <513A02FC.4070208@genband.com> Date: Fri, 08 Mar 2013 09:25:48 -0600 From: Chris Friesen MIME-Version: 1.0 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 Sender: owner-linux-mm@kvack.org List-ID: To: Howard Chu Cc: "Kirill A. Shutemov" , Johannes Weiner , Jan Kara , linux-kernel , linux-mm@kvack.org 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, 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