From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933704Ab3CIBWX (ORCPT ); Fri, 8 Mar 2013 20:22:23 -0500 Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120]:42926 "EHLO cdptpa-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932716Ab3CIBWV (ORCPT ); Fri, 8 Mar 2013 20:22:21 -0500 X-Authority-Analysis: v=2.0 cv=cYNQXw/M c=1 sm=0 a=C56BoFkcj+OI1kjAe8jE5A==:17 a=MtVMNMWb1ewA:10 a=mBswGg73kkcA:10 a=S1A5HrydsesA:10 a=8nJEP1OIZ-IA:10 a=fxJcL_dCAAAA:8 a=VrFzeNeFecIA:10 a=QfKxxUxMAAAA:8 a=ULGdlB65cfvei5oWAMAA:9 a=wPNLvfGTeEIA:10 a=C56BoFkcj+OI1kjAe8jE5A==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 142.196.87.46 Message-ID: <513A8ECB.8000504@ubuntu.com> Date: Fri, 08 Mar 2013 20:22:19 -0500 From: Phillip Susi User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130105 Thunderbird/17.0.2 MIME-Version: 1.0 To: Howard Chu CC: Chris Friesen , "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> X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 03/08/2013 10:00 AM, Howard Chu wrote: > Yes, that's what I was thinking. I added a > posix_madvise(..POSIX_MADV_RANDOM) but that had no effect on the > test. Yep, that's because it isn't implemented. You might try MADV_WILLNEED to schedule it to be read in first. I believe that will only read in the requested page, without additional readahead, and then when you fault on the page, it already has IO scheduled, so the extra readahead will also be skipped. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with undefined - http://www.enigmail.net/ iQEcBAEBAgAGBQJROo7GAAoJEJrBOlT6nu759SAH+wRhoUIZUuzNGrhfUJ6RnwV8 VjFyftBCAsdC+Mzq81Da3KJOi+BdYV8VbkYNPzbKll5AnxzL5Udvbdyf9SkROhug UgLWHe8pC6ZtHfSvWBCqS1YDLkzw+TiWwJzuL5iUEDC2NGuUJQ5SbhwyTEypvWai pdPZeFVyhLAKOtAUwD5e/5vhBWSq2M1TG2C7BUCow2fbJ6kil+kWuXtiDeNPvtUk 4FwabL8zHA9pNtMlHB0cUrn5W3VQYGqeTaDngjyLxR1gw7uFQn52G47IPe2LAMGx 58L/tHjbkSY9oukGiMHoF1jiaFqJqV1pw+Q2P7S+0XsU8JdW6CmzotTqDmcozqE= =DOZT -----END PGP SIGNATURE-----