From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756942AbbCMTPI (ORCPT ); Fri, 13 Mar 2015 15:15:08 -0400 Received: from prod-mail-xrelay06.akamai.com ([96.6.114.98]:55018 "EHLO prod-mail-xrelay06.akamai.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752943AbbCMTPD (ORCPT ); Fri, 13 Mar 2015 15:15:03 -0400 X-Greylist: delayed 342 seconds by postgrey-1.27 at vger.kernel.org; Fri, 13 Mar 2015 15:15:03 EDT Date: Fri, 13 Mar 2015 15:09:15 -0400 From: Eric B Munson To: Rik van Riel Cc: Andrew Morton , Vlastimil Babka , Thomas Gleixner , Christoph Lameter , Peter Zijlstra , Mel Gorman , David Rientjes , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V5] Allow compaction of unevictable pages Message-ID: <20150313190915.GA12589@akamai.com> References: <1426267597-25811-1-git-send-email-emunson@akamai.com> <550332CE.7040404@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="SUOF0GtieIMvvwua" Content-Disposition: inline In-Reply-To: <550332CE.7040404@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --SUOF0GtieIMvvwua Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, 13 Mar 2015, Rik van Riel wrote: > On 03/13/2015 01:26 PM, Eric B Munson wrote: >=20 > > --- a/mm/compaction.c > > +++ b/mm/compaction.c > > @@ -1046,6 +1046,8 @@ typedef enum { > > ISOLATE_SUCCESS, /* Pages isolated, migrate */ > > } isolate_migrate_t; > > =20 > > +int sysctl_compact_unevictable; > > + > > /* > > * Isolate all pages that can be migrated from the first suitable bloc= k, > > * starting at the block pointed to by the migrate scanner pfn within >=20 > I suspect that the use cases where users absolutely do not want > unevictable pages migrated are special cases, and it may make > sense to enable sysctl_compact_unevictable by default. Given that sysctl_compact_unevictable=3D0 is the way the kernel behaves now and the push back against always enabling compaction on unevictable pages, I left the default to be the behavior as it is today. I agree that this is likely the minority case, but I'd really like Peter Z or someone else from real time to say that they are okay with the default changing. --SUOF0GtieIMvvwua Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJVAzXbAAoJELbVsDOpoOa9EssQAITn6Nsh9eTl0J8jUrDuC2V2 b0McdIKX1u8DlydKOKUyvJfKxM6XElGVVQZTpQRBS3QPq0mxYztOm6fn+6JVWsJk QQhfTTiPSfg5BiYHC6SuyAIarEoOzgC6DCKnMddND/tvjQ4j/e/wlxjYjASO+IpI xo0EVRt7BUCoj/fyoPKRyDtFlAs+GAXdOQ2JCGlcVv9msSemtHO/JSgCF+ffXhlF G1JXYaHpdH7xkuRaXHun0qea8BueA4FZpjsfZPG9OVX83aHU8wRDCmZBLguIyJQf XYpvItbUmIo0O5APjPUylYS8IXaQJVOgJjxMVsv2HoZ8J8js7apIGt96Kaw2QbtG ED3N1YKUiA9ajqehbyNheNUtAUAOWeNVVVGL0NH4oXJtgR1sCxvcu/xPVULoWphH 5TRyTJ/B1xCVuzfCHU9clGrCbORDhgNWpFFzZN8QzY+8CqGbe7fBrtjc4s23ZWJv QNPscDDdeOlTVnQNLfyWxwKPQ0aE2/NGLjRH7l4nNDEyICwvPYaaQxz44Y7vUv9X yQZh5s5ESuPcixXRLSGNjLxK97Wg0/DTV75VqGNLDIKEqrHUKIAg/cwfYQhbG4vC m4sDTDf3btr/NxgnlJ0yD5r4RUpQtecm3hE/YD7U4MCN4vfvLACscADTGmJeMaib G+at4wC91x0L6x97vtZg =IOEw -----END PGP SIGNATURE----- --SUOF0GtieIMvvwua--