From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f52.google.com (mail-pa0-f52.google.com [209.85.220.52]) by kanga.kvack.org (Postfix) with ESMTP id 58F416B0035 for ; Fri, 9 May 2014 11:49:44 -0400 (EDT) Received: by mail-pa0-f52.google.com with SMTP id fa1so400948pad.25 for ; Fri, 09 May 2014 08:49:44 -0700 (PDT) Received: from mail-pd0-x234.google.com (mail-pd0-x234.google.com [2607:f8b0:400e:c02::234]) by mx.google.com with ESMTPS id ot9si2235215pac.53.2014.05.09.08.49.43 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 09 May 2014 08:49:43 -0700 (PDT) Received: by mail-pd0-f180.google.com with SMTP id y10so3838298pdj.39 for ; Fri, 09 May 2014 08:49:43 -0700 (PDT) From: Michal Nazarewicz Subject: Re: [PATCH v2 2/2] mm/compaction: avoid rescanning pageblocks in isolate_freepages In-Reply-To: <1399464550-26447-2-git-send-email-vbabka@suse.cz> References: <1399464550-26447-1-git-send-email-vbabka@suse.cz> <1399464550-26447-2-git-send-email-vbabka@suse.cz> Date: Fri, 09 May 2014 08:49:35 -0700 Message-ID: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="=-=-=" Sender: owner-linux-mm@kvack.org List-ID: To: Vlastimil Babka , Andrew Morton , David Rientjes Cc: Hugh Dickins , Greg Thelen , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Minchan Kim , Mel Gorman , Joonsoo Kim , Bartlomiej Zolnierkiewicz , Naoya Horiguchi , Christoph Lameter , Rik van Riel --=-=-= Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On Wed, May 07 2014, Vlastimil Babka wrote: > The compaction free scanner in isolate_freepages() currently remembers PF= N of > the highest pageblock where it successfully isolates, to be used as the > starting pageblock for the next invocation. The rationale behind this is = that > page migration might return free pages to the allocator when migration fa= ils > and we don't want to skip them if the compaction continues. > > Since migration now returns free pages back to compaction code where they= can > be reused, this is no longer a concern. This patch changes isolate_freepa= ges() > so that the PFN for restarting is updated with each pageblock where isola= tion > is attempted. Using stress-highalloc from mmtests, this resulted in 10% > reduction of the pages scanned by the free scanner. > > Note that the somewhat similar functionality that records highest success= ful > pageblock in zone->compact_cached_free_pfn, remains unchanged. This cache= is > used when the whole compaction is restarted, not for multiple invocations= of > the free scanner during single compaction. > > Signed-off-by: Vlastimil Babka > Cc: Minchan Kim > Cc: Mel Gorman > Cc: Joonsoo Kim > Cc: Bartlomiej Zolnierkiewicz > Cc: Michal Nazarewicz Acked-by: Michal Nazarewicz > Cc: Naoya Horiguchi > Cc: Christoph Lameter > Cc: Rik van Riel > --- > v2: no changes, just keep patches together > > mm/compaction.c | 18 ++++++------------ > 1 file changed, 6 insertions(+), 12 deletions(-) > --=20 Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=3D./ `o ..o | Computer Science, Micha=C5=82 =E2=80=9Cmina86=E2=80=9D Nazarewicz = (o o) ooo +------ooO--(_)--Ooo-- --=-=-= Content-Type: multipart/signed; boundary="==-=-="; micalg=pgp-sha1; protocol="application/pgp-signature" --==-=-= Content-Type: text/plain --==-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQIcBAEBAgAGBQJTbPkPAAoJECBgQBJQdR/0RLcP/0AAvkxxjS2riJKTHRTWd/aJ 2aiLce1bXE7jeZ9w86p5jJzdh0WygXTw4gUgv53JVo2qj6oBlb6r4uwS3tsn+CeU oK7EpLbCHJ2KzzTjMr662xwogg/8NPsdvMY+phghebfdTFxl+SYUm5yvHi2zsJRZ enO+Rei9gZnZLi2AQiBPi/qVnjeu2pkIm2ty99G2GWpqi4uKfWy6U595jkuPnYhr sG0ptclWFM9JJ12DfPerbiZFddq/wmFQJaLVEBcrLO0GiHpJ2KK4inKC5jP1R5uu KcBXFc8Lm907PElA1Mqe2NjALbVpfN4+n0/M1Ye8ZL74yzy68CZCLueHAWw+m+Ia 399uKqUzW3xdNFzJ2tcZApdpjsWg2MHr3ilFSvpejS+i4tgMJeiWszQ7ZKx6zTHd 5lZH6Jd5NC4mENrfb8o5Vs2ghOCp3t0+o6EN/x/AMAsW/uWFYtWvCxDwmAdAjRpY CVCbf236O1DP7s9xH4kWUxPcd/bVUJGT1fhSHTxUioEi18Qnd3hma+GcBbStIw2M tqeoC5kS50ExKhVmg3WVAI0FC/uphdugt+kBV6Q+K05zfXQyp1dTgO/yqjbsxqCK h+TcGctFLeNPQfpUtUcgc/wVnrcUuFZArU1CyZPLPDfWFI3jNVzHY9Wq26QxZ5hE wUwzCQZK4DWaEFuc6CA6 =d7uz -----END PGP SIGNATURE----- --==-=-=-- --=-=-=-- -- 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