From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx176.postini.com [74.125.245.176]) by kanga.kvack.org (Postfix) with SMTP id 484BA6B00C1 for ; Tue, 11 Sep 2012 07:16:05 -0400 (EDT) Received: by weys10 with SMTP id s10so293955wey.14 for ; Tue, 11 Sep 2012 04:16:03 -0700 (PDT) From: Michal Nazarewicz Subject: Re: [PATCH] mm: cma: Discard clean pages during contiguous allocation instead of migration In-Reply-To: <1347324112-14134-1-git-send-email-minchan@kernel.org> References: <1347324112-14134-1-git-send-email-minchan@kernel.org> Date: Tue, 11 Sep 2012 13:15:56 +0200 Message-ID: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="=-=-=" Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim , Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Kyungmin Park , Marek Szyprowski , Rik van Riel , Mel Gorman --=-=-= Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On Tue, Sep 11 2012, Minchan Kim wrote: > This patch drops clean cache pages instead of migration during > alloc_contig_range() to minimise allocation latency by reducing the amount > of migration is necessary. It's useful for CMA because latency of migrati= on > is more important than evicting the background processes working set. > In addition, as pages are reclaimed then fewer free pages for migration > targets are required so it avoids memory reclaiming to get free pages, > which is a contributory factor to increased latency. > > * from v1 > * drop migrate_mode_t > * add reclaim_clean_pages_from_list instad of MIGRATE_DISCARD support -= Mel > > I measured elapsed time of __alloc_contig_migrate_range which migrates > 10M in 40M movable zone in QEMU machine. > > Before - 146ms, After - 7ms > > Cc: Marek Szyprowski > Cc: Michal Nazarewicz Acked-by: Michal Nazarewicz Thanks! --=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 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iQIcBAEBAgAGBQJQTx1sAAoJECBgQBJQdR/0rcAP/34tPp7PJzehiwRqe7xBd/7W dmjRpYfGP08EvaxUgxPRdC/EAZTpgBy/jsVoa1vEXc1rAM3pCwKR3L5cTFd8xc4o /mKYzWAQy3N9zF/VrZiicZqLoguZJs9jqQoyqY9sO8qaMYqzQ92ETof1gsIGAv7J tx4UlECDu1tQrp9cDSMcP97Z1JnMh3hJ2V1cLrouW4nuQBCcImF3eR5NdEM84pEC rhBCmonm2X7SwPWkmc7tWXOEiqT3h9O7WGOl8Qc2JFDINVYXsGJFCwUC1LRIHqOt zFjwOmOeOdrqog6Wf2hRY7LpCzSjWsmz6MP747dJOZxlv+cdocIF6ibj6ZgoHjJj Ced0baWmH7fi963o9czgwO6JGeQ5swS06b+etFTwurQaRqNYc7nXhMoMZppaFuRq kEEfTbf2fkRONVoaWhUI7smSt7HH4zAjKlfN1YTXCy/fey2B37X7tBhQZsrGGwvm xn1zPXnxcrffu6L8afiPHqswFZCLX+Ta8KdPQvQP2ir23WPZ3P5f9VBt9e77uYng gu+2u8+zIalS9OPfZiUI2VB/xfR5TdR1HJZQHU4Xl/KzcWiQyjrKWamjnh3nxRfg G7BfNuwhZVnM+vDzjc+DHr56uJnxEAf9NMnKv6a9gXZRQHdI4QiImkAnZfhNtjSl /zy9TV9nwTkRcYhbKOHq =C9Mk -----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