Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750800AbWC0IlV (ORCPT ); Mon, 27 Mar 2006 03:41:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750805AbWC0IlV (ORCPT ); Mon, 27 Mar 2006 03:41:21 -0500 Received: from turing-police.cc.vt.edu ([128.173.14.107]:11660 "EHLO turing-police.cc.vt.edu") by vger.kernel.org with ESMTP id S1750800AbWC0IlV (ORCPT ); Mon, 27 Mar 2006 03:41:21 -0500 Message-Id: <200603270840.k2R8e92V024551@turing-police.cc.vt.edu> X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.1-RC3 To: "Randy.Dunlap" , Linus Torvalds , Andrew Morton Cc: Linda Walsh , linux-kernel@vger.kernel.org Subject: [PATCH] 2.6.16 Block I/O Schedulers - document runtime selection In-Reply-To: Your message of "Sun, 26 Mar 2006 22:19:52 PST." <20060326221952.6f0e20a2.rdunlap@xenotime.net> From: Valdis.Kletnieks@vt.edu References: <4426377C.7000605@tlinx.org> <200603260706.k2Q76thB030947@turing-police.cc.vt.edu> <442759FB.8090309@tlinx.org> <20060326221952.6f0e20a2.rdunlap@xenotime.net> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1143448808_18690P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Mon, 27 Mar 2006 03:40:09 -0500 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2315 Lines: 63 --==_Exmh_1143448808_18690P Content-Type: text/plain; charset=us-ascii On Sun, 26 Mar 2006 22:19:52 PST, "Randy.Dunlap" said: > Patches accepted... Please summarize what you have found, even if not in > patch format (and I'll make it a patch). From: Valdis Kletnieks We added the ability to change a block device's IO elevator scheduler both at kernel boot and on-the-fly, but we only documented the elevator= boot parameter. Add a quick how-to on doing it on the fly. Signed-off-by: Valdis Kletnieks --- --- linux-2.6.16-mm1/Documentation/block/switching-sched.txt.new 2006-03-27 03:26:25.000000000 -0500 +++ linux-2.6.16-mm1/Documentation/block/switching-sched.txt 2006-03-27 03:33:39.000000000 -0500 @@ -0,0 +1,22 @@ +As of the Linux 2.6.mumble kernel, it is now possible to change the +IO scheduler for a given block device on the fly (thus making it possible, +for instance, to set the CFQ scheduler for the system default, but +set a specific device to use the anticipatory or noop schedulers - which +can improve that device's throughput). + +To set a specific scheduler, simply do this: + +echo SCHEDNAME > /sys/block/DEV/queue/scheduler + +where SCHEDNAME is the name of a defined IO scheduler, and DEV is the +device name (hda, hdb, sga, or whatever you happen to have). + +The list of defined schedulers can be found by simply doing +a "cat /sys/block/DEV/queue/scheduler" - the list of valid names +will be displayed, with the currently selected scheduler in brackets: + +# cat /sys/block/hda/queue/scheduler +noop anticipatory deadline [cfq] +# echo anticipatory > /sys/block/hda/queue/scheduler +# cat /sys/block/hda/queue/scheduler +noop [anticipatory] deadline cfq --==_Exmh_1143448808_18690P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2.2 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iD8DBQFEJ6TocC3lWbTT17ARAjClAKD308kG9z4z0XYNVjchBMOgQwJ7bgCcDdIY GT4R8EJSfWS41FEPUIt8uhg= =WL79 -----END PGP SIGNATURE----- --==_Exmh_1143448808_18690P-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/