From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 4487D6B004D for ; Wed, 30 Nov 2011 08:04:20 -0500 (EST) Received: from /spool/local by e06smtp13.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 30 Nov 2011 13:04:16 -0000 Received: from d06av03.portsmouth.uk.ibm.com (d06av03.portsmouth.uk.ibm.com [9.149.37.213]) by d06nrmr1507.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id pAUD4CGx2629818 for ; Wed, 30 Nov 2011 13:04:14 GMT Received: from d06av03.portsmouth.uk.ibm.com (localhost.localdomain [127.0.0.1]) by d06av03.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id pAUD4BCX008238 for ; Wed, 30 Nov 2011 06:04:12 -0700 Message-ID: <4ED629CB.401@linux.vnet.ibm.com> Date: Wed, 30 Nov 2011 14:04:11 +0100 From: Christian Ehrhardt MIME-Version: 1.0 Subject: Re: [PATCH 2/8] readahead: make default readahead size a kernel parameter References: <20111121091819.394895091@intel.com> <20111121093846.251104145@intel.com> <20111121100137.GC5084@infradead.org> <20111121113540.GB8895@localhost> <20111124222822.GG29519@quack.suse.cz> <20111125003633.GP2386@dastard> <20111128023922.GA2141@localhost> In-Reply-To: <20111128023922.GA2141@localhost> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Wu Fengguang Cc: Dave Chinner , Jan Kara , Christoph Hellwig , Andrew Morton , Linux Memory Management List , "linux-fsdevel@vger.kernel.org" , Ankit Jain , Rik van Riel , Nikanth Karthikesan , LKML , Andi Kleen On 11/28/2011 03:39 AM, Wu Fengguang wrote: > On Fri, Nov 25, 2011 at 08:36:33AM +0800, Dave Chinner wrote: >> On Thu, Nov 24, 2011 at 11:28:22PM +0100, Jan Kara wrote: >>> On Mon 21-11-11 19:35:40, Wu Fengguang wrote: >>>> On Mon, Nov 21, 2011 at 06:01:37PM +0800, Christoph Hellwig wrote: >>>>> On Mon, Nov 21, 2011 at 05:18:21PM +0800, Wu Fengguang wrote: >>>>>> From: Nikanth Karthikesan >>>>>> [...] >> >> And one that has already been in use for exactly this purpose for >> years. Indeed, it's far more flexible because you can give different >> types of devices different default readahead settings quite easily, >> and it you can set different defaults for just about any tunable >> parameter (e.g. readahead, ctq depth, max IO sizes, etc) in the same >> way. > > I'm interested in this usage, too. Would you share some of your rules? > FYI - This is an example of a rules Suse delivers in SLES @ s390 for a while now. With little modifications it could be used for all Dave mentioned above. cat /etc/udev/rules.d/60-readahead.rules # # Rules to set an increased default max readahead size for s390 disk devices # This file should be installed in /etc/udev/rules.d # SUBSYSTEM!="block", GOTO="ra_end" ACTION!="add", GOTO="ra_end" # on device add set initial readahead to 512 (instead of in kernel 128) KERNEL=="sd*[!0-9]", ATTR{queue/read_ahead_kb}="512" KERNEL=="dasd*[!0-9]", ATTR{queue/read_ahead_kb}="512" LABEL="ra_end" -- Grusse / regards, Christian Ehrhardt IBM Linux Technology Center, System z Linux Performance -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org