From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id 37A736B0047 for ; Mon, 22 Feb 2010 03:16:57 -0500 (EST) Received: from d06nrmr1407.portsmouth.uk.ibm.com (d06nrmr1407.portsmouth.uk.ibm.com [9.149.38.185]) by mtagate3.uk.ibm.com (8.13.1/8.13.1) with ESMTP id o1M8Gs8S001204 for ; Mon, 22 Feb 2010 08:16:54 GMT Received: from d06av03.portsmouth.uk.ibm.com (d06av03.portsmouth.uk.ibm.com [9.149.37.213]) by d06nrmr1407.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o1M8Gr9m852172 for ; Mon, 22 Feb 2010 08:16:53 GMT Received: from d06av03.portsmouth.uk.ibm.com (loopback [127.0.0.1]) by d06av03.portsmouth.uk.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id o1M8Grtx032377 for ; Mon, 22 Feb 2010 08:16:53 GMT Message-ID: <4B823D70.80800@linux.vnet.ibm.com> Date: Mon, 22 Feb 2010 09:16:48 +0100 From: Christian Ehrhardt MIME-Version: 1.0 Subject: Re: [PATCH v2] Make VM_MAX_READAHEAD a kernel parameter References: <201002091659.27037.knikanth@suse.de> <201002111715.04411.knikanth@suse.de> <20100214213724.GA28392@discord.disaster> <201002151006.37294.knikanth@suse.de> <20100221142600.GA10036@localhost> In-Reply-To: <20100221142600.GA10036@localhost> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org To: Wu Fengguang Cc: Nikanth Karthikesan , Dave Chinner , Ankit Jain , Andrew Morton , "balbir@linux.vnet.ibm.com" , Jens Axboe , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" List-ID: Wu Fengguang wrote: > Nikanth, > >> I didn't want to impose artificial restrictions. I think Wu's patch set would >> be adding some restrictions, like minimum readahead. He could fix it when he >> modifies the patch to include in his patch set. > > OK, I imposed a larger bound -- 128MB. > And values 1-4095 (more exactly: PAGE_CACHE_SIZE) are prohibited mainly to > catch "readahead=128" where the user really means to do 128 _KB_ readahead. > > Christian, with this patch and more patches to scale down readahead > size on small memory/device size, I guess it's no longer necessary to > introduce a CONFIG_READAHEAD_SIZE? Yes as I mentioned before a kernel parameter supersedes a config symbol in my opinion too. -> agreed > Thanks, > Fengguang > --- -- 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/ . Don't email: email@kvack.org