Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752352Ab0BVIQ4 (ORCPT ); Mon, 22 Feb 2010 03:16:56 -0500 Received: from mtagate4.uk.ibm.com ([194.196.100.164]:46180 "EHLO mtagate4.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751126Ab0BVIQz (ORCPT ); Mon, 22 Feb 2010 03:16:55 -0500 Message-ID: <4B823D70.80800@linux.vnet.ibm.com> Date: Mon, 22 Feb 2010 09:16:48 +0100 From: Christian Ehrhardt User-Agent: Thunderbird 2.0.0.23 (X11/20090817) MIME-Version: 1.0 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" 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: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1108 Lines: 34 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 > --- -- Gr?sse / regards, Christian Ehrhardt IBM Linux Technology Center, System z Linux Performance -- 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/