Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268992AbUIXQu3 (ORCPT ); Fri, 24 Sep 2004 12:50:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268944AbUIXQq1 (ORCPT ); Fri, 24 Sep 2004 12:46:27 -0400 Received: from e2.ny.us.ibm.com ([32.97.182.102]:6860 "EHLO e2.ny.us.ibm.com") by vger.kernel.org with ESMTP id S268981AbUIXQpq (ORCPT ); Fri, 24 Sep 2004 12:45:46 -0400 Message-ID: <41544FDB.8090401@austin.ibm.com> Date: Fri, 24 Sep 2004 11:48:27 -0500 From: Steven Pratt User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Nick Piggin CC: Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH/RFC] Simplified Readahead References: <4152F46D.1060200@austin.ibm.com> <20040923194216.1f2b7b05.akpm@osdl.org> <41543FE2.5040807@austin.ibm.com> <41544876.4040302@yahoo.com.au> In-Reply-To: <41544876.4040302@yahoo.com.au> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1451 Lines: 50 Nick Piggin wrote: > Steven Pratt wrote: > >> Andrew Morton wrote: >> >>> Steven Pratt wrote: >>> >>> >>>> would like to offer up an alternative simplified design which will >>>> not only make the code easier to maintain, >>>> >>> >>> >>> We won't know that until all functionality is in place. >>> >> >> Ok, but both you and Nick indicated that the queue congestion isn't >> needed, > > I would have thought that always doing the readahead would provide a > more graceful degradation, assuming the readahead algorithm is fairly > accurate, and copes with things like readahead thrashing (which we > hope is the case). Yes, that is exactly my thought. I think this is what the new code does. > >>> I do think we should skip the I/O for POSIX_FADV_WILLNEED against a >>> congested queue. I can't immediately think of a good reason for >>> skipping >>> the I/O for normal readahead. >>> >> > > I don't see why you should skip the readahead for FADVISE_WILLNEED > either. Presumably if someone needs this, they really need it. We > should aim for optimal behaviour when the apis are being used > correctly... Ok, great, since this is what it does. Thanks, Steve - 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/