From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2992797AbXDYQIt (ORCPT ); Wed, 25 Apr 2007 12:08:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2992800AbXDYQIt (ORCPT ); Wed, 25 Apr 2007 12:08:49 -0400 Received: from one.firstfloor.org ([213.235.205.2]:50186 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2992797AbXDYQIs (ORCPT ); Wed, 25 Apr 2007 12:08:48 -0400 Date: Wed, 25 Apr 2007 18:08:44 +0200 From: Andi Kleen To: Andi Kleen , Andrew Morton , Oleg Nesterov , Steven Pratt , Ram Pai , linux-kernel@vger.kernel.org Subject: Re: [RFC][PATCH] on-demand readahead Message-ID: <20070425160844.GA30132@one.firstfloor.org> References: <377506695.54393@ustc.edu.cn> <20070425160400.GA27954@mail.ustc.edu.cn> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070425160400.GA27954@mail.ustc.edu.cn> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > Yeah, the on-demand readahead can avoid _all_ lookups for small in-cache files. How? > But what do you mean by AS? struct address_space > > You seem to have a lot of magic numbers. They probably all need symbols and > > explanations. > > The magic numbers are for easier testings, and will be removed in > future. For now, they enables convenient comparing of the two > algorithms in one kernel. I mean the 16 and 4 not the sysctl > > If this new algorithm has been further tested and approved, I'll > re-submit the patch in a cleaner, standalone form. The adaptive > readahead patches can be dropped then. They may better be reworked as > a kernel module. If they actually help and don't cause regressions they shouldn't be a module, but integrated eventually Just it has to be all step by step. > > > Your white space also needs some work. > > White space in patch description? In the code indentation. -Andi