Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751808AbWEFBLW (ORCPT ); Fri, 5 May 2006 21:11:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751809AbWEFBLW (ORCPT ); Fri, 5 May 2006 21:11:22 -0400 Received: from smtp.ustc.edu.cn ([202.38.64.16]:12745 "HELO ustc.edu.cn") by vger.kernel.org with SMTP id S1751808AbWEFBLV (ORCPT ); Fri, 5 May 2006 21:11:21 -0400 Message-ID: <346877876.18033@ustc.edu.cn> X-EYOUMAIL-SMTPAUTH: wfg@mail.ustc.edu.cn Date: Sat, 6 May 2006 09:11:25 +0800 From: Wu Fengguang To: Rik van Riel Cc: Linus Torvalds , linux-kernel@vger.kernel.org, Andrew Morton , Jens Axboe , Nick Piggin , Badari Pulavarty Subject: Re: [RFC] kernel facilities for cache prefetching Message-ID: <20060506011125.GA9099@mail.ustc.edu.cn> Mail-Followup-To: Wu Fengguang , Rik van Riel , Linus Torvalds , linux-kernel@vger.kernel.org, Andrew Morton , Jens Axboe , Nick Piggin , Badari Pulavarty References: <346556235.24875@ustc.edu.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.11+cvs20060126 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 865 Lines: 25 On Wed, May 03, 2006 at 06:20:29PM -0400, Rik van Riel wrote: > Why not simply read everything in a whole file at a time > at boot time, while we still have enough free memory ? Sure it helps, though may be unnecessary once we can rely on userspace pre-caching tools to do it in a more accurate and efficient way. The main concern would be inter-file/inter-buffer readahead. I have some data to support it: % wc -l hda* startup.files 1743 hda2_buffers <== my / 335 hda3_buffers <== my /home 1130 startup.files 3208 total The above cache sizes sum up to ~110MB, so it's about 36KB per seek. Thanks, Wu - 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/