From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264561AbUE0O0B (ORCPT ); Thu, 27 May 2004 10:26:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264562AbUE0O0B (ORCPT ); Thu, 27 May 2004 10:26:01 -0400 Received: from dial249.pm3abing3.abingdonpm.naxs.com ([216.98.75.249]:12241 "EHLO animx.eu.org") by vger.kernel.org with ESMTP id S264561AbUE0OZ6 (ORCPT ); Thu, 27 May 2004 10:25:58 -0400 Date: Thu, 27 May 2004 10:34:14 -0400 From: Wakko Warner To: Nick Piggin Cc: linux-kernel@vger.kernel.org Subject: Re: why swap at all? Message-ID: <20040527103414.A31572@animx.eu.org> References: <40B4590A.1090006@yahoo.com.au> <40B4667B.5040303@nodivisions.com> <40B46A57.4050209@yahoo.com.au> <20040526161127.A30461@animx.eu.org> <40B583BC.7030706@yahoo.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.95.3i In-Reply-To: <40B583BC.7030706@yahoo.com.au>; from Nick Piggin on Thu, May 27, 2004 at 03:59:24PM +1000 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > > I have a question about that. I keep a debian mirror on one of my machines. > > there is over 70000 files. If I run find on that tree while it's > > downloading the file list, it doesn't take as long. I thought it would be > > nice if there was some way I could keep that in memory. The box has 256mb > > ram no swap. It is configured as diskless. > > > > You mean that if you prime the cache by running find on the tree, > your actual operation doesn't take as long? Yup. Running the mirror doesn't matter really. I start that before I retire at the end of the day. > I don't doubt this. Slab cache is shrunk aggressively compared to > page cache. Traditionally I think this has been due at least in > part to some failure cases in the balancing there resulting in slab > growing out of control with some systems. Where it gets me is the 2nd mirror I have on a usb disk. Updating it takes a while. Although priming the cache on the machine where the usb disk is is a bit quicker than where the mirror is (rsync over tcp/ip). Both disks use ext3, but the machine the usb is on has way more memory, usb2, and overall quicker than the other. > These failure cases should be fixed now, and slab vs pagecache is > probably something that should be looked at again. I really need > to get my hands on a 2GB+ system before I'd be game to start > fiddling with too much stuff though. I've been wanting to upgrade that machine to 768mb, but I don't know if it'll handle it. -- Lab tests show that use of micro$oft causes cancer in lab animals