From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265399AbUEZJ66 (ORCPT ); Wed, 26 May 2004 05:58:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265400AbUEZJ66 (ORCPT ); Wed, 26 May 2004 05:58:58 -0400 Received: from smtp105.mail.sc5.yahoo.com ([66.163.169.225]:45671 "HELO smtp105.mail.sc5.yahoo.com") by vger.kernel.org with SMTP id S265399AbUEZJ65 (ORCPT ); Wed, 26 May 2004 05:58:57 -0400 Message-ID: <40B46A57.4050209@yahoo.com.au> Date: Wed, 26 May 2004 19:58:47 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040401 Debian/1.6-4 X-Accept-Language: en MIME-Version: 1.0 To: orders@nodivisions.com CC: linux-kernel@vger.kernel.org Subject: Re: why swap at all? References: <40B4590A.1090006@yahoo.com.au> <40B4667B.5040303@nodivisions.com> In-Reply-To: <40B4667B.5040303@nodivisions.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Anthony DiSante wrote: > Nick Piggin wrote: > >> The VM doesn't always get it right, and to make matters worse, desktop >> users don't appreciate their long running jobs finishing earlier, but >> *hate* having to wait a few seconds for a window to appear if it hasn't >> been used for 24 hours. > > > Come on, that is quite an exaggeration. It can happen in a span of > minutes -- after rsyncing a dir to a backup dir, for example, which > fills ram rather quickly with cache I'll never use again. Or after > configuring and compiling a package, which does the same thing. > rsync is something known to break the VM's use-once heuristics. I'm looking at that. > As you said, the VM doesn't, in fact, always get it right. If 512MB > worked before when it was half swap, 512MB of pure ram will work too, > only faster. I don't see how adding more swap at that point could > increase performance unless you are keeping your ram full of non-cached > pages, and that's never the case for me -- my ram is almost always half > cached pages. > It can.