From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 16 Sep 2001 13:30:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 16 Sep 2001 13:30:25 -0400 Received: from family.zawodny.com ([63.174.200.26]:33555 "EHLO family.zawodny.com") by vger.kernel.org with ESMTP id ; Sun, 16 Sep 2001 13:30:09 -0400 Date: Sun, 16 Sep 2001 10:18:45 -0700 From: Jeremy Zawodny To: Ricardo Galli Cc: linux-kernel@vger.kernel.org Subject: Re: broken VM in 2.4.10-pre9 Message-ID: <20010916101845.A14285@peach.zawodny.com> In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.3.20i X-message-flag: Mailbox corrupt. Please upgrade your mail software. X-Uptime: 10:16:35 up 49 days, 8:14, 10 users, load average: 0.00, 0.00, 0.00 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Sep 16, 2001 at 07:06:45PM +0200, Ricardo Galli wrote: > On Sun, 16 Sep 2001, Rik van Riel wrote: > > > > > Is there a way to tell the VM to prune its cache? Or a way to limit > > > the amount of cache it uses? > > > > Not yet, I'll make a quick hack for this when I get back next > > week. It's pretty obvious now that the 2.4 kernel cannot get > > enough information to select the right pages to evict from > > memory. > > .... > > On Sun, 16 Sep 2001, Jeremy Zawodny wrote: > > > > Agreed. I'd be great if there was an option to say "Don't swap out > > memory that was allocated by these programs. If you run out of disk > > buffers, toss the oldest ones and start re-using them." > > More easy though (for cases of listening mp3's and backups): cache > pages that were accesed only "once"(*) several seconds ago must be > discarded first. It only implies a check against an access counter > and a "last accesed" epoch fields of the page. Yeah, something along those lines would be great. It would keep a big (13 GB) drive to drive file copy from causing a large (400MB) and relatively active process from having its memory swapped out (and then back in 20 seconds later). Imagine watching that for 45 minutes while a backup that used to take 5-8 minutes runs. Jeremy -- Jeremy D. Zawodny | Perl, Web, MySQL, Linux Magazine, Yahoo! | http://jeremy.zawodny.com/