From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965646AbXDMXBq (ORCPT ); Fri, 13 Apr 2007 19:01:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965679AbXDMXBq (ORCPT ); Fri, 13 Apr 2007 19:01:46 -0400 Received: from crown.reflexsecurity.com ([72.54.139.163]:46387 "EHLO crown.reflexsecurity.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965646AbXDMXBp (ORCPT ); Fri, 13 Apr 2007 19:01:45 -0400 X-Reflex-Keepalives: . Date: Fri, 13 Apr 2007 19:01:39 -0400 From: Jason Lunz To: Andrew Morton Cc: Cameron Schaus , linux-kernel@vger.kernel.org Subject: Re: 2.6.20 OOM with 8Gb RAM Message-ID: <20070413230139.GB6783@metaxa.reflex> References: <20070412173830.GA31323@schaus.ca> <20070412121553.c7fd3249.akpm@linux-foundation.org> <20070413223935.GA6783@metaxa.reflex> <20070413154653.21fdb914.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070413154653.21fdb914.akpm@linux-foundation.org> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 13, 2007 at 03:46:53PM -0700, Andrew Morton wrote: > > If I want to run a system entirely from ram with a compressed filesystem > > image mounted on /, is it better to store that image in a ramdisk, or on > > a tmpfs and mount it via loopback? > > Store it all in ramfs, no loopback needed? I used to put everything in a tmpfs on /, and that certainly works. But most files in a typical image are rarely used and it's a pity to have lots of little files taking up a 4k page each. You get pretty big savings by compressing the system into a squashfs and mounting that, so the question becomes: where to put the squashfs? ramdisk or loopback mount it from tmpfs/ramfs? iirc, the problems with loopback have to do with writeout, which isn't a problem here since squashfs is readonly. Jason