Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030416AbVKPSpK (ORCPT ); Wed, 16 Nov 2005 13:45:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030421AbVKPSpK (ORCPT ); Wed, 16 Nov 2005 13:45:10 -0500 Received: from emailhub.stusta.mhn.de ([141.84.69.5]:61455 "HELO mailout.stusta.mhn.de") by vger.kernel.org with SMTP id S1030416AbVKPSpI (ORCPT ); Wed, 16 Nov 2005 13:45:08 -0500 Date: Wed, 16 Nov 2005 19:45:08 +0100 From: Adrian Bunk To: Andi Kleen Cc: Arjan van de Ven , Oliver Neukum , jmerkey , =?iso-8859-1?Q?J=F6rn?= Engel , alex14641@yahoo.com, linux-kernel@vger.kernel.org Subject: Re: [2.6 patch] i386: always use 4k stacks Message-ID: <20051116184508.GP5735@stusta.de> References: <20051116005034.73421.qmail@web50210.mail.yahoo.com> <200511161630.59588.oliver@neukum.org> <1132155482.2834.42.camel@laptopd505.fenrus.org> <200511161710.05526.ak@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <200511161710.05526.ak@suse.de> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1604 Lines: 43 On Wed, Nov 16, 2005 at 05:10:04PM +0100, Andi Kleen wrote: > On Wednesday 16 November 2005 16:38, Arjan van de Ven wrote: > > On Wed, 2005-11-16 at 16:30 +0100, Oliver Neukum wrote: > > > Am Mittwoch, 16. November 2005 15:42 schrieb jmerkey: > > > > Map a blank ro page beneath the address range when stack memory is > > > > mapped is trap on page faults to the page when folks go off the end of > > > > th e stack. > > > > > > > > Easy to find. > > > > > > Provided you can easily trigger it. I don't see how that is a given. > > > > the same is true for a unified 8k stack or for the 4k/4k split though. > > Ok sure there's a 1.5Kb difference on the one side.. (but a 2Kb gain on > > the other side) > > I was always in favour of 8K process stacks + irq stacks. Works great on x86-64. J?rn did some analysis regarding possible call paths > 3k. Our goal is to achieve a stack usage < 3k with a safety margin of 1k. The problem is similar no matter whether you have 4k or 8k stacks, but with 4k stacks you have the additional benefits of order 0 allocations and less memory usage. > -Andi cu Adrian -- "Is there not promise of rain?" Ling Tan asked suddenly out of the darkness. There had been need of rain for many days. "Only a promise," Lao Er said. Pearl S. Buck - Dragon Seed - 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/