From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264530AbUE0OQ7 (ORCPT ); Thu, 27 May 2004 10:16:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264550AbUE0OQ7 (ORCPT ); Thu, 27 May 2004 10:16:59 -0400 Received: from mail.fh-wedel.de ([213.39.232.194]:3470 "EHLO mail.fh-wedel.de") by vger.kernel.org with ESMTP id S264530AbUE0OQw (ORCPT ); Thu, 27 May 2004 10:16:52 -0400 Date: Thu, 27 May 2004 16:15:47 +0200 From: =?iso-8859-1?Q?J=F6rn?= Engel To: Andrea Arcangeli Cc: Andi Kleen , "David S. Miller" , mingo@elte.hu, riel@redhat.com, torvalds@osdl.org, arjanv@redhat.com, linux-kernel@vger.kernel.org Subject: Re: 4k stacks in 2.6 Message-ID: <20040527141547.GC23194@wohnheim.fh-wedel.de> References: <1ZQpn-1Rx-1@gated-at.bofh.it> <1ZQz8-1Yh-15@gated-at.bofh.it> <1ZRFf-2Vt-3@gated-at.bofh.it> <203Zu-4aT-15@gated-at.bofh.it> <206b3-5WN-33@gated-at.bofh.it> <20baw-1Lz-15@gated-at.bofh.it> <20040527112705.GA21190@wohnheim.fh-wedel.de> <20040527134950.GB3889@dualathlon.random> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20040527134950.GB3889@dualathlon.random> User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 27 May 2004 15:49:50 +0200, Andrea Arcangeli wrote: > On Thu, May 27, 2004 at 01:27:05PM +0200, Jörn Engel wrote: > > Cool! If that is included, I don't have any objections against 4k > > stacks anymore. > > note that it will introduce an huge slowdown, there's no way to enable > that in production. But for testing it's fine. Would it be possible to add something short to the function preamble on x86 then? Similar to this code, maybe: if (!(stack_pointer & 0xe00)) /* less than 512 bytes left */ *NULL = 1; Not sure how this can be translated into short and fast x86 assembler, but if it is possible, I would really like to have it. Then all we have left to do is make sure no function ever uses more than 512 bytes. Famous last words, I know. Jörn -- Time? What's that? Time is only worth what you do with it. -- Theo de Raadt