From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763695AbYDYRk0 (ORCPT ); Fri, 25 Apr 2008 13:40:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760934AbYDYRkN (ORCPT ); Fri, 25 Apr 2008 13:40:13 -0400 Received: from main.gmane.org ([80.91.229.2]:48390 "EHLO ciao.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760107AbYDYRkM (ORCPT ); Fri, 25 Apr 2008 13:40:12 -0400 X-Injected-Via-Gmane: http://gmane.org/ To: linux-kernel@vger.kernel.org From: Parag Warudkar Subject: Re: x86: 4kstacks default Date: Fri, 25 Apr 2008 17:39:53 +0000 (UTC) Message-ID: References: <200804181737.m3IHbabI010051@hera.kernel.org> <20080418142934.38ce6bf4.akpm@linux-foundation.org> <20080419142329.GA5339@elte.hu> <20080419104911.07d299ef.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: main.gmane.org User-Agent: Loom/3.14 (http://gmane.org/) X-Loom-IP: 68.60.35.179 (Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton linux-foundation.org> writes: > > > On Sat, 19 Apr 2008 16:23:29 +0200 Ingo Molnar elte.hu> wrote: > > > > * Andrew Morton linux-foundation.org> wrote: > > > > > > config 4KSTACKS > > > > bool "Use 4Kb for kernel stacks instead of 8Kb" > > > > - depends on DEBUG_KERNEL > > > > depends on X86_32 > > > > + default y > > > > > > This patch will cause kernels to crash. > > > > what mainline kernels crash and how will they crash? > > There has been a dribble of reports - I don't have the links handy, nor did > I search for them. > > > Fedora and other > > distros have had 4K stacks enabled for years: > > > > $ grep 4K /boot/config-2.6.24-9.fc9 > > CONFIG_4KSTACKS=y Here is a report - Fedora 8 default kernel, Mac Mini file server, Not Tainted. Attempt to copy 100Gb+ of data from a hfsplus file system on a USB drive to a firewire drive with XFS filesystem - I got a nasty panic with a huge stack backtrace. I gave up and switched to Ubuntu. With a stock kernel.org kernel I was able to successfully copy the data over. I still have the machine and the restored drives and can try to reproduce it with Fedora 9 w/4K stacks if anyone thinks it is worthwhile (i.e. fixable). Parag