From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mikulas Patocka Date: Sat, 21 Jun 2008 00:37:15 +0000 Subject: Re: stack overflow on Sparc64 Message-Id: List-Id: References: <20080620.152847.169209890.davem@davemloft.net> <20080620.154716.75920403.davem@davemloft.net> In-Reply-To: <20080620.154716.75920403.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Miller Cc: sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org, agk@redhat.com On Fri, 20 Jun 2008, David Miller wrote: > From: Mikulas Patocka > Date: Fri, 20 Jun 2008 18:36:09 -0400 (EDT) > >> On Fri, 20 Jun 2008, David Miller wrote: >> >>> Yes for debugging and other things it has to stay. >> >> If you want it to stay, then it doesn't make sense to make functions >> tail-call-friendly --- because it should not crash with or without >> debugging. > > On the contrary, of course it makes sense to do so. > > When debugging is disabled, the kernel will run faster. > > We have to fix the stack usage in either case, but from a > performance standpoint when debugging is disabled the > tail-call friendly layout is still highly desirable. I agree, but performance is different problem than stack overflows. I put all the patches for this overflow problem here: http://people.redhat.com/mpatocka/patches/kernel-stack-overflow Mikulas From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757337AbYFUAha (ORCPT ); Fri, 20 Jun 2008 20:37:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754299AbYFUAhU (ORCPT ); Fri, 20 Jun 2008 20:37:20 -0400 Received: from mx1.redhat.com ([66.187.233.31]:46869 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753307AbYFUAhT (ORCPT ); Fri, 20 Jun 2008 20:37:19 -0400 Date: Fri, 20 Jun 2008 20:37:15 -0400 (EDT) From: Mikulas Patocka To: David Miller cc: sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org, agk@redhat.com Subject: Re: stack overflow on Sparc64 In-Reply-To: <20080620.154716.75920403.davem@davemloft.net> Message-ID: References: <20080620.152847.169209890.davem@davemloft.net> <20080620.154716.75920403.davem@davemloft.net> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 20 Jun 2008, David Miller wrote: > From: Mikulas Patocka > Date: Fri, 20 Jun 2008 18:36:09 -0400 (EDT) > >> On Fri, 20 Jun 2008, David Miller wrote: >> >>> Yes for debugging and other things it has to stay. >> >> If you want it to stay, then it doesn't make sense to make functions >> tail-call-friendly --- because it should not crash with or without >> debugging. > > On the contrary, of course it makes sense to do so. > > When debugging is disabled, the kernel will run faster. > > We have to fix the stack usage in either case, but from a > performance standpoint when debugging is disabled the > tail-call friendly layout is still highly desirable. I agree, but performance is different problem than stack overflows. I put all the patches for this overflow problem here: http://people.redhat.com/mpatocka/patches/kernel-stack-overflow Mikulas