From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262073AbVF0Qh0 (ORCPT ); Mon, 27 Jun 2005 12:37:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262084AbVF0PBC (ORCPT ); Mon, 27 Jun 2005 11:01:02 -0400 Received: from nevyn.them.org ([66.93.172.17]:54976 "EHLO nevyn.them.org") by vger.kernel.org with ESMTP id S262049AbVF0OAh (ORCPT ); Mon, 27 Jun 2005 10:00:37 -0400 Date: Mon, 27 Jun 2005 10:00:29 -0400 From: Daniel Jacobowitz To: Vivek Goyal Cc: Andrew Morton , Adrian Bunk , fastboot@lists.osdl.org, linux-kernel@vger.kernel.org, gdb@sources.redhat.com Subject: Re: [Fastboot] Re: [-mm patch] i386: enable REGPARM by default Message-ID: <20050627140029.GB29121@nevyn.them.org> Mail-Followup-To: Vivek Goyal , Andrew Morton , Adrian Bunk , fastboot@lists.osdl.org, linux-kernel@vger.kernel.org, gdb@sources.redhat.com References: <20050624200916.GJ6656@stusta.de> <20050624132826.4cdfb63c.akpm@osdl.org> <20050627132941.GD3764@in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050627132941.GD3764@in.ibm.com> User-Agent: Mutt/1.5.8i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 27, 2005 at 06:59:41PM +0530, Vivek Goyal wrote: > On Fri, Jun 24, 2005 at 01:28:26PM -0700, Andrew Morton wrote: > > Adrian Bunk wrote: > > > > > > This patch: > > > - removes the dependency of REGPARM on EXPERIMENTAL > > > - let REGPARM default to y > > > > hm, a compromise. > > > > One other concern I have with this is that I expect -mregparm will make > > kgdb (and now crashdump) less useful. When incoming args are on the stack > > you have a good chance of being able to see what their value is by walking > > the stack slots. > > > > When the incoming args are in registers I'd expect that it would be a lot > > harder (or impossible) to work out their value. > > > > Have the kdump guys thought about (or encountered) this? GDB is more than capable of handling this - if your compiler is saving arguments to the stack and dumping out useful information for the debugger about where it put them. Recent GCC versions are generally pretty good about either saving the argument or clearly telling GDB that it was not saved. -- Daniel Jacobowitz CodeSourcery, LLC