From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757973AbYBDUkW (ORCPT ); Mon, 4 Feb 2008 15:40:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755664AbYBDUkG (ORCPT ); Mon, 4 Feb 2008 15:40:06 -0500 Received: from terminus.zytor.com ([198.137.202.10]:54903 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755081AbYBDUkE (ORCPT ); Mon, 4 Feb 2008 15:40:04 -0500 Message-ID: <47A777FD.7080208@zytor.com> Date: Mon, 04 Feb 2008 12:39:25 -0800 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.9 (X11/20071115) MIME-Version: 1.0 To: Ingo Molnar CC: Sam Ravnborg , Cyrill Gorcunov , Andi Kleen , Thomas Gleixner , LKML Subject: Re: [PATCH] x86: vmlinux_64.lds.S - use THREAD_SIZE instead of numeric constant References: <20080204171037.GA6743@cvg> <20080204202241.GA16919@uranus.ravnborg.org> <20080204203315.GA31341@elte.hu> In-Reply-To: <20080204203315.GA31341@elte.hu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ingo Molnar wrote: > * Sam Ravnborg wrote: > >> Hi Cyrill. >> On Mon, Feb 04, 2008 at 08:10:37PM +0300, Cyrill Gorcunov wrote: >>> Signed-off-by: Cyrill Gorcunov >> The patch looks simple but please explain why you do what you do. It >> took me some digging before I could convince mysleft this was indeed a >> correct change. And I am pretty sure you did the same investigation >> yourself. >> >> A comment like: >> >> arch/x866/kernel/inittask.c require all variables allocated in >> the section .data.init_task to be aligned with THREAD_SIZE. >> >> would have made me happy. > > Btw., given that on x86 we've moved away from the %esp based task stack > trick and use an %fs based Percpu-Data-Area (PDA) to access the current > task pointer, this alignment might not be necessary anymore. It's a > historic relic of the mask-%esp trick. > Was that *ever* used on x86-64? I thought x86-64 always used %gs for this. -hpa