From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757329Ab2IJOGR (ORCPT ); Mon, 10 Sep 2012 10:06:17 -0400 Received: from terminus.zytor.com ([198.137.202.10]:60103 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757068Ab2IJOGO (ORCPT ); Mon, 10 Sep 2012 10:06:14 -0400 Message-ID: <504DF3BC.30708@zytor.com> Date: Mon, 10 Sep 2012 07:05:48 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120828 Thunderbird/15.0 MIME-Version: 1.0 To: Jan Beulich CC: mingo@elte.hu, tglx@linutronix.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/4] x86/xor: improve XMM register spill/fill References: <504DFB5B020000780009A327@nat28.tlf.novell.com> In-Reply-To: <504DFB5B020000780009A327@nat28.tlf.novell.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/10/2012 05:38 AM, Jan Beulich wrote: > +/* > + * By forcing the alignment beyond the default of 16 bytes, we make the > + * compiler guarantee the alignment. Passing -mincoming-stack-boundary=3 > + * (which would have been the better global alternative, as the kernel > + * never guarantees better stack alignment) isn't permitted on x86-64. > + */ The very latest gcc should handle it, and in fact we compile with -mstack-alignment=3 if gcc accepts it (if it is not yet upstream it will be soon.) This affects the validity of this patch. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.