Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932526AbXIUVOQ (ORCPT ); Fri, 21 Sep 2007 17:14:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1764931AbXIUVNq (ORCPT ); Fri, 21 Sep 2007 17:13:46 -0400 Received: from mx1.redhat.com ([66.187.233.31]:41124 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1764787AbXIUVNp (ORCPT ); Fri, 21 Sep 2007 17:13:45 -0400 Date: Fri, 21 Sep 2007 17:13:41 -0400 From: Dave Jones To: Andi Kleen Cc: patches@x86-64.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] [20/45] x86_64: Use 8 byte stack alignment when possible Message-ID: <20070921211341.GC8127@redhat.com> Mail-Followup-To: Dave Jones , Andi Kleen , patches@x86-64.org, linux-kernel@vger.kernel.org References: <200709211044.901175000@suse.de> <20070921204502.2C61D14EFF@wotan.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070921204502.2C61D14EFF@wotan.suse.de> User-Agent: Mutt/1.5.14 (2007-02-12) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 803 Lines: 21 On Fri, Sep 21, 2007 at 10:45:02PM +0200, Andi Kleen wrote: > > Kernel doesn't use SSE2, so it doesn't need 16 byte alignment. Also > the stack can be already unaligned so letting the compiler align > is useless. This may make some stack frames smaller. > Only works with very recent gcc 4.3 My gcc 4.1.2 from Fedora 7 (with who knows what backported) references this in its manpage. How was it broken before 4.3 ? (I'm curious if I'll suddenly see not expected behaviour with this change with that compiler). Dave -- http://www.codemonkey.org.uk - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/