Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934335AbXHORDc (ORCPT ); Wed, 15 Aug 2007 13:03:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934113AbXHORCs (ORCPT ); Wed, 15 Aug 2007 13:02:48 -0400 Received: from mx1.redhat.com ([66.187.233.31]:54294 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934193AbXHORCr (ORCPT ); Wed, 15 Aug 2007 13:02:47 -0400 Message-ID: <46C3319F.4050809@redhat.com> Date: Wed, 15 Aug 2007 13:02:23 -0400 From: Chris Snook User-Agent: Thunderbird 1.5.0.12 (Macintosh/20070509) MIME-Version: 1.0 To: Herbert Xu CC: Andi Kleen , sebastian@breakpoint.cc, linux-kernel@vger.kernel.org Subject: Re: [patch 1/2] i386: use asm() like the other atomic operations already do. References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1084 Lines: 25 Herbert Xu wrote: > Andi Kleen wrote: >>> My config with march=pentium-m and gcc (GCC) 4.1.2 (Gentoo 4.1.2): >>> text data bss dec hex filename >>> 3434150 249176 176128 3859454 3ae3fe atomic_normal/vmlinux >>> 3435308 249176 176128 3860612 3ae884 atomic_inlineasm/vmlinux >> What is the difference between atomic_normal and atomic_inlineasm? > > The inline asm stops certain optimisations from occuring. > > I'm still unconvinced why we need this because nobody has > brought up any examples of kernel code that legitimately > need this. There's plenty of kernel code that *wants* this though. If we can reduce the need for register-clobbering barriers, shrink our binaries, shrink our code, improve performance, and avoid heisenbugs, I think it's a win, whether or not we *need* it. -- Chris - 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/