From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752500AbZHAWGw (ORCPT ); Sat, 1 Aug 2009 18:06:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752468AbZHAWGw (ORCPT ); Sat, 1 Aug 2009 18:06:52 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:32955 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752440AbZHAWGv (ORCPT ); Sat, 1 Aug 2009 18:06:51 -0400 Date: Sat, 1 Aug 2009 15:04:55 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: "H. Peter Anvin" cc: Ingo Molnar , Thomas Gleixner , Linux Kernel Mailing List , Tejun Heo Subject: Re: [GIT PULL] Additional x86 fixes for 2.6.31-rc5 In-Reply-To: <4A7499BA.2000405@zytor.com> Message-ID: References: <200907311813.n6VIDe9S023442@voreg.hos.anvin.org> <20090731195705.GA12270@elte.hu> <4A7499BA.2000405@zytor.com> User-Agent: Alpine 2.01 (LFD 1184 2008-12-16) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 1 Aug 2009, H. Peter Anvin wrote: > > This is clearly better... now the semi-obvious question becomes if there > is any way we can get compiler support to do better and migrate to that > as the compiler allows. Well, even if we had compiler support, we'd have to basically then wait forever to make sure everybody has a supported compiler. So I think we're better off not worrying too much about that - it's not going to happen any time in the near future. I've now tested my patch, and it seems to result in a working kernel too. > In particular, if I remember right the problem with using __thread for > percpu was exactly that the current cpuness can change almost anywhere, > unless preemption is disabled. That shouldn't matter. If it uses '%gs', it should all just work automatically. But if gcc does something different for thread-local, it's basically useless. Linus