From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753393AbZALMoU (ORCPT ); Mon, 12 Jan 2009 07:44:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751762AbZALMoK (ORCPT ); Mon, 12 Jan 2009 07:44:10 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:46817 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751491AbZALMoJ (ORCPT ); Mon, 12 Jan 2009 07:44:09 -0500 Date: Mon, 12 Jan 2009 13:44:01 +0100 From: Ingo Molnar To: Jiri Kosina Cc: Jeremy Fitzhardinge , linux-kernel@vger.kernel.org, Thomas Gleixner , "H. Peter Anvin" Subject: Re: [PATCH] x86: remove byte locks Message-ID: <20090112124401.GA31939@elte.hu> References: <20090112120743.GC24266@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: 0.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.5 required=5.9 tests=BAYES_40 autolearn=no SpamAssassin version=3.2.3 0.5 BAYES_40 BODY: Bayesian spam probability is 20 to 40% [score: 0.3601] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Jiri Kosina wrote: > On Mon, 12 Jan 2009, Ingo Molnar wrote: > > > > Remove byte locks implementation, which was introduced by Jeremy in > > > 8efcbab6 ("paravirt: introduce a "lock-byte" spinlock implementation"), > > > but turned out to be dead code that is not used by any in-kernel > > > virtualization guest (Xen uses its own variant of spinlocks implementation > > > and KVM is not planning to move to byte locks). > > > > > > Signed-off-by: Jiri Kosina > > > --- > > > arch/x86/include/asm/paravirt.h | 2 - > > > arch/x86/include/asm/spinlock.h | 66 +-------------------------------- > > > arch/x86/kernel/paravirt-spinlocks.c | 10 ----- > > > 3 files changed, 2 insertions(+), 76 deletions(-) > > didnt you send a patch in this lkml thread: > > > > Subject: Re: Is 386 processor still supported? > > > that makes use of byte-locks on i386 ? > > I did, but that patch was bogus, as we indeed don't support smp on M386. > > This is totally independent -- it just removes dead code (byte locks) that > has no in-tree user at all. > > > But i guess we should solve M386 and M486 by only allowing it on !SMP, > > hence spinlock support is moot there, right? > > Agreed. But that's a different issue. ok. Jeremy, can we apply Jiri's patch or do you still have plans with that code? Ingo