From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934204AbcA0R4p (ORCPT ); Wed, 27 Jan 2016 12:56:45 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57858 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932953AbcA0R4n (ORCPT ); Wed, 27 Jan 2016 12:56:43 -0500 Date: Wed, 27 Jan 2016 19:56:37 +0200 From: "Michael S. Tsirkin" To: Linus Torvalds Cc: Linux Kernel Mailing List , Davidlohr Bueso , Peter Zijlstra , Ingo Molnar , Thomas Gleixner , "Paul E. McKenney" , the arch/x86 maintainers , Davidlohr Bueso , "H. Peter Anvin" , virtualization , Borislav Petkov , Andy Lutomirski , Ingo Molnar , Andy Lutomirski , Andrey Konovalov , Borislav Petkov Subject: Re: [PATCH v4 5/5] x86: drop mfence in favor of lock+addl Message-ID: <20160127195314-mutt-send-email-mst@redhat.com> References: <1453904765-11073-1-git-send-email-mst@redhat.com> <1453904765-11073-6-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 27, 2016 at 09:37:45AM -0800, Linus Torvalds wrote: > On Wed, Jan 27, 2016 at 7:10 AM, Michael S. Tsirkin wrote: > > > > -#define __smp_mb() mb() > > +#define __smp_mb() asm volatile("lock; addl $0,-4(%%esp)" ::: "memory", "cc") > > So this doesn't look right for x86-64. Using %esp rather than %rsp. > How did that even work for you? > > Linus Oops, didn't test this version properly. Pls disregard, I'll repost after some proper testing. -- MST