From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753759AbcALWKc (ORCPT ); Tue, 12 Jan 2016 17:10:32 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45912 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753700AbcALWK3 (ORCPT ); Tue, 12 Jan 2016 17:10:29 -0500 Date: Wed, 13 Jan 2016 00:10:24 +0200 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org, Linus Torvalds Cc: Davidlohr Bueso , Peter Zijlstra , Ingo Molnar , Thomas Gleixner , "Paul E. McKenney" , the arch/x86 maintainers , Davidlohr Bueso , "H. Peter Anvin" , virtualization , Ingo Molnar , Andy Lutomirski , Borislav Petkov , Andrey Konovalov Subject: [PATCH v2 3/3] x86: tweak the comment about use of wmb for IO Message-ID: <1452635935-5439-4-git-send-email-mst@redhat.com> References: <1452635935-5439-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1452635935-5439-1-git-send-email-mst@redhat.com> X-Mutt-Fcc: =sent Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On x86, we *do* still use the non-nop rmb/wmb for IO barriers, but even that is generally questionable. Leave them around as historial unless somebody can point to a case where they care about the performance, but tweak the comment so people don't think they are strictly required in all cases. Signed-off-by: Michael S. Tsirkin --- arch/x86/include/asm/barrier.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h index eb220b8..924cd44 100644 --- a/arch/x86/include/asm/barrier.h +++ b/arch/x86/include/asm/barrier.h @@ -6,7 +6,7 @@ /* * Force strict CPU ordering. - * And yes, this is required on UP too when we're talking + * And yes, this might be required on UP too when we're talking * to devices. */ -- MST