From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757646AbZEVUcw (ORCPT ); Fri, 22 May 2009 16:32:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756259AbZEVUcp (ORCPT ); Fri, 22 May 2009 16:32:45 -0400 Received: from mx-out2.daemonmail.net ([216.104.160.39]:49210 "EHLO mx-out2.daemonmail.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755165AbZEVUco convert rfc822-to-8bit (ORCPT ); Fri, 22 May 2009 16:32:44 -0400 From: "Michael S. Zick" Reply-To: lkml@morethan.org To: Samuel Thibault Subject: Re: [BUG FIX] Make x86_32 uni-processor Atomic ops, Atomic Date: Fri, 22 May 2009 15:32:41 -0500 User-Agent: KMail/1.9.9 Cc: Andi Kleen , linux-kernel@vger.kernel.org References: <200905221139.26941.lkml@morethan.org> <200905221453.41895.lkml@morethan.org> <20090522200536.GZ10166@const.famille.thibault.fr> In-Reply-To: <20090522200536.GZ10166@const.famille.thibault.fr> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Content-Disposition: inline Message-Id: <200905221532.43775.lkml@morethan.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri May 22 2009, Samuel Thibault wrote: > Michael S. Zick, le Fri 22 May 2009 14:53:39 -0500, a écrit : > > Ref: http://developer.intel.com/Assets/PDF/manual/253666.pdf > > Manual page: 3-590 PDF page: 638 > > Summary: Processors prior to P-4 can take an interrupt between > > the read cycle and the write cycle. Which is why opcode 0xF0 exists. > > Where do you see page 638/639 talking about interrupts? It talks about > multi-processor machines. > No - it talks about "exclusive memory access" - You got bus master DMA in your test machine? You also have an older than P-4 single processor? Look people, I just reported what I found from testing - Please don't shoot the messanger. If it: "Does not make a difference" then it "Should not make a difference" but it does, try it yourself. Its safe (if LOCK_PREFIX is in the proper places) - the machine will ignore the opcode if is recent enough to not need it - just trust the cpu's micro-code. Mike > Samuel > >