Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755532Ab1EER5R (ORCPT ); Thu, 5 May 2011 13:57:17 -0400 Received: from one.firstfloor.org ([213.235.205.2]:59613 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752882Ab1EER5Q (ORCPT ); Thu, 5 May 2011 13:57:16 -0400 Date: Thu, 5 May 2011 19:57:13 +0200 From: Andi Kleen To: john stultz Cc: Andi Kleen , lkml , Paul Mackerras , "Paul E. McKenney" , Anton Blanchard , Thomas Gleixner Subject: Re: [PATCH] time: Add locking to xtime access in get_seconds() Message-ID: <20110505175713.GG2925@one.firstfloor.org> References: <1304478708-1273-1-git-send-email-john.stultz@linaro.org> <1304564090.2943.36.camel@work-vm> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1304564090.2943.36.camel@work-vm> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 711 Lines: 20 > I suspect the reason this hasn't been triggered on x86 or power6 is due > to compiler or processor optimizations reordering the assignment to in > effect make it atomic. Or maybe the timing window to see the issue is > harder to observe? On x86 all aligned stores are atomic. So I don't see how this could be a problem ever. Are you saying that on P6 only atomic stores are atomic? If that's the case again I suspect other code will be affected too. -Andi > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/