From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964811AbWGYTHW (ORCPT ); Tue, 25 Jul 2006 15:07:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964812AbWGYTHE (ORCPT ); Tue, 25 Jul 2006 15:07:04 -0400 Received: from mail-in-05.arcor-online.net ([151.189.21.45]:65235 "EHLO mail-in-05.arcor-online.net") by vger.kernel.org with ESMTP id S964811AbWGYTHB (ORCPT ); Tue, 25 Jul 2006 15:07:01 -0400 In-Reply-To: <1153852204.5665.10.camel@basalt.austin.ibm.com> References: <20060718091807.467468000@sous-sol.org> <20060718091956.905130000@sous-sol.org> <1153852204.5665.10.camel@basalt.austin.ibm.com> Mime-Version: 1.0 (Apple Message framework v750) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: Cc: Chris Wright , linux-kernel@vger.kernel.org, Andrew Morton , virtualization@lists.osdl.org, Jeremy Fitzhardinge , xen-devel@lists.xensource.com, Ian Pratt , xen-ppc-devel Content-Transfer-Encoding: 7bit From: Segher Boessenkool Subject: Re: [RFC PATCH 28/33] Add Xen grant table support Date: Tue, 25 Jul 2006 21:06:51 +0200 To: Hollis Blanchard X-Mailer: Apple Mail (2.750) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > I object to these uses of (synch_)cmpxchg on a uint16_t in common > code. > Many architectures, including PowerPC, do not support 2-byte atomic > operations, but this code is common to all Xen architectures. RMW operations you mean, I suppose. On PowerPC, all (naturally aligned) halfword operations are atomic; there do not exist any RMW operations; but word and doubleword atomic RMW operations can be emulated. Boils down to the same thing of course, but it isn't the same ;-) Segher