From owner-freebsd-alpha Fri Dec 15 11:36: 0 2000 From owner-freebsd-alpha@FreeBSD.ORG Fri Dec 15 11:35:59 2000 Return-Path: Delivered-To: freebsd-alpha@freebsd.org Received: from pike.osd.bsdi.com (pike.osd.bsdi.com [204.216.28.222]) by hub.freebsd.org (Postfix) with ESMTP id 9518037B6A0 for ; Fri, 15 Dec 2000 11:35:54 -0800 (PST) Received: from laptop.baldwin.cx (john@jhb-laptop.osd.bsdi.com [204.216.28.241]) by pike.osd.bsdi.com (8.11.1/8.9.3) with ESMTP id eBFJZVE24862; Fri, 15 Dec 2000 11:35:31 -0800 (PST) (envelope-from jhb@FreeBSD.org) Message-ID: X-Mailer: XFMail 1.4.0 on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <20001215193443.B62048@cicely5.cicely.de> Date: Fri, 15 Dec 2000 11:35:47 -0800 (PST) From: John Baldwin To: Bernd Walter Subject: RE: mb and wmb in atomic_ Cc: freebsd-alpha@FreeBSD.org Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On 15-Dec-00 Bernd Walter wrote: > Why are the mb and wmb operations needed in the atomic_ functions? > If I understood it correctly the locked operations are in synced > with others CPUs and there is no memory operation beside the variable > itself. They should probably only be used with the 'acq' and 'rel' variants. Hmm, btw, it looks like I have the order of the barriers in the 'acq' and 'rel' variants wrong. The barriers should be on the inside, not the outside. Anyone disagree? -- John Baldwin -- http://www.FreeBSD.org/~jhb/ PGP Key: http://www.baldwin.cx/~john/pgpkey.asc "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message