From owner-freebsd-smp Sat Dec 9 8: 2:44 2000 From owner-freebsd-smp@FreeBSD.ORG Sat Dec 9 08:02:41 2000 Return-Path: Delivered-To: freebsd-smp@freebsd.org Received: from berserker.bsdi.com (berserker.twistedbit.com [199.79.183.1]) by hub.freebsd.org (Postfix) with ESMTP id F19D737B6A9; Sat, 9 Dec 2000 08:02:37 -0800 (PST) Received: from berserker.bsdi.com (cp@localhost.bsdi.com [127.0.0.1]) by berserker.bsdi.com (8.11.1/8.9.3) with ESMTP id eB9G2UH06249; Sat, 9 Dec 2000 09:02:30 -0700 (MST) (envelope-from cp@berserker.bsdi.com) Message-Id: <200012091602.eB9G2UH06249@berserker.bsdi.com> To: arun@sharmas.dhs.org Cc: jhb@FreeBSD.ORG, smp@FreeBSD.ORG Subject: Re: Userland atomic assignments In-reply-to: Your message of "Fri, 08 Dec 2000 22:20:15 PST." <200012090620.WAA28099@sharmas.dhs.org> From: Chuck Paterson Date: Sat, 09 Dec 2000 09:02:30 -0700 Sender: cp@berserker.bsdi.com Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org } }However, the complexity comes from memory ordering issues. All of x86 boxes }ensure sequential consistency. } Sequenctial consistency from a single processor, which may well be what you meant. Writes from different processors to different cache lines are not ordered with respect to one another. Also writes from one processor are not at all ordered with respect to reads from another processor. What is guaranteed is that writes from a single processor will be ordered with respect to one another as viewed from any processor. Chuck To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message