From owner-freebsd-current Wed Jan 17 9:44:31 2001 Delivered-To: freebsd-current@freebsd.org Received: from critter.freebsd.dk (flutter.freebsd.dk [212.242.40.147]) by hub.freebsd.org (Postfix) with ESMTP id 5FAE037B400; Wed, 17 Jan 2001 09:44:11 -0800 (PST) Received: from critter (localhost [127.0.0.1]) by critter.freebsd.dk (8.11.1/8.11.1) with ESMTP id f0HHi4Z53514; Wed, 17 Jan 2001 18:44:04 +0100 (CET) (envelope-from phk@critter.freebsd.dk) To: Robert Drehmel Cc: John Baldwin , Garrett Wollman , current@FreeBSD.ORG, Peter Jeremy Subject: Re: Atomic breakage? In-Reply-To: Your message of "Wed, 17 Jan 2001 18:36:16 +0100." <3A65D810.6304785A@gizmo.quizbot.org> Date: Wed, 17 Jan 2001 18:44:04 +0100 Message-ID: <53512.979753444@critter> From: Poul-Henning Kamp Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In message <3A65D810.6304785A@gizmo.quizbot.org>, Robert Drehmel writes: >In , John Baldwin wrote: >> Early Pentiums (<= P90) don't support CX8 or so I've heard, which make this >> slightly more complicated, as for a pentium we would have to use a function >> pointer that we setup during probe. Also, during a SMP boot we would have to >> panic if CX8 wasn't enabled on all CPU's. > >P75 (stepping 5): > >cmpxchg8 was actually introduced with the Pentium processors, >as Mr. Wollman already wrote. Either way, it's precense should be determined by looking at the CPUID feature bit. It's the only reliable way. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message