From owner-freebsd-smp Tue Nov 23 6:11:24 1999 Delivered-To: freebsd-smp@freebsd.org Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.40.131]) by hub.freebsd.org (Postfix) with ESMTP id B4465152DD for ; Tue, 23 Nov 1999 06:11:18 -0800 (PST) (envelope-from phk@critter.freebsd.dk) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.9.3/8.9.2) with ESMTP id PAA28650; Tue, 23 Nov 1999 15:09:59 +0100 (CET) (envelope-from phk@critter.freebsd.dk) To: Peter Wemm Cc: Tommy Hallgren , freebsd-smp@FreeBSD.ORG Subject: Re: Matt's new unlock optimiazation In-reply-to: Your message of "Tue, 23 Nov 1999 22:01:28 +0800." <19991123140128.3A7D41C6D@overcee.netplex.com.au> Date: Tue, 23 Nov 1999 15:09:59 +0100 Message-ID: <28648.943366199@critter.freebsd.dk> From: Poul-Henning Kamp Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org In message <19991123140128.3A7D41C6D@overcee.netplex.com.au>, Peter Wemm writes : >Tommy Hallgren wrote: >> Hi subscribers! >> >> FYI, this popped up in the linux-kern mailing-list: >> http://boudicca.tux.org/hypermail/linux-kernel/this-week/0060.html >> >> The entire thread is here: >> http://boudicca.tux.org/hypermail/linux-kernel/this-week/subject.html#start >> >> The subject is: spin_unlock optimization(i386) > >A bit worrying, to say the least, especially coming from Linus (even moreso >in light of his work at transmeta and what they're doing with/to Intel cpu's). We (Peter and I :-) actually have been there once before, in what '96 or '97 when we got SMP on its legs. I didn't comment on Matts stuff because I didn't want to upset him, but I agree with Linus: This doesn't work unless other serialization is added to the code. -- Poul-Henning Kamp FreeBSD coreteam member phk@FreeBSD.ORG "Real hackers run -current on their laptop." FreeBSD -- It will take a long time before progress goes too far! To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message