From owner-freebsd-smp Tue Nov 23 10:23:42 1999 Delivered-To: freebsd-smp@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [216.240.41.2]) by hub.freebsd.org (Postfix) with ESMTP id 96D641532E for ; Tue, 23 Nov 1999 10:23:33 -0800 (PST) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.3/8.9.1) id KAA10338; Tue, 23 Nov 1999 10:23:24 -0800 (PST) (envelope-from dillon) Date: Tue, 23 Nov 1999 10:23:24 -0800 (PST) From: Matthew Dillon Message-Id: <199911231823.KAA10338@apollo.backplane.com> To: Peter Wemm , Tommy Hallgren , freebsd-smp@FreeBSD.ORG Subject: Re: Found it ... Re: Matt's new unlock optimiazation References: <19991123140128.3A7D41C6D@overcee.netplex.com.au> <199911231703.JAA09896@apollo.backplane.com> <199911231751.JAA10135@apollo.backplane.com> <199911231819.KAA10294@apollo.backplane.com> Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org : All we need is a serializing instruction. CPUID will do the trick, but : actually doing a locked instruction on private memory (verses shared : memory) is going to be faster. : with cpuid XXXXXXXX ns <--- change to 13 : lock/private 47 ns (same with or without segment override) : lock/shared 160 ns (with cpu contention) Oops, correction. cpuid is fastest -- 13 ns. I had mistakenly turned on two of the tests in the assembly. -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message