From owner-freebsd-smp Thu May 30 16:37:58 1996 Return-Path: owner-smp Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id QAA16064 for smp-outgoing; Thu, 30 May 1996 16:37:58 -0700 (PDT) Received: from tfs.com (tfs.com [140.145.250.1]) by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id QAA16047 for ; Thu, 30 May 1996 16:37:51 -0700 (PDT) Received: from critter.tfs.com by tfs.com (smail3.1.28.1) with SMTP id m0uPHHk-0003x7C; Thu, 30 May 96 16:37 PDT Received: from critter.tfs.com (localhost [127.0.0.1]) by critter.tfs.com (8.7.5/8.6.12) with ESMTP id XAA05517; Thu, 30 May 1996 23:37:29 GMT To: erich@uruk.org cc: freebsd-smp@freebsd.org Subject: Re: How do you get the SMP code In-reply-to: Your message of "Thu, 30 May 1996 16:27:24 MST." <199605302327.QAA08265@uruk.org> Date: Thu, 30 May 1996 23:37:29 +0000 Message-ID: <5515.833499449@critter.tfs.com> From: Poul-Henning Kamp Sender: owner-smp@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > If you're going to use it a lot, load the APIC id once in a routine (or > for that matter, index a "logical CPU number" and keep it around instead). But where would I keep it my dear man ? :-) I will always have to start out at the APIC_ID... We don't have any "per-cpu" VM (this is different from "terrys" code). > On both Pentium and Pentium Pro, you have the time-stamp counter. The > only problem with this is during periods when your clock input is slowed > down or halted, such as for power-down... but any other clock would > probably suffer the same fate. check out the IBM POWER design. The other problem with the cycle counter is that it will cost you much time to convert from some random resolution (6.666 ns) to a standard on (1 ns). -- Poul-Henning Kamp | phk@FreeBSD.ORG FreeBSD Core-team. http://www.freebsd.org/~phk | phk@login.dknet.dk Private mailbox. whois: [PHK] | phk@ref.tfs.com TRW Financial Systems, Inc. Future will arrive by its own means, progress not so.