From owner-cvs-all Sat Jun 22 9:42:22 2002 Delivered-To: cvs-all@freebsd.org Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.86.163]) by hub.freebsd.org (Postfix) with ESMTP id 63BA137B401; Sat, 22 Jun 2002 09:42:18 -0700 (PDT) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.12.3/8.12.2) with ESMTP id g5MGeOCn000649; Sat, 22 Jun 2002 18:40:25 +0200 (CEST) (envelope-from phk@critter.freebsd.dk) To: Luigi Rizzo Cc: Mark Peek , cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/i386/isa clock.c In-Reply-To: Your message of "Sat, 22 Jun 2002 09:32:50 PDT." <20020622093250.C92778@iguana.icir.org> Date: Sat, 22 Jun 2002 18:40:24 +0200 Message-ID: <648.1024764024@critter.freebsd.dk> From: Poul-Henning Kamp Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG In message <20020622093250.C92778@iguana.icir.org>, Luigi Rizzo writes: >On Sat, Jun 22, 2002 at 09:30:19AM -0700, Mark Peek wrote: >> mp 2002/06/22 09:30:19 PDT >> >> Modified files: >> sys/i386/isa clock.c >> Log: >> Clock frequencies reported by sysctl should be unsigned values. Discovered >> when machdep.tsc_freq returned a negative number on a 2.2GHz Xeon. > >so we have a couple of years before hitting another barrier with 4GHz >boxes... It's mostly harmless to make it a 64bit quantity, but there is a nasty division in the timecounter-windup function which would get nastier. I have been playing with a model where the division is done once and for all, and any frequency correction is done by multiplication with a precomputed fiddle-factor. That would make it entirely harmless to make it 64bit. -- 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 cvs-all" in the body of the message