Date: Sat, 22 Jun 2002 18:40:24 +0200 From: Poul-Henning Kamp <phk@critter.freebsd.dk> To: Luigi Rizzo <rizzo@icir.org> Cc: Mark Peek <mp@FreeBSD.org>, cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/i386/isa clock.c Message-ID: <648.1024764024@critter.freebsd.dk> In-Reply-To: Your message of "Sat, 22 Jun 2002 09:32:50 PDT." <20020622093250.C92778@iguana.icir.org>
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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
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