Date: Thu, 6 Feb 2003 11:19:40 +1030 From: Greg 'groggy' Lehey <grog@FreeBSD.org> To: Poul-Henning Kamp <phk@FreeBSD.org> Cc: all-committers@FreeBSD.org, legacy-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/i386/include clock.h src/sys/i386/i386 tsc.c Message-ID: <20030206004940.GH26321@wantadilla.lemis.com> In-Reply-To: <200302050920.h159KeQ1048771@repoman.freebsd.org> References: <200302050920.h159KeQ1048771@repoman.freebsd.org>
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On Wednesday, 5 February 2003 at 1:20:40 -0800, Poul-Henning Kamp wrote: > phk 2003/02/05 01:20:40 PST > > Modified files: > sys/i386/include clock.h > sys/i386/i386 tsc.c > Log: > i386/i386/tsc.c was repo-copied from i386/isa/clock.c. > > Remove all the stuff that does not relate to the TSC. > > Change the calibration to use DELAY(1000000) rather than trying to check > it against the CMOS RTC, this drastically increases precision: > > Using 25 samples on a Athlon 700MHz UP machine I find: > > stddev min max average > CMOS 22200 Hz -74980 Hz 34301 Hz 704928721 Hz > DELAY 1805 Hz -1984 Hz 2678 Hz 704937583 Hz > > (The difference between the two averages is not statistically significant.) Does this get rid of the "microuptime went backwards" problem? Greg -- See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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