Date: Mon, 21 Jun 1999 07:20:01 -0700 (PDT) From: John.Shue@symmetron.com (John A. Shue) To: freebsd-bugs@FreeBSD.org Subject: Re: kern/12022: System clock timewarps Message-ID: <199906211420.HAA68946@freefall.freebsd.org>
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The following reply was made to PR kern/12022; it has been noted by GNATS. From: John.Shue@symmetron.com (John A. Shue) To: <freebsd-gnats-submit@freebsd.org>, <dwhite@pond.net> Cc: <phk@critter.freebsd.dk>, <cdillon@wolves.k12.mo.us>, <andyo@prime.net.ua> Subject: Re: kern/12022: System clock timewarps Date: Mon, 21 Jun 1999 10:10:36 -0400 Here is a temporary hack that fixes the timewarps on my Pentium-100MHz machine. I use the sysctl command to change the TSC setting from whatever the timecounter code detected to the speed of my processor. To run this command at boot, I created a file in the /usr/local/etc/rc.d directory called buggy_TSC_fix.sh (contents of this file are listed at the end of this email). With this fix, my clock has gone from being 25 minutes fast every 2 hours to being 0.1 seconds fast every 2 hours. I have also added a line to my /etc/crontab to run ntpdate every 2 hours. Also, while testing this fix out, I booted up with the absolutely worst TSC probe yet: 64MHz. Here is a list of all the TSC probes for my 100MHz machine since I installed 3.2-RELEASE: Timecounter "TSC" frequency 75000994 Hz Timecounter "TSC" frequency 76695754 Hz Timecounter "TSC" frequency 79001605 Hz Timecounter "TSC" frequency 79001623 Hz Timecounter "TSC" frequency 76001260 Hz Timecounter "TSC" frequency 81001327 Hz Timecounter "TSC" frequency 64001215 Hz Hopefully the TSC probing code gets fixed so that this temporary fix can be removed someday. buggy_TSC_fix.sh ---------------- #!/bin/sh # # replace 100000000 with the speed of your processor in hertz. /sbin/sysctl -w machdep.tsc_freq=100000000 > /dev/null && echo -n ' buggy_TSC_fix' --end-of-file--- -john --------------- John A. Shue 4000 Legato Road, Suite 600 Fairfax, VA 22033 (703) 591-5559 (703) 591-6337 FAX To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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