Date: Tue, 30 Jun 1998 20:15:28 +0200 (SAT) From: John Hay <jhay@mikom.csir.co.za> To: phk@critter.freebsd.dk (Poul-Henning Kamp) Cc: freebsd-smp@FreeBSD.ORG Subject: Re: time problem? Message-ID: <199806301815.UAA19361@zibbi.mikom.csir.co.za> In-Reply-To: <9570.899103386@critter.freebsd.dk> from Poul-Henning Kamp at "Jun 29, 98 08:56:26 am"
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> > >---------------- > >A: 899000790.981073054 #29011 D: 1.000004191 > >A: 899000792.826104370 #29012 D: 1.845031316 > >A: 899016109.813482765 #44329 D: 0.999940488 > >A: 899016111.668519664 #44330 D: 1.855036899 > >---------- > > > >So on sequence numbers 29012 and 44330, I have gained .85 seconds > >in the space of a second. For the 15000 seconds between 29012 and > >44329 there were no glitches or jumps. > > Now, one source of this could be interrupts diasabled for too long, > since your timestamps depend on the sio interrupt that would be my > primary suspect. > I would have thought that disabling interrupts for too long would cause the machine to loose time not to gain it? I followed Tony Li's advice and started ntpd again on the machine with no local reference clocks and the machine has now been up for more than 24 hours with no jumps at all, so it looks like it is calling nanotime() from within the sio interrupt that causes the problems. :-( So what are my options then? Can I somehow run the sio interrupts at a lower priority? I would really prefer to have the pps signal on the serial port, because the port is already used to read the serial stream from the GPS. John -- John Hay -- John.Hay@mikom.csir.co.za To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message
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