> -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Anthony > Atkielski > Sent: Thursday, May 05, 2005 4:14 AM > To: [email protected] > Subject: Re: Clock running fast > > > Ted Mittelstaedt writes: > > > Anthony, you really need to look in the code sometime: > > It takes a very long time to find relevant sections of code, and unless > the author was very conscientious, there are usually few or no > explanatory comments, anyway. >
find /usr/src/sys -print |grep "whateveryourlookingfor" can help. > > /usr/src/sys/dev/acpica/acpi_timer.c > > Thanks. > > > * If all tests of the counter succeed, use the ACPI-fast method. If > > * at least one failed, default to using the safe routine, which reads > > * the timer multiple times to get a consistent value before > returning. > > Whatever that means. > TSC, dummy, or i8254, probably depending on the results of other tests. > > /usr/src/sys/i386/isa/clock.c > > /usr/src/sys/i386/i386/tsc.c > > Thanks > > > /* > > * We can not use the TSC if we support APM. Precise timekeeping > > * on an APM'ed machine is at best a fools pursuit, since > > * any and all of the time spent in various SMM code can't > > * be reliably accounted for. Reading the RTC is your only > > * source of reliable time info. The i8254 looses too of course > > * but we need to have some kind of time... > > * We don't know at this point whether APM is going to be used > > * or not, nor when it might be activated. Play it safe. > > */ > > Hmm. I think APM is turned off on my machine, at least that's what > FreeBSD says. The manual for the MB doesn't say anything > about SMI use. > I don't like the idea of a motherboard stealing cycles from my machine; > it sounds way too much like a virus, and a virus built into > the hardware > is the worst nightmare. > It is probably a tossup between the i8254 driver taking cycles to run and an internal kernel counter based off the CPU clock taking cycles to run. Ted > -- > Anthony > > > _______________________________________________ > [email protected] mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to > "[EMAIL PROTECTED]" > _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
