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Re: TSC clock going backwards on suspend/resume



ad%NetBSD.org@localhost said:
> Did you set TSC as timecounter by hand? 

No it was just selected:
$ /sbin/sysctl -a|grep -i tsc
kern.timecounter.choice = TSC(q=3000, f=1995145200 Hz) clockinterrupt(q=0, 
f=100
 Hz) ichlpcib0(q=1000, f=3579545 Hz) ACPI-Fast(q=1000, f=3579545 Hz) 
lapic(q=-10
0, f=166336869 Hz) i8254(q=100, f=1193182 Hz) dummy(q=-1000000, f=1000000 Hz)
kern.timecounter.hardware = TSC
machdep.tsc_freq = 1995145200

> Undocumented mess where? 

It is not explained what the "drift" and "skew" are about,
and the *sync* functions are usually called twice for no
obvious reason. (I've cargo-culted this, perhaps it wasn't
necessary. If it was necessary it should be handled within
the functions, not by the caller.)

> DDB does not halt and re-INIT CPUs.

I've just instrumented binuptime() and the test was triggered
after a DDB trap. Might need research, but there is something.

best regards
Matthias




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