pthread_cond_timedwait() broken in 9-stable? [possible answer]

[Julian Elischer]

kern.timecounter.tick: 1
kern.timecounter.choice: TSC-low(1000) i8254(0) HPET(950) 
ACPI-fast(900) dummy(-1000000)
kern.timecounter.hardware: ACPI-fast
kern.timecounter.stepwarnings: 0

switching the machine from TSC_low to ACPI-fast  fixes the problem.

in 8.x it used to default to ACPI
but I used to switch it to "TSC" to get better performance.

I wonder why TSC-low is now bad to use..
maybe the TSCs are not as well sychronised as they were in 8.x?
maybe the pthreads code didn't get the memo about changing timers?