Strange 'hangs' with RELENG_9

[Alexander Motin]

On 01/19/12 22:03, Andriy Gapon wrote:
> on 19/01/2012 21:24 László Károlyi said the following:
>> On 2012.01.19., at 18:18, Andriy Gapon wrote:
>>
>>> Please provide output of the following sysctls:
>>> sysctl kern.eventtimer
>>> sysctl kern.timecounter
>>
>>
>> [root at sys ~]# sysctl kern.eventtimer
>> kern.eventtimer.choice: HPET(450) HPET1(450) HPET2(450) LAPIC(400) i8254(100) RTC(0)
>> kern.eventtimer.et.LAPIC.flags: 15
>> kern.eventtimer.et.LAPIC.frequency: 0
>> kern.eventtimer.et.LAPIC.quality: 400
>> kern.eventtimer.et.i8254.flags: 1
>> kern.eventtimer.et.i8254.frequency: 1193182
>> kern.eventtimer.et.i8254.quality: 100
>> kern.eventtimer.et.HPET.flags: 3
>> kern.eventtimer.et.HPET.frequency: 14318180
>> kern.eventtimer.et.HPET.quality: 450
>> kern.eventtimer.et.HPET1.flags: 3
>> kern.eventtimer.et.HPET1.frequency: 14318180
>> kern.eventtimer.et.HPET1.quality: 450
>> kern.eventtimer.et.HPET2.flags: 3
>> kern.eventtimer.et.HPET2.frequency: 14318180
>> kern.eventtimer.et.HPET2.quality: 450
>> kern.eventtimer.et.RTC.flags: 17
>> kern.eventtimer.et.RTC.frequency: 32768
>> kern.eventtimer.et.RTC.quality: 0
>> kern.eventtimer.periodic: 0
>> kern.eventtimer.timer: HPET
>> kern.eventtimer.idletick: 0
>> kern.eventtimer.singlemul: 2
>> [root at sys ~]# sysctl kern.timecounter
>> kern.timecounter.tick: 1
>> kern.timecounter.choice: TSC-low(800) HPET(950) i8254(0) ACPI-fast(900) dummy(-1000000)
>> kern.timecounter.hardware: HPET
>> kern.timecounter.stepwarnings: 0
>> kern.timecounter.tc.ACPI-fast.mask: 4294967295
>> kern.timecounter.tc.ACPI-fast.counter: 3649705857
>> kern.timecounter.tc.ACPI-fast.frequency: 3579545
>> kern.timecounter.tc.ACPI-fast.quality: 900
>> kern.timecounter.tc.i8254.mask: 65535
>> kern.timecounter.tc.i8254.counter: 27536
>> kern.timecounter.tc.i8254.frequency: 1193182
>> kern.timecounter.tc.i8254.quality: 0
>> kern.timecounter.tc.HPET.mask: 4294967295
>> kern.timecounter.tc.HPET.counter: 1224089625
>> kern.timecounter.tc.HPET.frequency: 14318180
>> kern.timecounter.tc.HPET.quality: 950
>> kern.timecounter.tc.TSC-low.mask: 4294967295
>> kern.timecounter.tc.TSC-low.counter: 1655163352
>> kern.timecounter.tc.TSC-low.frequency: 11772185
>> kern.timecounter.tc.TSC-low.quality: 800
>> kern.timecounter.smp_tsc: 1
>> kern.timecounter.invariant_tsc: 1
>
> I wonder whether there could be an interference between HPET being used as
> timecounter and HPET being used as an event timer.
> Alexander, what do you think?

I don't expect interference between them. HPET timecounter just reads 
same hardware counter that is also read by comparators for eventtimer 
interrupts generation. Theoretically they could interfere if that timer 
was stopped during comparators programming, but it is not.

> László, can you please try changing kern.timecounter.hardware to TSC-low or
> ACPI-fast?

-- 
Alexander Motin