Clock stalls on Sabertooth 990FX

[Alexander Motin]

On 15.08.2011 22:18, Joe Schaefer wrote:
> On Mon, Aug 15, 2011 at 9:31 AM, Joe Schaefer<joesuf4 at gmail.com>  wrote:
>> On Mon, Aug 15, 2011 at 8:32 AM, Andriy Gapon<avg at freebsd.org>  wrote:
>>> on 13/08/2011 20:16 Joe Schaefer said the following:
>>>> Brand new machine with a Phenom II X6 1100T and under chronic load
>>>> the clock will stop running periodically until the machine eventually completely
>>>> freezes.  Note: during these stalls the kernel is still running, the
>>>> machine is still
>>>> mostly responsive, it's just that the clock is frozen in time.
>>>>
>>>> I've disabled Turbo mode in the bios and toyed with just about every
>>>> other setting but nothing seems to resolve this problem.  Based on the behavior
>>>> of the machine (just making buildworld will eventually kill it, upping
>>>> the -j flag
>>>> just kills it faster), I'm guessing it has something to do with the
>>>> Digi+ VRM features
>>>> but again nothing I've tried modifying in the bios seems to help.
>>>>
>>>> I've tried both 8.2-RELEASE and FreeBSD 9 (head).  Running head now with
>>>> a dtrace enabled kernel.
>>>>
>>>> Suggestions?
>>>
>>> On head, start with checking what source is used for driving clocks:
>>> sysctl kern.eventtimer
>>
>> % sysctl kern.eventtimer                                  [master]
>> 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.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.i8254.flags: 1
>> kern.eventtimer.et.i8254.frequency: 1193182
>> kern.eventtimer.et.i8254.quality: 100
>> 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
>     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> Changing this to "i8254" seems to have resolved the stalls.
> I'm running buildworld -j12 without issue.  More than willing
> to test out a patch or two against head if anyone's still
> interested, otherwise I've thrown the change into loader.conf
> and will move along quietly.

8.2-RELEASE you've mentioned doesn't have event timers subsystem and 
HPET timer driver. That makes me think it is strange at least. Can you 
try also LAPIC timer and do alike experiments with kern.timeocunter?

Also, please check whether kern.timecounter.tc.X.counter value changes 
for the selected timercounter and whether you are receiving timer 
interrupts in `vmstat -i`

-- 
Alexander Motin