Clock stalls on Sabertooth 990FX

[Alexander Motin]

On 15.08.2011 23:57, Joe Schaefer wrote:
> On Mon, Aug 15, 2011 at 4:35 PM, Alexander Motin<mav at freebsd.org>  wrote:
>> 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?
>
> My problems with 8.2-RELEASE may have been network based.  I don't recall
> precisely if the clock was stalling there, my guess is no based on
> what you wrote.
>
> I'll test LAPIC next ... so far so good.  Just so I'm clear, you'd
> like me to tweak
> kern.timecounter.hardware as well?  (Currently it's HPET).

Yes. Instead. Ticking clock depends on both timecounter and eventtimer.

>> 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