Re: High CPU temp, suspend problem - xen 4.1.5-pre, linux 3.7.x

[Marek Marczykowski <marmarek@invisiblethingslab.com>]

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On 27.03.2013 17:56, Andrew Cooper wrote:
> On 27/03/2013 15:47, Konrad Rzeszutek Wilk wrote:
>> On Wed, Mar 27, 2013 at 02:52:14PM +0000, Andrew Cooper wrote:
>>> On 27/03/2013 14:46, Andrew Cooper wrote:
>>>> On 27/03/2013 14:31, Marek Marczykowski wrote:
>>>>> On 27.03.2013 09:52, Jan Beulich wrote:
>>>>>>>>> On 26.03.13 at 19:50, Andrew Cooper <andrew.cooper3@citrix.com> wrote:
>>>>>>> So vector e9 doesn't appear to be programmed in anywhere.
>>>>>> Quite obviously, as it's the 8259A vector for IRQ 9. The question
>>>>>> really is why an IRQ appears on that vector in the first place. The
>>>>>> 8259A resume code _should_ leave all IRQs masked on a fully
>>>>>> IO-APIC system (see my question raised yesterday).
>>>>>>
>>>>>> And that's also why I suggested, for an experiment, to fiddle with
>>>>>> the loop exit condition to exclude legacy vectors (which wouldn't
>>>>>> be a final solution, but would at least tell us whether the direction
>>>>>> is the right one). In the end, besides understanding why an
>>>>>> interrupt on vector E9 gets raised at all, we may also need to
>>>>>> tweak the IRQ migration logic to not do anything on legacy IRQs,
>>>>>> but that would need to happen earlier than in
>>>>>> smp_irq_move_cleanup_interrupt(). Considering that 4.3
>>>>>> apparently doesn't have this problem, we may need to go hunt for
>>>>>> a change that isn't directly connected to this, yet deals with the
>>>>>> problem as a side effect (at least I don't recall any particular fix
>>>>>> since 4.2). One aspect here is the double mapping of legacy IRQs
>>>>>> (once to their IO-APIC vector, and once to their legacy vector,
>>>>>> i.e. vector_irq[] having two entries pointing to the same IRQ).
>>>>> So tried change loop condition to LAST_DYNAMIC_VECTOR and it doesn't hit that
>>>>> BUG/ASSERT. But still it doesn't work - only CPU0 used by scheduler, also some
>>>>> errors from dom0 kernel, and errors about PCI devices used by domU(1).
>>>>>
>>>>> Messages from resume (different tries):
>>>>> http://duch.mimuw.edu.pl/~marmarek/qubes/xen-4.1-last-dynamic-vector.log
>>>>> http://duch.mimuw.edu.pl/~marmarek/qubes/xen-4.1-last-dynamic-vector2.log
>>>>>
>>>>> Also one time I've got fatal page fault error, earlier in resume (it isn't
>>>>> deterministic):
>>>>> http://duch.mimuw.edu.pl/~marmarek/qubes/xen-4.1-resume-page-fault.log
>>>>>
>>>> This pagefault is a Null structure pointer dereference, likely the
>>>> scheduling data.  At a first glance, it looks related to the assertion
>>>> failures I have been seeing sporadically in testing, but unable to
>>>> reproduce reliably.  There seems to be something quite dodgy with
>>>> interaction of vcpu_wake and scheduling loops.
>>>>
>>>> The other logs indicate that dom0 appears to have a domain id of 1,
>>>> which is sure to cause problems.
>>> Actually - ignore this
>>>
>>> >From the log,
>>>
>>> (XEN) physdev.c:153: dom0: can't create irq for msi!
>>> [  113.637037] xhci_hcd 0000:03:00.0: xen map irq failed -22 for 32752
>>> domain
>>> (XEN) physdev.c:153: dom0: can't create irq for msi!
>>> [  113.657911] xhci_hcd 0000:03:00.0: xen map irq failed -22 for 32752
>>> domain
>>>
>>> and later
>>>
>>> (XEN) physdev.c:153: dom1: can't create irq for msi!
>>> [  121.909814] pciback 0000:00:19.0: xen map irq failed -22 for 1 domain
>>> [  121.954080] error enable msi for guest 1 status ffffffea
>>> (XEN) physdev.c:153: dom1: can't create irq for msi!
>>> [  122.035355] pciback 0000:00:19.0: xen map irq failed -22 for 1 domain
>>> [  122.044421] error enable msi for guest 1 status ffffffea
>>>
>>> I think that there is a separate bug where mapped irqs are not unmapped
>>> on the suspend path.
>> You thinking this is a Linux (xen irq machinery) issue? Meaning it should
>> end up calling PHYSDEV_unmap_pirq as part of the suspend process?
> 
> I am not sure.  Without looking at the code, I am only speculating.
> 
> Beyond that, the main question is about the expected behaviour.  Do we
> expect dom0/U to unmap its irqs and remap them after resume?  What do we
> expect from domains which are unaware of the host sleep action?

BTW this is the case: domain 1 isn't fully aware of sleep. It have some PCI
devices assigned. The only action taken there before suspend is shutdown
network interfaces (without this system hanged during suspend).

-- 
Best Regards / Pozdrawiam,
Marek Marczykowski
Invisible Things Lab


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