Re: computer stalls instead of reboot

["Sven Köhler" <sven.koehler@gmail.com>]

Am 09.09.2011 14:01, schrieb Andrew Cooper:
> On 09/09/11 00:40, Sven Köhler wrote:
>> Am 09.09.2011 01:17, schrieb Andrew Cooper:
>>> Does your "remote" method involve actually pushing the reset button, and
>>> does this method actually work under normal circumstances?
>> I think, there is a device connected to the connector on the
>> motherboard, to which the reset button would normally be attached.
> 
> Ok, in which case the state your computer is getting into is a very
> broken state, if the reset button is not working
> 
>>> As for the problem itself, do you have C states enabled in the BIOS? 
>>> This sounds similar to several errata published for the i7 series.
>> I'm not sure how to tell whether C states are disabled/enabled.
>> What would those BIOS options typically be called?
> 
> That is too bios dependent to say for sure, but typically "C states" or
> "deep sleep", with some intel ones going for "C1e"
> 
>> Also, should I enable or disable them, in order to workaround those
>> errata that you mention?
> 
> They should be disabled.  The errata state that there are several
> situations when moving in and our of deep c states which cause
> processors to lock up irreparably.

Thanks for you help so far. I will try to disable the C-states as soon
as I have the time.

One more thing: are you aware of any way for telling from inside dom0
whether these C-states are enabled/disabled? Is the kernel or the xen
hypervisor able to tell whether they are active?

Also, is there any xen hypervisor command line option to disable the use
of them?


Regards,
  Sven