Jeremy Fitzhardinge wrote:
> On 09/24/09 17:27, Jiang, Yunhong wrote:
>> Do you mean logical offlining or physical offlining? I think
> logical offlining is tested long before. For physical
> offlining, I implement it but I have no platform to test still.
>>
>> In fact , it is a tricky to physical offlining a cpu (or,
> more precisely speaking, socket) because that means we need
> offline all memory behind a socket. But it can be used for
> socket migration, i.e. put down the old CPU and bring up a
> spare CPU, in that situation, we need CPU offlining. We are
> still working on socket migration.
>>
>
> I see. I guess it makes it hard when the CPUs are also the memory
> controllers.
>
>> Yes, also MCE.
>> And, are you sure currently the microcode driver really not
> called in hotplug of vcpus? Will vcpu online not trigger the
> CPU_online notifier?
>>
>
> I would expect vcpu hotplug will call the usual notifiers as expected,
> but drivers which really care about pcpus don't have much use for
> those notifications.
Yes.
>>> This could do with some clarification. Is this case that a newly
>>> added pcpu already appears to be online?
>>>
>> Because the vIRQ notification for pcpu hotplug from xen
> hypervisor is async, so maybe it happens after the pcpu is
> onlined by user. (i.e., the online notification and hotplug
> notification is merged)
>>
>
> I'm not sure I follow. Are you saying this is an expected race, and
> that this printk is just for debugging?
Yes, exactly.
--jyh
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
Home