Re: [PATCH] KVM breaks CPU hotplug

Avi Kivity
2007-03-26T10:58:17Z

Avi Kivity wrote:
> Shaohua Li wrote:
>> When testing CPU hotplug, I found cpu can't be onlined with kvm enabled
>> sometimes. The reason is smp_call_function_single is a nop if the thread
>> is running on the target cpu. I think CPU_ONLINE case doesn't require
>> the fix as the online CPU isn't plugged into sheduler yet.
>>
>>
>
> I think this is not enough, because:
>
> - this path is preemptible code, so the test (this_cpu == cpu) can run
> one on cpu and execute later code on another
>> + this_cpu = get_cpu();

...

>> + put_cpu();

Sorry, I see you handled that. But the other argument (scheduling vcpus
later on same cpu) still holds, I think.

--
error compiling committee.c: too many arguments to function