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RE: [Xen-ia64-devel] xen_timer_interrupt: can someone explain thecode ?



>From: Xu, Anthony
>Sent: 2006年2月20日 9:56
>>Why current must be always awaken in VTI ?
>>      if (VMX_DOMAIN(current))
>>              vcpu_wake(current);
>
>This vcpu_wake is invoked here because of the same reason of below
>vcpu_wake() being invoked, if below vcpu_wake can be removed, the above
>one can also be removed. Vcpu_timer_expired always failed for VTI
>domain, so an extra vcpu_wake is invoked  for VTIdomain.

It should be abandoned, which was added previously because people thought that 
vcpu_wake might influence policy of scheduler but actually it wouldn't. 

Thanks,
Kevin
>
>
>> This is the core job.
>> The only question is why vcpu_wake ?
>>      if (!is_idle_domain(current->domain))  {
>>              if (vcpu_timer_expired(current)) {
>>                      vcpu_pend_timer(current);
>>                      // ensure another timer interrupt
>> happens even if domain doesn't
>>                      vcpu_set_next_timer(current);
>>                      vcpu_wake(current);
>>              }
>>      }
>>      new_itm = local_cpu_data->itm_next;
>
>
>
>
>Thanks,
>-Anthony
>
>
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>
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