Re: [PATCH V2 RFC 2/3] kvm: Handle yield_to failure return code for potential undercommit case

[Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>]

On 10/31/2012 06:11 PM, Raghavendra K T wrote:
> On 10/31/2012 06:08 PM, Avi Kivity wrote:
>> On 10/29/2012 04:07 PM, Raghavendra K T wrote:
>>> From: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
>>>
>>> Also we do not update last boosted vcpu in failure cases.
>>>
>>>   #endif
>>> +
>>>   void kvm_vcpu_on_spin(struct kvm_vcpu *me)
>>>   {
>>>       struct kvm *kvm = me->kvm;
>>> @@ -1727,11 +1727,12 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me)
>>>                   continue;
>>>               if (!kvm_vcpu_eligible_for_directed_yield(vcpu))
>>>                   continue;
>>> -            if (kvm_vcpu_yield_to(vcpu)) {
>>> +
>>> +            yielded = kvm_vcpu_yield_to(vcpu);
>>> +            if (yielded > 0)
>>>                   kvm->last_boosted_vcpu = i;
>>> -                yielded = 1;
>>> +            if (yielded)
>>>                   break;
>>> -            }
>>>           }
>>
>> If yielded == -ESRCH, should we not try to yield to another vcpu?
>>
>
>   Yes. plan is to abort the iteration. since it means we are mostly
> undercommitted.

Sorry if it was ambiguous. I wanted to say we do not want to continue
yield to another vcpu..