Re: [PATCH v2 1/4] KVM: add spinlock optimization framework

[Paolo Bonzini]

On 08/08/2017 10:42, David Hildenbrand wrote:
> 
>> +bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu)
>> +{
>> +	return false;
>> +}
> 
> why don't we need an EXPORT_SYMBOL here?

Is it used outside the KVM module?  I think no architecture actually needs
to export it.

>> -void kvm_vcpu_on_spin(struct kvm_vcpu *me)
>> +void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool me_in_kern)
>>  {
>>  	struct kvm *kvm = me->kvm;
>>  	struct kvm_vcpu *vcpu;
>> @@ -2348,6 +2348,8 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me)
>>  				continue;
>>  			if (swait_active(&vcpu->wq) && !kvm_arch_vcpu_runnable(vcpu))
>>  				continue;
>> +			if (me_in_kern && !kvm_arch_vcpu_in_kernel(vcpu))
>> +				continue;
> 
> 
> hm, does this patch compile? (me_in_kern)

Why not? :)  This is what I have: