Re: [PATCH] KVM: Boost vCPU candidiate in user mode which is delivering interrupt

[Paolo Bonzini]

On 19/04/21 18:32, Sean Christopherson wrote:
> If false positives are a big concern, what about adding another pass to the loop
> and only yielding to usermode vCPUs with interrupts in the second full pass?
> I.e. give vCPUs that are already in kernel mode priority, and only yield to
> handle an interrupt if there are no vCPUs in kernel mode.
>
> kvm_arch_dy_runnable() pulls in pv_unhalted, which seems like a good thing.

pv_unhalted won't help if you're waiting for a kernel spinlock though, 
would it?  Doing two passes (or looking for a "best" candidate that 
prefers kernel mode vCPUs to user mode vCPUs waiting for an interrupt) 
seems like the best choice overall.

Paolo