Re: [patch 3/3] KVM: x86: add tracepoint to wait_lapic_expire

Paolo Bonzini
2014-12-16T12:19:12Z

On 16/12/2014 13:15, Marcelo Tosatti wrote:
> > Let's add guest_tsc - tsc_deadline to the tracepoint. This should
> > simplify the tuning of the parameter.
>
> total_delay is very close to that, except the summands are
>
> 1000 + 1000 + ... + "remainder"
>
> Yes?

Almost: guest_tsc - tsc_deadline will be negative if the vmentry
overshot the original tsc_deadline. In that case, total_delay will be zero.

> BTW its very easy to tune the parameter with the kvm-unit-test test
> (the optimal value is clear). I'll write a document.

Nice benefit of the test. :)

Paolo