Re: [PATCH v2] kvm: Replace vcpu->swait with rcuwait

[Paolo Bonzini]

On 21/04/20 20:07, Davidlohr Bueso wrote:
>> 
> 
> I should have looked closer here - I was thinking about the return
> value of rcuwait_wait_event. Yes, that signal_pending check you
> mention makes the sleep semantics change bogus as interruptible is no
> longer just to avoid contributing to the load balance.
> 
> And yes, unfortunately adding prepare_to and finish_rcuwait() looks
> like the most reasonable approach to keeping the tracepoint
> semantics. I also considered extending rcuwait_wait_event() by
> another parameter to pass back to the caller if there was any wait at
> all, but that enlarges the call and is probably less generic.

Yes, at some point the usual prepare_to/finish APIs become simpler.

> I'll send another version keeping the current sleep and tracepoint 
> semantics.

Thanks---and sorry, I should have noticed that way earlier.

Paolo