Re: [PATCH/RFC] KVM: track pid for VCPU only on KVM_RUN ioctl

David Hildenbrand
2014-08-19T14:52:36Z

> >> Hmm. We want to not only reduce, we want them be zero.
> >> In addition to a reworked MP_STATE patch set, we might be able to change the code to call "KVM_S390_INITIAL_RESET" only from the cpu thread itself.
> >> If that simplifies things, we could avoid doing KVM_S390_INITIAL_RESET on CPU creation, because we know that all kernel version will do an implicit cpu reset on cpu creation anyway. Can you have a try on this as well when reworking that code? We could then fix this rcu performance penalty independent from getting rid of that ioctl.
> >>
> >> Christian
> >>
> >
> > Already working on it, only one ioctl left on vcpu creation that is called
> > from wrong context, trying to hide from me. Restarts and resets are already
>
> Maybe its the synchronize when the oldpid is 0? Can you check the patch that I just sent?

Already got that in my code. Seems to be an architecture specific one called
from wrong context. (actually it is the third one being called
after SET_MP_STATE and SET_SIGNAL_MASK).

A few more minutes and I should have it :)

David

>
> > blasting fast.
> >
> > David
> >
>