Re: vtime accounting

Paolo Bonzini
2017-03-15T08:10:04Z

On 14/03/2017 22:52, Radim Krčmář wrote:
>> If my statement above about needing interrupts disabled when dealing
>> with vtime, then considering this begins to sound interesting, also
>> given that the vtime thing is not entirely free and we're dealing with
>> the hot path of receiving IPIs here, for example.
> I'm liking it less and less the more I read. :)
> CONTEXT_USER vtime is coupled with context tracking and going out of
> CONTEXT_KERNEL means that RCU cannot be used in between. Using
> CONTEXT_GUEST from load/put would change the meaning of contexts ...

CONTEXT_GUEST is an RCU extended quiescent state, doing it from load to
put makes no sense. PF_VCPU from load to put on the other hand might
make some sense.

Paolo