Re: [PATCH 09/25] xen: Account for time stolen by Xen

Andi Kleen
2007-04-25T18:15:29Z

On Wednesday 25 April 2007 20:13:34 Jeremy Fitzhardinge wrote:
> Andi Kleen wrote:
> >> +
> >> + do {
> >> + state_time = state->state_entry_time;
> >> + barrier();
> >>
> >
> > Should be likely rmb
>
> We discussed this, and decided that it wasn't necessary. The state is
> always updated by the current CPU, so if it changes under our feet it
> will be because we were preempted, and so that should shoot down any
> speculated reads.

Then the barrier shouldn't be needed at all?

Anyways needs comments

-Andi