Re: [PATCH v2 5/6] KVM-GST: adjust scheduler cpu power

Peter Zijlstra
2011-02-01T20:04:02Z

On Tue, 2011-02-01 at 17:55 -0200, Glauber Costa wrote:
>
> update_rq_clock_task still have to keep track of what was the last steal
> time value we saw, in the same way it does for irq.

Right, the CONFIG_SCHED_PARAVIRT patch I sent earlier adds a
prev_steal_time member to struct rq for this purpose.

> One option is to
> call update_rq_clock_task from inside kvm-code, but I don't really like
> it very much.

Why would you need to call anything from the kvm code?

Simply make u64 steal_time_clock(int cpu) a paravirt function with u64
native_steal_time_clock(int cpu) { return 0ULL; }. Possibly avoid the
whole CONFIG_SCHED_PARAVIRT block in update_rq_clock_task() for !
paravirt guests.