Messages in this thread | | | Subject | Re: [PATCH 16/16] KVM-GST: adjust scheduler cpu power | From | Peter Zijlstra <> | Date | Tue, 25 Jan 2011 21:13:06 +0100 |
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On Tue, 2011-01-25 at 18:02 -0200, Glauber Costa wrote:
> I fail to see how does clock_task influence cpu power. > If we also have to touch clock_task for better accounting of other > stuff, it is a separate story. > But for cpu_power, I really fail. Please enlighten me.
static void update_rq_clock_task(struct rq *rq, s64 delta) { s64 irq_delta;
irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time;
if (irq_delta > delta) irq_delta = delta;
rq->prev_irq_time += irq_delta; delta -= irq_delta; rq->clock_task += delta;
if (irq_delta && sched_feat(NONIRQ_POWER)) sched_rt_avg_update(rq, irq_delta); }
its done through that sched_rt_avg_update() (should probably rename that), it computes a floating average of time not spend on fair tasks.
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