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Venki Pallipadi <venkatesh.pallipadi@intel.com> writes:
> > +void tick_nohz_stop_idle(int cpu)> +{> + struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
> +> + if (ts->idle_active) {> + ktime_t now, delta;> + now = ktime_get();
That could be PM timer read costing thousands of cycles.
For going into idle it's probably not a real problem, but it could
seriously affect out of idle latencies.
You would really need a cheaper per CPU timer that doesn't
stop in idle (which rules out sched_clock). It's all unfortunately
quite messy.
-Andi
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