Re: [RFC 1/4] sched/core: Introduce per_cpu counter to track latency sensitive tasks

From: Pavan Kondeti
Date: Fri May 08 2020 - 04:40:17 EST


On Thu, May 07, 2020 at 07:07:20PM +0530, Parth Shah wrote:
> The "nr_lat_sensitive" per_cpu variable provides hints on the possible
> number of latency-sensitive tasks occupying the CPU. This hints further
> helps in inhibiting the CPUIDLE governor from calling deeper IDLE states
> (next patches includes this).
>

Can you please explain the intended use case here? Once a latency sensitive
task is created, it prevents c-state on a CPU whether the task runs again
or not in the near future.

I assume, either these latency sensitive tasks won't be around for long time
or applications set/reset latency sensitive nice value dynamically.

Thanks,
Pavan
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