20-24 September 2021
US/Pacific timezone

Improving responsiveness of interactive CFS tasks using util_est

20 Sep 2021, 10:20
Microconference1/Virtual-Room (LPC Virtual)


LPC Virtual

Scheduler MC Scheduler MC


Mr Vincent Donnefort (Arm)


One of the most significant metrics for good user experience on a mobile
device is how quickly the system can react to load changes.

Util_est is used in mainline to create a more stable signal for per-task
demand, which is the maximum of the task util_est and PELT utilization
(known as the task utilization).
In case PELT utilization becomes higher than util_est, the behaviour of
that task is changing and it needs more resources than previously allocated.
The responsiveness of the task can be improved by boosting the task
utilization during this time beyond its PELT utilization.

This presentation describes an implementation of this idea and shows how
it improves behaviour on an Android device.

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Primary author

Mr Vincent Donnefort (Arm)

Presentation Materials