Why is there a for_each_sched_entity macro in task_tick_fair function called on system tick? According to me, only the run time characteristics of the current task should be updated. Why does it call entity_tick for the entire hierarchy of the current process?
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Marco Bonelli
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Lucifer Poltergeist
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CFS supports hierarchies of tasks, where entire subtrees can have their CPU usage accounting and quota aggregated. This features is used to implement cpu cgroups and CFS group scheduling. A interior node of the task tree can be thought of a as a virtual task than represents the CPU usage of its subtree.
Benjamin Peterson
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