159c14f039
Schedtune is the framework we use in Android to allow userspace task classification and provides a CGroup controller which has two attributes per group. * schedtune.boost * schedtune.prefer_idle Schedtune itself provides task and CPU utilization boosting. EAS in the fair scheduler uses boosted utilization and prefer_idle status to control the algorithm used for wakeup task placement. Boosting: The task utilization signal, which is derived from PELT signals and properly scaled to be architecture and frequency invariant, is used by EAS as an estimation of the task requirements in terms of CPU bandwidth. Schedtune allows userspace to assign a percentage boost to each group and this boost is used to calculate an additional utilization margin. The margin added to the original utilization is: 1. computed based on the "boosting strategy" in use 2. proportional to boost value defined by the "taskgroup" value The boosted signal is used by EAS for task placement, and boosted CPU utilization (if boosted tasks are running) is given when schedutil requests utilization. Prefer_idle: When this attribute is 1 for a group, this is used as a signal from userspace that tasks in this group need to be serviced with the minimum latency possible. Previous versions of schedtune had much more functionality around allowing a more tuneable tradeoff between performand and energy, however this has not been used a lot up until now. If necessary, we can easily resurrect it based upon old code. Change-Id: Ie2fd63d82f604f34bcbc7e1ca9b5af1bdcc037e0 Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com> Signed-off-by: Chris Redpath <chris.redpath@arm.com>
34 lines
771 B
C
34 lines
771 B
C
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#ifdef CONFIG_SCHED_TUNE
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#include <linux/reciprocal_div.h>
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/*
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* System energy normalization constants
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*/
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struct target_nrg {
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unsigned long min_power;
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unsigned long max_power;
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struct reciprocal_value rdiv;
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};
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int schedtune_cpu_boost(int cpu);
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int schedtune_task_boost(struct task_struct *tsk);
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int schedtune_prefer_idle(struct task_struct *tsk);
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void schedtune_enqueue_task(struct task_struct *p, int cpu);
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void schedtune_dequeue_task(struct task_struct *p, int cpu);
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#else /* CONFIG_SCHED_TUNE */
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#define schedtune_cpu_boost(cpu) 0
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#define schedtune_task_boost(tsk) 0
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#define schedtune_prefer_idle(tsk) 0
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#define schedtune_enqueue_task(task, cpu) do { } while (0)
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#define schedtune_dequeue_task(task, cpu) do { } while (0)
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#endif /* CONFIG_SCHED_TUNE */
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