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Commit 4585a266 authored by Juri Lelli's avatar Juri Lelli Committed by Dmitry Shmidt
Browse files

ANDROID: sched/fair: add triggers for OPP change requests 



Each time a task is {en,de}queued we might need to adapt the current
frequency to the new usage. Add triggers on {en,de}queue_task_fair() for
this purpose.  Only trigger a freq request if we are effectively waking up
or going to sleep.  Filter out load balancing related calls to reduce the
number of triggers.

[smuckle@linaro.org: resolve merge conflicts, define task_new,
 use renamed static key sched_freq]

cc: Ingo Molnar <mingo@redhat.com>
cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: default avatarJuri Lelli <juri.lelli@arm.com>
Signed-off-by: default avatarSteve Muckle <smuckle@linaro.org>
Signed-off-by: default avatarAndres Oportus <andresoportus@google.com>
parent 3b6188e5

kernel/sched/fair.c

+45 −1
Original line number Diff line number Diff line
@@ -4528,6 +4528,21 @@ static inline void hrtick_update(struct rq *rq) 
}

#endif



static unsigned long capacity_orig_of(int cpu);

static int cpu_util(int cpu);



static void update_capacity_of(int cpu)

{

	unsigned long req_cap;



	if (!sched_freq())

		return;



	/* Convert scale-invariant capacity to cpu. */

	req_cap = cpu_util(cpu) * SCHED_CAPACITY_SCALE / capacity_orig_of(cpu);

	set_cfs_cpu_capacity(cpu, true, req_cap);

}



static bool cpu_overutilized(int cpu);



/*
@@ -4585,6 +4600,20 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) 
		if (!task_new && !rq->rd->overutilized &&

		    cpu_overutilized(rq->cpu))

			rq->rd->overutilized = true;



		/*

		 * We want to potentially trigger a freq switch

		 * request only for tasks that are waking up; this is

		 * because we get here also during load balancing, but

		 * in these cases it seems wise to trigger as single

		 * request after load balancing is done.

		 *

		 * XXX: how about fork()? Do we need a special

		 *      flag/something to tell if we are here after a

		 *      fork() (wakeup_task_new)?

		 */

		if (!task_new)

			update_capacity_of(cpu_of(rq));

	}

	hrtick_update(rq);

}
@@ -4642,9 +4671,24 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) 
		update_cfs_shares(cfs_rq);

	}



	if (!se)

	if (!se) {

		sub_nr_running(rq, 1);



		/*

		 * We want to potentially trigger a freq switch

		 * request only for tasks that are going to sleep;

		 * this is because we get here also during load

		 * balancing, but in these cases it seems wise to

		 * trigger as single request after load balancing is

		 * done.

		 */

		if (task_sleep) {

			if (rq->cfs.nr_running)

				update_capacity_of(cpu_of(rq));

			else if (sched_freq())

				set_cfs_cpu_capacity(cpu_of(rq), false, 0);

		}

	}

	hrtick_update(rq);

}