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: Juri Lelli <juri.lelli@arm.com>
Signed-off-by: Steve Muckle <smuckle@linaro.org>
+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);
/*
static bool cpu_overutilized(int cpu);
/*
if (!task_new && !rq->rd->overutilized &&
cpu_overutilized(rq->cpu))
rq->rd->overutilized = true;
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));
update_cfs_shares(cfs_rq);
}
update_cfs_shares(cfs_rq);
}
+ /*
+ * 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);
+ }
+ }