[PATCH] sched/debug: Add new tracepoints to track util_est

From: vincent . donnefort
Date: Wed May 27 2020 - 12:40:03 EST


From: Vincent Donnefort <vincent.donnefort@xxxxxxx>

The util_est signals are key elements for EAS task placement and
frequency selection. Having tracepoints to track these signals enables
load-tracking and schedutil testing and/or debugging by a toolkit.

Signed-off-by: Vincent Donnefort <vincent.donnefort@xxxxxxx>

diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index ed168b0..04f9a4c 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -634,6 +634,14 @@ DECLARE_TRACE(sched_overutilized_tp,
TP_PROTO(struct root_domain *rd, bool overutilized),
TP_ARGS(rd, overutilized));

+DECLARE_TRACE(sched_util_est_cfs_tp,
+ TP_PROTO(struct cfs_rq *cfs_rq),
+ TP_ARGS(cfs_rq));
+
+DECLARE_TRACE(sched_util_est_se_tp,
+ TP_PROTO(struct sched_entity *se),
+ TP_ARGS(se));
+
#endif /* _TRACE_SCHED_H */

/* This part must be outside protection */
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 9228236..ecff02b 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -35,6 +35,8 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_dl_tp);
EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_irq_tp);
EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_se_tp);
EXPORT_TRACEPOINT_SYMBOL_GPL(sched_overutilized_tp);
+EXPORT_TRACEPOINT_SYMBOL_GPL(sched_util_est_cfs_tp);
+EXPORT_TRACEPOINT_SYMBOL_GPL(sched_util_est_se_tp);

DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 174d2df..cfc0e06 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3922,6 +3922,8 @@ static inline void util_est_enqueue(struct cfs_rq *cfs_rq,
enqueued = cfs_rq->avg.util_est.enqueued;
enqueued += _task_util_est(p);
WRITE_ONCE(cfs_rq->avg.util_est.enqueued, enqueued);
+
+ trace_sched_util_est_cfs_tp(cfs_rq);
}

/*
@@ -3952,6 +3954,8 @@ util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p, bool task_sleep)
ue.enqueued -= min_t(unsigned int, ue.enqueued, _task_util_est(p));
WRITE_ONCE(cfs_rq->avg.util_est.enqueued, ue.enqueued);

+ trace_sched_util_est_cfs_tp(cfs_rq);
+
/*
* Skip update of task's estimated utilization when the task has not
* yet completed an activation, e.g. being migrated.
@@ -4017,6 +4021,8 @@ util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p, bool task_sleep)
ue.ewma >>= UTIL_EST_WEIGHT_SHIFT;
done:
WRITE_ONCE(p->se.avg.util_est, ue);
+
+ trace_sched_util_est_se_tp(&p->se);
}

static inline int task_fits_capacity(struct task_struct *p, long capacity)
--
2.7.4