[RFC 3/8] sched/deadline: add some tracepoints

[Luca Abeni <luca.abeni@unitn.it>]

From: Juri Lelli <juri.lelli@arm.com>

These tracepoints can be used to check the active bandwidth
tracking and to show SCHED_DEADLINE parameters

Signed-off-by: Juri Lelli <juri.lelli@arm.com>
---
 include/trace/events/sched.h | 69 ++++++++++++++++++++++++++++++++++++++++++++
 kernel/sched/deadline.c      |  6 ++++
 2 files changed, 75 insertions(+)

diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index 9b90c57..52644c7 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -408,6 +408,75 @@ DEFINE_EVENT(sched_stat_runtime, sched_stat_runtime,
 	     TP_ARGS(tsk, runtime, vruntime));
 
 /*
+ * Tracepoint for accounting running bandwidth of active SCHED_DEADLINE
+ * tasks (XXX specific to SCHED_FLAG_GRUB).
+ */
+DECLARE_EVENT_CLASS(sched_stat_running_bw,
+
+	TP_PROTO(struct task_struct *tsk, u64 tsk_bw, s64 running_bw),
+
+	TP_ARGS(tsk, tsk_bw, running_bw),
+
+	TP_STRUCT__entry(
+		__array( char,	comm,	TASK_COMM_LEN	)
+		__field( pid_t,	pid			)
+		__field( u64,	tsk_bw			)
+		__field( s64,	running_bw		)
+		__field( int,	cpu			)
+	),
+
+	TP_fast_assign(
+		memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);
+		__entry->cpu		= task_cpu(tsk);
+		__entry->pid		= tsk->pid;
+		__entry->tsk_bw		= tsk_bw;
+		__entry->running_bw	= running_bw;
+	),
+
+	TP_printk("comm=%s pid=%d cpu=%d tsk_bw=%Lu running_bw=%Ld ",
+			__entry->comm, __entry->pid, __entry->cpu,
+			(unsigned long long)__entry->tsk_bw,
+			(unsigned long long)__entry->running_bw)
+);
+
+DEFINE_EVENT(sched_stat_running_bw, sched_stat_running_bw_add,
+	     TP_PROTO(struct task_struct *tsk, u64 tsk_bw, s64 running_bw),
+	     TP_ARGS(tsk, tsk_bw, running_bw));
+
+DEFINE_EVENT(sched_stat_running_bw, sched_stat_running_bw_clear,
+	     TP_PROTO(struct task_struct *tsk, u64 tsk_bw, s64 running_bw),
+	     TP_ARGS(tsk, tsk_bw, running_bw));
+/*
+ * Tracepoint for showing actual parameters of SCHED_DEADLINE
+ * tasks.
+ */
+TRACE_EVENT(sched_stat_params_dl,
+
+	TP_PROTO(struct task_struct *tsk, s64 runtime, u64 deadline),
+
+	TP_ARGS(tsk, runtime, deadline),
+
+	TP_STRUCT__entry(
+		__array( char,	comm,	TASK_COMM_LEN	)
+		__field( pid_t,	pid			)
+		__field( s64,	runtime			)
+		__field( u64,	deadline		)
+	),
+
+	TP_fast_assign(
+		memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);
+		__entry->pid		= tsk->pid;
+		__entry->runtime	= runtime;
+		__entry->deadline	= deadline;
+	),
+
+	TP_printk("comm=%s pid=%d runtime=%Ld [ns] deadline=%Lu",
+			__entry->comm, __entry->pid,
+			__entry->runtime, __entry->deadline)
+);
+
+
+/*
  * Tracepoint for showing priority inheritance modifying a tasks
  * priority.
  */
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 8d7ee79..d8e9962 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -18,6 +18,8 @@
 
 #include <linux/slab.h>
 
+#include <trace/events/sched.h>
+
 struct dl_bandwidth def_dl_bandwidth;
 
 static inline struct task_struct *dl_task_of(struct sched_dl_entity *dl_se)
@@ -48,6 +50,7 @@ static void add_running_bw(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq)
 	u64 se_bw = dl_se->dl_bw;
 
 	dl_rq->running_bw += se_bw;
+	trace_sched_stat_running_bw_add(dl_task_of(dl_se), se_bw, dl_rq->running_bw);
 }
 
 static void clear_running_bw(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq)
@@ -55,6 +58,7 @@ static void clear_running_bw(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq)
 	u64 se_bw = dl_se->dl_bw;
 
 	dl_rq->running_bw -= se_bw;
+	trace_sched_stat_running_bw_clear(dl_task_of(dl_se), se_bw, dl_rq->running_bw);
 	if (dl_rq->running_bw < 0) {
 		WARN_ON(1);
 		dl_rq->running_bw = 0;
@@ -770,6 +774,7 @@ static void update_curr_dl(struct rq *rq)
 	sched_rt_avg_update(rq, delta_exec);
 
 	dl_se->runtime -= dl_se->dl_yielded ? 0 : delta_exec;
+	trace_sched_stat_params_dl(curr, dl_se->runtime, dl_se->deadline);
 	if (dl_runtime_exceeded(dl_se)) {
 		dl_se->dl_throttled = 1;
 		__dequeue_task_dl(rq, curr, 0);
@@ -987,6 +992,7 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)
 	}
 
 	enqueue_dl_entity(&p->dl, pi_se, flags);
+	trace_sched_stat_params_dl(p, p->dl.runtime, p->dl.deadline);
 
 	if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
 		enqueue_pushable_dl_task(rq, p);
-- 
1.9.1