[PATCH 4/4] tracing/sched: Add sched_rt_setprio tracepoint

[Steven Rostedt <rostedt@goodmis.org>]

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From: Steven Rostedt <srostedt@redhat.com>

Add a tracepoint that shows the priority of a task being boosted
via priority inheritance.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 include/trace/events/sched.h |   25 +++++++++++++++++++++++++
 kernel/sched.c               |    1 +
 2 files changed, 26 insertions(+), 0 deletions(-)

diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index 0e0c108..8feb641 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -398,6 +398,31 @@ DEFINE_EVENT_PRINT(sched_rt_push_pull, sched_rt_pull,
 			__entry->comm, __entry->pid,
 			__entry->prio, __entry->cpu));
 
+TRACE_EVENT(sched_rt_setprio,
+
+	TP_PROTO(struct task_struct *tsk, int newprio),
+
+	TP_ARGS(tsk, newprio),
+
+	TP_STRUCT__entry(
+		__array( char,	comm,	TASK_COMM_LEN	)
+		__field( pid_t,	pid			)
+		__field( int,	oldprio			)
+		__field( int,	newprio			)
+	),
+
+	TP_fast_assign(
+		memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);
+		__entry->pid		= tsk->pid;
+		__entry->oldprio	= tsk->prio;
+		__entry->newprio	= newprio;
+	),
+
+	TP_printk("comm=%s pid=%d oldprio=%d newprio=%d",
+			__entry->comm, __entry->pid,
+			__entry->oldprio, __entry->newprio)
+);
+
 #endif /* _TRACE_SCHED_H */
 
 /* This part must be outside protection */
diff --git a/kernel/sched.c b/kernel/sched.c
index ed09d4f..4d4f35e 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4358,6 +4358,7 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
 
 	rq = task_rq_lock(p, &flags);
 
+	trace_sched_rt_setprio(p, prio);
 	oldprio = p->prio;
 	prev_class = p->sched_class;
 	on_rq = p->se.on_rq;
-- 
1.7.1