4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
commit 4ff648decf4712d39f184fc2df3163f43975575a upstream.
Since the following commit:
b91473ff6e97 ("sched,tracing: Update trace_sched_pi_setprio()")
the sched_pi_setprio trace point shows the "newprio" during a deboost:
|futex sched_pi_setprio: comm=futex_requeue_p pid"34 oldprio˜ newprio=3D98
|futex sched_switch: prev_comm=futex_requeue_p prev_pid"34 prev_prio=120
This patch open codes __rt_effective_prio() in the tracepoint as the
'newprio' to get the old behaviour back / the correct priority:
|futex sched_pi_setprio: comm=futex_requeue_p pid"20 oldprio˜ newprio=3D120
|futex sched_switch: prev_comm=futex_requeue_p prev_pid"20 prev_prio=120
Peter suggested to open code the new priority so people using tracehook
could get the deadline data out.
Reported-by: Mansky Christian <man@xxxxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Fixes: b91473ff6e97 ("sched,tracing: Update trace_sched_pi_setprio()")
Link: http://lkml.kernel.org/r/20180524132647.gg6ziuogczdmjjzu@xxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/trace/events/sched.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -435,7 +435,9 @@ TRACE_EVENT(sched_pi_setprio,
memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);
__entry->pid = tsk->pid;
__entry->oldprio = tsk->prio;
- __entry->newprio = pi_task ? pi_task->prio : tsk->prio;
+ __entry->newprio = pi_task ?
+ min(tsk->normal_prio, pi_task->prio) :
+ tsk->normal_prio;
/* XXX SCHED_DEADLINE bits missing */
),
