Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 52/53] sched, tracing: Fix trace_sched_pi_setprio() for deboosting | Date | Tue, 10 Jul 2018 20:25:28 +0200 |
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4.14-stable review patch. If anyone has any objections, please let me know.
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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@keba.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: b91473ff6e97 ("sched,tracing: Update trace_sched_pi_setprio()") Link: http://lkml.kernel.org/r/20180524132647.gg6ziuogczdmjjzu@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- 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 */ ),
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