From e5ade162a11a11659ec7838ce87f748a58abed2a Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Thu, 24 May 2018 15:26:48 +0200 Subject: [PATCH] sched, tracing: Fix trace_sched_pi_setprio() for deboosting MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit BugLink: http://bugs.launchpad.net/bugs/1808399 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 Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Fixes: b91473ff6e97 ("sched,tracing: Update trace_sched_pi_setprio()") Link: http://lkml.kernel.org/r/20180524132647.gg6ziuogczdmjjzu@linutronix.de Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman Signed-off-by: Kamal Mostafa Signed-off-by: Khalid Elmously --- include/trace/events/sched.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index bc01e06bc716..0be866c91f62 100644 --- 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 */ ), -- 2.39.2