diff options
| author |   Anna-Maria Gleixner <anna-maria@linutronix.de> | 2019-03-21 13:09:21 +0100 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2019-03-24 20:29:33 +0100 |
| commit | f28d3d5346e97e60c81f933ac89ccf015430e5cf (patch) | |
| tree | 64147609da31c5f0091f50e60eb3eae6f20e4438 /include/trace | |
| parent | timer/trace: Replace deprecated vsprintf pointer extension %pf by %ps (diff) | |
| download | linux-dev-f28d3d5346e97e60c81f933ac89ccf015430e5cf.tar.xz linux-dev-f28d3d5346e97e60c81f933ac89ccf015430e5cf.zip | |
timer/trace: Improve timer tracing
Timers are added to the timer wheel off by one. This is required in
case a timer is queued directly before incrementing jiffies to prevent
early timer expiry.
When reading a timer trace and relying only on the expiry time of the timer
in the timer_start trace point and on the now in the timer_expiry_entry
trace point, it seems that the timer fires late. With the current
timer_expiry_entry trace point information only now=jiffies is printed but
not the value of base->clk. This makes it impossible to draw a conclusion
to the index of base->clk and makes it impossible to examine timer problems
without additional trace points.
Therefore add the base->clk value to the timer_expire_entry trace
point, to be able to calculate the index the timer base is located at
during collecting expired timers.
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: fweisbec@gmail.com
Cc: peterz@infradead.org
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20190321120921.16463-5-anna-maria@linutronix.de
Diffstat (limited to 'include/trace')
| -rw-r--r-- | include/trace/events/timer.h | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h index da975d69c453..b7a904825e7d 100644 --- a/include/trace/events/timer.h +++ b/include/trace/events/timer.h @@ -89,24 +89,27 @@ TRACE_EVENT(timer_start, */ TRACE_EVENT(timer_expire_entry, - TP_PROTO(struct timer_list *timer), + TP_PROTO(struct timer_list *timer, unsigned long baseclk), - TP_ARGS(timer), + TP_ARGS(timer, baseclk), TP_STRUCT__entry( __field( void *, timer ) __field( unsigned long, now ) __field( void *, function) + __field( unsigned long, baseclk ) ), TP_fast_assign( __entry->timer = timer; __entry->now = jiffies; __entry->function = timer->function; + __entry->baseclk = baseclk; ), - TP_printk("timer=%p function=%ps now=%lu", - __entry->timer, __entry->function, __entry->now) + TP_printk("timer=%p function=%ps now=%lu baseclk=%lu", + __entry->timer, __entry->function, __entry->now, + __entry->baseclk) ); /** |