linux/include/trace/events/timer.h
Thomas Gleixner 0eeda71bc3 timer: Replace timer base by a cpu index
Instead of storing a pointer to the per cpu tvec_base we can simply
cache a CPU index in the timer_list and use that to get hold of the
correct per cpu tvec_base. This is only used in lock_timer_base() and
the slightly larger code is peanuts versus the spinlock operation and
the d-cache foot print of the timer wheel.

Aside of that this allows to get rid of following nuisances:

 - boot_tvec_base

   That statically allocated 4k bss data is just kept around so the
   timer has a home when it gets statically initialized. It serves no
   other purpose.

   With the CPU index we assign the timer to CPU0 at static
   initialization time and therefor can avoid the whole boot_tvec_base
   dance.  That also simplifies the init code, which just can use the
   per cpu base.

   Before:
     text	   data	    bss	    dec	    hex	filename
    17491	   9201	   4160	  30852	   7884	../build/kernel/time/timer.o
   After:
     text	   data	    bss	    dec	    hex	filename
    17440	   9193	      0	  26633	   6809	../build/kernel/time/timer.o

 - Overloading the base pointer with various flags

   The CPU index has enough space to hold the flags (deferrable,
   irqsafe) so we can get rid of the extra masking and bit fiddling
   with the base pointer.

As a benefit we reduce the size of struct timer_list on 64 bit
machines. 4 - 8 bytes, a size reduction up to 15% per struct timer_list,
which is a real win as we have tons of them embedded in other structs.

This changes also the newly added deferrable printout of the timer
start trace point to capture and print all timer->flags, which allows
us to decode the target cpu of the timer as well.

We might have used bitfields for this, but that would change the
static initializers and the init function for no value to accomodate
big endian bitfields.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Joonwoo Park <joonwoop@codeaurora.org>
Cc: Wenbo Wang <wenbo.wang@memblaze.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Badhri Jagan Sridharan <Badhri@google.com>
Link: http://lkml.kernel.org/r/20150526224511.950084301@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-06-19 15:18:27 +02:00

355 lines
7.9 KiB
C

#undef TRACE_SYSTEM
#define TRACE_SYSTEM timer
#if !defined(_TRACE_TIMER_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_TIMER_H
#include <linux/tracepoint.h>
#include <linux/hrtimer.h>
#include <linux/timer.h>
DECLARE_EVENT_CLASS(timer_class,
TP_PROTO(struct timer_list *timer),
TP_ARGS(timer),
TP_STRUCT__entry(
__field( void *, timer )
),
TP_fast_assign(
__entry->timer = timer;
),
TP_printk("timer=%p", __entry->timer)
);
/**
* timer_init - called when the timer is initialized
* @timer: pointer to struct timer_list
*/
DEFINE_EVENT(timer_class, timer_init,
TP_PROTO(struct timer_list *timer),
TP_ARGS(timer)
);
/**
* timer_start - called when the timer is started
* @timer: pointer to struct timer_list
* @expires: the timers expiry time
*/
TRACE_EVENT(timer_start,
TP_PROTO(struct timer_list *timer,
unsigned long expires,
unsigned int flags),
TP_ARGS(timer, expires, flags),
TP_STRUCT__entry(
__field( void *, timer )
__field( void *, function )
__field( unsigned long, expires )
__field( unsigned long, now )
__field( unsigned int, flags )
),
TP_fast_assign(
__entry->timer = timer;
__entry->function = timer->function;
__entry->expires = expires;
__entry->now = jiffies;
__entry->flags = flags;
),
TP_printk("timer=%p function=%pf expires=%lu [timeout=%ld] flags=0x%08x",
__entry->timer, __entry->function, __entry->expires,
(long)__entry->expires - __entry->now, __entry->flags)
);
/**
* timer_expire_entry - called immediately before the timer callback
* @timer: pointer to struct timer_list
*
* Allows to determine the timer latency.
*/
TRACE_EVENT(timer_expire_entry,
TP_PROTO(struct timer_list *timer),
TP_ARGS(timer),
TP_STRUCT__entry(
__field( void *, timer )
__field( unsigned long, now )
__field( void *, function)
),
TP_fast_assign(
__entry->timer = timer;
__entry->now = jiffies;
__entry->function = timer->function;
),
TP_printk("timer=%p function=%pf now=%lu", __entry->timer, __entry->function,__entry->now)
);
/**
* timer_expire_exit - called immediately after the timer callback returns
* @timer: pointer to struct timer_list
*
* When used in combination with the timer_expire_entry tracepoint we can
* determine the runtime of the timer callback function.
*
* NOTE: Do NOT derefernce timer in TP_fast_assign. The pointer might
* be invalid. We solely track the pointer.
*/
DEFINE_EVENT(timer_class, timer_expire_exit,
TP_PROTO(struct timer_list *timer),
TP_ARGS(timer)
);
/**
* timer_cancel - called when the timer is canceled
* @timer: pointer to struct timer_list
*/
DEFINE_EVENT(timer_class, timer_cancel,
TP_PROTO(struct timer_list *timer),
TP_ARGS(timer)
);
/**
* hrtimer_init - called when the hrtimer is initialized
* @hrtimer: pointer to struct hrtimer
* @clockid: the hrtimers clock
* @mode: the hrtimers mode
*/
TRACE_EVENT(hrtimer_init,
TP_PROTO(struct hrtimer *hrtimer, clockid_t clockid,
enum hrtimer_mode mode),
TP_ARGS(hrtimer, clockid, mode),
TP_STRUCT__entry(
__field( void *, hrtimer )
__field( clockid_t, clockid )
__field( enum hrtimer_mode, mode )
),
TP_fast_assign(
__entry->hrtimer = hrtimer;
__entry->clockid = clockid;
__entry->mode = mode;
),
TP_printk("hrtimer=%p clockid=%s mode=%s", __entry->hrtimer,
__entry->clockid == CLOCK_REALTIME ?
"CLOCK_REALTIME" : "CLOCK_MONOTONIC",
__entry->mode == HRTIMER_MODE_ABS ?
"HRTIMER_MODE_ABS" : "HRTIMER_MODE_REL")
);
/**
* hrtimer_start - called when the hrtimer is started
* @hrtimer: pointer to struct hrtimer
*/
TRACE_EVENT(hrtimer_start,
TP_PROTO(struct hrtimer *hrtimer),
TP_ARGS(hrtimer),
TP_STRUCT__entry(
__field( void *, hrtimer )
__field( void *, function )
__field( s64, expires )
__field( s64, softexpires )
),
TP_fast_assign(
__entry->hrtimer = hrtimer;
__entry->function = hrtimer->function;
__entry->expires = hrtimer_get_expires(hrtimer).tv64;
__entry->softexpires = hrtimer_get_softexpires(hrtimer).tv64;
),
TP_printk("hrtimer=%p function=%pf expires=%llu softexpires=%llu",
__entry->hrtimer, __entry->function,
(unsigned long long)ktime_to_ns((ktime_t) {
.tv64 = __entry->expires }),
(unsigned long long)ktime_to_ns((ktime_t) {
.tv64 = __entry->softexpires }))
);
/**
* hrtimer_expire_entry - called immediately before the hrtimer callback
* @hrtimer: pointer to struct hrtimer
* @now: pointer to variable which contains current time of the
* timers base.
*
* Allows to determine the timer latency.
*/
TRACE_EVENT(hrtimer_expire_entry,
TP_PROTO(struct hrtimer *hrtimer, ktime_t *now),
TP_ARGS(hrtimer, now),
TP_STRUCT__entry(
__field( void *, hrtimer )
__field( s64, now )
__field( void *, function)
),
TP_fast_assign(
__entry->hrtimer = hrtimer;
__entry->now = now->tv64;
__entry->function = hrtimer->function;
),
TP_printk("hrtimer=%p function=%pf now=%llu", __entry->hrtimer, __entry->function,
(unsigned long long)ktime_to_ns((ktime_t) { .tv64 = __entry->now }))
);
DECLARE_EVENT_CLASS(hrtimer_class,
TP_PROTO(struct hrtimer *hrtimer),
TP_ARGS(hrtimer),
TP_STRUCT__entry(
__field( void *, hrtimer )
),
TP_fast_assign(
__entry->hrtimer = hrtimer;
),
TP_printk("hrtimer=%p", __entry->hrtimer)
);
/**
* hrtimer_expire_exit - called immediately after the hrtimer callback returns
* @hrtimer: pointer to struct hrtimer
*
* When used in combination with the hrtimer_expire_entry tracepoint we can
* determine the runtime of the callback function.
*/
DEFINE_EVENT(hrtimer_class, hrtimer_expire_exit,
TP_PROTO(struct hrtimer *hrtimer),
TP_ARGS(hrtimer)
);
/**
* hrtimer_cancel - called when the hrtimer is canceled
* @hrtimer: pointer to struct hrtimer
*/
DEFINE_EVENT(hrtimer_class, hrtimer_cancel,
TP_PROTO(struct hrtimer *hrtimer),
TP_ARGS(hrtimer)
);
/**
* itimer_state - called when itimer is started or canceled
* @which: name of the interval timer
* @value: the itimers value, itimer is canceled if value->it_value is
* zero, otherwise it is started
* @expires: the itimers expiry time
*/
TRACE_EVENT(itimer_state,
TP_PROTO(int which, const struct itimerval *const value,
cputime_t expires),
TP_ARGS(which, value, expires),
TP_STRUCT__entry(
__field( int, which )
__field( cputime_t, expires )
__field( long, value_sec )
__field( long, value_usec )
__field( long, interval_sec )
__field( long, interval_usec )
),
TP_fast_assign(
__entry->which = which;
__entry->expires = expires;
__entry->value_sec = value->it_value.tv_sec;
__entry->value_usec = value->it_value.tv_usec;
__entry->interval_sec = value->it_interval.tv_sec;
__entry->interval_usec = value->it_interval.tv_usec;
),
TP_printk("which=%d expires=%llu it_value=%ld.%ld it_interval=%ld.%ld",
__entry->which, (unsigned long long)__entry->expires,
__entry->value_sec, __entry->value_usec,
__entry->interval_sec, __entry->interval_usec)
);
/**
* itimer_expire - called when itimer expires
* @which: type of the interval timer
* @pid: pid of the process which owns the timer
* @now: current time, used to calculate the latency of itimer
*/
TRACE_EVENT(itimer_expire,
TP_PROTO(int which, struct pid *pid, cputime_t now),
TP_ARGS(which, pid, now),
TP_STRUCT__entry(
__field( int , which )
__field( pid_t, pid )
__field( cputime_t, now )
),
TP_fast_assign(
__entry->which = which;
__entry->now = now;
__entry->pid = pid_nr(pid);
),
TP_printk("which=%d pid=%d now=%llu", __entry->which,
(int) __entry->pid, (unsigned long long)__entry->now)
);
#ifdef CONFIG_NO_HZ_COMMON
TRACE_EVENT(tick_stop,
TP_PROTO(int success, char *error_msg),
TP_ARGS(success, error_msg),
TP_STRUCT__entry(
__field( int , success )
__string( msg, error_msg )
),
TP_fast_assign(
__entry->success = success;
__assign_str(msg, error_msg);
),
TP_printk("success=%s msg=%s", __entry->success ? "yes" : "no", __get_str(msg))
);
#endif
#endif /* _TRACE_TIMER_H */
/* This part must be outside protection */
#include <trace/define_trace.h>