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timers: Add tracepoints for timer_list timers 

Add tracepoints which cover the timer life cycle. The tracepoints are
integrated with the already existing debug_object debug points as far
as possible.

Based on patches from 
Mathieu: http://marc.info/?l=linux-kernel&m=123791201816247&w=2
and 
Anton: http://marc.info/?l=linux-kernel&m=124331396919301&w=2

[ tglx: Fixed timeout value in timer_start tracepoint, massaged
  comments and made the printk's more readable ]

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Zhaolei <zhaolei@cn.fujitsu.com>
LKML-Reference: <4A7F8A9B.3040201@cn.fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Xiao Guangrong 2009-08-10 10:48:59 +08:00 committed by Thomas Gleixner
parent f71bb0ac5e
commit 2b022e3d4b
2 changed files with 165 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

137
include/trace/events/timer.h Normal file
View File

@ -0,0 +1,137 @@
#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/timer.h>
/**
* timer_init - called when the timer is initialized
* @timer: pointer to struct timer_list
*/
TRACE_EVENT(timer_init,
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_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),
TP_ARGS(timer, expires),
TP_STRUCT__entry(
__field( void *, timer )
__field( void *, function )
__field( unsigned long, expires )
__field( unsigned long, now )
),
TP_fast_assign(
__entry->timer = timer;
__entry->function = timer->function;
__entry->expires = expires;
__entry->now = jiffies;
),
TP_printk("timer %p: func %pf, expires %lu, timeout %ld",
__entry->timer, __entry->function, __entry->expires,
(long)__entry->expires - __entry->now)
);
/**
* 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 )
),
TP_fast_assign(
__entry->timer = timer;
__entry->now = jiffies;
),
TP_printk("timer %p: now %lu", __entry->timer, __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.
*/
TRACE_EVENT(timer_expire_exit,
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_cancel - called when the timer is canceled
* @timer: pointer to struct timer_list
*/
TRACE_EVENT(timer_cancel,
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)
);
#endif /* _TRACE_TIMER_H */
/* This part must be outside protection */
#include <trace/define_trace.h>

32
kernel/timer.c
View File

@ -46,6 +46,9 @@
#include <asm/timex.h>
#include <asm/io.h>
#define CREATE_TRACE_POINTS
#include <trace/events/timer.h>
u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES;
EXPORT_SYMBOL(jiffies_64);
@ -521,6 +524,25 @@ static inline void debug_timer_activate(struct timer_list *timer) { }
static inline void debug_timer_deactivate(struct timer_list *timer) { }
#endif
static inline void debug_init(struct timer_list *timer)
{
debug_timer_init(timer);
trace_timer_init(timer);
}
static inline void
debug_activate(struct timer_list *timer, unsigned long expires)
{
debug_timer_activate(timer);
trace_timer_start(timer, expires);
}
static inline void debug_deactivate(struct timer_list *timer)
{
debug_timer_deactivate(timer);
trace_timer_cancel(timer);
}
static void __init_timer(struct timer_list *timer,
const char *name,
struct lock_class_key *key)
@ -549,7 +571,7 @@ void init_timer_key(struct timer_list *timer,
const char *name,
struct lock_class_key *key)
{
debug_timer_init(timer);
debug_init(timer);
__init_timer(timer, name, key);
}
EXPORT_SYMBOL(init_timer_key);
@ -568,7 +590,7 @@ static inline void detach_timer(struct timer_list *timer,
{
struct list_head *entry = &timer->entry;
debug_timer_deactivate(timer);
debug_deactivate(timer);
__list_del(entry->prev, entry->next);
if (clear_pending)
@ -632,7 +654,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
goto out_unlock;
}
debug_timer_activate(timer);
debug_activate(timer, expires);
new_base = __get_cpu_var(tvec_bases);
@ -787,7 +809,7 @@ void add_timer_on(struct timer_list *timer, int cpu)
BUG_ON(timer_pending(timer) || !timer->function);
spin_lock_irqsave(&base->lock, flags);
timer_set_base(timer, base);
debug_timer_activate(timer);
debug_activate(timer, timer->expires);
if (time_before(timer->expires, base->next_timer) &&
!tbase_get_deferrable(timer->base))
base->next_timer = timer->expires;
@ -1000,7 +1022,9 @@ static inline void __run_timers(struct tvec_base *base)
*/
lock_map_acquire(&lockdep_map);
trace_timer_expire_entry(timer);
fn(data);
trace_timer_expire_exit(timer);
lock_map_release(&lockdep_map);