[PATCH v3] time: alarmtimer: Add the trcepoints for alarmtimer

[Baolin Wang <baolin.wang@linaro.org>]

For system debugging, we usually want to know who sets one alarm timer, the
time of the timer, when the timer started and fired and so on. Thus adding
tracepoints can help us trace the alarmtimer information.

For example, when we debug the system supend/resume, if the system is always
resumed by RTC alarm, we can find out which process set the alarm timer to
resume system by below trace log:

......
Binder:2976_6-3473  [005] d..2  1076.587732: alarmtimer_start: process:Binder:2976_6
alarmtimer type:ALARM_BOOTTIME expires:1234154000000 time: 1970-1-1 0:20:35

Binder:2976_7-3480  [002] d..2  1076.592707: alarmtimer_cancel: process:Binder:2976_7
alarmtimer type:ALARM_BOOTTIME expires:1325463060000000000 time: 2012-1-2 0:11:0

Binder:2976_7-3480  [002] d..2  1076.592731: alarmtimer_start: process:Binder:2976_7
alarmtimer type:ALARM_BOOTTIME expires:1325378040000000000 time: 2012-1-1 0:34:0

system_server-2976  [003] d..2  1076.605587: alarmtimer_cancel: process:system_server
alarmtimer type:ALARM_BOOTTIME expires:1234154000000 time: 1970-1-1 0:20:35

system_server-2976  [003] d..2  1076.605608: alarmtimer_start: process:system_server
alarmtimer type:ALARM_BOOTTIME expires:1234155000000 time: 1970-1-1 0:20:35

system_server-3000  [002] ...1  1087.737565: alarmtimer_suspend: alarmtimer type:ALARM_BOOTTIME
expires time: 2012-1-1 0:34:0
......

>From the trace log, we can find out the 'Binder:2976_7' process set one alarm
timer which resumes the system.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
Changes since v2:
 - Add TRACE_DEFINE_ENUM() macros.
 - Change the time variables type to save space in the ring buffer.
 - Add trace_alarmtimer_suspend_enabled() in case of tracing is not enabled.

Changes since v1:
 - Fix the kbuild error.
 - Modify the changelog with adding trace log.
---
 include/trace/events/alarmtimer.h |  137 +++++++++++++++++++++++++++++++++++++
 kernel/time/alarmtimer.c          |   23 ++++++-
 2 files changed, 157 insertions(+), 3 deletions(-)
 create mode 100644 include/trace/events/alarmtimer.h

diff --git a/include/trace/events/alarmtimer.h b/include/trace/events/alarmtimer.h
new file mode 100644
index 0000000..6a34bc9
--- /dev/null
+++ b/include/trace/events/alarmtimer.h
@@ -0,0 +1,137 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM alarmtimer
+
+#if !defined(_TRACE_ALARMTIMER_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_ALARMTIMER_H
+
+#include <linux/alarmtimer.h>
+#include <linux/rtc.h>
+#include <linux/tracepoint.h>
+
+TRACE_DEFINE_ENUM(ALARM_REALTIME);
+TRACE_DEFINE_ENUM(ALARM_BOOTTIME);
+
+#define show_alarm_type(type)	__print_flags(type, " | ",	\
+	{ 1 << ALARM_REALTIME, "ALARM_REALTIME" },		\
+	{ 1 << ALARM_BOOTTIME, "ALARM_BOOTTIME" })
+
+DECLARE_EVENT_CLASS(alarm_setting,
+
+	TP_PROTO(struct rtc_time *rtc_time, int flag),
+
+	TP_ARGS(rtc_time, flag),
+
+	TP_STRUCT__entry(
+		__field(unsigned char, second)
+		__field(unsigned char, minute)
+		__field(unsigned char, hour)
+		__field(unsigned char, day)
+		__field(unsigned char, mon)
+		__field(unsigned short, year)
+		__field(unsigned char, alarm_type)
+	),
+
+	TP_fast_assign(
+		__entry->second = rtc_time->tm_sec;
+		__entry->minute = rtc_time->tm_min;
+		__entry->hour = rtc_time->tm_hour;
+		__entry->day = rtc_time->tm_mday;
+		__entry->mon = rtc_time->tm_mon;
+		__entry->year = rtc_time->tm_year;
+		__entry->alarm_type = flag;
+	),
+
+	TP_printk("alarmtimer type:%s expires time: %hu-%u-%u %u:%u:%u",
+		  show_alarm_type((1 << __entry->alarm_type)),
+		  __entry->year + 1900,
+		  __entry->mon + 1,
+		  __entry->day,
+		  __entry->hour,
+		  __entry->minute,
+		  __entry->second
+	)
+);
+
+DEFINE_EVENT(alarm_setting, alarmtimer_suspend,
+
+	TP_PROTO(struct rtc_time *time, int flag),
+
+	TP_ARGS(time, flag)
+);
+
+DECLARE_EVENT_CLASS(alarm_processing,
+
+	TP_PROTO(struct alarm *alarm, char *process_name),
+
+	TP_ARGS(alarm, process_name),
+
+	TP_STRUCT__entry(
+		__field(unsigned long long, expires)
+		__field(unsigned char, second)
+		__field(unsigned char, minute)
+		__field(unsigned char, hour)
+		__field(unsigned char, day)
+		__field(unsigned char, mon)
+		__field(unsigned short, year)
+		__field(unsigned char, alarm_type)
+		__string(name, process_name)
+	),
+
+	TP_fast_assign(
+		__entry->expires = alarm->node.expires.tv64;
+		__entry->second = rtc_ktime_to_tm(alarm->node.expires).tm_sec;
+		__entry->minute = rtc_ktime_to_tm(alarm->node.expires).tm_min;
+		__entry->hour = rtc_ktime_to_tm(alarm->node.expires).tm_hour;
+		__entry->day = rtc_ktime_to_tm(alarm->node.expires).tm_mday;
+		__entry->mon = rtc_ktime_to_tm(alarm->node.expires).tm_mon;
+		__entry->year = rtc_ktime_to_tm(alarm->node.expires).tm_year;
+		__entry->alarm_type = alarm->type;
+		__assign_str(name, process_name);
+	),
+
+	TP_printk("process:%s alarmtimer type:%s expires:%llu "
+		  "time: %hu-%u-%u %u:%u:%u",
+		  __get_str(name),
+		  show_alarm_type((1 << __entry->alarm_type)),
+		  __entry->expires,
+		  __entry->year + 1900,
+		  __entry->mon + 1,
+		  __entry->day,
+		  __entry->hour,
+		  __entry->minute,
+		  __entry->second
+	)
+);
+
+DEFINE_EVENT(alarm_processing, alarmtimer_fired,
+
+	TP_PROTO(struct alarm *alarm, char *process_name),
+
+	TP_ARGS(alarm, process_name)
+);
+
+DEFINE_EVENT(alarm_processing, alarmtimer_start,
+
+	TP_PROTO(struct alarm *alarm, char *process_name),
+
+	TP_ARGS(alarm, process_name)
+);
+
+DEFINE_EVENT(alarm_processing, alarmtimer_restart,
+
+	TP_PROTO(struct alarm *alarm, char *process_name),
+
+	TP_ARGS(alarm, process_name)
+);
+
+DEFINE_EVENT(alarm_processing, alarmtimer_cancel,
+
+	TP_PROTO(struct alarm *alarm, char *process_name),
+
+	TP_ARGS(alarm, process_name)
+);
+
+#endif /* _TRACE_ALARMTIMER_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index c3aad68..7cd15eb 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -26,6 +26,9 @@
 #include <linux/workqueue.h>
 #include <linux/freezer.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/alarmtimer.h>
+
 /**
  * struct alarm_base - Alarm timer bases
  * @lock:		Lock for syncrhonized access to the base
@@ -194,6 +197,7 @@ static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer)
 	}
 	spin_unlock_irqrestore(&base->lock, flags);
 
+	trace_alarmtimer_fired(alarm, NULL);
 	return ret;
 
 }
@@ -218,11 +222,11 @@ EXPORT_SYMBOL_GPL(alarm_expires_remaining);
  */
 static int alarmtimer_suspend(struct device *dev)
 {
-	struct rtc_time tm;
+	struct rtc_time tm, tm_set;
 	ktime_t min, now;
 	unsigned long flags;
 	struct rtc_device *rtc;
-	int i;
+	int i, type = 0;
 	int ret;
 
 	spin_lock_irqsave(&freezer_delta_lock, flags);
@@ -247,8 +251,10 @@ static int alarmtimer_suspend(struct device *dev)
 		if (!next)
 			continue;
 		delta = ktime_sub(next->expires, base->gettime());
-		if (!min.tv64 || (delta.tv64 < min.tv64))
+		if (!min.tv64 || (delta.tv64 < min.tv64)) {
 			min = delta;
+			type = i;
+		}
 	}
 	if (min.tv64 == 0)
 		return 0;
@@ -264,6 +270,11 @@ static int alarmtimer_suspend(struct device *dev)
 	now = rtc_tm_to_ktime(tm);
 	now = ktime_add(now, min);
 
+	if (trace_alarmtimer_suspend_enabled()) {
+		tm_set = rtc_ktime_to_tm(now);
+		trace_alarmtimer_suspend(&tm_set, type);
+	}
+
 	/* Set alarm, if in the past reject suspend briefly to handle */
 	ret = rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0));
 	if (ret < 0)
@@ -342,6 +353,8 @@ void alarm_start(struct alarm *alarm, ktime_t start)
 	alarmtimer_enqueue(base, alarm);
 	hrtimer_start(&alarm->timer, alarm->node.expires, HRTIMER_MODE_ABS);
 	spin_unlock_irqrestore(&base->lock, flags);
+
+	trace_alarmtimer_start(alarm, current->comm);
 }
 EXPORT_SYMBOL_GPL(alarm_start);
 
@@ -369,6 +382,8 @@ void alarm_restart(struct alarm *alarm)
 	hrtimer_restart(&alarm->timer);
 	alarmtimer_enqueue(base, alarm);
 	spin_unlock_irqrestore(&base->lock, flags);
+
+	trace_alarmtimer_restart(alarm, current->comm);
 }
 EXPORT_SYMBOL_GPL(alarm_restart);
 
@@ -390,6 +405,8 @@ int alarm_try_to_cancel(struct alarm *alarm)
 	if (ret >= 0)
 		alarmtimer_dequeue(base, alarm);
 	spin_unlock_irqrestore(&base->lock, flags);
+
+	trace_alarmtimer_cancel(alarm, current->comm);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(alarm_try_to_cancel);
-- 
1.7.9.5