new file mode 100644
@@ -0,0 +1,92 @@
+#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" })
+
+TRACE_EVENT(alarmtimer_suspend,
+
+ TP_PROTO(ktime_t expires, int flag),
+
+ TP_ARGS(expires, flag),
+
+ TP_STRUCT__entry(
+ __field(s64, expires)
+ __field(unsigned char, alarm_type)
+ ),
+
+ TP_fast_assign(
+ __entry->expires = expires.tv64;
+ __entry->alarm_type = flag;
+ ),
+
+ TP_printk("alarmtimer type:%s expires:%llu",
+ show_alarm_type((1 << __entry->alarm_type)),
+ __entry->expires
+ )
+);
+
+DECLARE_EVENT_CLASS(alarm_class,
+
+ TP_PROTO(struct alarm *alarm, ktime_t now),
+
+ TP_ARGS(alarm, now),
+
+ TP_STRUCT__entry(
+ __field(void *, alarm)
+ __field(unsigned char, alarm_type)
+ __field(s64, expires)
+ __field(s64, now)
+ ),
+
+ TP_fast_assign(
+ __entry->alarm = alarm;
+ __entry->alarm_type = alarm->type;
+ __entry->expires = alarm->node.expires.tv64;
+ __entry->now = now.tv64;
+ ),
+
+ TP_printk("alarmtimer:%p type:%s expires:%llu now:%llu",
+ __entry->alarm,
+ show_alarm_type((1 << __entry->alarm_type)),
+ __entry->expires,
+ __entry->now
+ )
+);
+
+DEFINE_EVENT(alarm_class, alarmtimer_fired,
+
+ TP_PROTO(struct alarm *alarm, ktime_t now),
+
+ TP_ARGS(alarm, now)
+);
+
+DEFINE_EVENT(alarm_class, alarmtimer_start,
+
+ TP_PROTO(struct alarm *alarm, ktime_t now),
+
+ TP_ARGS(alarm, now)
+);
+
+DEFINE_EVENT(alarm_class, alarmtimer_cancel,
+
+ TP_PROTO(struct alarm *alarm, ktime_t now),
+
+ TP_ARGS(alarm, now)
+);
+
+#endif /* _TRACE_ALARMTIMER_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
@@ -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, base->gettime());
return ret;
}
@@ -222,7 +226,7 @@ static int alarmtimer_suspend(struct device *dev)
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 +270,8 @@ static int alarmtimer_suspend(struct device *dev)
now = rtc_tm_to_ktime(tm);
now = ktime_add(now, min);
+ trace_alarmtimer_suspend(now, 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 +350,8 @@ 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, base->gettime());
}
EXPORT_SYMBOL_GPL(alarm_start);
@@ -390,6 +400,8 @@ 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, base->gettime());
return ret;
}
EXPORT_SYMBOL_GPL(alarm_try_to_cancel);
For system debugging, we sometimes 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:3292_2-3304 [000] d..2 149.981123: alarmtimer_cancel: alarmtimer:ffffffc1319a7800 type:ALARM_REALTIME expires:1325463120000000000 now:1325376810370370245 Binder:3292_2-3304 [000] d..2 149.981136: alarmtimer_start: alarmtimer:ffffffc1319a7800 type:ALARM_REALTIME expires:1325376840000000000 now:1325376810370384591 Binder:3292_9-3953 [000] d..2 150.212991: alarmtimer_cancel: alarmtimer:ffffffc1319a5a00 type:ALARM_BOOTTIME expires:179552000000 now:150154008122 Binder:3292_9-3953 [000] d..2 150.213006: alarmtimer_start: alarmtimer:ffffffc1319a5a00 type:ALARM_BOOTTIME expires:179551000000 now:150154025622 ...... system_server-3000 [002] ...1 162.701940: alarmtimer_suspend: alarmtimer type:ALARM_REALTIME expires:1325376839802714584 ...... From the trace log, we can find out the 'Binder:3292_2' process set one alarm timer which resumes the system. Signed-off-by: Baolin Wang <baolin.wang@linaro.org> --- Changes since v2: - Save time as s64 type. - Remove 'process_name' parameter and add 'now' parameter. - Rename the trace event name. - Remove restart trace event. - Other optimization. --- include/trace/events/alarmtimer.h | 92 +++++++++++++++++++++++++++++++++++++ kernel/time/alarmtimer.c | 16 ++++++- 2 files changed, 106 insertions(+), 2 deletions(-) create mode 100644 include/trace/events/alarmtimer.h -- 1.7.9.5