[PATCH 1/6] trace: add tracepoints to timekeeping code - xtime changes

[David Ahern]

Trace points in timekeeping.c where xtime is modified by a user
or ntp.

Signed-off-by: David Ahern <dsahern@xxxxxxxxx>
---
 include/trace/events/timekeeping.h |   43 ++++++++++++++++++++++++++++++++++++
 kernel/time/timekeeping.c          |    8 ++++++
 2 files changed, 51 insertions(+), 0 deletions(-)
 create mode 100644 include/trace/events/timekeeping.h

diff --git a/include/trace/events/timekeeping.h b/include/trace/events/timekeeping.h
new file mode 100644
index 0000000..3d5d083
--- /dev/null
+++ b/include/trace/events/timekeeping.h
@@ -0,0 +1,43 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM timekeeping
+
+#if !defined(_TRACE_TIMEKEEP_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_TIMEKEEP_H
+
+#include <linux/tracepoint.h>
+#include <linux/time.h>
+
+DECLARE_EVENT_CLASS(tod_template,
+
+	TP_PROTO(const struct timespec *tv),
+
+	TP_ARGS(tv),
+
+	TP_STRUCT__entry(
+		__field( __kernel_time_t,	tv_sec)
+		__field( long,			tv_nsec)
+	),
+
+	TP_fast_assign(
+		__entry->tv_sec  = tv->tv_sec;
+		__entry->tv_nsec = tv->tv_nsec;
+	),
+
+	TP_printk("tv_sec=%ld tv_nsec=%ld", __entry->tv_sec, __entry->tv_nsec)
+);
+
+DEFINE_EVENT(tod_template, settimeofday,
+	TP_PROTO(const struct timespec *tv),
+	TP_ARGS(tv));
+
+DEFINE_EVENT(tod_template, timekeeping_inject_offset,
+	TP_PROTO(const struct timespec *tv),
+	TP_ARGS(tv));
+
+DEFINE_EVENT(tod_template, timekeeping_inject_sleeptime,
+	TP_PROTO(const struct timespec *tv),
+	TP_ARGS(tv));
+#endif /*  _TRACE_TIMEKEEP_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 342408c..fda1af1 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -21,6 +21,9 @@
 #include <linux/tick.h>
 #include <linux/stop_machine.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/timekeeping.h>
+
 /* Structure holding internal timekeeping values. */
 struct timekeeper {
 	/* Current clocksource used for timekeeping. */
@@ -361,6 +364,8 @@ int do_settimeofday(const struct timespec *tv)
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
+	trace_settimeofday(tv);
+
 	write_seqlock_irqsave(&xtime_lock, flags);
 
 	timekeeping_forward_now();
@@ -406,6 +411,8 @@ int timekeeping_inject_offset(struct timespec *ts)
 	timekeeping_forward_now();
 
 	xtime = timespec_add(xtime, *ts);
+	trace_timekeeping_inject_offset(&xtime);
+
 	wall_to_monotonic = timespec_sub(wall_to_monotonic, *ts);
 
 	timekeeper.ntp_error = 0;
@@ -605,6 +612,7 @@ static struct timespec timekeeping_suspend_time;
 static void __timekeeping_inject_sleeptime(struct timespec *delta)
 {
 	xtime = timespec_add(xtime, *delta);
+	trace_timekeeping_inject_sleeptime(&xtime);
 	wall_to_monotonic = timespec_sub(wall_to_monotonic, *delta);
 	total_sleep_time = timespec_add(total_sleep_time, *delta);
 }
-- 
1.7.5.2

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