[PATCH 2/2] ftrace: Show raw time stamp on stats per cpu using counter or tsc mode for trace_clock

[Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>]

Show raw time stamp values for stats per cpu if you choose counter or tsc mode
for trace_clock. Although a unit of tracing time stamp is nsec in local or global mode,
the units in counter and TSC mode are tracing counter and cycles respectively.

Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
---

 kernel/trace/trace.c |   23 +++++++++++++++++------
 1 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 3068374..83e5c6a 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4396,13 +4396,24 @@ tracing_stats_read(struct file *filp, char __user *ubuf,
 	cnt = ring_buffer_bytes_cpu(tr->buffer, cpu);
 	trace_seq_printf(s, "bytes: %ld\n", cnt);
 
-	t = ns2usecs(ring_buffer_oldest_event_ts(tr->buffer, cpu));
-	usec_rem = do_div(t, USEC_PER_SEC);
-	trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n", t, usec_rem);
+	if (trace_clocks[trace_clock_id].in_ns) {
+		/* local or global for trace_clock */
+		t = ns2usecs(ring_buffer_oldest_event_ts(tr->buffer, cpu));
+		usec_rem = do_div(t, USEC_PER_SEC);
+		trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n",
+								t, usec_rem);
+
+		t = ns2usecs(ring_buffer_time_stamp(tr->buffer, cpu));
+		usec_rem = do_div(t, USEC_PER_SEC);
+		trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem);
+	} else {
+		/* counter or tsc mode for trace_clock */
+		trace_seq_printf(s, "oldest event ts: %llu\n",
+				ring_buffer_oldest_event_ts(tr->buffer, cpu));
 
-	t = ns2usecs(ring_buffer_time_stamp(tr->buffer, cpu));
-	usec_rem = do_div(t, USEC_PER_SEC);
-	trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem);
+		trace_seq_printf(s, "now ts: %llu\n",
+				ring_buffer_time_stamp(tr->buffer, cpu));
+	}
 
 	count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len);