[PATCH 4.8 030/140] perf intel-pt: Fix estimated timestamps for cycle-accurate mode

[Greg Kroah-Hartman]

4.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Adrian Hunter <adrian.hunter@xxxxxxxxx>

commit 51ee6481fa8e879cc942bcc1b0af713e158b7a98 upstream.

In cycle-accurate mode, timestamps can be calculated from CYC packets.
The decoder also estimates timestamps based on the number of
instructions since the last timestamp. For that to work in
cycle-accurate mode, the instruction count needs to be reset to zero
when a timestamp is calculated from a CYC packet, but that wasn't
happening, so fix it.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1475062896-22274-1-git-send-email-adrian.hunter@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 tools/perf/util/intel-pt-decoder/intel-pt-decoder.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -1323,6 +1323,8 @@ static void intel_pt_calc_cyc_timestamp(
 			     timestamp, decoder->timestamp);
 	else
 		decoder->timestamp = timestamp;
+
+	decoder->timestamp_insn_cnt = 0;
 }
 
 /* Walk PSB+ packets when already in sync. */