[tip:perf/urgent] perf intel-pt: Fix estimated timestamps for cycle-accurate mode

From: tip-bot for Adrian Hunter
Date: Thu Oct 06 2016 - 18:40:53 EST

Commit-ID: 51ee6481fa8e879cc942bcc1b0af713e158b7a98
Gitweb: http://git.kernel.org/tip/51ee6481fa8e879cc942bcc1b0af713e158b7a98
Author: Adrian Hunter <adrian.hunter@xxxxxxxxx>
AuthorDate: Wed, 28 Sep 2016 14:41:35 +0300
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 5 Oct 2016 08:15:29 -0300

perf intel-pt: Fix estimated timestamps for cycle-accurate mode

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>
Cc: stable@xxxxxxxxxxxxxxx # v4.3+
Link: http://lkml.kernel.org/r/1475062896-22274-1-git-send-email-adrian.hunter@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
index 7591a0c..3d1d446 100644
--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -1353,6 +1353,8 @@ static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
timestamp, decoder->timestamp);
decoder->timestamp = timestamp;
+ decoder->timestamp_insn_cnt = 0;

/* Walk PSB+ packets when already in sync. */