4.9-stable patches

[thirdparty/kernel/stable-queue.git] / releases / 4.8.5 / perf-intel-pt-fix-estimated-timestamps-for-cycle-accurate-mode.patch

From 51ee6481fa8e879cc942bcc1b0af713e158b7a98 Mon Sep 17 00:00:00 2001
From: Adrian Hunter <adrian.hunter@intel.com>
Date: Wed, 28 Sep 2016 14:41:35 +0300
Subject: perf intel-pt: Fix estimated timestamps for cycle-accurate mode

From: Adrian Hunter <adrian.hunter@intel.com>

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

---
 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. */