[PATCH] perf tools: Fix Intel BTS/PT timestamp handling

From: Adrian Hunter
Date: Thu Aug 20 2015 - 04:54:26 EST


Events that don't sample the timestamp have a timestamp
value of -1. Intel BTS and Intel PT processing wasn't
taking that into account. This is particularly noticeable
with Intel BTS because timestamps are not requested by
default. Then, if the conversion of -1 to TSC results
in a small number, the processing is unaffected.
However if the conversion results in a big number, then
the data is processed prematurely before relevant sideband
data like mmap events, which in turn results in samples
with unknown dsos.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
tools/perf/util/intel-bts.c | 2 +-
tools/perf/util/intel-pt.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/intel-bts.c b/tools/perf/util/intel-bts.c
index dce99cfb1309..ea768625ab5b 100644
--- a/tools/perf/util/intel-bts.c
+++ b/tools/perf/util/intel-bts.c
@@ -610,7 +610,7 @@ static int intel_bts_process_event(struct perf_session *session,
return -EINVAL;
}

- if (sample->time)
+ if (sample->time && sample->time != (u64)-1)
timestamp = perf_time_to_tsc(sample->time, &bts->tc);
else
timestamp = 0;
diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
index 2a4a4120473b..a5acd2fe2447 100644
--- a/tools/perf/util/intel-pt.c
+++ b/tools/perf/util/intel-pt.c
@@ -1450,7 +1450,7 @@ static int intel_pt_process_event(struct perf_session *session,
return -EINVAL;
}

- if (sample->time)
+ if (sample->time && sample->time != (u64)-1)
timestamp = perf_time_to_tsc(sample->time, &pt->tc);
else
timestamp = 0;
--
1.9.1

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