perf intel-pt: Fix CYC timestamp calculation after OVF

CYC packet timestamp calculation depends upon CBR which was being
cleared upon overflow (OVF). That can cause errors due to failing to
synchronize with sideband events. Even if a CBR change has been lost,
the old CBR is still a better estimate than zero. So remove the clearing
of CBR.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20190206103947.15750-4-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

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 ecd25cdc1d3e226bf52222d7027d8b6885126aee..a54d6c9a460184ffd096e5c6cb367cea301c369c 100644 (file)
--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -1395,7 +1395,6 @@ static int intel_pt_overflow(struct intel_pt_decoder *decoder)
 {
        intel_pt_log("ERROR: Buffer overflow\n");
        intel_pt_clear_tx_flags(decoder);
-       decoder->cbr = 0;
        decoder->timestamp_insn_cnt = 0;
        decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
        decoder->overflow = true;