[PATCH 4.14] perf intel-pt: Fix CYC timestamps after standalone CBR

Adrian Hunter
2023-07-12T15:23:19Z

commit 430635a0ef1ce958b7b4311f172694ece2c692b8 upstream

After a standalone CBR (not associated with TSC), update the cycles
reference timestamp and reset the cycle count, so that CYC timestamps
are calculated relative to that point with the new frequency.

Fixes: cc33618619cefc6d ("perf tools: Add Intel PT support for decoding CYC packets")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230403154831.8651-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
(cherry picked from commit 430635a0ef1ce958b7b4311f172694ece2c692b8)
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
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 e2a6c22959f2..aabd42378552 100644
--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -1499,6 +1499,8 @@ static void intel_pt_calc_cbr(struct intel_pt_decoder *decoder)

decoder->cbr = cbr;
decoder->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
+ decoder->cyc_ref_timestamp = decoder->timestamp;
+ decoder->cycle_cnt = 0;
}

static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
--
2.34.1