Hi,
This change has a soft dependency on [1], but assuming the name/location of the new sysfs interface (ts_source) doesn't change, it should be safe to apply.
The new 'ts_source' interface allows perf to detect if the timestamps in the trace correspond to the value of CNTVCT_EL0, which we can convert to a perf timestamp and store it in the instruction and branch samples.
Due to the way the trace is compressed and decoded by OpenCSD, we only know the precise time of the first instruction in a range, but I think for now this is better than not having timestamps at all...
Thanks, German
[1] https://lore.kernel.org/all/20220503123537.1003035-1-german.gomez@arm.com/
German Gomez (4): perf pmu: Add function to check if a pmu file exists perf cs_etm: Keep separate symbols for ETMv4 and ETE parameters perf cs_etm: Record ts_source in AUXTRACE_INFO for ETMv4 and ETE perf cs_etm: Set the time field in the synthetic samples
tools/perf/arch/arm/util/cs-etm.c | 89 +++++++++++++++++++-- tools/perf/util/cs-etm.c | 126 +++++++++++++++++++++++++----- tools/perf/util/cs-etm.h | 13 ++- tools/perf/util/pmu.c | 17 ++++ tools/perf/util/pmu.h | 2 + 5 files changed, 221 insertions(+), 26 deletions(-)