benchmark/test/perf_counters_test.cc
Mircea Trofin 376ebc2635
Support optional, user-directed collection of performance counters (#1114)
* Support optional, user-directed collection of performance counters

The patch allows an engineer wishing to drill into the root causes
of a regression, for example. Currently, only single threaded runs
are supported. The feature is a build-time opt in, and then a runtime
opt in.

The engineer may run the benchmark executable, passing a list of
performance counter names (using libpfm's naming scheme) at the
command line. The counter values will then be collected and reported
back as UserCounters.

This is different from #240 in that it is a benchmark user opt-in, and
the counter collection is transparent to the benchmark.

Currently, this is only supported on platforms where libpfm is
supported.

libpfm: http://perfmon2.sourceforge.net/

* 'Use' values param in Snapshot when BENCHMARK_OS_WINDOWS

This is to avoid unused parameter warning-as-error

* Added missing include for <vector> in perf_counters.cc

* Moved doc to docs

* Added license blurbs
2021-04-28 09:25:29 +01:00

28 lines
650 B
C++

#undef NDEBUG
#include "../src/perf_counters.h"
#include "benchmark/benchmark.h"
#include "output_test.h"
void BM_Simple(benchmark::State& state) {
for (auto _ : state) {
benchmark::DoNotOptimize(state.iterations());
}
}
BENCHMARK(BM_Simple);
ADD_CASES(TC_JSONOut, {{"\"name\": \"BM_Simple\",$"}});
void CheckSimple(Results const& e) {
CHECK_COUNTER_VALUE(e, double, "CYCLES", GT, 0);
CHECK_COUNTER_VALUE(e, double, "BRANCHES", GT, 0.0);
}
CHECK_BENCHMARK_RESULTS("BM_Simple", &CheckSimple);
int main(int argc, char* argv[]) {
if (!benchmark::internal::PerfCounters::kSupported) {
return 0;
}
RunOutputTests(argc, argv);
}