* State: Initialize counters with kAvgIteration in constructor
Previously, `counters` was updated in `PauseTiming()` with
`counters[name] += Counter(measurement, kAvgIteration)`.
The first `counters[name]` call inserts a counter with no flags.
There is no `operator+=` for `Counter`, so the insertion is done
by converting the `Counter` to a `double`, then constructing a
`Counter` to insert from the `double`, which drops the flags.
Pre-insert the `Counter` with the correct flags, then only
update `Counter::value`.
Introduced in 1c64a36 ([perf-counters] Fix pause/resume (#1643)).
* perf_counters_test.cc: Don't divide by iterations
Perf counters are now divided by iterations, so dividing again
in the test is wrong.
* State: Fix shadowed param error
* benchmark.cc: Fix clang-tidy error
---------
Co-authored-by: dominic <510002+dmah42@users.noreply.github.com>
* perf_counters_gtest: Make test pass on Android
Tested on Pixel 3 and Pixel 6. Reduce test to the intersection of
what passes on all platforms.
Pixel 6 doesn't support BRANCHES, and only supports two perf
counters.
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Co-authored-by: dominic <510002+dmah42@users.noreply.github.com>
* [perf-counters] Fix pause/resume
Using `state.PauseTiming() / state.ResumeTiming()` was broken.
Thanks [@virajbshah] for the the repro testcase.
* ran clang-format over the whole perf_counters_test.cc
* Remove check that perf counters are 0 on `Pause`, since `Pause`/`Resume`
sequences would cause a non-0 counter value
* both upper and lower bound for the with/without resume counters
---------
Co-authored-by: dominic <510002+dmah42@users.noreply.github.com>
* Add pfm CI actions for bazel
* Fix problems in unit test.
* Undo enabling the CI tests for pfm - github CI machines seemingly do not support performance counters.
* Remove commented code - can be revisited in github history when needed, and there's a comment explaining the rationale behind the new test code.
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Co-authored-by: Andy Christiansen <achristiansen@google.com>
Co-authored-by: dominic <510002+dmah42@users.noreply.github.com>
* 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
