[Telemetry] Output average GPU frequency from power metric

[Telemetry] Output average GPU frequency from power metric

Add a result for 'gpu_average_frequency_hz' to the power metric. This represents a weighted average of the P-States over the time the GPU was active.

Also correctly convert hz -> mhz in powermetrics output.

BUG=357106
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=261421

[tonyg, 2014-04-01 16:19:43]

Please address the comment, but lgtm in advance to avoid a timezone round trip.

https://codereview.chromium.org/220963003/diff/1/tools/perf/metrics/power.py
File tools/perf/metrics/power.py (right):

https://codereview.chromium.org/220963003/diff/1/tools/perf/metrics/power.py#...
tools/perf/metrics/power.py:90: results.Add('gpu_average_frequency_hz', 'hz',
gpu_freq_hz)
Seems like we're missing the multiplication from mhz to hz.

Perhaps the unittest should check for this stat in the test that is based on a
static powermetrics output file.

Finally, should we check for the existence of 'gpu' and 'average_frequency_mhz'
before trying to access it and just silently not output this stat if
unavailable?

[jeremy, 2014-04-02 07:29:56]

I'd actually like another round of review if that's ok...

1. Turns out powermetrics reports all frequences in hz, I added a conversion to
mhz which affects more than just the gpu metric - it also corrects the cpu
frequency numbers (which are output by the API but never used for anything).

2. The powermetrics unit tests already have a testcase for this since this was
data we already parsed - just didn't report it to the dashboard.

[tonyg, 2014-04-02 16:32:23]

lgtm after another nit

https://codereview.chromium.org/220963003/diff/20001/tools/perf/metrics/power.py
File tools/perf/metrics/power.py (right):

https://codereview.chromium.org/220963003/diff/20001/tools/perf/metrics/power...
tools/perf/metrics/power.py:92: results.Add('gpu_average_frequency_hz', 'hz',
gpu_freq_mhz * 10 ** 6)
Let's put the API in hz and do whatever conversions there on that side instead.
I like the idea of using unscaled units in all of those stats APIs.

[jeremy, 2014-04-03 09:26:30]

The CQ bit was checked by jeremy@chromium.org

[commit-bot: I haz the power, 2014-04-03 09:26:54]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jeremy@chromium.org/220963003/40001

[commit-bot: I haz the power, 2014-04-03 14:59:12]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-04-03 14:59:12]

Commit queue rejected this change because the description was changed
between the time the change entered the commit queue and the time it
was ready to commit. You can safely check the commit box again.

[jeremy, 2014-04-03 15:38:45]

The CQ bit was checked by jeremy@chromium.org

[commit-bot: I haz the power, 2014-04-03 15:40:21]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jeremy@chromium.org/220963003/40001

[commit-bot: I haz the power, 2014-04-03 15:47:34]

Change committed as 261421