derived: add DerivedSurfaceFlingerStats

Add DerivedSurfaceFlingerStats that parse output from
SurfaceFlingerFramesInstrument to produce FPS data and rendering
statistics.

devlib/__init__.py

@@ -13,7 +13,7 @@ from devlib.instrument import Instrument, InstrumentChannel, Measurement, Measur
 from devlib.instrument import MEASUREMENT_TYPES, INSTANTANEOUS, CONTINUOUS
 from devlib.instrument.daq import DaqInstrument
 from devlib.instrument.energy_probe import EnergyProbeInstrument
-from devlib.instrument.frames import GfxInfoFramesInstrument
+from devlib.instrument.frames import GfxInfoFramesInstrument, SurfaceFlingerFramesInstrument
 from devlib.instrument.hwmon import HwmonInstrument
 from devlib.instrument.monsoon import MonsoonInstrument
 from devlib.instrument.netstats import NetstatsInstrument
@@ -21,7 +21,7 @@ from devlib.instrument.gem5power import Gem5PowerInstrument
 
 from devlib.derived import DerivedMeasurements, DerivedMetric
 from devlib.derived.energy import DerivedEnergyMeasurements
-from devlib.derived.fps import DerivedGfxInfoStats
+from devlib.derived.fps import DerivedGfxInfoStats, DerivedSurfaceFlingerStats
 
 from devlib.trace.ftrace import FtraceCollector
 

devlib/derived/fps.py

@@ -9,6 +9,7 @@ except ImportError:
     pd = None
 
 from devlib import DerivedMeasurements, DerivedMetric, MeasurementsCsv, InstrumentChannel
+from devlib.exception import HostError
 from devlib.utils.rendering import gfxinfo_get_last_dump, VSYNC_INTERVAL
 from devlib.utils.types import numeric
 
@@ -135,3 +136,79 @@ class DerivedGfxInfoStats(DerivedFpsStats):
                 DerivedMetric('total_frames', frame_count, 'frames'),
                 MeasurementsCsv(csv_file)]
 
+
+class DerivedSurfaceFlingerStats(DerivedFpsStats):
+
+    def _process_with_pandas(self, measurements_csv):
+        data = pd.read_csv(measurements_csv.path)
+
+        # fiter out bogus frames.
+        bogus_frames_filter = data.actual_present_time_us != 0x7fffffffffffffff
+        actual_present_times = data.actual_present_time_us[bogus_frames_filter]
+        actual_present_time_deltas = actual_present_times.diff().dropna()
+
+        vsyncs_to_compose = actual_present_time_deltas.div(VSYNC_INTERVAL)
+        vsyncs_to_compose.apply(lambda x: int(round(x, 0)))
+
+        # drop values lower than drop_threshold FPS as real in-game frame
+        # rate is unlikely to drop below that (except on loading screens
+        # etc, which should not be factored in frame rate calculation).
+        per_frame_fps = (1.0 / (vsyncs_to_compose.multiply(VSYNC_INTERVAL / 1e9)))
+        keep_filter = per_frame_fps > self.drop_threshold
+        filtered_vsyncs_to_compose = vsyncs_to_compose[keep_filter]
+        per_frame_fps.name = 'fps'
+
+        csv_file = self._get_csv_file_name(measurements_csv.path)
+        per_frame_fps.to_csv(csv_file, index=False, header=True)
+
+        if not filtered_vsyncs_to_compose.empty:
+            fps = 0
+            total_vsyncs = filtered_vsyncs_to_compose.sum()
+            frame_count = filtered_vsyncs_to_compose.size
+
+            if total_vsyncs:
+                fps = 1e9 * frame_count / (VSYNC_INTERVAL * total_vsyncs)
+
+            janks = self._calc_janks(filtered_vsyncs_to_compose)
+            not_at_vsync = self._calc_not_at_vsync(vsyncs_to_compose)
+        else:
+            fps = 0
+            frame_count = 0
+            janks = 0
+            not_at_vsync = 0
+
+        return [DerivedMetric('fps', fps, 'fps'),
+                DerivedMetric('total_frames', frame_count, 'frames'),
+                MeasurementsCsv(csv_file),
+                DerivedMetric('janks', janks, 'count'),
+                DerivedMetric('janks_pc', janks * 100 / frame_count, 'percent'),
+                DerivedMetric('missed_vsync', not_at_vsync, 'count')]
+
+    def _process_without_pandas(self, measurements_csv):
+        # Given that SurfaceFlinger has been deprecated in favor of GfxInfo,
+        # it does not seem worth it implementing this.
+        raise HostError('Please install "pandas" Python package to process SurfaceFlinger frames')
+
+    @staticmethod
+    def _calc_janks(filtered_vsyncs_to_compose):
+        """
+        Internal method for calculating jank frames.
+        """
+        pause_latency = 20
+        vtc_deltas = filtered_vsyncs_to_compose.diff().dropna()
+        vtc_deltas = vtc_deltas.abs()
+        janks = vtc_deltas.apply(lambda x: (pause_latency > x > 1.5) and 1 or 0).sum()
+
+        return janks
+
+    @staticmethod
+    def _calc_not_at_vsync(vsyncs_to_compose):
+        """
+        Internal method for calculating the number of frames that did not
+        render in a single vsync cycle.
+        """
+        epsilon = 0.0001
+        func = lambda x: (abs(x - 1.0) > epsilon) and 1 or 0
+        not_at_vsync = vsyncs_to_compose.apply(func).sum()
+
+        return not_at_vsync

doc/derived_measurements.rst

@@ -179,3 +179,43 @@ FPS / Rendering
    Please see the `gfxinfo documentation`_ for details.
 
 .. _gfxinfo documentation: https://developer.android.com/training/testing/performance.html
+
+
+.. class:: DerivedSurfaceFlingerStats(drop_threshold=5, suffix='-fps', filename=None, outdir=None)
+
+   Produces FPS (frames-per-second) and other dervied statistics from
+   :class:`SurfaceFlingerFramesInstrument` output. This takes several optional
+   parameters in creation:
+
+   :param drop_threshold: FPS in an application, such as a game, which this
+                          processor is primarily targeted at, cannot reasonably
+                          drop to a very low value. This is specified to this
+                          threhold. If an FPS for a frame is computed to be
+                          lower than this treshold, it will be dropped on the
+                          assumption that frame rednering was suspended by the
+                          system (e.g. when idling), or there was some sort of
+                          error, and therefore this should be used in
+                          performance calculations. defaults to ``5``.
+   :param  suffix: The name of the gerated per-frame FPS csv file will be
+                   derived from the input frames csv file by appending this
+                   suffix. This cannot be specified at the same time as
+                   a ``filename``.
+   :param filename: As an alternative to the suffix, a complete file name for
+                    FPS csv can be specified. This cannot be used at the same
+                    time as the ``suffix``.
+   :param outdir: By default, the FPS csv file will be placed in the same
+                  directory as the input frames csv file. This can be changed
+                  by specifying an alternate directory here
+
+   .. warning:: Specifying both ``filename`` and ``oudir`` will mean that exactly
+                the same file will be used for FPS output on each invocation of
+                ``process()`` (even for different inputs) resulting in previous
+                results being overwritten.
+
+.. method:: DerivedSurfaceFlingerStats.process(measurement_csv)
+
+   Process the fames csv generated by :class:`SurfaceFlingerFramesInstrument` and
+   returns a list containing exactly three entries: :class:`DerivedMetric`\ s
+   ``fps`` and ``total_frames``, followed by a :class:`MeasurentCsv` containing
+   per-frame FPSs values, followed by ``janks`` ``janks_pc``, and
+   ``missed_vsync`` metrics.