Telemetry: Quiescent power benchmarks for Mac

tools/perf/metrics/cpu.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 from telemetry.value import scalar
 
 from metrics import Metric
 
 
 class CpuMetric(Metric):
@@ skipping 14 matching lines @@
 
   def Stop(self, page, tab):
     assert self._start_cpu, 'Must call Start() first'
     self._stop_cpu = self._browser.cpu_stats
 
   # Optional argument trace_name is not in base class Metric.
   # pylint: disable=W0221
   def AddResults(self, tab, results, trace_name='cpu_utilization'):
     assert self._stop_cpu, 'Must call Stop() first'
     cpu_stats = _SubtractCpuStats(self._stop_cpu, self._start_cpu)
+
+    # FIXME: Renderer process CPU times are impossible to compare correctly.
+    # http://crbug.com/419786#c11
+    if 'Renderer' in cpu_stats:
+      del cpu_stats['Renderer']
+
     # Add a result for each process type.
     for process_type in cpu_stats:
       trace_name_for_process = '%s_%s' % (trace_name, process_type.lower())
       cpu_percent = 100 * cpu_stats[process_type]
       results.AddValue(scalar.ScalarValue(
           results.current_page, 'cpu_utilization.%s' % trace_name_for_process,
           '%', cpu_percent, important=False))
 
 
 def _SubtractCpuStats(cpu_stats, start_cpu_stats):
@@ skipping 26 matching lines @@
     # Linux kernel starts with a value close to an overflow, so correction is
     # necessary.
     if total_time < 0:
       total_time += 2**32
     # Assert that the arguments were given in the correct order.
     assert total_time > 0 and total_time < 2**31, (
         'Expected total_time > 0, was: %d' % total_time)
     cpu_usage[process_type] = float(cpu_process_time) / total_time
   return cpu_usage