[Android] Move perf utilities into devil.

build/android/pylib/perf/perf_control.py

-# Copyright 2013 The Chromium Authors. All rights reserved.
+# Copyright 2015 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.
 
-import atexit
-import logging
+# pylint: disable=unused-wildcard-import
+# pylint: disable=wildcard-import
 
-from devil.android import device_errors
-
-
-class PerfControl(object):
-  """Provides methods for setting the performance mode of a device."""
-  _CPU_PATH = '/sys/devices/system/cpu'
-  _KERNEL_MAX = '/sys/devices/system/cpu/kernel_max'
-
-  def __init__(self, device):
-    self._device = device
-    # this will raise an AdbCommandFailedError if no CPU files are found
-    self._cpu_files = self._device.RunShellCommand(
-        'ls -d cpu[0-9]*', cwd=self._CPU_PATH, check_return=True, as_root=True)
-    assert self._cpu_files, 'Failed to detect CPUs.'
-    self._cpu_file_list = ' '.join(self._cpu_files)
-    logging.info('CPUs found: %s', self._cpu_file_list)
-    self._have_mpdecision = self._device.FileExists('/system/bin/mpdecision')
-
-  def SetHighPerfMode(self):
-    """Sets the highest stable performance mode for the device."""
-    try:
-      self._device.EnableRoot()
-    except device_errors.CommandFailedError:
-      message = 'Need root for performance mode. Results may be NOISY!!'
-      logging.warning(message)
-      # Add an additional warning at exit, such that it's clear that any results
-      # may be different/noisy (due to the lack of intended performance mode).
-      atexit.register(logging.warning, message)
-      return
-
-    product_model = self._device.product_model
-    # TODO(epenner): Enable on all devices (http://crbug.com/383566)
-    if 'Nexus 4' == product_model:
-      self._ForceAllCpusOnline(True)
-      if not self._AllCpusAreOnline():
-        logging.warning('Failed to force CPUs online. Results may be NOISY!')
-      self._SetScalingGovernorInternal('performance')
-    elif 'Nexus 5' == product_model:
-      self._ForceAllCpusOnline(True)
-      if not self._AllCpusAreOnline():
-        logging.warning('Failed to force CPUs online. Results may be NOISY!')
-      self._SetScalingGovernorInternal('performance')
-      self._SetScalingMaxFreq(1190400)
-      self._SetMaxGpuClock(200000000)
-    else:
-      self._SetScalingGovernorInternal('performance')
-
-  def SetPerfProfilingMode(self):
-    """Enables all cores for reliable perf profiling."""
-    self._ForceAllCpusOnline(True)
-    self._SetScalingGovernorInternal('performance')
-    if not self._AllCpusAreOnline():
-      if not self._device.HasRoot():
-        raise RuntimeError('Need root to force CPUs online.')
-      raise RuntimeError('Failed to force CPUs online.')
-
-  def SetDefaultPerfMode(self):
-    """Sets the performance mode for the device to its default mode."""
-    if not self._device.HasRoot():
-      return
-    product_model = self._device.product_model
-    if 'Nexus 5' == product_model:
-      if self._AllCpusAreOnline():
-        self._SetScalingMaxFreq(2265600)
-        self._SetMaxGpuClock(450000000)
-
-    governor_mode = {
-        'GT-I9300': 'pegasusq',
-        'Galaxy Nexus': 'interactive',
-        'Nexus 4': 'ondemand',
-        'Nexus 5': 'ondemand',
-        'Nexus 7': 'interactive',
-        'Nexus 10': 'interactive'
-    }.get(product_model, 'ondemand')
-    self._SetScalingGovernorInternal(governor_mode)
-    self._ForceAllCpusOnline(False)
-
-  def GetCpuInfo(self):
-    online = (output.rstrip() == '1' and status == 0
-              for (_, output, status) in self._ForEachCpu('cat "$CPU/online"'))
-    governor = (output.rstrip() if status == 0 else None
-                for (_, output, status)
-                in self._ForEachCpu('cat "$CPU/cpufreq/scaling_governor"'))
-    return zip(self._cpu_files, online, governor)
-
-  def _ForEachCpu(self, cmd):
-    script = '; '.join([
-        'for CPU in %s' % self._cpu_file_list,
-        'do %s' % cmd,
-        'echo -n "%~%$?%~%"',
-        'done'
-    ])
-    output = self._device.RunShellCommand(
-        script, cwd=self._CPU_PATH, check_return=True, as_root=True)
-    output = '\n'.join(output).split('%~%')
-    return zip(self._cpu_files, output[0::2], (int(c) for c in output[1::2]))
-
-  def _WriteEachCpuFile(self, path, value):
-    results = self._ForEachCpu(
-        'test -e "$CPU/{path}" && echo {value} > "$CPU/{path}"'.format(
-            path=path, value=value))
-    cpus = ' '.join(cpu for (cpu, _, status) in results if status == 0)
-    if cpus:
-      logging.info('Successfully set %s to %r on: %s', path, value, cpus)
-    else:
-      logging.warning('Failed to set %s to %r on any cpus', path, value)
-
-  def _SetScalingGovernorInternal(self, value):
-    self._WriteEachCpuFile('cpufreq/scaling_governor', value)
-
-  def _SetScalingMaxFreq(self, value):
-    self._WriteEachCpuFile('cpufreq/scaling_max_freq', '%d' % value)
-
-  def _SetMaxGpuClock(self, value):
-    self._device.WriteFile('/sys/class/kgsl/kgsl-3d0/max_gpuclk',
-                           str(value),
-                           as_root=True)
-
-  def _AllCpusAreOnline(self):
-    results = self._ForEachCpu('cat "$CPU/online"')
-    # TODO(epenner): Investigate why file may be missing
-    # (http://crbug.com/397118)
-    return all(output.rstrip() == '1' and status == 0
-               for (cpu, output, status) in results
-               if cpu != 'cpu0')
-
-  def _ForceAllCpusOnline(self, force_online):
-    """Enable all CPUs on a device.
-
-    Some vendors (or only Qualcomm?) hot-plug their CPUs, which can add noise
-    to measurements:
-    - In perf, samples are only taken for the CPUs that are online when the
-      measurement is started.
-    - The scaling governor can't be set for an offline CPU and frequency scaling
-      on newly enabled CPUs adds noise to both perf and tracing measurements.
-
-    It appears Qualcomm is the only vendor that hot-plugs CPUs, and on Qualcomm
-    this is done by "mpdecision".
-
-    """
-    if self._have_mpdecision:
-      script = 'stop mpdecision' if force_online else 'start mpdecision'
-      self._device.RunShellCommand(script, check_return=True, as_root=True)
-
-    if not self._have_mpdecision and not self._AllCpusAreOnline():
-      logging.warning('Unexpected cpu hot plugging detected.')
-
-    if force_online:
-      self._ForEachCpu('echo 1 > "$CPU/online"')
+from devil.android.perf.perf_control import *