| # 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. |
| |
| import atexit |
| import logging |
| import re |
| |
| from devil.android import device_errors |
| |
| logger = logging.getLogger(__name__) |
| |
| |
| class PerfControl(object): |
| """Provides methods for setting the performance mode of a device.""" |
| |
| _AVAILABLE_GOVERNORS_REL_PATH = 'cpufreq/scaling_available_governors' |
| _CPU_FILE_PATTERN = re.compile(r'^cpu\d+$') |
| _CPU_PATH = '/sys/devices/system/cpu' |
| _KERNEL_MAX = '/sys/devices/system/cpu/kernel_max' |
| |
| def __init__(self, device): |
| self._device = device |
| self._cpu_files = [ |
| filename |
| for filename in self._device.ListDirectory(self._CPU_PATH, as_root=True) |
| if self._CPU_FILE_PATTERN.match(filename)] |
| assert self._cpu_files, 'Failed to detect CPUs.' |
| self._cpu_file_list = ' '.join(self._cpu_files) |
| logger.info('CPUs found: %s', self._cpu_file_list) |
| |
| self._have_mpdecision = self._device.FileExists('/system/bin/mpdecision') |
| |
| raw = self._ReadEachCpuFile(self._AVAILABLE_GOVERNORS_REL_PATH) |
| self._available_governors = [ |
| (cpu, raw_governors.strip().split() if not exit_code else None) |
| for cpu, raw_governors, exit_code in raw] |
| |
| 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!!' |
| logger.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(logger.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(): |
| logger.warning('Failed to force CPUs online. Results may be NOISY!') |
| self.SetScalingGovernor('performance') |
| elif 'Nexus 5' == product_model: |
| self._ForceAllCpusOnline(True) |
| if not self._AllCpusAreOnline(): |
| logger.warning('Failed to force CPUs online. Results may be NOISY!') |
| self.SetScalingGovernor('performance') |
| self._SetScalingMaxFreq(1190400) |
| self._SetMaxGpuClock(200000000) |
| else: |
| self.SetScalingGovernor('performance') |
| |
| def SetPerfProfilingMode(self): |
| """Enables all cores for reliable perf profiling.""" |
| self._ForceAllCpusOnline(True) |
| self.SetScalingGovernor('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.SetScalingGovernor(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, shell=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): |
| self._ConditionallyWriteEachCpuFile(path, value, condition='true') |
| |
| def _ConditionallyWriteEachCpuFile(self, path, value, condition): |
| template = ( |
| '{condition} && test -e "$CPU/{path}" && echo {value} > "$CPU/{path}"') |
| results = self._ForEachCpu( |
| template.format(path=path, value=value, condition=condition)) |
| cpus = ' '.join(cpu for (cpu, _, status) in results if status == 0) |
| if cpus: |
| logger.info('Successfully set %s to %r on: %s', path, value, cpus) |
| else: |
| logger.warning('Failed to set %s to %r on any cpus', path, value) |
| |
| def _ReadEachCpuFile(self, path): |
| return self._ForEachCpu( |
| 'cat "$CPU/{path}"'.format(path=path)) |
| |
| def SetScalingGovernor(self, value): |
| """Sets the scaling governor to the given value on all possible CPUs. |
| |
| This does not attempt to set a governor to a value not reported as available |
| on the corresponding CPU. |
| |
| Args: |
| value: [string] The new governor value. |
| """ |
| condition = 'test -e "{path}" && grep -q {value} {path}'.format( |
| path=('${CPU}/%s' % self._AVAILABLE_GOVERNORS_REL_PATH), |
| value=value) |
| self._ConditionallyWriteEachCpuFile( |
| 'cpufreq/scaling_governor', value, condition) |
| |
| def GetScalingGovernor(self): |
| """Gets the currently set governor for each CPU. |
| |
| Returns: |
| An iterable of 2-tuples, each containing the cpu and the current |
| governor. |
| """ |
| raw = self._ReadEachCpuFile('cpufreq/scaling_governor') |
| return [ |
| (cpu, raw_governor.strip() if not exit_code else None) |
| for cpu, raw_governor, exit_code in raw] |
| |
| def ListAvailableGovernors(self): |
| """Returns the list of available governors for each CPU. |
| |
| Returns: |
| An iterable of 2-tuples, each containing the cpu and a list of available |
| governors for that cpu. |
| """ |
| return self._available_governors |
| |
| 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 "$CPU/online"') |
| # TODO(epenner): Investigate why file may be missing |
| # (http://crbug.com/397118) |
| return all(output.rstrip() == '1' and status == 0 |
| for (cpu, output, status) in results |
| if cpu != 'cpu0') |
| |
| def _ForceAllCpusOnline(self, force_online): |
| """Enable all CPUs on a device. |
| |
| Some vendors (or only Qualcomm?) hot-plug their CPUs, which can add noise |
| to measurements: |
| - In perf, samples are only taken for the CPUs that are online when the |
| measurement is started. |
| - The scaling governor can't be set for an offline CPU and frequency scaling |
| on newly enabled CPUs adds noise to both perf and tracing measurements. |
| |
| It appears Qualcomm is the only vendor that hot-plugs CPUs, and on Qualcomm |
| this is done by "mpdecision". |
| |
| """ |
| if self._have_mpdecision: |
| cmd = ['stop', 'mpdecision'] if force_online else ['start', 'mpdecision'] |
| self._device.RunShellCommand(cmd, check_return=True, as_root=True) |
| |
| if not self._have_mpdecision and not self._AllCpusAreOnline(): |
| logger.warning('Unexpected cpu hot plugging detected.') |
| |
| if force_online: |
| self._ForEachCpu('echo 1 > "$CPU/online"') |
