| #pylint: disable-msg=C0111 |
| |
| # Copyright (c) 2011 The Chromium OS 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 logging, os, platform, re, signal, tempfile, time, uuid |
| from autotest_lib.client.common_lib import error |
| from autotest_lib.client.common_lib import utils |
| |
| class TimeoutError(error.TestError): |
| """Error raised when we time out when waiting on a condition.""" |
| pass |
| |
| |
| class Crossystem(object): |
| """A wrapper for the crossystem utility.""" |
| |
| def __init__(self, client): |
| self.cros_system_data = {} |
| self._client = client |
| |
| def init(self): |
| self.cros_system_data = {} |
| (_, fname) = tempfile.mkstemp() |
| f = open(fname, 'w') |
| self._client.run('crossystem', stdout_tee=f) |
| f.close() |
| text = utils.read_file(fname) |
| for line in text.splitlines(): |
| assignment_string = line.split('#')[0] |
| if not assignment_string.count('='): |
| continue |
| (name, value) = assignment_string.split('=', 1) |
| self.cros_system_data[name.strip()] = value.strip() |
| os.remove(fname) |
| |
| def __getattr__(self, name): |
| """ |
| Retrieve a crosssystem attribute. |
| |
| The call crossystemobject.name() will return the crossystem reported |
| string. |
| """ |
| return lambda : self.cros_system_data[name] |
| |
| |
| def get_oldest_pid_by_name(name): |
| """ |
| Return the oldest pid of a process whose name perfectly matches |name|. |
| |
| name is an egrep expression, which will be matched against the entire name |
| of processes on the system. For example: |
| |
| get_oldest_pid_by_name('chrome') |
| |
| on a system running |
| 8600 ? 00:00:04 chrome |
| 8601 ? 00:00:00 chrome |
| 8602 ? 00:00:00 chrome-sandbox |
| |
| would return 8600, as that's the oldest process that matches. |
| chrome-sandbox would not be matched. |
| |
| Arguments: |
| name: egrep expression to match. Will be anchored at the beginning and |
| end of the match string. |
| |
| Returns: |
| pid as an integer, or None if one cannot be found. |
| |
| Raises: |
| ValueError if pgrep returns something odd. |
| """ |
| str_pid = utils.system_output( |
| 'pgrep -o ^%s$' % name, ignore_status=True).rstrip() |
| if str_pid: |
| return int(str_pid) |
| |
| |
| def get_oldest_by_name(name): |
| """Return pid and command line of oldest process whose name matches |name|. |
| |
| @param name: egrep expression to match desired process name. |
| @return: A tuple of (pid, command_line) of the oldest process whose name |
| matches |name|. |
| |
| """ |
| pid = get_oldest_pid_by_name(name) |
| if pid: |
| command_line = utils.system_output('ps -p %i -o command=' % pid, |
| ignore_status=True).rstrip() |
| return (pid, command_line) |
| |
| |
| def get_chrome_remote_debugging_port(): |
| """Returns remote debugging port for Chrome. |
| |
| Parse chrome process's command line argument to get the remote debugging |
| port. |
| """ |
| pid, command = get_oldest_by_name('chrome') |
| matches = re.search('--remote-debugging-port=([0-9]+)', command) |
| if matches: |
| return int(matches.group(1)) |
| |
| |
| def get_process_list(name, command_line=None): |
| """ |
| Return the list of pid for matching process |name command_line|. |
| |
| on a system running |
| 31475 ? 0:06 /opt/google/chrome/chrome --allow-webui-compositing - |
| 31478 ? 0:00 /opt/google/chrome/chrome-sandbox /opt/google/chrome/ |
| 31485 ? 0:00 /opt/google/chrome/chrome --type=zygote --log-level=1 |
| 31532 ? 1:05 /opt/google/chrome/chrome --type=renderer |
| |
| get_process_list('chrome') |
| would return ['31475', '31485', '31532'] |
| |
| get_process_list('chrome', '--type=renderer') |
| would return ['31532'] |
| |
| Arguments: |
| name: process name to search for. If command_line is provided, name is |
| matched against full command line. If command_line is not provided, |
| name is only matched against the process name. |
| command line: when command line is passed, the full process command line |
| is used for matching. |
| |
| Returns: |
| list of PIDs of the matching processes. |
| |
| """ |
| # TODO(rohitbm) crbug.com/268861 |
| flag = '-x' if not command_line else '-f' |
| name = '\'%s.*%s\'' % (name, command_line) if command_line else name |
| str_pid = utils.system_output( |
| 'pgrep %s %s' % (flag, name), ignore_status=True).rstrip() |
| return str_pid |
| |
| |
| def nuke_process_by_name(name, with_prejudice=False): |
| try: |
| pid = get_oldest_pid_by_name(name) |
| except Exception as e: |
| logging.error(e) |
| return |
| if pid is None: |
| raise error.AutoservPidAlreadyDeadError( |
| 'No process matching %s.' % name) |
| if with_prejudice: |
| utils.nuke_pid(pid, [signal.SIGKILL]) |
| else: |
| utils.nuke_pid(pid) |
| |
| |
| def poll_for_condition( |
| condition, exception=None, timeout=10, sleep_interval=0.1, desc=None): |
| """Poll until a condition becomes true. |
| |
| Arguments: |
| condition: function taking no args and returning bool |
| exception: exception to throw if condition doesn't become true |
| timeout: maximum number of seconds to wait |
| sleep_interval: time to sleep between polls |
| desc: description of default TimeoutError used if 'exception' is None |
| |
| Returns: |
| The true value that caused the poll loop to terminate. |
| |
| Raises: |
| 'exception' arg if supplied; site_utils.TimeoutError otherwise |
| """ |
| start_time = time.time() |
| while True: |
| value = condition() |
| if value: |
| return value |
| if time.time() + sleep_interval - start_time > timeout: |
| if exception: |
| logging.error(exception) |
| raise exception |
| |
| if desc: |
| desc = 'Timed out waiting for condition: %s' % desc |
| else: |
| desc = 'Timed out waiting for unnamed condition' |
| logging.error(desc) |
| raise TimeoutError, desc |
| |
| time.sleep(sleep_interval) |
| |
| |
| def save_vm_state(checkpoint): |
| """Saves the current state of the virtual machine. |
| |
| This function is a NOOP if the test is not running under a virtual machine |
| with the USB serial port redirected. |
| |
| Arguments: |
| checkpoint - Name used to identify this state |
| |
| Returns: |
| None |
| """ |
| # The QEMU monitor has been redirected to the guest serial port located at |
| # /dev/ttyUSB0. To save the state of the VM, we just send the 'savevm' |
| # command to the serial port. |
| proc = platform.processor() |
| if 'QEMU' in proc and os.path.exists('/dev/ttyUSB0'): |
| logging.info('Saving VM state "%s"', checkpoint) |
| serial = open('/dev/ttyUSB0', 'w') |
| serial.write("savevm %s\r\n" % checkpoint) |
| logging.info('Done saving VM state "%s"', checkpoint) |
| |
| |
| def check_raw_dmesg(dmesg, message_level, whitelist): |
| """Checks dmesg for unexpected warnings. |
| |
| This function parses dmesg for message with message_level <= message_level |
| which do not appear in the whitelist. |
| |
| Arguments: |
| dmesg - string containing raw dmesg buffer |
| message_level - minimum message priority to check |
| whitelist - messages to ignore |
| |
| Returns: |
| List of unexpected warnings |
| """ |
| whitelist_re = re.compile(r'(%s)' % '|'.join(whitelist)) |
| unexpected = [] |
| for line in dmesg.splitlines(): |
| if int(line[1]) <= message_level: |
| stripped_line = line.split('] ', 1)[1] |
| if whitelist_re.search(stripped_line): |
| continue |
| unexpected.append(stripped_line) |
| return unexpected |
| |
| def verify_mesg_set(mesg, regex, whitelist): |
| """Verifies that the exact set of messages are present in a text. |
| |
| This function finds all strings in the text matching a certain regex, and |
| then verifies that all expected strings are present in the set, and no |
| unexpected strings are there. |
| |
| Arguments: |
| mesg - the mutiline text to be scanned |
| regex - regular expression to match |
| whitelist - messages to find in the output, a list of strings |
| (potentially regexes) to look for in the filtered output. All these |
| strings must be there, and no other strings should be present in the |
| filtered output. |
| |
| Returns: |
| string of inconsistent findings (i.e. an empty string on success). |
| """ |
| |
| rv = [] |
| |
| missing_strings = [] |
| present_strings = [] |
| for line in mesg.splitlines(): |
| if not re.search(r'%s' % regex, line): |
| continue |
| present_strings.append(line.split('] ', 1)[1]) |
| |
| for string in whitelist: |
| for present_string in list(present_strings): |
| if re.search(r'^%s$' % string, present_string): |
| present_strings.remove(present_string) |
| break |
| else: |
| missing_strings.append(string) |
| |
| if present_strings: |
| rv.append('unexpected strings:') |
| rv.extend(present_strings) |
| if missing_strings: |
| rv.append('missing strings:') |
| rv.extend(missing_strings) |
| |
| return '\n'.join(rv) |
| |
| |
| def target_is_pie(): |
| """Returns whether the toolchain produces a PIE (position independent |
| executable) by default. |
| |
| Arguments: |
| None |
| |
| Returns: |
| True if the target toolchain produces a PIE by default. |
| False otherwise. |
| """ |
| |
| |
| command = 'echo | ${CC} -E -dD -P - | grep -i pie' |
| result = utils.system_output(command, retain_output=True, |
| ignore_status=True) |
| if re.search('#define __PIE__', result): |
| return True |
| else: |
| return False |
| |
| def target_is_x86(): |
| """Returns whether the toolchain produces an x86 object |
| |
| Arguments: |
| None |
| |
| Returns: |
| True if the target toolchain produces an x86 object |
| False otherwise. |
| """ |
| |
| |
| command = 'echo | ${CC} -E -dD -P - | grep -i 86' |
| result = utils.system_output(command, retain_output=True, |
| ignore_status=True) |
| if re.search('__i386__', result) or re.search('__x86_64__', result): |
| return True |
| else: |
| return False |
| |
| def mounts(): |
| ret = [] |
| for line in file('/proc/mounts'): |
| m = re.match(r'(?P<src>\S+) (?P<dest>\S+) (?P<type>\S+) (?P<opts>\S+).*', line) |
| if m: |
| ret.append(m.groupdict()) |
| return ret |
| |
| def is_mountpoint(path): |
| return path in [ m['dest'] for m in mounts() ] |
| |
| def require_mountpoint(path): |
| """ |
| Raises an exception if path is not a mountpoint. |
| """ |
| if not is_mountpoint(path): |
| raise error.TestFail('Path not mounted: "%s"' % path) |
| |
| def random_username(): |
| return str(uuid.uuid4()) + '@example.com' |
| |
| |
| def parse_cmd_output(command, run_method=utils.run): |
| """Runs a command on a host object to retrieve host attributes. |
| |
| The command should output to stdout in the format of: |
| <key> = <value> # <optional_comment> |
| |
| |
| @param command: Command to execute on the host. |
| @param run_method: Function to use to execute the command. Defaults to |
| utils.run so that the command will be executed locally. |
| Can be replace with a host.run call so that it will |
| execute on a DUT or external machine. Method must accept |
| a command argument, stdout_tee and stderr_tee args and |
| return a result object with a string attribute stdout |
| which will be parsed. |
| |
| @returns a dictionary mapping host attributes to their values. |
| """ |
| result = {} |
| # Suppresses stdout so that the files are not printed to the logs. |
| cmd_result = run_method(command, stdout_tee=None, stderr_tee=None) |
| for line in cmd_result.stdout.splitlines(): |
| # Lines are of the format "<key> = <value> # <comment>" |
| key_value = re.match('^\s*(?P<key>[^ ]+)\s*=\s*(?P<value>[^ ]+)' |
| '(?:\s*#.*)?$', line) |
| if key_value: |
| result[key_value.group('key')] = key_value.group('value') |
| return result |
| |
| |
| def set_from_keyval_output(out, delimiter=' '): |
| """Parse delimiter-separated key-val output into a set of tuples. |
| |
| Output is expected to be multiline text output from a command. |
| Stuffs the key-vals into tuples in a set to be later compared. |
| |
| e.g. deactivated 0 |
| disableForceClear 0 |
| ==> set(('deactivated', '0'), ('disableForceClear', '0')) |
| |
| @param out: multiple lines of space-separated key-val pairs. |
| @param delimiter: character that separates key from val. Usually a |
| space but may be '=' or something else. |
| @return set of key-val tuples. |
| """ |
| results = set() |
| kv_match_re = re.compile('([^ ]+)%s(.*)' % delimiter) |
| for linecr in out.splitlines(): |
| match = kv_match_re.match(linecr.strip()) |
| if match: |
| results.add((match.group(1), match.group(2))) |
| return results |
| |
| |
| def get_cpu_usage(): |
| """Returns machine's CPU usage. |
| |
| This function uses /proc/stat to identify CPU usage. |
| Returns: |
| A dictionary with 'user', 'nice', 'system' and 'idle' values. |
| Sample dictionary: |
| { |
| 'user': 254544, |
| 'nice': 9, |
| 'system': 254768, |
| 'idle': 2859878, |
| } |
| """ |
| proc_stat = open('/proc/stat') |
| cpu_usage_str = proc_stat.readline().split() |
| proc_stat.close() |
| return { |
| 'user': int(cpu_usage_str[1]), |
| 'nice': int(cpu_usage_str[2]), |
| 'system': int(cpu_usage_str[3]), |
| 'idle': int(cpu_usage_str[4]) |
| } |
| |
| |
| def compute_active_cpu_time(cpu_usage_start, cpu_usage_end): |
| """Computes the fraction of CPU time spent non-idling. |
| |
| This function should be invoked using before/after values from calls to |
| get_cpu_usage(). |
| """ |
| time_active_end = (cpu_usage_end['user'] + cpu_usage_end['nice'] + |
| cpu_usage_end['system']) |
| time_active_start = (cpu_usage_start['user'] + cpu_usage_start['nice'] + |
| cpu_usage_start['system']) |
| total_time_end = (cpu_usage_end['user'] + cpu_usage_end['nice'] + |
| cpu_usage_end['system'] + cpu_usage_end['idle']) |
| total_time_start = (cpu_usage_start['user'] + cpu_usage_start['nice'] + |
| cpu_usage_start['system'] + cpu_usage_start['idle']) |
| return ((float(time_active_end) - time_active_start) / |
| (total_time_end - total_time_start)) |
| |
| |
| def is_pgo_mode(): |
| return 'USE_PGO' in os.environ |
| |
| |
| def wait_for_idle_cpu(timeout, utilization): |
| """Waits for the CPU to become idle (< utilization). |
| |
| Args: |
| timeout: The longest time in seconds to wait before throwing an error. |
| utilization: The CPU usage below which the system should be considered |
| idle (between 0 and 1.0 independent of cores/hyperthreads). |
| """ |
| time_passed = 0.0 |
| fraction_active_time = 1.0 |
| sleep_time = 1 |
| logging.info('Starting to wait up to %.1fs for idle CPU...', timeout) |
| while fraction_active_time >= utilization: |
| cpu_usage_start = get_cpu_usage() |
| # Split timeout interval into not too many chunks to limit log spew. |
| # Start at 1 second, increase exponentially |
| time.sleep(sleep_time) |
| time_passed += sleep_time |
| sleep_time = min(16.0, 2.0 * sleep_time) |
| cpu_usage_end = get_cpu_usage() |
| fraction_active_time = \ |
| compute_active_cpu_time(cpu_usage_start, cpu_usage_end) |
| logging.info('After waiting %.1fs CPU utilization is %.3f.', |
| time_passed, fraction_active_time) |
| if time_passed > timeout: |
| logging.warning('CPU did not become idle.') |
| log_process_activity() |
| # crosbug.com/37389 |
| if is_pgo_mode(): |
| logging.info('Still continuing because we are in PGO mode.') |
| return True |
| |
| return False |
| logging.info('Wait for idle CPU took %.1fs (utilization = %.3f).', |
| time_passed, fraction_active_time) |
| return True |
| |
| |
| def log_process_activity(): |
| """Logs the output of top. |
| |
| Useful to debug performance tests and to find runaway processes. |
| """ |
| logging.info('Logging current process activity using top.') |
| cmd = 'top -b -n1 -c' |
| output = utils.run(cmd) |
| logging.info(output) |
| |
| |
| def wait_for_cool_machine(): |
| # TODO(ihf): Implement this. The concept of a cool machine is very |
| # architecture specific. We either need a good heuristic or a table of |
| # board specific temperatures. |
| time.sleep(1.0) |
| return True |
| |
| |
| # System paths for machine performance state. |
| _CPUINFO = '/proc/cpuinfo' |
| _KERNEL_MAX = '/sys/devices/system/cpu/kernel_max' |
| _MEMINFO = '/proc/meminfo' |
| _TEMP_SENSOR_RE = 'Reading temperature...([0-9]*)' |
| |
| |
| def _get_line_from_file(path, line): |
| """ |
| line can be an integer or |
| line can be a string that matches the beginning of the line |
| """ |
| f = open(path) |
| if (isinstance(line, int)): |
| l = f.readline() |
| for _ in range(0, line): |
| l = f.readline() |
| return l |
| else: |
| for l in f: |
| if l.startswith(line): |
| return l |
| return None |
| |
| |
| def _get_match_from_file(path, line, prefix, postfix): |
| """ |
| Matches line in path and returns string between first prefix and postfix. |
| """ |
| match = _get_line_from_file(path, line) |
| # Strip everything from front of line including prefix. |
| if prefix: |
| match = re.split(prefix, match)[1] |
| # Strip everything from back of string including first occurence of postfix. |
| if postfix: |
| match = re.split(postfix, match)[0] |
| return match |
| |
| |
| def _get_float_from_file(path, line, prefix, postfix): |
| match = _get_match_from_file(path, line, prefix, postfix) |
| return float(match) |
| |
| |
| def _get_int_from_file(path, line, prefix, postfix): |
| match = _get_match_from_file(path, line, prefix, postfix) |
| return int(match) |
| |
| |
| def _get_hex_from_file(path, line, prefix, postfix): |
| match = _get_match_from_file(path, line, prefix, postfix) |
| return int(match, 16) |
| |
| |
| def _get_hwmon_paths(file_pattern): |
| """ |
| Returns a list of paths to the temperature sensors. |
| """ |
| # Some systems like daisy_spring only have the virtual hwmon. |
| # And other systems like rambi only have coretemp.0. See crbug.com/360249. |
| # /sys/class/hwmon/hwmon*/ |
| # /sys/devices/virtual/hwmon/hwmon*/ |
| # /sys/devices/platform/coretemp.0/ |
| cmd = 'find /sys/ -name "' + file_pattern + '"' |
| paths = utils.run(cmd, verbose=False).stdout.splitlines() |
| return paths |
| |
| |
| def get_temperature_critical(): |
| """ |
| Returns temperature at which we will see some throttling in the system. |
| """ |
| min_temperature = 1000.0 |
| paths = _get_hwmon_paths('temp*_crit') |
| for path in paths: |
| temperature = _get_float_from_file(path, 0, None, None) * 0.001 |
| # Today typical for Intel is 98'C to 105'C while ARM is 85'C. Clamp to |
| # the lowest known value. |
| if ((min_temperature < 60.0) or min_temperature > 150.0): |
| min_temperature = 85.0 |
| |
| min_temperature = min(temperature, min_temperature) |
| return min_temperature |
| |
| |
| def get_temperature_input_max(): |
| """ |
| Returns the maximum currently observed temperature. |
| """ |
| max_temperature = -1000.0 |
| paths = _get_hwmon_paths('temp*_input') |
| for path in paths: |
| temperature = _get_float_from_file(path, 0, None, None) * 0.001 |
| max_temperature = max(temperature, max_temperature) |
| # Sanity check for real world values. |
| assert ((max_temperature > 10.0) and |
| (max_temperature < 150.0)), 'Unreasonable temperature.' |
| return max_temperature |
| |
| |
| def get_ec_temperatures(): |
| """ |
| Uses ectool to return a list of all sensor temperatures in Celsius. |
| """ |
| temperatures = [] |
| # TODO(ihf): On all ARM boards I tested 'ectool temps all' returns 200K |
| # for all sensors. Remove this check once crbug.com/358342 is fixed. |
| if 'arm' in utils.get_arch(): |
| return temperatures |
| try: |
| full_cmd = 'ectool temps all' |
| lines = utils.run(full_cmd, verbose=False).stdout.splitlines() |
| for line in lines: |
| temperature = int(line.split(': ')[1]) - 273 |
| temperatures.append(temperature) |
| except Exception: |
| logging.warn('Unable to read temperature sensors using ectool.') |
| for temperature in temperatures: |
| # Sanity check for real world values. |
| assert ((temperature > 10.0) and |
| (temperature < 150.0)), 'Unreasonable temperature.' |
| return temperatures |
| |
| |
| def get_cpu_cache_size(): |
| """ |
| Returns the last level CPU cache size in kBytes. |
| """ |
| cache_size = _get_int_from_file(_CPUINFO, 'cache size', ': ', ' KB') |
| # Sanity check. |
| assert cache_size >= 64, 'Unreasonably small cache.' |
| return cache_size |
| |
| |
| def get_cpu_model_frequency(): |
| """ |
| Returns the model frequency from the CPU model name on Intel only. This |
| might be redundant with get_cpu_max_frequency. Unit is Hz. |
| """ |
| frequency = _get_float_from_file(_CPUINFO, 'model name', ' @ ', 'GHz') |
| return 1.e9 * frequency |
| |
| |
| def get_cpu_max_frequency(): |
| """ |
| Returns the largest of the max CPU core frequencies. The unit is Hz. |
| """ |
| max_frequency = -1 |
| paths = _get_cpufreq_paths('cpuinfo_max_freq') |
| for path in paths: |
| # Convert from kHz to Hz. |
| frequency = 1000 * _get_float_from_file(path, 0, None, None) |
| max_frequency = max(frequency, max_frequency) |
| # Sanity check. |
| assert max_frequency > 1e8, 'Unreasonably low CPU frequency.' |
| return max_frequency |
| |
| |
| def get_cpu_min_frequency(): |
| """ |
| Returns the smallest of the minimum CPU core frequencies. |
| """ |
| min_frequency = 1e20 |
| paths = _get_cpufreq_paths('cpuinfo_min_freq') |
| for path in paths: |
| frequency = _get_float_from_file(path, 0, None, None) |
| min_frequency = min(frequency, min_frequency) |
| # Sanity check. |
| assert min_frequency > 1e8, 'Unreasonably low CPU frequency.' |
| return min_frequency |
| |
| |
| def get_cpu_model(): |
| """ |
| Returns the CPU model. |
| Only works on Intel. |
| """ |
| cpu_model = _get_int_from_file(_CPUINFO, 'model\t', ': ', None) |
| return cpu_model |
| |
| |
| def get_cpu_family(): |
| """ |
| Returns the CPU family. |
| Only works on Intel. |
| """ |
| cpu_family = _get_int_from_file(_CPUINFO, 'cpu family\t', ': ', None) |
| return cpu_family |
| |
| |
| def get_board(): |
| """ |
| Get the ChromeOS release board name from /etc/lsb-release. |
| """ |
| f = open('/etc/lsb-release') |
| try: |
| return re.search('BOARD=(.*)', f.read()).group(1) |
| finally: |
| f.close() |
| |
| |
| def get_board_with_frequency_and_memory(): |
| """ |
| Returns a board name modified with CPU frequency and memory size to |
| differentiate between different board variants. For instance |
| link -> link_1.8GHz_4GB. |
| """ |
| board_name = get_board() |
| # Rounded to nearest GB and GHz. |
| memory = int(round(get_mem_total()/1024.0)) |
| # Convert frequency to GHz with 1 digit accuracy after the decimal point. |
| frequency = int(round(get_cpu_max_frequency() * 1e-8)) * 0.1 |
| board = "%s_%1.1fGHz_%dGB" % (board_name, frequency, memory) |
| return board |
| |
| |
| def get_mem_total(): |
| """ |
| Returns the total memory available in the system in MBytes. |
| """ |
| mem_total = _get_float_from_file(_MEMINFO, 'MemTotal:', 'MemTotal:', ' kB') |
| # Sanity check, all Chromebooks have at least 1GB of memory. |
| assert mem_total > 1024*1024, 'Unreasonable amount of memory.' |
| return mem_total / 1024 |
| |
| |
| def get_mem_free(): |
| """ |
| Returns the currently free memory in the system in MBytes. |
| """ |
| mem_free = _get_float_from_file(_MEMINFO, 'MemFree:', 'MemFree:', ' kB') |
| return mem_free / 1024 |
| |
| |
| def get_kernel_max(): |
| """ |
| Returns content of kernel_max. |
| """ |
| kernel_max = _get_int_from_file(_KERNEL_MAX, 0, None, None) |
| # Sanity check. |
| assert ((kernel_max > 0) and (kernel_max < 257)), 'Unreasonable kernel_max.' |
| return kernel_max |
| |
| |
| def set_high_performance_mode(): |
| """ |
| Sets the kernel governor mode to the highest setting. |
| Returns previous governor state. |
| """ |
| original_governors = get_scaling_governor_states() |
| set_scaling_governors('performance') |
| return original_governors |
| |
| |
| def set_scaling_governors(value): |
| """ |
| Sets all scaling governor to string value. |
| Sample values: 'performance', 'interactive', 'ondemand', 'powersave'. |
| """ |
| paths = _get_cpufreq_paths('scaling_governor') |
| for path in paths: |
| cmd = 'sudo echo %s > %s' % (value, path) |
| logging.info('Writing scaling governor mode \'%s\' -> %s', value, path) |
| utils.system(cmd) |
| |
| |
| def _get_cpufreq_paths(filename): |
| """ |
| Returns a list of paths to the governors. |
| """ |
| cmd = 'ls /sys/devices/system/cpu/cpu*/cpufreq/' + filename |
| paths = utils.run(cmd, verbose=False).stdout.splitlines() |
| return paths |
| |
| |
| def get_scaling_governor_states(): |
| """ |
| Returns a list of (performance governor path, current state) tuples. |
| """ |
| paths = _get_cpufreq_paths('scaling_governor') |
| path_value_list = [] |
| for path in paths: |
| value = _get_line_from_file(path, 0) |
| path_value_list.append((path, value)) |
| return path_value_list |
| |
| |
| def restore_scaling_governor_states(path_value_list): |
| """ |
| Restores governor states. Inverse operation to get_scaling_governor_states. |
| """ |
| for (path, value) in path_value_list: |
| cmd = 'sudo echo %s > %s' % (value, path) |
| utils.system(cmd) |
