# Copyright 2013-2015 ARM Limited
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# pylint: disable=W0613,E1101,W0201
import os
import re
import itertools
from wlauto import Instrument, Executable, Parameter
from wlauto.exceptions import ConfigError
from wlauto.utils.misc import ensure_file_directory_exists as _f
from wlauto.utils.types import arguments, list_of_strs
PERF_COMMAND_TEMPLATE = '{} stat {} {} sleep 1000 > {} 2>&1 '
DEVICE_RESULTS_FILE = '/data/local/perf_results.txt'
HOST_RESULTS_FILE_BASENAME = 'perf.txt'
PERF_COUNT_REGEX = re.compile(r'^\s*(\d+)\s*(.*?)\s*(\[\s*\d+\.\d+%\s*\])?\s*$')
class PerfInstrument(Instrument):
name = 'perf'
description = """
Perf is a Linux profiling with performance counters.
Performance counters are CPU hardware registers that count hardware events
such as instructions executed, cache-misses suffered, or branches
mispredicted. They form a basis for profiling applications to trace dynamic
control flow and identify hotspots.
pref accepts options and events. If no option is given the default '-a' is
used. For events, the default events are migrations and cs. They both can
be specified in the config file.
Events must be provided as a list that contains them and they will look like
this ::
perf_events = ['migrations', 'cs']
Events can be obtained by typing the following in the command line on the
device ::
perf list
Whereas options, they can be provided as a single string as following ::
perf_options = '-a -i'
Options can be obtained by running the following in the command line ::
man perf-record
"""
parameters = [
Parameter('events', kind=list_of_strs, default=['migrations', 'cs'],
global_alias='perf_events',
constraint=(lambda x: x, 'must not be empty.'),
description="""Specifies the events to be counted."""),
Parameter('optionstring', kind=arguments, default='-a',
global_alias='perf_options',
description="""Specifies options to be used for the perf command. This
may be a list of option strings, in which case, multiple instances of perf
will be kicked off -- one for each option string. This may be used to e.g.
collected different events from different big.LITTLE clusters.
"""),
Parameter('labels', kind=list_of_strs, default=None,
global_alias='perf_labels',
description="""Provides labels for pref output. If specified, the number of
labels must match the number of ``optionstring``\ s.
"""),
]
def on_run_init(self, context):
if not self.device.is_installed('perf'):
binary = context.resolver.get(Executable(self, self.device.abi, 'perf'))
self.device.install(binary)
self.commands = self._build_commands()
def setup(self, context):
self._clean_device()
def start(self, context):
for command in self.commands:
self.device.kick_off(command)
def stop(self, context):
self.device.killall('sleep')
def update_result(self, context):
for label in self.labels:
device_file = self._get_device_outfile(label)
host_relpath = os.path.join('perf', os.path.basename(device_file))
host_file = _f(os.path.join(context.output_directory, host_relpath))
self.device.pull_file(device_file, host_file)
context.add_iteration_artifact(label, kind='raw', path=host_relpath)
with open(host_file) as fh:
in_results_section = False
for line in fh:
if 'Performance counter stats' in line:
in_results_section = True
fh.next() # skip the following blank line
if in_results_section:
if not line.strip(): # blank line
in_results_section = False
break
else:
line = line.split('#')[0] # comment
match = PERF_COUNT_REGEX.search(line)
if match:
count = int(match.group(1))
metric = '{}_{}'.format(label, match.group(2))
context.result.add_metric(metric, count)
def teardown(self, context): # pylint: disable=R0201
self._clean_device()
def validate(self):
if isinstance(self.optionstring, list):
self.optionstrings = self.optionstring
else:
self.optionstrings = [self.optionstring]
if isinstance(self.events[0], list): # we know events are non-empty due to param constraint pylint: disable=access-member-before-definition
self.events = self.events
else:
self.events = [self.events]
if not self.labels: # pylint: disable=E0203
self.labels = ['perf_{}'.format(i) for i in xrange(len(self.optionstrings))]
if not len(self.labels) == len(self.optionstrings):
raise ConfigError('The number of labels must match the number of optstrings provided for perf.')
def _build_commands(self):
events = itertools.cycle(self.events)
commands = []
for opts, label in itertools.izip(self.optionstrings, self.labels):
commands.append(self._build_perf_command(opts, events.next(), label))
return commands
def _clean_device(self):
for label in self.labels:
filepath = self._get_device_outfile(label)
self.device.delete_file(filepath)
def _get_device_outfile(self, label):
return self.device.path.join(self.device.working_directory, '{}.out'.format(label))
def _build_perf_command(self, options, events, label):
event_string = ' '.join(['-e {}'.format(e) for e in events])
command = PERF_COMMAND_TEMPLATE.format('perf',
options or '',
event_string,
self._get_device_outfile(label))
return command