instruments/perf: Port the perf instrument to WA3

wa/instruments/perf.py

@@ -0,0 +1,138 @@
+#    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=unused-argument
+import os
+import re
+
+from devlib.trace.perf import PerfCollector
+
+from wa import Instrument, Parameter
+from wa.utils.types import list_or_string, list_of_strs
+
+PERF_COUNT_REGEX = re.compile(r'^(CPU\d+)?\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-stat
+    """
+
+    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=list_or_string, 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.
+                  """),
+        Parameter('force_install', kind=bool, default=False,
+                  description="""
+                  always install perf binary even if perf is already present on the device.
+                  """),
+    ]
+
+    def __init__(self, target, **kwargs):
+        super(PerfInstrument, self).__init__(target, **kwargs)
+        self.collector = None
+
+    def initialize(self, context):
+        self.collector = PerfCollector(self.target,
+                                       self.events,
+                                       self.optionstring,
+                                       self.labels,
+                                       self.force_install)
+
+    def setup(self, context):
+        self.collector.reset()
+
+    def start(self, context):
+        self.collector.start()
+
+    def stop(self, context):
+        self.collector.stop()
+
+    def update_output(self, context):
+        self.logger.info('Extracting reports from target...')
+        outdir = os.path.join(context.output_directory, 'perf')
+        self.collector.get_trace(outdir)
+
+        for host_file in os.listdir(outdir):
+            label = host_file.split('.out')[0]
+            host_file_path = os.path.join(outdir, host_file)
+            context.add_artifact(label, host_file_path, 'raw')
+            with open(host_file_path) as fh:
+                in_results_section = False
+                for line in fh:
+                    if 'Performance counter stats' in line:
+                        in_results_section = True
+                        next(fh)  # 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:
+                                classifiers = {}
+                                cpu = match.group(1)
+                                if cpu is not None:
+                                    classifiers['cpu'] = int(cpu.replace('CPU', ''))
+                                count = int(match.group(2))
+                                metric = '{}_{}'.format(label, match.group(3))
+                                context.add_metric(metric, count, classifiers=classifiers)
+
+    def teardown(self, context):
+        self.collector.reset()