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# Copyright 2013-2017 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
from __future__ import division
import os
from devlib import FtraceCollector
from wa import Instrument, Parameter
from wa.framework import signal
from wa.framework.instrument import very_slow
from wa.framework.exception import InstrumentError
from wa.utils.types import list_of_strings
from wa.utils.misc import which
OUTPUT_TRACE_FILE = 'trace.dat'
OUTPUT_TEXT_FILE = '{}.txt'.format(os.path.splitext(OUTPUT_TRACE_FILE)[0])
TIMEOUT = 180
class TraceCmdInstrument(Instrument):
name = 'trace-cmd'
description = """
trace-cmd is an instrument which interacts with ftrace Linux kernel internal
tracer
From trace-cmd man page:
trace-cmd command interacts with the ftrace tracer that is built inside the
Linux kernel. It interfaces with the ftrace specific files found in the
debugfs file system under the tracing directory.
trace-cmd reads a list of events it will trace, which can be specified in
the config file as follows ::
trace_events = ['irq*', 'power*']
If no event is specified, a default set of events that are generally considered useful
for debugging/profiling purposes will be enabled.
The list of available events can be obtained by rooting and running the
following command line on the device ::
trace-cmd list
You may also specify ``trace_buffer_size`` setting which must be an integer
that will be used to set the ftrace buffer size. It will be interpreted as
KB::
trace_cmd_buffer_size = 8000
The maximum buffer size varies from device to device, but there is a
maximum and trying to set buffer size beyond that will fail. If you plan
on collecting a lot of trace over long periods of time, the buffer size
will not be enough and you will only get trace for the last portion of your
run. To deal with this you can set the ``trace_mode`` setting to
``'record'`` (the default is ``'start'``)::
trace_cmd_mode = 'record'
This will cause trace-cmd to trace into file(s) on disk, rather than the
buffer, and so the limit for the max size of the trace is set by the
storage available on device. Bear in mind that ``'record'`` mode *is* more
intrusive than the default, so if you do not plan on generating a lot of
trace, it is best to use the default ``'start'`` mode.
.. note:: Mode names correspond to the underlying trace-cmd executable's
command used to implement them. You can find out more about what
is happening in each case from trace-cmd documentation:
https://lwn.net/Articles/341902/.
This instrument comes with an trace-cmd binary that will be copied and used
on the device, however post-processing will be, by default, done on-host and you must
have trace-cmd installed and in your path. On Ubuntu systems, this may be
done with::
sudo apt-get install trace-cmd
Alternatively, you may set ``report_on_target`` parameter to ``True`` to enable on-target
processing (this is useful when running on non-Linux hosts, but is likely to take longer
and may fail on particularly resource-constrained targets).
"""
parameters = [
Parameter('events', kind=list_of_strings,
default=['sched*', 'irq*', 'power*', 'thermal*'],
global_alias='trace_events',
description="""
Specifies the list of events to be traced. Each event in the
list will be passed to trace-cmd with -e parameter and must
be in the format accepted by trace-cmd.
"""),
Parameter('functions', kind=list_of_strings,
global_alias='trace_functions',
description="""
Specifies the list of functions to be traced.
"""),
Parameter('buffer_size', kind=int, default=None,
global_alias='trace_buffer_size',
description="""
Attempt to set ftrace buffer size to the specified value (in
KB). Default buffer size may need to be increased for
long-running workloads, or if a large number of events have
been enabled. Note: there is a maximum size that the buffer
can be set, and that varies from device to device. Attempting
to set buffer size higher than this will fail. In that case,
this instrument will set the size to the highest possible
value by going down from the specified size in
``buffer_size_step`` intervals.
"""),
Parameter('buffer_size_step', kind=int, default=1000,
global_alias='trace_buffer_size_step',
description="""
Defines the decremental step used if the specified
``buffer_size`` could not be set. This will be subtracted
form the buffer size until set succeeds or size is reduced to
1MB.
"""),
Parameter('report', kind=bool, default=True,
description="""
Specifies whether reporting should be performed once the
binary trace has been generated.
"""),
Parameter('no_install', kind=bool, default=False,
description="""
Do not install the bundled trace-cmd and use the one on the
device instead. If there is not already a trace-cmd on the
device, an error is raised.
"""),
Parameter('report_on_target', kind=bool, default=False,
description="""
When enabled generation of reports will be done host-side
because the generated file is very large. If trace-cmd is not
available on the host device this setting can be disabled and
the report will be generated on the target device.
.. note:: This requires the latest version of trace-cmd to be
installed on the host (the one in your
distribution's repos may be too old).
"""),
]
def __init__(self, target, **kwargs):
super(TraceCmdInstrument, self).__init__(target, **kwargs)
self.collector = None
def initialize(self, context):
if not self.target.is_rooted:
raise InstrumentError('trace-cmd instrument cannot be used on an unrooted device.')
collector_params = dict(
events=self.events,
functions=self.functions,
buffer_size=self.buffer_size,
buffer_size_step=1000,
automark=False,
autoreport=True,
autoview=False,
no_install=self.no_install,
strict=False,
report_on_target=False,
)
if self.report and self.report_on_target:
collector_params['autoreport'] = True
collector_params['report_on_target'] = True
else:
collector_params['autoreport'] = False
collector_params['report_on_target'] = False
self.collector = FtraceCollector(self.target, **collector_params)
# Register ourselves as absolute last event before and
# first after so we can mark the trace at the right time
signal.connect(self.mark_start, signal.BEFORE_WORKLOAD_EXECUTION, priority=11)
signal.connect(self.mark_stop, signal.AFTER_WORKLOAD_EXECUTION, priority=11)
def setup(self, context):
self.collector.reset()
@very_slow
def start(self, context):
self.collector.start()
@very_slow
def stop(self, context):
self.collector.stop()
def update_output(self, context): # NOQA pylint: disable=R0912
outfile = os.path.join(context.output_directory, 'trace.dat')
self.collector.get_trace(outfile)
context.add_artifact('trace-cmd-bin', outfile, 'data')
if self.report:
if not self.report_on_target:
textfile = os.path.join(context.output_directory, 'trace.txt')
self.collector.report(outfile, textfile)
context.add_artifact('trace-cmd-txt', textfile, 'export')
def teardown(self, context):
path = self.target.path.join(self.target.working_directory, OUTPUT_TRACE_FILE)
self.target.remove(path)
if self.report_on_target:
path = self.target.path.join(self.target.working_directory, OUTPUT_TEXT_FILE)
self.target.remove(path)
def validate(self):
if self.report and not self.report_on_target and not which('trace-cmd'):
raise InstrumentError('trace-cmd is not in PATH; is it installed?')
def mark_start(self, context):
if self.is_enabled:
self.collector.mark_start()
def mark_stop(self, context):
if self.is_enabled:
self.collector.mark_stop()
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