# Copyright 2013-2018 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 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 self.logger.info('Extracting trace from target...') 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: textfile = os.path.join(context.output_directory, 'trace.txt') if not self.report_on_target: 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()