blob: 41cb5b94ed3abdaa13c8553f0211f3563775ff58 [file] [log] [blame]
Function tracer profiler for autotest.
@author: David Sharp (
import logging, os, signal, time
from autotest_lib.client.bin import profiler, utils
from autotest_lib.client.common_lib import error
class ftrace(profiler.profiler):
ftrace profiler for autotest. It builds ftrace from souce and runs
trace-cmd with configurable parameters.
@see: git://
version = 1
mountpoint = '/sys/kernel/debug'
tracing_dir = os.path.join(mountpoint, 'tracing')
def join_command(cmd):
Shell escape the command for BgJob. grmbl.
@param cmd: Command list.
result = []
for arg in cmd:
arg = '"%s"' % utils.sh_escape(arg)
result += [arg]
return ' '.join(result)
def setup(self, tarball='trace-cmd.tar.bz2', **kwargs):
Build and install trace-cmd from source.
The tarball was obtained by checking the git repo at 09-14-2010,
removing the Documentation and the .git folders, and compressing
@param tarball: Path to trace-cmd tarball.
@param **kwargs: Dictionary with additional parameters.
self.tarball = utils.unmap_url(self.bindir, tarball, self.tmpdir)
utils.extract_tarball_to_dir(self.tarball, self.srcdir)
utils.make("prefix='%s'" % self.builddir)
utils.make("prefix='%s' install" % self.builddir)
def initialize(self, tracepoints, buffer_size_kb=1408, **kwargs):
Initialize ftrace profiler.
@param tracepoints: List containing a mix of tracpoint names and
(tracepoint name, filter) tuples. Tracepoint names are as
accepted by trace-cmd -e, eg "syscalls", or
"syscalls:sys_enter_read". Filters are as accepted by
trace-cmd -f, eg "((sig >= 10 && sig < 15) || sig == 17)"
@param buffer_size_kb: Set the size of the ring buffer (per cpu).
self.trace_cmd_args = ['-b', str(buffer_size_kb)]
for tracepoint in tracepoints:
if isinstance(tracepoint, tuple):
tracepoint, event_filter = tracepoint
event_filter = None
self.trace_cmd_args += ['-e', tracepoint]
if event_filter:
self.trace_cmd_args += ['-f', event_filter]
self.builddir = os.path.join(self.bindir, 'build')
if not os.path.isdir(self.builddir):
self.trace_cmd = os.path.join(self.builddir, 'bin', 'trace-cmd')
def start(self, test):
Start ftrace profiler
@param test: Autotest test in which the profiler will operate on.
# Make sure debugfs is mounted and tracing disabled.
utils.system('%s reset' % self.trace_cmd)
output_dir = os.path.join(test.profdir, 'ftrace')
if not os.path.isdir(output_dir):
self.output = os.path.join(output_dir, 'trace.dat')
cmd = [self.trace_cmd, 'record', '-o', self.output]
cmd += self.trace_cmd_args
self.record_job = utils.BgJob(self.join_command(cmd),
# Wait for tracing to be enabled. If trace-cmd dies before enabling
# tracing, then there was a problem.
tracing_on = os.path.join(self.tracing_dir, 'tracing_on')
while (self.record_job.sp.poll() is None and
utils.read_file(tracing_on).strip() != '1'):
if self.record_job.sp.poll() is not None:
raise error.CmdError(self.record_job.command,
'trace-cmd exited early.')
def stop(self, test):
Stop ftrace profiler.
@param test: Autotest test in which the profiler will operate on.
os.kill(, signal.SIGINT)
# shrink the buffer to free memory.
utils.system('%s reset -b 1' % self.trace_cmd)
#compress output
utils.system('bzip2 %s' % self.output)
compressed_output = self.output + '.bz2'
# if the compressed trace file is large (10MB), just delete it.
compressed_output_size = os.path.getsize(compressed_output)
if compressed_output_size > 10*1024*1024:
logging.warning('Deleting large trace file %s (%d bytes)',
compressed_output, compressed_output_size)
# remove per-cpu files in case trace-cmd died.
utils.system('rm -f %s.cpu*' % self.output)