Merge remote branch 'cros/upstream' into tempbranch3

client/profilers/ftrace/ftrace.py

+"""
+Function tracer profiler for autotest.
+
+@author: David Sharp (dhsharp@google.com)
+"""
+import logging, os, signal, time
+from autotest_lib.client.bin import profiler, utils
+
+
+class ftrace(profiler.profiler):
+    """
+    ftrace profiler for autotest. It builds ftrace from souce and runs
+    trace-cmd with configurable parameters.
+
+    @see: git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/trace-cmd.git
+    """
+    version = 1
+
+    mountpoint = '/sys/kernel/debug'
+    tracing_dir = os.path.join(mountpoint, 'tracing')
+
+    @staticmethod
+    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
+        it.
+
+        @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)
+        os.chdir(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.job.require_gcc()
+        self.trace_cmd_args = ['-b', str(buffer_size_kb)]
+        for tracepoint in tracepoints:
+            if isinstance(tracepoint, tuple):
+                tracepoint, event_filter = tracepoint
+            else:
+                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):
+            os.makedirs(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):
+            os.makedirs(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),
+                                      stderr_tee=utils.TEE_TO_LOGS)
+
+        # 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'):
+            time.sleep(0.1)
+        if self.record_job.sp.poll() is not None:
+            utils.join_bg_jobs([self.record_job])
+            raise error.CmdError(self.record_job.command,
+                                 self.record_job.sp.returncode,
+                                 'trace-cmd exited early.')
+
+    def stop(self, test):
+        """
+        Stop ftrace profiler.
+
+        @param test: Autotest test in which the profiler will operate on.
+        """
+        os.kill(self.record_job.sp.pid, signal.SIGINT)
+        utils.join_bg_jobs([self.record_job])
+        # 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.warn('Deleting large trace file %s (%d bytes)',
+                         compressed_output, compressed_output_size)
+            os.remove(compressed_output)
+        # remove per-cpu files in case trace-cmd died.
+        utils.system('rm -f %s.cpu*' % self.output)