client/tests/btreplay/btreplay.py

import time
from autotest_lib.client.bin import test, os_dep, autotest_utils
from autotest_lib.client.common_lib import error, utils


class btreplay(test.test):
	version = 1

	# http://brick.kernel.dk/snaps/blktrace-git-latest.tar.gz
	def setup(self, tarball = 'blktrace-git-latest.tar.gz'):
		tarball = autotest_utils.unmap_url(self.bindir, tarball,
		                                   self.tmpdir)
		autotest_utils.extract_tarball_to_dir(tarball, self.srcdir)

		self.job.setup_dep(['libaio'])
		libs = '-L' + self.autodir + '/deps/libaio/lib -laio'
		cflags = '-I ' + self.autodir + '/deps/libaio/include'
		var_libs = 'LIBS="' + libs + '"'
		var_cflags  = 'CFLAGS="' + cflags + '"'
		self.make_flags = var_libs + ' ' + var_cflags

		os.chdir(self.srcdir)
		utils.system('patch -p1 < ../Makefile.patch')
		utils.system(self.make_flags + ' make')


	def initialize(self):
		self.ldlib = 'LD_LIBRARY_PATH=%s/deps/libaio/lib'%(self.autodir)

        
        def _run_btreplay(self, dev, devices, tmpdir, extra_args):
                alldevs="-d /dev/"+dev
                alldnames = dev
                for d in devices.split():
                        alldevs += " -d /dev/"+d
                        alldnames += " "+d

                # convert the trace (assumed to be in this test's base
                # directory) into btreplay's required format
                utils.system("./btreplay/btrecord -d .. -D "+tmpdir+" "+dev)

                # time a replay that omits "thinktime" between requests
                # (by use of the -N flag)
                utils.system(self.ldlib+" /usr/bin/time ./btreplay/btreplay -d "+\
                        tmpdir+" -N -W "+dev+" "+extra_args+" 2>&1")

                # trace a replay that reproduces inter-request delays, and
                # analyse the trace with btt to determine the average request
                # completion latency
                utils.system("./blktrace -D "+tmpdir+" "+alldevs+" >/dev/null &")
                utils.system(self.ldlib+" ./btreplay/btreplay -d "+tmpdir+" -W "+\
                        dev+" "+extra_args)
                utils.system("killall -INT blktrace")
		
		# wait until blktrace is really done
		slept = 0.0
		while utils.system("ps -C blktrace > /dev/null",
			     ignore_status=True) == 0:
			time.sleep(0.1)
			slept += 0.1
			if slept > 30.0:
				utils.system("killall -9 blktrace")
				raise error.TestError("blktrace failed to exit after 30 seconds")
                utils.system("./blkparse -q -D "+tmpdir+" -d "+tmpdir+\
                        "/trace.bin -O "+alldnames+" >/dev/null")
                utils.system("./btt/btt -i "+tmpdir+"/trace.bin")
        
	def execute(self, iterations = 1, dev="", devices="",
			extra_args = '', tmpdir = None):
                # @dev: The device against which the trace will be replayed.
                #       e.g. "sdb" or "md_d1"
                # @devices: A space-separated list of the underlying devices
                #    which make up dev, e.g. "sdb sdc". You only need to set
                #    devices if dev is an MD, LVM, or similar device;
                #    otherwise leave it as an empty string.

		if not tmpdir:
			tmpdir = self.tmpdir

		os.chdir(self.srcdir)

		profilers = self.job.profilers
		if not profilers.only():
			for i in range(iterations):
				self._run_btreplay(dev, devices, tmpdir, extra_args)

		# Do a profiling run if necessary
		if profilers.present():
			profilers.start(self)
			self._run_btreplay(dev, devices, tmpdir, extra_args)
			profilers.stop(self)
			profilers.report(self)

		self.job.stdout.filehandle.flush()
		self.__format_results(open(self.debugdir + '/stdout').read())


	def __format_results(self, results):
		out = open(self.resultsdir + '/keyval', 'w')
		lines = results.split('\n')

		for n in range(len(lines)):
			if lines[n].strip() == "==================== All Devices ====================":
				words = lines[n-2].split()
				s = words[1].strip('sytem').split(':')
				e = words[2].strip('elapsd').split(':')
				break

		systime = 0.0
		for n in range(len(s)):
			i = (len(s)-1) - n
			systime += float(s[i])*(60**n)
		elapsed = 0.0
		for n in range(len(e)):
			i = (len(e)-1) - n
			elapsed += float(e[i])*(60**n)

		q2c = 0.0
		for line in lines:
			words = line.split()
			if len(words) < 3:
				continue
			if words[0] == 'Q2C':
				q2c = float(words[2])
				break

		
		print >> out, """\
time=%f
systime=%f
avg_q2c_latency=%f
""" % (elapsed, systime, q2c)
		out.close()