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      1 # Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
      2 # Use of this source code is governed by a BSD-style license that can be
      3 # found in the LICENSE file.
      4 
      5 import logging
      6 
      7 from autotest_lib.client.bin import test
      8 from autotest_lib.client.common_lib import error, utils
      9 from autotest_lib.client.cros import service_stopper
     10 
     11 class hardware_MemoryThroughput(test.test):
     12     """Autotest for measuring memory throughput.
     13 
     14     This uses mem_bw with different parameters to measure memory and cache
     15     throughput.
     16 
     17     Private Attributes:
     18       _results: dict containing keyvals with throughput measurements
     19       _services: service_stopper.ServiceStopper object
     20     """
     21     version = 1
     22 
     23     def _run_benchmarks(self, test, warmup, num_iterations, parallel, sizes):
     24         """Run the benchmark.
     25 
     26         This runs the bw_mem benchmark from lmbench 3 and fills out results.
     27         Args:
     28           test: string containing either rd, rdwr, cp, bzero, or bcopy
     29           warmup:  integer amount of time to spend warming up in microseconds.
     30           num_iterations: integer number of times to run the benchmark on each
     31             size.
     32           parallel: integer number of instances to run in parallel
     33           sizes: list of integer sizes in bytes to run
     34         """
     35         r = {}
     36 
     37         for size in sizes:
     38             cmd = 'bw_mem -P %d -W %d -N %d %d %s 2>&1' % (parallel, warmup,
     39                                                            num_iterations,
     40                                                            size, test)
     41             logging.debug('cmd: %s', cmd)
     42             out = utils.system_output(cmd)
     43             logging.debug('Output: %s', out)
     44 
     45             lines = out.splitlines()
     46             if len(lines) != 1:
     47                 raise error.TestFail('invalid amount of output from bw_mem')
     48 
     49             s = lines[0].split()
     50             if len(s) == 2:
     51                 bw = float(s[1])
     52                 if bw <= 0:
     53                     raise error.TestFail('invalid throughput %f' % bw)
     54                 key = ('MB_per_second_' + test + '-' +
     55                        str(parallel) + '-thread-' +
     56                        str(size / 1024) + 'KB')
     57                 self._results[key] = bw
     58             else:
     59                 raise error.TestFail('invalid output line %s' % lines[0])
     60 
     61 
     62     def initialize(self):
     63         super(hardware_MemoryThroughput, self).initialize()
     64         self._results = {}
     65         stop = [ 'ui' ]
     66         stop.extend(service_stopper.ServiceStopper.POWER_DRAW_SERVICES)
     67         self._services = service_stopper.ServiceStopper(stop)
     68         self._services.stop_services()
     69 
     70 
     71     def run_once(self, test='bcopy', warmup=100, num_iterations=20,
     72                  parallel=1, sizes= [ 4096, 192 * 1024, 32 * 1024 * 1024 ]):
     73         self._run_benchmarks(test, warmup, num_iterations, parallel,
     74                              sizes)
     75         self.write_perf_keyval(self._results)
     76 
     77 
     78     def cleanup(self):
     79         self._services.restore_services()
     80         super(hardware_MemoryThroughput, self).cleanup()
     81