Android: adds device affinity for perf tests.

build/android/test_runner.py

 #!/usr/bin/env python
 #
 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Runs all types of tests from one unified interface."""
 
 import collections
 import logging
@@ skipping 615 matching lines @@
       num_retries=options.num_retries)
 
   report_results.LogFull(
       results=results,
       test_type='Monkey',
       test_package='Monkey')
 
   return exit_code
 
 
-def _RunPerfTests(options, args, error_func, devices):
+def _RunPerfTests(options, args, error_func):
   """Subcommand of RunTestsCommands which runs perf tests."""
   perf_options = ProcessPerfTestOptions(options, args, error_func)
   # Just print the results from a single previously executed step.
   if perf_options.print_step:
     return perf_test_runner.PrintTestOutput(perf_options.print_step)
 
-  runner_factory, tests = perf_setup.Setup(perf_options)
+  runner_factory, tests, devices = perf_setup.Setup(perf_options)
 
+  # shard=False means that each device will get the full list of tests
+  # and then each one will decide their own affinity.
+  # shard=True means each device will pop the next test available from a queue,
+  # which increases throughput but have no affinity.
   results, _ = test_dispatcher.RunTests(
-      tests, runner_factory, devices, shard=True, test_timeout=None,
+      tests, runner_factory, devices, shard=False, test_timeout=None,
       num_retries=options.num_retries)
 
   report_results.LogFull(
       results=results,
       test_type='Perf',
       test_package='Perf')
 
   if perf_options.single_step:
     return perf_test_runner.PrintTestOutput('single_step')
 
@@ skipping 67 matching lines @@
     return _RunGTests(options, devices)
   elif command == 'linker':
     return _RunLinkerTests(options, devices)
   elif command == 'instrumentation':
     return _RunInstrumentationTests(options, option_parser.error, devices)
   elif command == 'uiautomator':
     return _RunUIAutomatorTests(options, option_parser.error, devices)
   elif command == 'monkey':
     return _RunMonkeyTests(options, option_parser.error, devices)
   elif command == 'perf':
-    return _RunPerfTests(options, args, option_parser.error, devices)
+    return _RunPerfTests(options, args, option_parser.error)
   else:
     raise Exception('Unknown test type.')
 
 
 def HelpCommand(command, _options, args, option_parser):
   """Display help for a certain command, or overall help.
 
   Args:
     command: String indicating the command that was received to trigger
         this function.
@@ skipping 60 matching lines @@
 
 def main():
   signal.signal(signal.SIGUSR1, DumpThreadStacks)
   option_parser = command_option_parser.CommandOptionParser(
       commands_dict=VALID_COMMANDS)
   return command_option_parser.ParseAndExecute(option_parser)
 
 
 if __name__ == '__main__':
   sys.exit(main())