build/android/pylib/perf/cache_control.py

   1 # Copyright 2013 The Chromium 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 from pylib import android_commands
   6 from pylib.device import device_utils
   7
   8 class CacheControl(object):
   9   _DROP_CACHES = '/proc/sys/vm/drop_caches'
  10
  11   def __init__(self, device):
  12     # TODO(jbudorick) Remove once telemetry gets switched over.
  13     if isinstance(device, android_commands.AndroidCommands):
  14       device = device_utils.DeviceUtils(device)
  15     self._device = device
  16
  17   def DropRamCaches(self):
  18     """Drops the filesystem ram caches for performance testing."""
  19     self._device.RunShellCommand('sync', as_root=True)
  20     self._device.WriteFile(CacheControl._DROP_CACHES, '3', as_root=True)
  21