Purge unpinned ashmem before parsing /proc/$pid/smaps.

build/android/pylib/android_commands.py

Index: build/android/pylib/android_commands.py
diff --git a/build/android/pylib/android_commands.py b/build/android/pylib/android_commands.py
index 1741619276ce56042a9a3df6f3b004fed1ebe3ad..516fba2c32b6da774053ed3dc23b6c62be3f2c06 100644
--- a/build/android/pylib/android_commands.py
+++ b/build/android/pylib/android_commands.py
@@ -21,6 +21,9 @@ import time
 
 import cmd_helper
 import constants
+
+from utils import host_path_finder
+
 try:
   from pylib import pexpect
 except:
@@ -1409,6 +1412,19 @@ class AndroidCommands(object):
     logging.warning('Could not find disk IO stats.')
     return None
 
+  def PurgeUnpinnedAshmem(self):
+    """Purges the unpinned ashmem memory for the whole system.
+
+    This can be used to make memory measurements more stable in particular.
+    """
+    host_path = host_path_finder.GetMostRecentHostPath('purge_ashmem')
+    if host_path:
+      device_path = os.path.join(constants.TEST_EXECUTABLE_DIR, 'purge_ashmem')
+      self.PushIfNeeded(host_path, device_path)
+      if self.RunShellCommand(device_path, log_result=True):
+        return
+    logging.error('Could not purge ashmem. Measurement might be unstable.')

[frankf, 2013/11/05 19:22:56]

Generally, we're moving to make these methods more pythonic which means throwing
an exception that the caller can handle however they wish instead of just
logging error which might go unnoticed and lost in the noise.

[Philippe, 2013/11/06 16:51:09]

Done.

+
   def GetMemoryUsageForPid(self, pid):
     """Returns the memory usage for given pid.