tools/android: Show the footprint of allocators in parse_smaps.py.

Adds an option to show the total footprint of an allocator (one of malloc(),
partition_alloc and V8) in parse_smaps.py.

Example output:
$ tools/android/native_lib_memory/parse_smaps.py --pid 12803 \
  --show-allocator-footprint partition_alloc
[...]
Footprint from partition_alloc: 13648 kB

Bug: 998048
Change-Id: I9b9b062565e56188979c43380a411bca0f2db282
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1781645
Commit-Queue: Benoit L <lizeb@chromium.org>
Reviewed-by: Egor Pasko <pasko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#693061}

tools/android/native_lib_memory/parse_smaps.py

@@ -21,6 +21,7 @@ from devil.android import device_utils
 
 class Mapping(object):
   """A single entry (mapping) in /proc/[pid]/smaps."""
+
   def __init__(self, start, end, permissions, offset, pathname):
     """Initializes an instance.
 
@@ -163,6 +164,17 @@ def _PrintSwapStats(mappings):
   _PrintMappingsMetric(mappings, 'Swap')
 
 
+def _FootprintForAnonymousMapping(mapping):
+  assert mapping.pathname.startswith('[anon:')
+  if (mapping.pathname == '[anon:libc_malloc]'
+      and mapping.fields['Shared_Dirty'] != 0):
+    # libc_malloc mappings can come from the zygote. In this case, the shared
+    # dirty memory is likely dirty in the zygote, don't count it.
+    return mapping.fields['Rss']
+  else:
+    return mapping.fields['Private_Dirty']
+
+
 def _PrintEstimatedFootprintStats(mappings, page_table_kb):
   print 'Private Dirty:'
   _PrintMappingsMetric(mappings, 'Private_Dirty')
@@ -178,7 +190,12 @@ def _PrintEstimatedFootprintStats(mappings, page_table_kb):
 
 
 def _ComputeEstimatedFootprint(mappings, page_table_kb):
-  """Returns the estimated footprint in kiB."""
+  """Returns the estimated footprint in kiB.
+
+  Args:
+    mappings: ([Mapping]) all process mappings.
+    page_table_kb: (int) Sizeof the page tables in kiB.
+  """
   footprint = page_table_kb
   for mapping in mappings:
     # Chrome shared memory.
@@ -187,12 +204,8 @@ def _ComputeEstimatedFootprint(mappings, page_table_kb):
     # account for its entirety.
     if mapping.pathname.startswith('/dev/ashmem/shared_memory'):
       footprint += mapping.fields['Rss']
-    elif mapping.pathname.startswith('[anon:libc_malloc]'):
-      if mapping.fields['Shared_Dirty'] == 0:
-        footprint += mapping.fields['Rss']
-      else:
-        footprint += mapping.fields['Private_Dirty']  # Shared dirty is likely
-                                                      # from the zygote.
+    elif mapping.pathname.startswith('[anon'):
+      footprint += _FootprintForAnonymousMapping(mapping)
     # Mappings without a name are most likely Chrome's native memory allocators:
     # v8, PartitionAlloc, Oilpan.
     # All of it should be charged to our process.
@@ -208,6 +221,21 @@ def _ComputeEstimatedFootprint(mappings, page_table_kb):
   return footprint
 
 
+def _ShowAllocatorFootprint(mappings, allocator):
+  """Shows the total footprint from a specific allocator.
+
+  Args:
+    mappings: ([Mapping]) all process mappings.
+    allocator: (str) Allocator name.
+  """
+  total_footprint = 0
+  pathname = '[anon:%s]' % allocator
+  for mapping in mappings:
+    if mapping.pathname == pathname:
+      total_footprint += _FootprintForAnonymousMapping(mapping)
+  print '\tFootprint from %s: %d kB' % (allocator, total_footprint)
+
+
 def _CreateArgumentParser():
   parser = argparse.ArgumentParser()
   parser.add_argument('--pid', help='PID.', required=True, type=int)
@@ -216,6 +244,10 @@ def _CreateArgumentParser():
                       action='store_true')
   parser.add_argument('--store-smaps', help='Store the smaps file locally',
                       action='store_true')
+  parser.add_argument('--show-allocator-footprint',
+                      help='Show the footprint from a given allocator',
+                      choices=['v8', 'libc_malloc', 'partition_alloc'],
+                      nargs='+')
   return parser
 
 
@@ -239,6 +271,11 @@ def main():
   else:
     _PrintSwapStats(mappings)
 
+  if args.show_allocator_footprint:
+    print '\n\nMemory Allocators footprint:'
+    for allocator in args.show_allocator_footprint:
+      _ShowAllocatorFootprint(mappings, allocator)
+
 
 if __name__ == '__main__':
   main()