Analyze contiguous physical memory chunks that mmap system call gives

physmem_alloc_analysis/physmem_alloc_analyzer.py

Index: physmem_alloc_analysis/physmem_alloc_analyzer.py
diff --git a/physmem_alloc_analysis/physmem_alloc_analyzer.py b/physmem_alloc_analysis/physmem_alloc_analyzer.py
new file mode 100644
index 0000000000000000000000000000000000000000..a60558130c4c46ec29a085ddce0f499c7fe1b9ab
--- /dev/null
+++ b/physmem_alloc_analysis/physmem_alloc_analyzer.py
@@ -0,0 +1,60 @@
+# Copyright 2015, Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+import operator
+
+
+def ExtractBits(val, offset_in_bits, size_in_bits):

[Mark Seaborn, 2015/07/01 19:21:23]

Not used; can be removed.

[ruiq, 2015/07/01 20:42:59]

Done.

+  return [(val >> offset_in_bits) & ((1 << size_in_bits) - 1),
+    size_in_bits]
+
+
+def GetResultPfns(log_filename):
+  for line in open(log_filename):
+    parts = line.strip('\n')[:-1].split(' ');
+    yield [int(part, 16) for part in parts]
+
+
+def Main():
+  counter = 0

[Mark Seaborn, 2015/07/01 19:21:23]

Not used

[ruiq, 2015/07/01 20:42:59]

Done.

+  cont_count = {}
+  for pfns in GetResultPfns('physmem_alloc_results'):
+    i1 = 0
+    i2 = 0
+    while i2 < len(pfns):
+      while i2 + 1 < len(pfns) and pfns[i2+1] - pfns[i2] == 1:
+        i2 += 1
+      size = i2 - i1 + 1
+      cont_count.setdefault(size, 0)
+      cont_count[size] += 1
+      i2 += 1
+      i1 = i2
+
+  total_pages = 0
+  for size, count in cont_count.iteritems():
+    total_pages += size * count
+  cont_fraction = {}

[Mark Seaborn, 2015/07/01 19:21:22]

I don't think you need to build another dict for this, do you?

It would be clearer to compute this fraction in the last "for" loop.

[ruiq, 2015/07/01 20:42:59]

Done.

+  for size, count in cont_count.iteritems():
+    cont_fraction[size] = 1.0 * size * count / total_pages
+
+  sorted_by_size = sorted(cont_fraction.items(), key=operator.itemgetter(0))

[Mark Seaborn, 2015/07/01 19:21:22]

Note that this is equivalent to:
sorted_by_size = sorted(cont_fraction.items())

because of how Python sorts tuples.

[ruiq, 2015/07/01 20:42:59]

Done.

+  for size, fraction in sorted_by_size:
+    count = cont_count[size]
+    size_total = size * count
+    print "%10d %10d %10d %10.2f" % (size, count, size_total, fraction)

[Mark Seaborn, 2015/07/01 19:21:22]

Nit: be consistent about whether you use ' or " for strings

[ruiq, 2015/07/01 20:42:59]

Done.

+
+
+if __name__ == '__main__':
+  Main()