[Telemetry] Add memory and IO stats to page cycler

tools/telemetry/telemetry/core/chrome/linux_platform_backend.py

Index: tools/telemetry/telemetry/core/chrome/linux_platform_backend.py
diff --git a/tools/telemetry/telemetry/core/chrome/linux_platform_backend.py b/tools/telemetry/telemetry/core/chrome/linux_platform_backend.py
new file mode 100644
index 0000000000000000000000000000000000000000..9c4267aac4f26c911bd4c086a26fc5e3e3e41808
--- /dev/null
+++ b/tools/telemetry/telemetry/core/chrome/linux_platform_backend.py
@@ -0,0 +1,71 @@
+# Copyright (c) 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.
+
+try:
+  import resource  # pylint: disable=F0401
+except ImportError:
+  resource = None  # Not available on all platforms
+import subprocess
+
+from telemetry.core.chrome import platform_backend
+
+
+class LinuxPlatformBackend(platform_backend.PlatformBackend):
+  def _GetProcFileDict(self, filename):
+    retval = {}
+    with open(filename, 'r') as f:
+      for line in f.readlines():
+        line = line.strip()
+        key_val = line.split(':')
+        assert len(key_val) == 2
+        try:
+          retval[key_val[0]] = int(key_val[1].replace('kB', ''))
+        except Exception:
+          pass
+    return retval
+
+  # pylint: disable=W0613
+  def StartRawDisplayFrameRateMeasurement(self, trace_tag):
+    raise NotImplementedError()
+
+  def StopRawDisplayFrameRateMeasurement(self):
+    raise NotImplementedError()
+
+  def IsThermallyThrottled(self):
+    raise NotImplementedError()
+
+  def HasBeenThermallyThrottled(self):
+    raise NotImplementedError()
+
+  def GetSystemCommitCharge(self):
+    meminfo = self._GetProcFileDict('/proc/meminfo')
+    return (meminfo['MemTotal'] - meminfo['MemFree'] - meminfo['Buffers'] -
+            meminfo['Cached'])
+
+  def GetMemoryStats(self, pid):
+    status = self._GetProcFileDict('/proc/%s/status' % pid)
+    stats = open('/proc/%s/stat' % pid, 'r').read().split(' ')
+    return {'VM': int(stats[22]),
+            'VMPeak': status['VmPeak'] * 1024,
+            'WorkingSetSize': int(stats[23]) * resource.getpagesize(),
+            'WorkingSetSizePeak': status['VmHWM'] * 1024}
+
+  def GetIOStats(self, pid):
+    io = self._GetProcFileDict('/proc/%s/io' % pid)
+    return {'ReadOperationCount': io['syscr'],
+            'WriteOperationCount': io['syscw'],
+            'ReadTransferCount': io['rchar'],
+            'WriteTransferCount': io['wchar']}
+
+  def GetChildPids(self, pid):
+    """Retunds a list of child pids of |pid|."""
+    child_pids = []
+    pid_ppid_list = subprocess.Popen(['ps', '-e', '-o', 'pid=', '-o', 'ppid='],
+                                     stdout=subprocess.PIPE).communicate()[0]
+    for pid_ppid in pid_ppid_list.splitlines():
+      curr_pid, curr_ppid = pid_ppid.split()
+      if int(curr_ppid) == pid:
+        child_pids.append(int(curr_pid))
+        child_pids.extend(self.GetChildPids(int(curr_pid)))
+    return child_pids