Telemetry / Memory benchmark fix: Separate histograms for different tests.

build/android/pylib/perf_tests_helper.py

 # Copyright (c) 2012 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.
 
 import re
 import sys
 
 import android_commands
 import json
 import math
@@ skipping 38 matching lines @@
   return geom_mean, math.sqrt(sum_of_squares / count)
 
 
 def _MeanAndStdDevFromList(values):
   avg = None
   sd = None
   if len(values) > 1:
     try:
       value = '[%s]' % ','.join([str(v) for v in values])
       avg = sum([float(v) for v in values]) / len(values)
       sqdiffs = [(float(v) - avg) ** 2 for v in values]

[nduca, 2013/02/13 18:45:55]

yeah, this shouldn't be in android... this library doesn't import cleanly on
windows for instance. perf only accidentally has a dependency on build/android
--- it shouuld only ever be *used* via telemetry.

can you copy the needed funcs from here into histogram.py direct?

[marja, 2013/02/14 13:06:53]

This function is used by PrintPerfResult, it needs to somehow be able to print
histogram results... Not sure what to do about this function. PrintPerfResult
shouldn't be here either. :/ (I left this alone in this CL.)

       variance = sum(sqdiffs) / (len(values) - 1)
       sd = math.sqrt(variance)
     except ValueError:
       value = ", ".join(values)
   else:
     value = values[0]
   return value, avg, sd
 
+def SubtractHistogram(histogram_json, start_histogram_json):

[marja, 2013/02/14 13:06:53]

And I moved this one away now.

+  """Subtracts a previous histogram from a histogram. Both parameters are json
+  serializations of histograms."""
+  histogram = json.loads(histogram_json)
+  start_histogram = json.loads(start_histogram_json)
+
+  start_histogram_buckets = dict()
+  for b in start_histogram['buckets']:
+    start_histogram_buckets[b['low']] = b['count']
+
+  new_buckets = []
+  for b in histogram['buckets']:
+    new_bucket = b
+    low = b['low']
+    if low in start_histogram_buckets:
+      new_bucket['count'] = b['count'] - start_histogram_buckets[low]
+    if new_bucket['count']:
+      new_buckets.append(new_bucket)
+  histogram['buckets'] = new_buckets
+  histogram['count'] -= start_histogram['count']
+
+  return json.dumps(histogram)
 
 def PrintPerfResult(measurement, trace, values, units, result_type='default',
                     print_to_stdout=True):
   """Prints numerical data to stdout in the format required by perf tests.
 
   The string args may be empty but they must not contain any colons (:) or
   equals signs (=).
 
   Args:
     measurement: A description of the quantity being measured, e.g. "vm_peak".
@@ skipping 82 matching lines @@
     """Tears down performance tests."""
     if self._original_scaling_governor:
       self._SetScalingGovernorInternal(self._original_scaling_governor)
     self._original_scaling_governor = None
 
   def _SetScalingGovernorInternal(self, value):
     for cpu in range(self._kernel_max + 1):
       scaling_governor_file = PerfTestSetup._SCALING_GOVERNOR_FMT % cpu
       if self._adb.FileExistsOnDevice(scaling_governor_file):
         self._adb.SetProtectedFileContents(scaling_governor_file, value)