Telemetry: Linux-based backends should return CPU results in seconds, not jiffies.

Review URL: https://codereview.chromium.org/684713003

Cr-Commit-Position: refs/heads/master@{#302004}

tools/telemetry/telemetry/core/platform/android_platform_backend_unittest.py

@@ -33,7 +33,7 @@ class AndroidPlatformBackendTest(unittest.TestCase):
     backend = android_platform_backend.AndroidPlatformBackend(
         android_device.AndroidDevice('12345'))
     cpu_stats = backend.GetCpuStats('7702')
-    self.assertEquals(cpu_stats, {'CpuProcessTime': 5.0})
+    self.assertEquals(cpu_stats, {'CpuProcessTime': 0.05})
 
   @benchmark.Disabled('chromeos')
   def testGetCpuStatsInvalidPID(self):

tools/telemetry/telemetry/core/platform/linux_based_platform_backend.py

@@ -14,7 +14,9 @@ from telemetry.core.platform import platform_backend
 
 class LinuxBasedPlatformBackend(platform_backend.PlatformBackend):
 
-  """Abstract platform containing functionality shared by all linux based OSes.
+  """Abstract platform containing functionality shared by all Linux based OSes.
+
+  This includes Android and ChromeOS.
 
   Subclasses must implement RunCommand, GetFileContents, GetPsOutput, and
   ParseCStateSample."""
@@ -38,19 +40,23 @@ class LinuxBasedPlatformBackend(platform_backend.PlatformBackend):
     return self._ConvertKbToByte(meminfo['MemTotal'])
 
   def GetCpuStats(self, pid):
+    results = {}
     stats = self._GetProcFileForPid(pid, 'stat')
     if not stats:
-      return {}
+      return results
     stats = stats.split()
     utime = float(stats[13])
     stime = float(stats[14])
     cpu_process_jiffies = utime + stime
-    return {'CpuProcessTime': cpu_process_jiffies}
+    clock_ticks = self.GetClockTicks()
+    results.update({'CpuProcessTime': cpu_process_jiffies / clock_ticks})
+    return results
 
   def GetCpuTimestamp(self):
     timer_list = self.GetFileContents('/proc/timer_list')
     total_jiffies = float(self._GetProcJiffies(timer_list))
-    return {'TotalTime': total_jiffies}
+    clock_ticks = self.GetClockTicks()
+    return {'TotalTime': total_jiffies / clock_ticks}
 
   def GetMemoryStats(self, pid):
     status_contents = self._GetProcFileForPid(pid, 'status')
@@ -84,6 +90,16 @@ class LinuxBasedPlatformBackend(platform_backend.PlatformBackend):
             'ReadTransferCount': int(io['rchar']),
             'WriteTransferCount': int(io['wchar'])}
 
+  @decorators.Cache
+  def GetClockTicks(self):
+    """Returns the number of clock ticks per second.
+
+    The proper way is to call os.sysconf('SC_CLK_TCK') but that is not easy to
+    do on Android/CrOS. In practice, nearly all Linux machines have a USER_HZ
+    of 100, so just return that.
+    """
+    return 100
+
   def GetFileContents(self, filename):
     raise NotImplementedError()
 

tools/telemetry/telemetry/core/platform/linux_based_platform_backend_unittest.py

@@ -23,21 +23,45 @@ class TestBackend(linux_based_platform_backend.LinuxBasedPlatformBackend):
   def GetFileContents(self, filename):
     return self._mock_files[filename]
 
+  def GetClockTicks(self):
+    return 41
+
 
 class LinuxBasedPlatformBackendTest(unittest.TestCase):
 
+  def SetMockFileInBackend(self, backend, real_file, mock_file):
+    with open(os.path.join(util.GetUnittestDataDir(), real_file)) as f:
+      backend.SetMockFile(mock_file, f.read())
+
+  def testGetCpuStatsBasic(self):
+    if not linux_based_platform_backend.resource:
+      logging.warning('Test not supported')
+      return
+
+    backend = TestBackend()
+    self.SetMockFileInBackend(backend, 'stat', '/proc/1/stat')
+    result = backend.GetCpuStats(1)
+    self.assertEquals(result, {'CpuProcessTime': 22.0})
+
+  def testGetCpuTimestampBasic(self):
+    if not linux_based_platform_backend.resource:
+      logging.warning('Test not supported')
+      return
+
+    backend = TestBackend()
+    self.SetMockFileInBackend(backend, 'timer_list', '/proc/timer_list')
+    result = backend.GetCpuTimestamp()
+    self.assertEquals(result, {'TotalTime': 105054633.0})
+
   def testGetMemoryStatsBasic(self):
     if not linux_based_platform_backend.resource:
       logging.warning('Test not supported')
       return
 
     backend = TestBackend()
-    with open(os.path.join(util.GetUnittestDataDir(), 'stat')) as f:
-      backend.SetMockFile('/proc/1/stat', f.read())
-    with open(os.path.join(util.GetUnittestDataDir(), 'status')) as f:
-      backend.SetMockFile('/proc/1/status', f.read())
-    with open(os.path.join(util.GetUnittestDataDir(), 'smaps')) as f:
-      backend.SetMockFile('/proc/1/smaps', f.read())
+    self.SetMockFileInBackend(backend, 'stat', '/proc/1/stat')
+    self.SetMockFileInBackend(backend, 'status', '/proc/1/status')
+    self.SetMockFileInBackend(backend, 'smaps', '/proc/1/smaps')
     result = backend.GetMemoryStats(1)
     self.assertEquals(result, {'PrivateDirty': 5324800,
                                'VM': 1025978368,
@@ -51,12 +75,9 @@ class LinuxBasedPlatformBackendTest(unittest.TestCase):
       return
 
     backend = TestBackend()
-    with open(os.path.join(util.GetUnittestDataDir(), 'stat')) as f:
-      backend.SetMockFile('/proc/1/stat', f.read())
-    with open(os.path.join(util.GetUnittestDataDir(), 'status_nohwm')) as f:
-      backend.SetMockFile('/proc/1/status', f.read())
-    with open(os.path.join(util.GetUnittestDataDir(), 'smaps')) as f:
-      backend.SetMockFile('/proc/1/smaps', f.read())
+    self.SetMockFileInBackend(backend, 'stat', '/proc/1/stat')
+    self.SetMockFileInBackend(backend, 'status_nohwm', '/proc/1/status')
+    self.SetMockFileInBackend(backend, 'smaps', '/proc/1/smaps')
     result = backend.GetMemoryStats(1)
     self.assertEquals(result, {'PrivateDirty': 5324800,
                                'VM': 1025978368,

tools/telemetry/unittest_data/timer_list

+Timer List Version: v0.7
+HRTIMER_MAX_CLOCK_BASES: 4
+now at 49390649032656 nsecs
+
+cpu: 0
+ clock 0:
+  .base:       0000000000000000
+  .index:      0
+  .resolution: 1 nsecs
+  .get_time:   ktime_get
+  .offset:     0 nsecs
+active timers:
+ #0: <0000000000000000>, hrtimer_wakeup, S:01, schedule_hrtimeout_range_clock, census_census_h/2343
+ # expires at 49390651724646-49390651774646 nsecs [in 2691990 to 2741990 nsecs]
+ #1: <0000000000000000>, hrtimer_wakeup, S:01, schedule_hrtimeout_range_clock, census_census_h/3680
+ # expires at 49390656983466-49390657033466 nsecs [in 7950810 to 8000810 nsecs]
+ clock 1:
+  .base:       0000000000000000
+  .index:      1
+  .resolution: 1 nsecs
+  .get_time:   ktime_get_real
+  .offset:     1414432541083798144 nsecs
+active timers:
+ #0: <0000000000000000>, hrtimer_wakeup, S:01, hrtimer_start_range_ns, mysqld/27245
+ # expires at 1414481934522781000-1414481934522831000 nsecs [in 1414432543873748344 to 1414432543873798344 nsecs]
+ #1: <0000000000000000>, hrtimer_wakeup, S:01, hrtimer_start_range_ns, DNS Res~ver #14/21520
+ # expires at 1414482222918140000-1414482222918190000 nsecs [in 1414432832269107344 to 1414432832269157344 nsecs]
+ clock 2:
+  .base:       0000000000000000
+  .index:      2
+  .resolution: 1 nsecs
+  .get_time:   ktime_get_boottime
+  .offset:     0 nsecs
+active timers:
+ clock 3:
+  .base:       0000000000000000
+  .index:      3
+  .resolution: 1 nsecs
+  .get_time:   ktime_get_clocktai
+  .offset:     1414432541083798144 nsecs
+active timers:
+  .expires_next   : 49390651774646 nsecs
+  .hres_active    : 1
+  .nr_events      : 9793846
+  .nr_retries     : 580
+  .nr_hangs       : 0
+  .max_hang_time  : 0 nsecs
+  .nohz_mode      : 2
+  .last_tick      : 49390648000000 nsecs
+  .tick_stopped   : 1
+  .idle_jiffies   : 4307239958
+  .idle_calls     : 16879086
+  .idle_sleeps    : 15799778
+  .idle_entrytime : 49390647721066 nsecs
+  .idle_waketime  : 49390647714831 nsecs
+  .idle_exittime  : 49390647489308 nsecs
+  .idle_sleeptime : 44326049938322 nsecs
+  .iowait_sleeptime: 1007311574977 nsecs
+  .last_jiffies   : 4307239958
+  .next_jiffies   : 4307239968
+  .idle_expires   : 49390684000000 nsecs
+jiffies: 4307239953