tools/power/mach_commands.py

   1 # This Source Code Form is subject to the terms of the Mozilla Public
   2 # License, v. 2.0. If a copy of the MPL was not distributed with this
   3 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   4
   5 from mach.decorators import Command, CommandArgument
   6 from packaging.version import Version
   7
   8
   9 def is_osx_10_10_or_greater(cls):
  10     import platform
  11
  12     release = platform.mac_ver()[0]
  13     return release and Version(release) >= Version("10.10")
  14
  15
  16 # Get system power consumption and related measurements.
  17 @Command(
  18     "power",
  19     category="misc",
  20     conditions=[is_osx_10_10_or_greater],
  21     description="Get system power consumption and related measurements for "
  22     "all running browsers. Available only on Mac OS X 10.10 and above. "
  23     "Requires root access.",
  24 )
  25 @CommandArgument(
  26     "-i",
  27     "--interval",
  28     type=int,
  29     default=30000,
  30     help="The sample period, measured in milliseconds. Defaults to 30000.",
  31 )
  32 def power(command_context, interval):
  33     """
  34     Get system power consumption and related measurements.
  35     """
  36     import os
  37     import re
  38     import subprocess
  39
  40     rapl = os.path.join(command_context.topobjdir, "dist", "bin", "rapl")
  41
  42     interval = str(interval)
  43
  44     # Run a trivial command with |sudo| to gain temporary root privileges
  45     # before |rapl| and |powermetrics| are called. This ensures that |rapl|
  46     # doesn't start measuring while |powermetrics| is waiting for the root
  47     # password to be entered.
  48     try:
  49         subprocess.check_call(["sudo", "true"])
  50     except Exception:
  51         print("\nsudo failed; aborting")
  52         return 1
  53
  54     # This runs rapl in the background because nothing in this script
  55     # depends on the output. This is good because we want |rapl| and
  56     # |powermetrics| to run at the same time.
  57     subprocess.Popen([rapl, "-n", "1", "-i", interval])
  58
  59     lines = subprocess.check_output(
  60         [
  61             "sudo",
  62             "powermetrics",
  63             "--samplers",
  64             "tasks",
  65             "--show-process-coalition",
  66             "--show-process-gpu",
  67             "-n",
  68             "1",
  69             "-i",
  70             interval,
  71         ],
  72         universal_newlines=True,
  73     )
  74
  75     # When run with --show-process-coalition, |powermetrics| groups outputs
  76     # into process coalitions, each of which has a leader.
  77     #
  78     # For example, when Firefox runs from the dock, its coalition looks
  79     # like this:
  80     #
  81     #   org.mozilla.firefox
  82     #     firefox
  83     #     plugin-container
  84     #
  85     # When Safari runs from the dock:
  86     #
  87     #   com.apple.Safari
  88     #     Safari
  89     #     com.apple.WebKit.Networking
  90     #     com.apple.WebKit.WebContent
  91     #     com.apple.WebKit.WebContent
  92     #
  93     # When Chrome runs from the dock:
  94     #
  95     #   com.google.Chrome
  96     #     Google Chrome
  97     #     Google Chrome Helper
  98     #     Google Chrome Helper
  99     #
 100     # In these cases, we want to print the whole coalition.
 101     #
 102     # Also, when you run any of them from the command line, things are the
 103     # same except that the leader is com.apple.Terminal and there may be
 104     # non-browser processes in the coalition, e.g.:
 105     #
 106     #  com.apple.Terminal
 107     #    firefox
 108     #    plugin-container
 109     #    <and possibly other, non-browser processes>
 110     #
 111     # Also, the WindowServer and kernel coalitions and processes are often
 112     # relevant.
 113     #
 114     # We want to print all these but omit uninteresting coalitions. We
 115     # could do this by properly parsing powermetrics output, but it's
 116     # simpler and more robust to just grep for a handful of identifying
 117     # strings.
 118
 119     print()  # blank line between |rapl| output and |powermetrics| output
 120
 121     for line in lines.splitlines():
 122         # Search for the following things.
 123         #
 124         # - '^Name' is for the columns headings line.
 125         #
 126         # - 'firefox' and 'plugin-container' are for Firefox
 127         #
 128         # - 'Safari\b' and 'WebKit' are for Safari. The '\b' excludes
 129         #   SafariCloudHistoryPush, which is a process that always
 130         #   runs, even when Safari isn't open.
 131         #
 132         # - 'Chrome' is for Chrome.
 133         #
 134         # - 'Terminal' is for the terminal. If no browser is running from
 135         #   within the terminal, it will show up unnecessarily. This is a
 136         #   minor disadvantage of this very simple parsing strategy.
 137         #
 138         # - 'WindowServer' is for the WindowServer.
 139         #
 140         # - 'kernel' is for the kernel.
 141         #
 142         if re.search(
 143             r"(^Name|firefox|plugin-container|Safari\b|WebKit|Chrome|Terminal|WindowServer|kernel)",  # NOQA: E501
 144             line,
 145         ):
 146             print(line)
 147
 148     return 0