LXR qemu/scripts/performance/topN

   1#!/usr/bin/env python3
   2
   3#  Print the top N most executed functions in QEMU using perf.
   4#  Syntax:
   5#  topN_perf.py [-h] [-n] <number of displayed top functions>  -- \
   6#           <qemu executable> [<qemu executable options>] \
   7#           <target executable> [<target execurable options>]
   8#
   9#  [-h] - Print the script arguments help message.
  10#  [-n] - Specify the number of top functions to print.
  11#       - If this flag is not specified, the tool defaults to 25.
  12#
  13#  Example of usage:
  14#  topN_perf.py -n 20 -- qemu-arm coulomb_double-arm
  15#
  16#  This file is a part of the project "TCG Continuous Benchmarking".
  17#
  18#  Copyright (C) 2020  Ahmed Karaman <ahmedkhaledkaraman@gmail.com>
  19#  Copyright (C) 2020  Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
  20#
  21#  This program is free software: you can redistribute it and/or modify
  22#  it under the terms of the GNU General Public License as published by
  23#  the Free Software Foundation, either version 2 of the License, or
  24#  (at your option) any later version.
  25#
  26#  This program is distributed in the hope that it will be useful,
  27#  but WITHOUT ANY WARRANTY; without even the implied warranty of
  28#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  29#  GNU General Public License for more details.
  30#
  31#  You should have received a copy of the GNU General Public License
  32#  along with this program. If not, see <https://www.gnu.org/licenses/>.
  33
  34import argparse
  35import os
  36import subprocess
  37import sys
  38
  39
  40# Parse the command line arguments
  41parser = argparse.ArgumentParser(
  42    usage='topN_perf.py [-h] [-n] <number of displayed top functions >  -- '
  43          '<qemu executable> [<qemu executable options>] '
  44          '<target executable> [<target executable options>]')
  45
  46parser.add_argument('-n', dest='top', type=int, default=25,
  47                    help='Specify the number of top functions to print.')
  48
  49parser.add_argument('command', type=str, nargs='+', help=argparse.SUPPRESS)
  50
  51args = parser.parse_args()
  52
  53# Extract the needed variables from the args
  54command = args.command
  55top = args.top
  56
  57# Insure that perf is installed
  58check_perf_presence = subprocess.run(["which", "perf"],
  59                                     stdout=subprocess.DEVNULL)
  60if check_perf_presence.returncode:
  61    sys.exit("Please install perf before running the script!")
  62
  63# Insure user has previllage to run perf
  64check_perf_executability = subprocess.run(["perf", "stat", "ls", "/"],
  65                                          stdout=subprocess.DEVNULL,
  66                                          stderr=subprocess.DEVNULL)
  67if check_perf_executability.returncode:
  68    sys.exit(
  69"""
  70Error:
  71You may not have permission to collect stats.
  72
  73Consider tweaking /proc/sys/kernel/perf_event_paranoid,
  74which controls use of the performance events system by
  75unprivileged users (without CAP_SYS_ADMIN).
  76
  77  -1: Allow use of (almost) all events by all users
  78      Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK
  79   0: Disallow ftrace function tracepoint by users without CAP_SYS_ADMIN
  80      Disallow raw tracepoint access by users without CAP_SYS_ADMIN
  81   1: Disallow CPU event access by users without CAP_SYS_ADMIN
  82   2: Disallow kernel profiling by users without CAP_SYS_ADMIN
  83
  84To make this setting permanent, edit /etc/sysctl.conf too, e.g.:
  85   kernel.perf_event_paranoid = -1
  86
  87* Alternatively, you can run this script under sudo privileges.
  88"""
  89)
  90
  91# Run perf record
  92perf_record = subprocess.run((["perf", "record", "--output=/tmp/perf.data"] +
  93                              command),
  94                             stdout=subprocess.DEVNULL,
  95                             stderr=subprocess.PIPE)
  96if perf_record.returncode:
  97    os.unlink('/tmp/perf.data')
  98    sys.exit(perf_record.stderr.decode("utf-8"))
  99
 100# Save perf report output to /tmp/perf_report.out
 101with open("/tmp/perf_report.out", "w") as output:
 102    perf_report = subprocess.run(
 103        ["perf", "report", "--input=/tmp/perf.data", "--stdio"],
 104        stdout=output,
 105        stderr=subprocess.PIPE)
 106    if perf_report.returncode:
 107        os.unlink('/tmp/perf.data')
 108        output.close()
 109        os.unlink('/tmp/perf_report.out')
 110        sys.exit(perf_report.stderr.decode("utf-8"))
 111
 112# Read the reported data to functions[]
 113functions = []
 114with open("/tmp/perf_report.out", "r") as data:
 115    # Only read lines that are not comments (comments start with #)
 116    # Only read lines that are not empty
 117    functions = [line for line in data.readlines() if line and line[0]
 118                 != '#' and line[0] != "\n"]
 119
 120# Limit the number of top functions to "top"
 121number_of_top_functions = top if len(functions) > top else len(functions)
 122
 123# Store the data of the top functions in top_functions[]
 124top_functions = functions[:number_of_top_functions]
 125
 126# Print table header
 127print('{:>4}  {:>10}  {:<30}  {}\n{}  {}  {}  {}'.format('No.',
 128                                                         'Percentage',
 129                                                         'Name',
 130                                                         'Invoked by',
 131                                                         '-' * 4,
 132                                                         '-' * 10,
 133                                                         '-' * 30,
 134                                                         '-' * 25))
 135
 136# Print top N functions
 137for (index, function) in enumerate(top_functions, start=1):
 138    function_data = function.split()
 139    function_percentage = function_data[0]
 140    function_name = function_data[-1]
 141    function_invoker = ' '.join(function_data[2:-2])
 142    print('{:>4}  {:>10}  {:<30}  {}'.format(index,
 143                                             function_percentage,
 144                                             function_name,
 145                                             function_invoker))
 146
 147# Remove intermediate files
 148os.unlink('/tmp/perf.data')
 149os.unlink('/tmp/perf_report.out')
 150