scripts/performance/topN_perf.py

   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
  34 import argparse
  35 import os
  36 import subprocess
  37 import sys
  38
  39
  40 # Parse the command line arguments
  41 parser = 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
  46 parser.add_argument('-n', dest='top', type=int, default=25,
  47                     help='Specify the number of top functions to print.')
  48
  49 parser.add_argument('command', type=str, nargs='+', help=argparse.SUPPRESS)
  50
  51 args = parser.parse_args()
  52
  53 # Extract the needed variables from the args
  54 command = args.command
  55 top = args.top
  56
  57 # Insure that perf is installed
  58 check_perf_presence = subprocess.run(["which", "perf"],
  59                                      stdout=subprocess.DEVNULL)
  60 if check_perf_presence.returncode:
  61     sys.exit("Please install perf before running the script!")
  62
  63 # Insure user has previllage to run perf
  64 check_perf_executability = subprocess.run(["perf", "stat", "ls", "/"],
  65                                           stdout=subprocess.DEVNULL,
  66                                           stderr=subprocess.DEVNULL)
  67 if check_perf_executability.returncode:
  68     sys.exit(
  69 """
  70 Error:
  71 You may not have permission to collect stats.
  72
  73 Consider tweaking /proc/sys/kernel/perf_event_paranoid,
  74 which controls use of the performance events system by
  75 unprivileged 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
  84 To 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
  92 perf_record = subprocess.run((["perf", "record", "--output=/tmp/perf.data"] +
  93                               command),
  94                              stdout=subprocess.DEVNULL,
  95                              stderr=subprocess.PIPE)
  96 if 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
 101 with 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[]
 113 functions = []
 114 with 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"
 121 number_of_top_functions = top if len(functions) > top else len(functions)
 122
 123 # Store the data of the top functions in top_functions[]
 124 top_functions = functions[:number_of_top_functions]
 125
 126 # Print table header
 127 print('{:>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
 137 for (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
 148 os.unlink('/tmp/perf.data')
 149 os.unlink('/tmp/perf_report.out')