topN_perf.py (5888B)
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')