scripts/performance: Add topN_perf.py script

Syntax:
topN_perf.py [-h] [-n] <number of displayed top functions>  -- \
                 <qemu executable> [<qemu executable options>] \
                 <target executable> [<target execurable options>]

[-h] - Print the script arguments help message.
[-n] - Specify the number of top functions to print.
     - If this flag is not specified, the tool defaults to 25.

Example of usage:
topN_perf.py -n 20 -- qemu-arm coulomb_double-arm

Example Output:
 No.  Percentage  Name                       Invoked by
----  ----------  -------------------------  -------------------------
   1      16.25%  float64_mul                qemu-x86_64
   2      12.01%  float64_sub                qemu-x86_64
   3      11.99%  float64_add                qemu-x86_64
   4       5.69%  helper_mulsd               qemu-x86_64
   5       4.68%  helper_addsd               qemu-x86_64
   6       4.43%  helper_lookup_tb_ptr       qemu-x86_64
   7       4.28%  helper_subsd               qemu-x86_64
   8       2.71%  f64_compare                qemu-x86_64
   9       2.71%  helper_ucomisd             qemu-x86_64
  10       1.04%  helper_pand_xmm            qemu-x86_64
  11       0.71%  float64_div                qemu-x86_64
  12       0.63%  helper_pxor_xmm            qemu-x86_64
  13       0.50%  0x00007f7b7004ef95         [JIT] tid 491
  14       0.50%  0x00007f7b70044e83         [JIT] tid 491
  15       0.36%  helper_por_xmm             qemu-x86_64
  16       0.32%  helper_cc_compute_all      qemu-x86_64
  17       0.30%  0x00007f7b700433f0         [JIT] tid 491
  18       0.30%  float64_compare_quiet      qemu-x86_64
  19       0.27%  soft_f64_addsub            qemu-x86_64
  20       0.26%  round_to_int               qemu-x86_64

Signed-off-by: Ahmed Karaman <ahmedkhaledkaraman@gmail.com>
Signed-off-by: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Reviewed-by: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Message-Id: <20200626164546.22102-2-ahmedkhaledkaraman@gmail.com>

1 files changed, 149 insertions, 0 deletions

diff --git a/scripts/performance/topN_perf.py b/scripts/performance/topN_perf.py
new file mode 100755
index 0000000000..07be195fc8
--- /dev/null
+++ b/scripts/performance/topN_perf.py
@@ -0,0 +1,149 @@
+#!/usr/bin/env python3
+
+#  Print the top N most executed functions in QEMU using perf.
+#  Syntax:
+#  topN_perf.py [-h] [-n] <number of displayed top functions>  -- \
+#           <qemu executable> [<qemu executable options>] \
+#           <target executable> [<target execurable options>]
+#
+#  [-h] - Print the script arguments help message.
+#  [-n] - Specify the number of top functions to print.
+#       - If this flag is not specified, the tool defaults to 25.
+#
+#  Example of usage:
+#  topN_perf.py -n 20 -- qemu-arm coulomb_double-arm
+#
+#  This file is a part of the project "TCG Continuous Benchmarking".
+#
+#  Copyright (C) 2020  Ahmed Karaman <ahmedkhaledkaraman@gmail.com>
+#  Copyright (C) 2020  Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
+#
+#  This program is free software: you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation, either version 2 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+import argparse
+import os
+import subprocess
+import sys
+
+
+# Parse the command line arguments
+parser = argparse.ArgumentParser(
+    usage='topN_perf.py [-h] [-n] <number of displayed top functions >  -- '
+          '<qemu executable> [<qemu executable options>] '
+          '<target executable> [<target executable options>]')
+
+parser.add_argument('-n', dest='top', type=int, default=25,
+                    help='Specify the number of top functions to print.')
+
+parser.add_argument('command', type=str, nargs='+', help=argparse.SUPPRESS)
+
+args = parser.parse_args()
+
+# Extract the needed variables from the args
+command = args.command
+top = args.top
+
+# Insure that perf is installed
+check_perf_presence = subprocess.run(["which", "perf"],
+                                     stdout=subprocess.DEVNULL)
+if check_perf_presence.returncode:
+    sys.exit("Please install perf before running the script!")
+
+# Insure user has previllage to run perf
+check_perf_executability = subprocess.run(["perf", "stat", "ls", "/"],
+                                          stdout=subprocess.DEVNULL,
+                                          stderr=subprocess.DEVNULL)
+if check_perf_executability.returncode:
+    sys.exit(
+"""
+Error:
+You may not have permission to collect stats.
+
+Consider tweaking /proc/sys/kernel/perf_event_paranoid,
+which controls use of the performance events system by
+unprivileged users (without CAP_SYS_ADMIN).
+
+  -1: Allow use of (almost) all events by all users
+      Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK
+   0: Disallow ftrace function tracepoint by users without CAP_SYS_ADMIN
+      Disallow raw tracepoint access by users without CAP_SYS_ADMIN
+   1: Disallow CPU event access by users without CAP_SYS_ADMIN
+   2: Disallow kernel profiling by users without CAP_SYS_ADMIN
+
+To make this setting permanent, edit /etc/sysctl.conf too, e.g.:
+   kernel.perf_event_paranoid = -1
+
+* Alternatively, you can run this script under sudo privileges.
+"""
+)
+
+# Run perf record
+perf_record = subprocess.run((["perf", "record", "--output=/tmp/perf.data"] +
+                              command),
+                             stdout=subprocess.DEVNULL,
+                             stderr=subprocess.PIPE)
+if perf_record.returncode:
+    os.unlink('/tmp/perf.data')
+    sys.exit(perf_record.stderr.decode("utf-8"))
+
+# Save perf report output to /tmp/perf_report.out
+with open("/tmp/perf_report.out", "w") as output:
+    perf_report = subprocess.run(
+        ["perf", "report", "--input=/tmp/perf.data", "--stdio"],
+        stdout=output,
+        stderr=subprocess.PIPE)
+    if perf_report.returncode:
+        os.unlink('/tmp/perf.data')
+        output.close()
+        os.unlink('/tmp/perf_report.out')
+        sys.exit(perf_report.stderr.decode("utf-8"))
+
+# Read the reported data to functions[]
+functions = []
+with open("/tmp/perf_report.out", "r") as data:
+    # Only read lines that are not comments (comments start with #)
+    # Only read lines that are not empty
+    functions = [line for line in data.readlines() if line and line[0]
+                 != '#' and line[0] != "\n"]
+
+# Limit the number of top functions to "top"
+number_of_top_functions = top if len(functions) > top else len(functions)
+
+# Store the data of the top functions in top_functions[]
+top_functions = functions[:number_of_top_functions]
+
+# Print table header
+print('{:>4}  {:>10}  {:<30}  {}\n{}  {}  {}  {}'.format('No.',
+                                                         'Percentage',
+                                                         'Name',
+                                                         'Invoked by',
+                                                         '-' * 4,
+                                                         '-' * 10,
+                                                         '-' * 30,
+                                                         '-' * 25))
+
+# Print top N functions
+for (index, function) in enumerate(top_functions, start=1):
+    function_data = function.split()
+    function_percentage = function_data[0]
+    function_name = function_data[-1]
+    function_invoker = ' '.join(function_data[2:-2])
+    print('{:>4}  {:>10}  {:<30}  {}'.format(index,
+                                             function_percentage,
+                                             function_name,
+                                             function_invoker))
+
+# Remove intermediate files
+os.unlink('/tmp/perf.data')
+os.unlink('/tmp/perf_report.out')