[PATCH 3/3] scripts/performance: Add perf_top_25.py script

[Ahmed Karaman <ahmedkhaledkaraman@gmail.com>]

Python script that prints the top 25 most executed functions in QEMU
using perf.

Signed-off-by: Ahmed Karaman <ahmedkhaledkaraman@gmail.com>
---
 scripts/performance/perf_top_25.py | 82 ++++++++++++++++++++++++++++++
 1 file changed, 82 insertions(+)
 create mode 100644 scripts/performance/perf_top_25.py

diff --git a/scripts/performance/perf_top_25.py b/scripts/performance/perf_top_25.py
new file mode 100644
index 0000000000..eaa8cce3c3
--- /dev/null
+++ b/scripts/performance/perf_top_25.py
@@ -0,0 +1,82 @@
+#!/usr/bin/env python3
+
+#  Print the top 25 most executed functions in QEMU using perf.
+#  Example Usage:
+#  perf_top_25.py <qemu-build>/x86_64-linux-user/qemu-x86_64 executable
+#
+#  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 os
+import sys
+
+# Ensure sufficient arguments
+if len(sys.argv) < 3:
+    print('Insufficient Script Arguments!')
+    sys.exit(1)
+
+# Get the qemu path and the executable + its arguments
+(qemu_path, executable) = (sys.argv[1], ' '.join(sys.argv[2:]))
+
+# Run perf repcord and report
+os.system('sudo perf record {} {} 2> /dev/null \
+            && sudo perf report --stdio > tmp.perf.data'
+          .format(qemu_path, executable))
+
+# Line number with the top function
+first_func_line = 11
+
+# Perf report output
+perf_data = []
+
+# Open perf report output and store it in perf_data
+with open('tmp.perf.data', 'r') as data:
+    perf_data = data.readlines()
+
+# Number of functions recorded by perf
+number_of_functions = len(perf_data) - first_func_line
+
+# Limit the number of top functions to 25
+number_of_top_functions = (25 if number_of_functions >
+                           25 else number_of_functions)
+
+# Store the data of the top functions in top_functions[]
+top_functions = perf_data[first_func_line:first_func_line
+                          + number_of_top_functions]
+
+# Print information headers
+print('{:>4}  {:>10}  {:<25}  {}\n{}  {}  {}  {}'.format('No.',
+                                                         'Percentage',
+                                                         'Name',
+                                                         'Caller',
+                                                         '-' * 4,
+                                                         '-' * 10,
+                                                         '-' * 25,
+                                                         '-' * 25,
+                                                         ))
+
+# Print top 25 functions
+for (index, function) in enumerate(top_functions, start=1):
+    function_data = function.split()
+    print('{:>4}  {:>10}  {:<25}  {}'.format(index,
+                                             function_data[0],
+                                             function_data[-1],
+                                             ' '.join(function_data[2:-2])))
+
+# Remove intermediate files
+os.system('sudo rm perf.data tmp.perf.data')
-- 
2.17.1