[PATCH 2/3] scripts/performance: Add callgrind_top_25.py script

[Ahmed Karaman <ahmedkhaledkaraman@gmail.com>]

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

Signed-off-by: Ahmed Karaman <ahmedkhaledkaraman@gmail.com>
---
 scripts/performance/callgrind_top_25.py | 95 +++++++++++++++++++++++++
 1 file changed, 95 insertions(+)
 create mode 100644 scripts/performance/callgrind_top_25.py

diff --git a/scripts/performance/callgrind_top_25.py b/scripts/performance/callgrind_top_25.py
new file mode 100644
index 0000000000..03b089a96d
--- /dev/null
+++ b/scripts/performance/callgrind_top_25.py
@@ -0,0 +1,95 @@
+#!/usr/bin/env python3
+
+#  Print the top 25 most executed functions in QEMU using callgrind.
+#  Example Usage:
+#  callgrind_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, executable) = (sys.argv[1], ' '.join(sys.argv[2:]))
+
+# Run callgrind and callgrind_annotate
+os.system('valgrind --tool=callgrind --callgrind-out-file=callgrind.data {} {} \
+            2 > / dev / null & & callgrind_annotate callgrind.data \
+            > tmp.callgrind.data'.
+          format(qemu, executable))
+
+# Line number with the total number of instructions
+number_of_instructions_line = 20
+
+# Line number with the top function
+first_func_line = 25
+
+# callgrind_annotate output
+callgrind_data = []
+
+# Open callgrind_annotate output and store it in callgrind_data
+with open('tmp.callgrind.data', 'r') as data:
+    callgrind_data = data.readlines()
+
+# Get the total number of instructions
+total_number_of_instructions = int(
+    callgrind_data[number_of_instructions_line].split(' ')[0].replace(',', ''))
+
+# Number of functions recorded by callgrind
+number_of_functions = len(callgrind_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_instructions_line)
+
+# Store the data of the top functions in top_functions[]
+top_functions = callgrind_data[first_func_line:
+                               first_func_line + number_of_top_functions]
+# Print information headers
+print('{:>4}  {:>10}  {:<25}  {}\n{}  {}  {}  {}'.format('No.',
+                                                         'Percentage',
+                                                         'Name',
+                                                         'Source File',
+                                                         '-' * 4,
+                                                         '-' * 10,
+                                                         '-' * 25,
+                                                         '-' * 30,
+                                                         ))
+
+# Print top 25 functions
+for (index, function) in enumerate(top_functions, start=1):
+    function_data = function.split()
+    # Calculate function percentage
+    percentage = (float(function_data[0].replace(
+        ',', '')) / total_number_of_instructions) * 100
+    # Get function source path and name
+    path, name = function_data[1].split(':')
+    # Print extracted data
+    print('{:>4}  {:>9.3f}%  {:<25}  {}'.format(index,
+                                                round(percentage, 3),
+                                                name,
+                                                path))
+
+# Remove intermediate files
+os.system('rm callgrind.data tmp.callgrind.data')
-- 
2.17.1