scripts/performance: Add topN_callgrind.py script

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

Syntax:
topN_callgrind.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_callgrind.py -n 20 -- qemu-arm coulomb_double-arm

Example Output:
No.  Percentage Function Name         Source File
----  --------- ------------------    ------------------------------
   1    24.577% 0x00000000082db000    ???
   2    20.467% float64_mul           <qemu>/fpu/softfloat.c
   3    14.720% float64_sub           <qemu>/fpu/softfloat.c
   4    13.864% float64_add           <qemu>/fpu/softfloat.c
   5     4.876% helper_mulsd          <qemu>/target/i386/ops_sse.h
   6     3.767% helper_subsd          <qemu>/target/i386/ops_sse.h
   7     3.549% helper_addsd          <qemu>/target/i386/ops_sse.h
   8     2.185% helper_ucomisd        <qemu>/target/i386/ops_sse.h
   9     1.667% helper_lookup_tb_ptr  <qemu>/include/exec/tb-lookup.h
  10     1.662% f64_compare           <qemu>/fpu/softfloat.c
  11     1.509% helper_lookup_tb_ptr  <qemu>/accel/tcg/tcg-runtime.c
  12     0.635% helper_lookup_tb_ptr  <qemu>/include/exec/exec-all.h
  13     0.616% float64_div           <qemu>/fpu/softfloat.c
  14     0.502% helper_pand_xmm       <qemu>/target/i386/ops_sse.h
  15     0.502% float64_mul           <qemu>/include/fpu/softfloat.h
  16     0.476% helper_lookup_tb_ptr  <qemu>/target/i386/cpu.h
  17     0.437% float64_compare_quiet <qemu>/fpu/softfloat.c
  18     0.414% helper_pxor_xmm       <qemu>/target/i386/ops_sse.h
  19     0.353% round_to_int          <qemu>/fpu/softfloat.c
  20     0.347% helper_cc_compute_all <qemu>/target/i386/cc_helper.c

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: <20200626164546.22102-3-ahmedkhaledkaraman@gmail.com>

scripts/performance/topN_callgrind.py

@@ -0,0 +1,140 @@
+#!/usr/bin/env python3
+
+#  Print the top N most executed functions in QEMU using callgrind.
+#  Syntax:
+#  topN_callgrind.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_callgrind.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_callgrind.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 valgrind is installed
+check_valgrind_presence = subprocess.run(["which", "valgrind"],
+                                         stdout=subprocess.DEVNULL)
+if check_valgrind_presence.returncode:
+    sys.exit("Please install valgrind before running the script!")
+
+# Run callgrind
+callgrind = subprocess.run((
+    ["valgrind", "--tool=callgrind", "--callgrind-out-file=/tmp/callgrind.data"]
+    + command),
+    stdout=subprocess.DEVNULL,
+    stderr=subprocess.PIPE)
+if callgrind.returncode:
+    sys.exit(callgrind.stderr.decode("utf-8"))
+
+# Save callgrind_annotate output to /tmp/callgrind_annotate.out
+with open("/tmp/callgrind_annotate.out", "w") as output:
+    callgrind_annotate = subprocess.run(["callgrind_annotate",
+                                         "/tmp/callgrind.data"],
+                                        stdout=output,
+                                        stderr=subprocess.PIPE)
+    if callgrind_annotate.returncode:
+        os.unlink('/tmp/callgrind.data')
+        output.close()
+        os.unlink('/tmp/callgrind_annotate.out')
+        sys.exit(callgrind_annotate.stderr.decode("utf-8"))
+
+# Read the callgrind_annotate output to callgrind_data[]
+callgrind_data = []
+with open('/tmp/callgrind_annotate.out', 'r') as data:
+    callgrind_data = data.readlines()
+
+# Line number with the total number of instructions
+total_instructions_line_number = 20
+
+# Get the total number of instructions
+total_instructions_line_data = callgrind_data[total_instructions_line_number]
+total_number_of_instructions = total_instructions_line_data.split(' ')[0]
+total_number_of_instructions = int(
+    total_number_of_instructions.replace(',', ''))
+
+# Line number with the top function
+first_func_line = 25
+
+# Number of functions recorded by callgrind, last two lines are always empty
+number_of_functions = len(callgrind_data) - first_func_line - 2
+
+# Limit the number of top functions to "top"
+number_of_top_functions = (top if number_of_functions >
+                           top else number_of_functions)
+
+# 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 table header
+print('{:>4}  {:>10}  {:<30}  {}\n{}  {}  {}  {}'.format('No.',
+                                                         'Percentage',
+                                                         'Function Name',
+                                                         'Source File',
+                                                         '-' * 4,
+                                                         '-' * 10,
+                                                         '-' * 30,
+                                                         '-' * 30,
+                                                         ))
+
+# Print top N functions
+for (index, function) in enumerate(top_functions, start=1):
+    function_data = function.split()
+    # Calculate function percentage
+    function_instructions = float(function_data[0].replace(',', ''))
+    function_percentage = (function_instructions /
+                           total_number_of_instructions)*100
+    # Get function name and source files path
+    function_source_file, function_name = function_data[1].split(':')
+    # Print extracted data
+    print('{:>4}  {:>9.3f}%  {:<30}  {}'.format(index,
+                                                round(function_percentage, 3),
+                                                function_name,
+                                                function_source_file))
+
+# Remove intermediate files
+os.unlink('/tmp/callgrind.data')
+os.unlink('/tmp/callgrind_annotate.out')