On Thursday, July 16, 2020, Ahmed Karaman <ahmedkhaledkaraman@gmail.com>
wrote:

> Python script that prints executed helpers of a QEMU invocation.
>
>
Hi, Ahmed.

You outlined the envisioned user workflow regarding this script in your
report. As I understand it, it generally goes like this:

1) The user first discovers helpers, and their performance data.
2) The user examines the callees of a particular helper of choice (usually,
the most instruction-consuming helper).
3) The user perhaps further examines a callee of a particular callee of the
particular helper.
4) The user continues this way until the conclusion can be drawn, or
maximal depth is reached.

The procedure might be time consuming since each step requires running an
emulation of the test program.

This makes me think that the faster and easier tool for the user (but, to
some, not that great, extent, harder for you) would be improved
list_helpers.py (and list_fn_calees.py) that provides list of all callees
for all helpers, in the tree form (so, callees of callees, callees of
callees of callees, etc.), rather than providing just a list of immediate
callees, like it currently does.

I think you can provide such functionality relatively easily using
recursion. See, let's say:

https://realpython.com/python-thinking-recursively/

Perhaps you can have a switch (let's say, --tree <yes|no>) that specifies
whether the script outputs just immediate callee list, or entire callee
tree.

Thanks,
Aleksandar


> Syntax:
> list_helpers.py [-h] -- \
>                <qemu executable> [<qemu executable options>] \
>                <target executable> [<target executable options>]
>
> [-h] - Print the script arguments help message.
>
> Example of usage:
> list_helpers.py -- qemu-mips coulomb_double-mips -n10
>
> Example output:
>  Total number of instructions: 108,933,695
>
>  Executed QEMU Helpers:
>
>  No. Ins     Percent  Calls Ins/Call Helper Name             Source File
>  --- ------- ------- ------ -------- --------------------
> ---------------
>    1 183,021  0.168%  1,305      140 helper_float_sub_d
> <qemu>/target/mips/fpu_helper.c
>    2 177,111  0.163%    770      230 helper_float_madd_d
>  <qemu>/target/mips/fpu_helper.c
>    3 171,537  0.157%  1,014      169 helper_float_mul_d
> <qemu>/target/mips/fpu_helper.c
>    4 157,298  0.144%  2,443       64 helper_lookup_tb_ptr
> <qemu>/accel/tcg/tcg-runtime.c
>    5 138,123  0.127%    897      153 helper_float_add_d
> <qemu>/target/mips/fpu_helper.c
>    6  47,083  0.043%    207      227 helper_float_msub_d
>  <qemu>/target/mips/fpu_helper.c
>    7  24,062  0.022%    487       49 helper_cmp_d_lt
>  <qemu>/target/mips/fpu_helper.c
>    8  22,910  0.021%    150      152 helper_float_div_d
> <qemu>/target/mips/fpu_helper.c
>    9  15,497  0.014%    321       48 helper_cmp_d_eq
>  <qemu>/target/mips/fpu_helper.c
>   10   9,100  0.008%     52      175 helper_float_trunc_w_d
> <qemu>/target/mips/fpu_helper.c
>   11   7,059  0.006%     10      705 helper_float_sqrt_d
>  <qemu>/target/mips/fpu_helper.c
>   12   3,000  0.003%     40       75 helper_cmp_d_ule
> <qemu>/target/mips/fpu_helper.c
>   13   2,720  0.002%     20      136 helper_float_cvtd_w
>  <qemu>/target/mips/fpu_helper.c
>   14   2,477  0.002%     27       91 helper_swl
> <qemu>/target/mips/op_helper.c
>   15   2,000  0.002%     40       50 helper_cmp_d_le
>  <qemu>/target/mips/fpu_helper.c
>   16   1,800  0.002%     40       45 helper_cmp_d_un
>  <qemu>/target/mips/fpu_helper.c
>   17   1,164  0.001%     12       97 helper_raise_exception_
> <qemu>/target/mips/op_helper.c
>   18     720  0.001%     10       72 helper_cmp_d_ult
> <qemu>/target/mips/fpu_helper.c
>   19     560  0.001%    140        4 helper_cfc1
>  <qemu>/target/mips/fpu_helper.c
>
> Signed-off-by: Ahmed Karaman <ahmedkhaledkaraman@gmail.com>
> ---
>  scripts/performance/list_helpers.py | 207 ++++++++++++++++++++++++++++
>  1 file changed, 207 insertions(+)
>  create mode 100755 scripts/performance/list_helpers.py
>
> diff --git a/scripts/performance/list_helpers.py
> b/scripts/performance/list_helpers.py
> new file mode 100755
> index 0000000000..a97c7ed4fe
> --- /dev/null
> +++ b/scripts/performance/list_helpers.py
> @@ -0,0 +1,207 @@
> +#!/usr/bin/env python3
> +
> +#  Print the executed helpers of a QEMU invocation.
> +#
> +#  Syntax:
> +#  list_helpers.py [-h] -- \
> +#                 <qemu executable> [<qemu executable options>] \
> +#                 <target executable> [<target executable options>]
> +#
> +#  [-h] - Print the script arguments help message.
> +#
> +#  Example of usage:
> +#  list_helpers.py -- qemu-mips coulomb_double-mips
> +#
> +#  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.c
> om>
> +#
> +#  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
> +import tempfile
> +
> +
> +def find_JIT_line(callgrind_data):
> +    """
> +    Search for the line with the JIT call in the callgrind_annotate
> +    output when ran using --tre=calling.
> +    All the helpers should be listed after that line.
> +
> +    Parameters:
> +    callgrind_data (list): callgrind_annotate output
> +
> +    Returns:
> +    (int): Line number of JIT call
> +    """
> +    line = -1
> +    for i in range(len(callgrind_data)):
> +        split_line = callgrind_data[i].split()
> +        if len(split_line) > 2 and \
> +                split_line[1] == "*" and \
> +                split_line[-1] == "[???]":
> +            line = i
> +            break
> +    return line
> +
> +
> +def get_helpers(JIT_line, callgrind_data):
> +    """
> +    Get all helpers data given the line number of the JIT call.
> +
> +    Parameters:
> +    JIT_line (int): Line number of the JIT call
> +    callgrind_data (list): callgrind_annotate output
> +
> +    Returns:
> +    (list):[[number_of_instructions(int), helper_name(str),
> +             number_of_calls(int), source_file(str)]]
> +    """
> +    helpers = []
> +    next_helper = JIT_line + 1
> +    while (callgrind_data[next_helper] != "\n"):
> +        split_line = callgrind_data[next_helper].split()
> +        number_of_instructions = int(split_line[0].replace(",", ""))
> +        source_file = split_line[2].split(":")[0]
> +        callee_name = split_line[2].split(":")[1]
> +        number_of_calls = int(split_line[3][1:-2])
> +        helpers.append([number_of_instructions, callee_name,
> +                        number_of_calls, source_file])
> +        next_helper += 1
> +    return sorted(helpers, reverse=True)
> +
> +
> +def main():
> +    # Parse the command line arguments
> +    parser = argparse.ArgumentParser(
> +        usage="list_helpers.py [-h] -- "
> +        "<qemu executable> [<qemu executable options>] "
> +        "<target executable> [<target executable options>]")
> +
> +    parser.add_argument("command", type=str, nargs="+",
> help=argparse.SUPPRESS)
> +
> +    args = parser.parse_args()
> +
> +    # Extract the needed variables from the args
> +    command = args.command
> +
> +    # Insure that valgrind is installed
> +    check_valgrind = subprocess.run(
> +        ["which", "valgrind"], stdout=subprocess.DEVNULL)
> +    if check_valgrind.returncode:
> +        sys.exit("Please install valgrind before running the script.")
> +
> +    # Save all intermediate files in a temporary directory
> +    with tempfile.TemporaryDirectory() as tmpdirname:
> +        # callgrind output file path
> +        data_path = os.path.join(tmpdirname, "callgrind.data")
> +        # callgrind_annotate output file path
> +        annotate_out_path = os.path.join(tmpdirname,
> "callgrind_annotate.out")
> +
> +        # Run callgrind
> +        callgrind = subprocess.run((["valgrind",
> +                                     "--tool=callgrind",
> +                                     "--callgrind-out-file=" + data_path]
> +                                    + command),
> +                                   stdout=subprocess.DEVNULL,
> +                                   stderr=subprocess.PIPE)
> +        if callgrind.returncode:
> +            sys.exit(callgrind.stderr.decode("utf-8"))
> +
> +        # Save callgrind_annotate output
> +        with open(annotate_out_path, "w") as output:
> +            callgrind_annotate = subprocess.run(
> +                ["callgrind_annotate", data_path,
> +                    "--threshold=100", "--tree=calling"],
> +                stdout=output,
> +                stderr=subprocess.PIPE)
> +            if callgrind_annotate.returncode:
> +                sys.exit(callgrind_annotate.stderr.decode("utf-8"))
> +
> +        # Read the callgrind_annotate output to callgrind_data[]
> +        callgrind_data = []
> +        with open(annotate_out_path, "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_instructions = total_instructions_line_data.split()[0]
> +
> +        print("Total number of instructions:
> {}\n".format(total_instructions))
> +
> +        # Remove commas and convert to int
> +        total_instructions = int(total_instructions.replace(",", ""))
> +
> +        # Line number with the JIT call
> +        JIT_line = find_JIT_line(callgrind_data)
> +        if JIT_line == -1:
> +            sys.exit("Couldn't locate the JIT call ... Exiting")
> +
> +        # Get helpers
> +        helpers = get_helpers(JIT_line, callgrind_data)
> +
> +        print("Executed QEMU Helpers:\n")
> +
> +        # Print table header
> +        print("{:>4}  {:>15}  {:>10}  {:>15}  {:>10}  {:<25}  {}".
> +              format(
> +                  "No.",
> +                  "Instructions",
> +                  "Percentage",
> +                  "Calls",
> +                  "Ins/Call",
> +                  "Helper Name",
> +                  "Source File")
> +              )
> +
> +        print("{:>4}  {:>15}  {:>10}  {:>15}  {:>10}  {:<25}  {}".
> +              format(
> +                  "-" * 4,
> +                  "-" * 15,
> +                  "-" * 10,
> +                  "-" * 15,
> +                  "-" * 10,
> +                  "-" * 25,
> +                  "-" * 30)
> +              )
> +
> +        for (index, callee) in enumerate(helpers, start=1):
> +            instructions = callee[0]
> +            percentage = (callee[0] / total_instructions) * 100
> +            calls = callee[2]
> +            instruction_per_call = int(callee[0] / callee[2])
> +            helper_name = callee[1]
> +            source_file = callee[3]
> +            # Print extracted data
> +            print("{:>4}  {:>15}  {:>9.3f}%  {:>15}  {:>10}  {:<25}  {}".
> +                  format(
> +                      index,
> +                      format(instructions, ","),
> +                      round(percentage, 3),
> +                      format(calls, ","),
> +                      format(instruction_per_call, ","),
> +                      helper_name,
> +                      source_file)
> +                  )
> +
> +
> +if __name__ == "__main__":
> +    main()
> --
> 2.17.1
>
>