Re: [PATCH 1/1] scripts/performance: Add dissect.py script

[Eric Blake]

On 7/1/20 8:04 AM, Ahmed Karaman wrote:
> Python script that dissects QEMU execution into three main phases:
> code generation, JIT execution and helpers execution.
>
> Syntax:
> dissect.py [-h] -- <qemu executable> [<qemu executable options>] \
>                   <target executable> [<target executable options>]
>
> [-h] - Print the script arguments help message.
>
> Example of usage:
> dissect.py -- qemu-arm coulomb_double-arm

Given the example usage...

> Example output:
> Total Instructions:        4,702,865,362
>
> Code Generation:             115,819,309         2.463%
> JIT Execution:             1,081,980,528        23.007%
> Helpers:                   3,505,065,525        74.530%
>
> Signed-off-by: Ahmed Karaman <ahmedkhaledkaraman@gmail.com>
> ---
>   scripts/performance/dissect.py | 165 +++++++++++++++++++++++++++++++++
>   1 file changed, 165 insertions(+)
>   create mode 100644 scripts/performance/dissect.py
>
> diff --git a/scripts/performance/dissect.py b/scripts/performance/dissect.py
> new file mode 100644

...this should have the executable bit set.


> +def get_JIT_line(callgrind_data):
> +    """
> +    Search for the first instance of the JIT call in
> +    the callgrind_annoutate output when ran using --tree=caller

annotate

> +    This is equivalent to the self number of instructions of JIT.
> +
> +    Parameters:
> +    callgrind_data (list): callgrind_annotate output
> +
> +    Returns:
> +    (int): Line number
> +   """
> +    line = -1
> +    for i in range(len(callgrind_data)):
> +        if callgrind_data[i].strip('\n') and \
> +                callgrind_data[i].split()[-1] == "[???]":
> +            line = i
> +            break
> +    if line == -1:
> +        sys.exit("Couldn't locate the JIT call ... Exiting!")

We tend to avoid ! at the end of error messages (it can come across as 
shouting at the user).

> +    return line
> +
> +
> +def main():
> +    # Parse the command line arguments
> +    parser = argparse.ArgumentParser(
> +        usage='dissect.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!")

and again

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org