Re: [PATCH] trace/simple: seperate hot paths of tracing fucntions

[Stefan Hajnoczi <stefanha@gmail.com>]

On Mon, May 19, 2025 at 2:52 PM Tanish Desai <tanishdesai37@gmail.com> wrote:
>
> Remove hot paths from .c file and added it in .h file to keep it inline.

Please include performance results in the commit description so it's
clear what impact this change has.

>
> Signed-off-by: Tanish Desai <tanishdesai37@gmail.com>
> ---
>  scripts/tracetool/backend/simple.py | 23 ++++++++++-------------

Please use scripts/get_maintainer.pl to find the emails to CC:

  $ scripts/get_maintainer.pl -f scripts/tracetool/backend/simple.py
  Stefan Hajnoczi <stefanha@redhat.com> (maintainer:Tracing)
  Mads Ynddal <mads@ynddal.dk> (reviewer:Tracing)
  qemu-devel@nongnu.org (open list:All patches CC here)

qemu-devel is a high-traffic list and maintainers may not see your
patches unless you CC them.

>  1 file changed, 10 insertions(+), 13 deletions(-)
>
> diff --git a/scripts/tracetool/backend/simple.py b/scripts/tracetool/backend/simple.py
> index a74d61fcd6..2688d4b64b 100644
> --- a/scripts/tracetool/backend/simple.py
> +++ b/scripts/tracetool/backend/simple.py
> @@ -36,8 +36,17 @@ def generate_h_begin(events, group):
>
>
>  def generate_h(event, group):
> -    out('    _simple_%(api)s(%(args)s);',
> +    event_id = 'TRACE_' + event.name.upper()
> +    if "vcpu" in event.properties:
> +        # already checked on the generic format code
> +        cond = "true"
> +    else:
> +        cond = "trace_event_get_state(%s)" % event_id
> +    out('    if (%(cond)s) {',
> +        '        _simple_%(api)s(%(args)s);',
> +        '    }',
>          api=event.api(),
> +        cond=cond,
>          args=", ".join(event.args.names()))
>
>
> @@ -72,22 +81,10 @@ def generate_c(event, group):
>      if len(event.args) == 0:
>          sizestr = '0'
>
> -    event_id = 'TRACE_' + event.name.upper()
> -    if "vcpu" in event.properties:
> -        # already checked on the generic format code
> -        cond = "true"
> -    else:
> -        cond = "trace_event_get_state(%s)" % event_id
> -
>      out('',
> -        '    if (!%(cond)s) {',
> -        '        return;',
> -        '    }',
> -        '',
>          '    if (trace_record_start(&rec, %(event_obj)s.id, %(size_str)s)) {',
>          '        return; /* Trace Buffer Full, Event Dropped ! */',
>          '    }',
> -        cond=cond,
>          event_obj=event.api(event.QEMU_EVENT),
>          size_str=sizestr)
>
> --
> 2.34.1
>
>