On Sun, Jun 01, 2025 at 06:12:30PM +0000, Tanish Desai wrote: > Moved rarely used (cold) code from the header file to the C file to avoid > unnecessary inlining and reduce binary size.
How much of a binary size reduction do you measure? Most trace events
are only called once, so the difference in code size is likely to be
small.
> This improves code organization
> and follows good practices for managing cold paths.
It's easier to understand the code generator and the generated code when
each trace event is implemented as a single function in the header file.
Splitting the trace event up adds complexity. I don't think this is a
step in the right direction.
>
> Signed-off-by: Tanish Desai <tanishdesa...@gmail.com>
> ---
> scripts/tracetool/backend/ftrace.py | 44 +++++++++++++++++++++--------
> 1 file changed, 32 insertions(+), 12 deletions(-)
>
> diff --git a/scripts/tracetool/backend/ftrace.py
> b/scripts/tracetool/backend/ftrace.py
> index baed2ae61c..c9717d7b42 100644
> --- a/scripts/tracetool/backend/ftrace.py
> +++ b/scripts/tracetool/backend/ftrace.py
> @@ -23,6 +23,10 @@
> def generate_h_begin(events, group):
> out('#include "trace/ftrace.h"',
> '')
> + for event in events:
> + out('void _ftrace_%(api)s(%(args)s);',
> + api=event.api(),
> + args=event.args)
>
>
> def generate_h(event, group):
> @@ -30,26 +34,42 @@ def generate_h(event, group):
> if len(event.args) > 0:
> argnames = ", " + argnames
>
> - out(' {',
> + out(' if (trace_event_get_state(%(event_id)s)) {',
> + ' _ftrace_%(api)s(%(args)s);',
> + ' }',
> + name=event.name,
> + args=", ".join(event.args.names()),
> + event_id="TRACE_" + event.name.upper(),
> + event_lineno=event.lineno,
> + event_filename=os.path.relpath(event.filename),
> + fmt=event.fmt.rstrip("\n"),
> + argnames=argnames,
> + api=event.api()
> + )
> +
> +
> +def generate_c(event, group):
> + argnames = ", ".join(event.args.names())
> + if len(event.args) > 0:
> + argnames = ", " + argnames
> + out('void _ftrace_%(api)s(%(args)s){',
> ' char ftrace_buf[MAX_TRACE_STRLEN];',
> ' int unused __attribute__ ((unused));',
> ' int trlen;',
> - ' if (trace_event_get_state(%(event_id)s)) {',
> '#line %(event_lineno)d "%(event_filename)s"',
> - ' trlen = snprintf(ftrace_buf, MAX_TRACE_STRLEN,',
> - ' "%(name)s " %(fmt)s "\\n"
> %(argnames)s);',
> + ' trlen = snprintf(ftrace_buf, MAX_TRACE_STRLEN,',
> '#line %(out_next_lineno)d "%(out_filename)s"',
> - ' trlen = MIN(trlen, MAX_TRACE_STRLEN - 1);',
> - ' unused = write(trace_marker_fd, ftrace_buf, trlen);',
> - ' }',
> - ' }',
> - name=event.name,
> - args=event.args,
> - event_id="TRACE_" + event.name.upper(),
> + ' "%(name)s " %(fmt)s "\\n" %(argnames)s);',
> + ' trlen = MIN(trlen, MAX_TRACE_STRLEN - 1);',
> + ' unused = write(trace_marker_fd, ftrace_buf, trlen);',
> + '}',
> event_lineno=event.lineno,
> event_filename=os.path.relpath(event.filename),
> + name=event.name,
> fmt=event.fmt.rstrip("\n"),
> - argnames=argnames)
> + argnames=argnames,
> + api=event.api(),
> + args=event.args)
>
>
> def generate_h_backend_dstate(event, group):
> --
> 2.34.1
>
signature.asc
Description: PGP signature
