Re: [RFC PATCH v2 1/4] rtla/osnoise: Add IPI tracking cmdline option

[Tomas Glozar]

st 17. 6. 2026 v 15:18 odesílatel Valentin Schneider
<vschneid@xxxxxxxxxx> napsal:
>
> Later commits will add IPI tracking to osnoise top. To avoid breaking
> existing scripts, this new feature will be gated behind a new -i option.
>
> Suggested-by: Tomas Glozar <tglozar@xxxxxxxxxx>

Thanks. Implementing this as a separate option also means we don't
have to worry about the performance impact in the general use case, as
the feature is not enabled by default.

If we decide to enable IPI tracking by default in the future, we can
just change the option to "--no-ipi" without breaking anything, as
libsubcmd generates all options in a pair by default (i.e. it
automatically recognizes --no-ipi when you define --ipi and vice
versa, unless explicitly disabled).

> Signed-off-by: Valentin Schneider <vschneid@xxxxxxxxxx>
> ---
>  Documentation/tools/rtla/rtla-osnoise-top.rst | 4 ++++
>  tools/tracing/rtla/src/cli.c                  | 1 +
>  tools/tracing/rtla/src/cli_p.h                | 3 +++
>  tools/tracing/rtla/src/common.h               | 1 +
>  4 files changed, 9 insertions(+)
>
> [truncated]
>
> --- a/tools/tracing/rtla/src/cli_p.h
> +++ b/tools/tracing/rtla/src/cli_p.h
> @@ -305,6 +305,9 @@ static int opt_filter_cb(const struct option *opt, const char *arg, int unset)
>         "the minimum delta to be considered a noise", \
>         opt_llong_callback)
>
> +#define OSNOISE_OPT_IPI OPT_BOOLEAN('i', "ipi", &params->common.ipi, \
> +       "track sources of IPIs")
> +

As IPI tracking is not a commonly used functionality, unlike e.g.
"-p/--period", and -i is already a different option for timerlat tools
(-i-/--irq), I'd suggest keeping just the long option, --ipi, like I
did for --on-threshold/--on-end (on Arnaldo's suggestion based on his
experience from perf [1]). This will make it clear to user the option
means "IPI detection" and not something else beginning with the letter
"i". We can always add a short option later if its use becomes common.

[1] https://lore.kernel.org/linux-trace-kernel/aEmWyPqQw2Ly7Jlu@x1/

> [truncated]

Tomas