Re: [Patch RFC 0/2] tracing: allow disabling compilation of specific trace systems

[Tal Shorer <tal.shorer@gmail.com>]

ping?

On Sat, Jun 20, 2015 at 11:21 PM, Tal Shorer <tal.shorer@gmail.com> wrote:
> Currently, enabling CONFIG_TRACING on a system comes as all-or-nothing: either
> tracepoints for all subsystems are compiled (with CONFIG_TRACING) or none of
> them do (without it).
>
> This caused me an unacceptable performance penalty (obviously SOME penalty was
> expected, but not one so severe) which made me revert the changes in
> configuration.
>
> The first patch in this series modifies the files that actually define the
> tracepoint to look for a preprocessor macro NOTRACE and define nops (as if
> CONFIG_TRACING was not set) instead of them.
>
> The second patch provides an example of how I see this working, with the gpio
> subsystem as the example for absolutely no reason.
> If this idea is deemed worth the time by the community, I'll create patches for
> the other subsystems.
>
> Tal Shorer (2):
>   tracing: allow disabling compilation of specific trace systems
>   tracing: gpio: add Kconfig option for enabling/disabling trace events
>
>  drivers/gpio/Kconfig         | 6 ++++++
>  include/linux/tracepoint.h   | 6 +++---
>  include/trace/define_trace.h | 2 +-
>  include/trace/events/gpio.h  | 4 ++++
>  4 files changed, 14 insertions(+), 4 deletions(-)
>
> --
> 2.2.2
>