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

From: Tal Shorer
Date: Mon Jul 06 2015 - 12:53:37 EST


On Fri, Jun 26, 2015 at 1:25 AM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> On Thu, 25 Jun 2015 23:41:17 +0300
> Tal Shorer <tal.shorer@xxxxxxxxx> wrote:
>
>> ping?
>
> I'm planning on looking at this after I've finished everything for the
> merge window. This came over the weekend (always a bad time), and the
> merge window opened. All new code needs to take a backseat while the
> merge window is opened.
>
> I may not get to this till next week. Feel free to ping me again then.
ping
>
> -- Steve
>
>
>>
>> On Sat, Jun 20, 2015 at 11:21 PM, Tal Shorer <tal.shorer@xxxxxxxxx> 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
>> >
>
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