Re: [PATCH 2/2] tracing: Add CONFIG_TRA CE_PRINTK_DEBUGGING to clean up kernel.h

On June 21, 2026 11:13:00 AM GMT+01:00, Thomas Gleixner <[email protected]> wrote:
>On Sun, Jun 21 2026 at 05:34, Steven Rostedt wrote:
>> Instead of having trace_printk.h included in kernel.h, create a config
>> TRACE_PRINTK_DEBUGGING that when set will update the CFLAGS in the
>> Makefile to allow developers to add trace_printk() without the need to add
>> the include for it. Having it included in the Makefile keeps it from being
>> in the dependency chain and it will not waste extra CPU cycles for those
>> building the kernel without using trace_printk.
>
>IOW, you make it worse just because.
>
>With the header being separate I add the three trace_printk()s and the
>include to the source file I'm investigating. The recompile will build
>exactly this source file.
>
>Having to enable the config knob will result in a full kernel rebuild
>for no value.
>
>Seriously?

Like having lockdep enabled, this would always be set in the development environment. It's not something to only enable when you need to add a trace_printk. If you don't want to rebuild everything, by all means add the include file by file. There's nothing preventing you to do that with this solution.

-- Steve 

P.S. I'm replying on my phone as I'm in the London Tube. Thus why I'm not trimming my email.


>
>Thanks,
>
>        tglx
>