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

On Sun, 21 Jun 2026 12:13:00 +0200
Thomas Gleixner [off-list ref] wrote:

On Sun, Jun 21 2026 at 05:34, Steven Rostedt wrote:

quoted

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.

Indeed...
Isn't trace_printk() just an extern?
Having it defined somewhere isn't going to make any difference to build times.

	David
 

Seriously?

Thanks,

        tglx