Re: [PATCH 0/2] tracing: Move trace_printk.h out of kernel.h

[Peter Zijlstra]

On Sun, Jun 21, 2026 at 05:34:30AM -0400, Steven Rostedt wrote:
> There's been complaints about trace_printk() being defined in kernel.h as it
> can increase the compilation time. As it is only used by some developers for
> debugging purposes, it should not be in kernel.h causing lots of wasted CPU
> cycles for those that do not ever care about it.
> 
> Instead, add a CONFIG_TRACE_PRINTK_DEBUGGING option that developers that do
> use it can set and not have to always remember to add #include <linux/trace_printk.h>
> to the files they add trace_printk() while debugging. It also means that
> those that do not have that config set will not have to worry about wasted
> CPU cycles as it is only include in the CFLAGS when the option is set, and
> its completely ignored otherwise.

Did you forget your C 101 class? If you use a function, you gotta
include the relevant header.

You don't see userspace saying: 'Hey, you know what, perhaps we should
add stdio.h to every other header, just in case someone wants to
printf()' either.

I really don't understand your argument. Yes, maybe someone will forget
and then either their editor (if they have a halfway modern setup with
LSP enabled) or their build will complain, but so what? This is all
trivial stuff, surely we have more pressing matters to concern outselves
with?