On Sat, Jan 03, 2026 at 02:57:58PM +0200, Andy Shevchenko wrote:

On Fri, Jan 02, 2026 at 07:50:59PM -0500, Joel Fernandes wrote:

quoted

On Mon, Dec 29, 2025 at 11:17:48AM -0500, Steven Rostedt wrote:

...

quoted

I use trace_printk() all the time for kernel, particularly RCU development.
One of the key usecases I have is dumping traces on panic (with panic on warn
and stop tracing on warn enabled). This is extremely useful since I can add
custom tracing and dump traces when rare conditions occur. I fixed several
bugs with this technique.

I also recommend keeping it convenient to use.

Okay, you know C, please share your opinion what header is the best to hold the
trace_printk.h to be included.

What if we include it on Makefile level, similarly to how W=1 works?

        make D=1 // trace_printk() is available
        make D=0 // trace_printk() is not available
        make     // trace_printk() is not available

Where D stands for debugging.

D=1 may be a default setting if you prefer, but the most important is
that every compilation unit will have an access to debugging without
polluting core headers.