Re: [PATCH v3 4/4] tracing: move tracing declarations from kernel.h to a dedicated header

From: Yury Norov

Date: Thu Dec 18 2025 - 15:52:20 EST


On Thu, Dec 18, 2025 at 10:34:07AM -0800, Randy Dunlap wrote:
>
>
> On 12/18/25 9:33 AM, Steven Rostedt wrote:
> > On Wed, 17 Dec 2025 22:59:33 -0500
> > Yury Norov <yury.norov@xxxxxxxxx> wrote:
> >
> >> I deem to drop trace_printk.h from kernel.h - it is more aligned with
> >> the idea of unloading the header. The original motivation to keep
> >> trace_printk.h in kernel.h was just because a similar printk.h is living
> >> there. But after all, this is a purely debugging header, so no need for
> >> almost every C file to bear debugging stuff.
> >
> > It is a big deal for debugging stuff. A lot of developers debug their code
> > with trace_printk(), and do the "shotgun approach", where they cut and
> > paste trace_printk()s all over their code in several files. Having to now add:
> >
> > #include <linux/trace_printk.h>
> >
> > whenever a trace_printk() is added is going to be a big PITA and slow down
> > all debugging efforts.
>
> Eh? Maybe a PITA, but surely not a big one.
> Slow down "all debugging efforts?"
> Please cut down on the hyperbole.

For me, removing trace_prink.h saves 1.5-2% of compile time:

Before:
#1 real 5m12.602s
#2 real 5m11.333s

After:
#1 real 5m6.190s
#2 real 5m7.151s

I'm building ubuntu-derived localyesconfig with a couple extra drivers.
Steven, if you're not absolutely against, lets drop the trace_printk.h?

Thanks,
Yury