Re: [PATCH v4 7/7] kernel.h: drop trace_printk.h
From: Andy Shevchenko
Date: Sat Dec 27 2025 - 09:46:05 EST
On Fri, Dec 26, 2025 at 11:58:48AM -0500, Steven Rostedt wrote:
> On Thu, 25 Dec 2025 12:09:29 -0500
> "Yury Norov (NVIDIA)" <yury.norov@xxxxxxxxx> wrote:
>
> > The trace_printk.h header is debugging-only by nature, but now it's
> > included by almost every compilation unit via kernel.h.
> >
> > Removing trace_printk.h saves 1.5-2% of compilation time on my
> > Ubuntu-derived x86_64/localyesconfig.
> >
> > There's ~30 files in the codebase, requiring trace_printk.h for
> > non-debugging reasons: mostly to disable tracing on panic or under
> > similar conditions. Include the header for those explicitly.
> >
> > This implicitly decouples linux/kernel.h and linux/instruction_pointer.h
> > as well, because it has been isolated to trace_printk.h early in the
> > series.
> >
> > Signed-off-by: Yury Norov (NVIDIA) <yury.norov@xxxxxxxxx>
>
> I'm still against this patch. It means every time someone adds
> trace_printk() they need to add the header for it.
>
> trace_printk() should be as available to the kernel as printk() is. If
> there's a place that one can add printk() without adding a header, then
> they should be able to add trace_printk() to that same location without
> adding any header. If that's not the case, then I'm adding an official
>
> Nacked-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
>
> I'm fine for trying other ways to speed up the compilation, but removing
> full access to trace_printk() isn't one of them.
I interpreted this as if the header inclusion should be moved from kernel.h
to printk.h as a compromise that satisfies all (?) stakeholders. Is it possible
approach?
--
With Best Regards,
Andy Shevchenko