Re: [GIT PULL] tracing: Updates for 7.2

[Linus Torvalds]

On Tue, 16 Jun 2026 at 15:01, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> tracing: Updates for v7.2:

I wondered why the heck this causes the whole kernel to be rebuilt,
when the diffstat looked fairly innocuous.

It's because it changed <linux/trace_printk.h>, which used to be part
of <linux/kernel.h> but was split out in commit bec261fec6d4
("tracing: move tracing declarations from kernel.h to a dedicated
header").

But the second stage of splitting it out - not including it from
<linux/kernel.h> - was never done, so now while the diffstat *looks*
innocuous, it is still as deadly to the build as an actual
<linux/kernel.h> change would be.

The intent was clearly to make people who actually needed the
trace_printk() functionality to include the header - that's what the
commit log says. But that's not how any of it works ;(

So all that commit did was to make things look like they wouldn't hurt
as much as they do, and that trivial change to that file causes a full
rebuild of the kernel.

I'm not seeing any patches even being discussed that would make only
files that need it to include that file and remove it from
linux/kernel.h that *everybody* uses. Yet that was the *only* point of
making it a separate header in the first place. Yury?

           Linus