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| author |   Ingo Molnar <mingo@kernel.org> | 2020-07-24 13:50:25 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-07-24 13:56:23 +0200 |
| commit | d19e789f068b3d633cbac430764962f404198022 (patch) | |
| tree | a28ff85a1c35d05b9712d43a53cc879a705ba2fb /include/linux/context_tracking.h | |
| parent | Merge tag 's390-5.8-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux into master (diff) | |
| download | linux-dev-d19e789f068b3d633cbac430764962f404198022.tar.xz linux-dev-d19e789f068b3d633cbac430764962f404198022.zip | |
compiler.h: Move instrumentation_begin()/end() to new <linux/instrumentation.h> header
Linus pointed out that compiler.h - which is a key header that gets included in every
single one of the 28,000+ kernel files during a kernel build - was bloated in:
655389666643: ("vmlinux.lds.h: Create section for protection against instrumentation")
Linus noted:
> I have pulled this, but do we really want to add this to a header file
> that is _so_ core that it gets included for basically every single
> file built?
>
> I don't even see those instrumentation_begin/end() things used
> anywhere right now.
>
> It seems excessive. That 53 lines is maybe not a lot, but it pushed
> that header file to over 12kB, and while it's mostly comments, it's
> extra IO and parsing basically for _every_ single file compiled in the
> kernel.
>
> For what appears to be absolutely zero upside right now, and I really
> don't see why this should be in such a core header file!
Move these primitives into a new header: <linux/instrumentation.h>, and include that
header in the headers that make use of it.
Unfortunately one of these headers is asm-generic/bug.h, which does get included
in a lot of places, similarly to compiler.h. So the de-bloating effect isn't as
good as we'd like it to be - but at least the interfaces are defined separately.
No change to functionality intended.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200604071921.GA1361070@gmail.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Diffstat (limited to 'include/linux/context_tracking.h')
| -rw-r--r-- | include/linux/context_tracking.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h index 981b880d5b60..d53cd331c4dd 100644 --- a/include/linux/context_tracking.h +++ b/include/linux/context_tracking.h @@ -5,6 +5,8 @@ #include <linux/sched.h> #include <linux/vtime.h> #include <linux/context_tracking_state.h> +#include <linux/instrumentation.h> + #include <asm/ptrace.h> |