Re: [PATCH v5 02/10] x86: Compile-time asm code validation

Josh Poimboeuf
2015-06-11T14:01:20Z

On Thu, Jun 11, 2015 at 08:08:07AM +0200, Ingo Molnar wrote:
>
> * Josh Poimboeuf <jpoimboe@redhat.com> wrote:
>
> > I should also mention that my proposed ia32_ptregs_common patch, which
> > duplicated the needed code, was more optimized for performance than code size.
> >
> > But if you're more worried about code size, we could turn ia32_ptregs_common
> > into a proper callable function, and then replace
> >
> > jmp ia32_ptregs_common
> >
> > with:
> >
> > call ia32_ptregs_common
> > ret
> >
> > So it becomes a regular call instead of a tail call. It only adds a few
> > instructions and the function is self-contained. Would that be good enough?
>
> No, debug info should not slow down the kernel, especially not code we write in
> assembly partly for performance.

Ok. I'll work on adding support for external jumps.

--
Josh