Re: [PATCH] sched: Work around undefined behavior in sched class checking

[Andi Kleen]

On 5/5/2021 9:41 AM, Nick Desaulniers wrote:
> On Wed, May 5, 2021 at 7:39 AM Andi Kleen <ak@xxxxxxxxxxxxxxx> wrote:
> > >   Would you please provide a
> > > minimal test case?
> > You can only reproduce it with a LTO build because it needs knowledge
> > between different translation units for this specific case.
> >
> > But gcc will totally do the optimization even without LTO if it can
> > prove the same inside a single TU.
> It would be helpful to isolate a test case that doesn't rely on LTO,
> if possible.

Like I wrote earlier we used to see it all the time in __pa_symbol 
before it used RELOC_HIDE. I bet if you make RELOC_HIDE a nop you'll see 
multiple instances.

But not sure why you want a test case?

-Andi