Re: [PATCH linux-next] powerpc: disable sanitizer in irq_soft_mask_set

[Zhouyi Zhou]

On Wed, Aug 24, 2022 at 12:50 AM Christophe Leroy
<christophe.leroy@xxxxxxxxxx> wrote:
>
>
>
> Le 23/08/2022 à 10:47, Christophe Leroy a écrit :
> >
> >
> > Le 23/08/2022 à 10:33, Michael Ellerman a écrit :
> >> Zhouyi Zhou <zhouzhouyi@xxxxxxxxx> writes:
> >>
> >> My worry is that this will force irq_soft_mask_set() out of line, which
> >> we would rather avoid. It's meant to be a fast path.
> >>
> >> In fact with this applied I see nearly 300 out-of-line copies of the
> >> function when building a defconfig, and ~1700 calls to it.
> >>
> >> Normally it is inlined at every call site.
> >>
> >>
> >> So I think I'm inclined to revert ef5b570d3700 ("powerpc/irq: Don't open
> >> code irq_soft_mask helpers").
> >
> > Could you revert it only partially ? In extenso, revert the
> > READ/WRITE_ONCE and bring back the inline asm in irq_soft_mask_return()
> >   and irq_soft_mask_set(), but keep other changes.
>
> I sent a patch doing that.
Thank Christophe for the fix. I am very glad to be of benefit to the
community ;-)
Also thank Michael and Paul for your constant encouragement and
guidance, I learned to use objdump to count the number of failed
inline function calls today ;-)

By the way, from my experiments, both gcc-11 and clang-14 behave the
same as Michael has described.

Cheers
Zhouyi
>
> Christophe