Re: [PATCH v7 2/4] s390/mm: Batch PTE updates in lazy MMU mode

From: Alexander Gordeev

Date: Fri Oct 02 2026 - 08:30:22 EST


On Fri, Oct 02, 2026 at 10:43:15AM +0200, Heiko Carstens wrote:
> > > Good point. But still, do you think it worth dropping the KASAN check?
> >
> > KASAN check for lowcore? I don't think we care - this is initialized to zero
> > anyway, so what could go wrong? Also given how frequently these operations are
> > used, yes, please drop KASAN checks.
>
> Of course you could still add an explicit KASAN/KCSAN check by adding an
> instrument_read() call (see e.g. s390's fpu-insn.h, which has plenty of them).
>
> But why do you think that would be helpful for a lowcore field, where it is
> known that is initialized to zero? What am I missing?

Nothing. I am going to adopt all your suggestions into the new version.

Thanks!