Re: [PATCH v2 0/5] treewide: remove unreachable memblock_reserve() return value checks in early boot

Hi Mike,

On Tue, Jul 7, 2026 at 3:17 PM Mike Rapoport <[email protected]> wrote:
>
> Hi Sang-Heon,
>
> On Tue, Jul 07, 2026 at 01:37:48AM +0900, Sang-Heon Jeon wrote:
> > memblock_reserve() can only return an error after memblock_allow_resize()
> > has been called. Before that it either succeeds or panics, never returning
> > an error.
> >
> > Before memblock_allow_resize() is called, the return value checks of
> > memblock_reserve() are unreachable and can be removed.
>
> I'd rather keep these checks.
>
> Removing them relies on internal details of memblock_reserve() implementation
> and the existing event sequence. If the code would move around relying on
> panic in memblock_reserve() may not be correct.
>
> And the few bytes and cycles the change saves do not worth the churn.

Makes sense to me.

But most early boot callers of memblock_reserve() don't check the
return value, so I thought we already rely on its internal behavior
anyway. So the few remaining checks just looked a bit inconsistent to
me.

Would you still prefer to keep these checks? If so, I'm fine with
dropping this patch series. It's not a big deal :)

Thank you for taking the time to review this series.

> --
> Sincerely yours,
> Mike.

Best Regards,
Sang-Heon Jeon