Re: sparc32: Init process fails to load with generic kmap atomic

From: Arnd Bergmann
Date: Tue Dec 22 2020 - 15:16:01 EST


On Tue, Dec 22, 2020 at 7:01 PM Andreas Larsson <andreas@xxxxxxxxxxx> wrote:
>
> Unfortunately I did not see this problem before I encountered it in
> master. Commit 3293efa9780712ad8504689e0c296d2bd33827d5
>
...
>
> I will have to continue to dig deeper into this in January. If anyone
> has any ideas how this could stem from this kmap patch, I am all ears.

I don't immediately see it, but an easy thing to try would be to
disable CONFIG_HIGHMEM. I don't know what the limits are
on sparc, but you can often change the virtual address layout
to reserve enough space for mapping all of the physical memory,
as e.g. CONFIG_VMSPLIT_2G does on x86 or arm.

There is also some discussion about eventually removing highmem
support from the kernel entirely.

Arnd