Re: [PATCH 3/4] ARM: drop CONFIG_HIGHPTE support

Linus Walleij
2024-12-11T13:33:04Z

On Tue, Dec 10, 2024 at 5:06 PM Arnd Bergmann <arnd@kernel.org> wrote:

> From: Arnd Bergmann <arnd@arndb.de>
>
> CONFIG_HIGHPTE was added in linux-2.6.32, a few years before 64-bit
> support. At the time it made sense, as the CONFIG_ARM_LPAE option allowed
> systems with 16GB of memory that made lowmem a particularly scarce
> resource, and the HIGHPTE implementation gave feature parity with 32-bit
> x86 and frv machines.
>
> Since Arm is the last architecture remaining that uses this, and almost
> no 32-bit machines support more than 4GB of RAM, the cost of continuing
> to maintain HIGHPTE seems unjustified, so remove it here to allow
> simplifying the generic page table handling.
>
> Link: https://lore.kernel.org/lkml/20241204103042.1904639-8-arnd@kernel.org/T/#u
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

I'm in favor of this if the x86 patch goes in. We need to get rid
of highmem anyway and this will need to happen sooner or later
either way.
Acked-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij