Re: [PATCH 04/16] x86/boot: Increase boot page table size

[Evgeniy Baskov]

On 2022-10-19 10:08, Ard Biesheuvel wrote:
> On Tue, 6 Sept 2022 at 12:41, Evgeniy Baskov <baskov@xxxxxxxxx> wrote:
> > Previous calculations ignored pages implicitly mapped by ACPI code,
>
> I'm not sure I understand what this means. Which ACPI code and which
> pages does it map?

Code from boot/compressed/{acpi.c,efi.c} that touches ACPI/EFI tables
is currently mapping pages that contain the tables implicitly by
causing page faults. And those mappings may require additional
memory for page tables. It became more apparent when I were removing
memory mapping from page fault handler.

> > so theoretical upper limit is higher than was set.
...