Re: [PATCH v4 2/5] mm/memory-failure: libstub: install the poisoned-memory EFI table

From: Breno Leitao

Date: Tue Sep 15 2026 - 05:33:47 EST


On Thu, Sep 10, 2026 at 06:11:53AM -0700, Breno Leitao wrote:
> So I'd say we have two options:
>
> 1) Keep it similar to unaccepted memory, with 2M granularity.
> - Pro : Similar mental model as unnacepted memory
> - Cons: 2 MB might be a bit wasteful
>
> 2) Move to a linked list like the RFC, keeping it outside of the EFI
> table.
> - Pro: Reduce the memory granularities to page instead of 2M blocs.
> - Cons: Another way of passing memory information between kexec
> kernels.
>
> Any any other option or strong preference?

Since nobody voiced a strong preference, I will stick with option (1),
the bitmap, for these reasons:

1) It follows the same mental model as unaccepted memory, which people
are already familiar with.

2) It is simpler to query at boot time, especially as the number of
poisoned memory regions grows. Walking a bitmap is easier than
walking a linked list when freeing memory back to the buddy
allocator.

--breno