Re: [PATCH v6 01/12] mm/vmalloc: fix vmalloc_to_page for huge vmap mappings

Andrew Morton
2020-08-21T20:08:00Z

On Sat, 22 Aug 2020 01:12:05 +1000 Nicholas Piggin <npiggin@gmail.com> wrote:

> vmalloc_to_page returns NULL for addresses mapped by larger pages[*].
> Whether or not a vmap is huge depends on the architecture details,
> alignments, boot options, etc., which the caller can not be expected
> to know. Therefore HUGE_VMAP is a regression for vmalloc_to_page.

I assume this doesn't matter in current mainline?

If wrong, then what are the user-visible effects and why no cc:stable?

> This change teaches vmalloc_to_page about larger pages, and returns
> the struct page that corresponds to the offset within the large page.
> This makes the API agnostic to mapping implementation details.