Re: [PATCH] selftests/mm: remove obsolete hugetlb vmemmap test

[Andrew Morton]

On Fri, 10 Jul 2026 17:24:27 +0800 Muchun Song <songmuchun@xxxxxxxxxxxxx> wrote:

> The hugetlb vmemmap selftest was added to check the old HVO
> layout where tail vmemmap pages reused the head page.  That
> assumption no longer matches the current HVO mapping layout.
> 
> HVO now keeps a private backing page for the head vmemmap page
> and remaps redundant tail vmemmap pages to a shared read-only
> backing page.  The old page flag check is therefore testing an
> obsolete implementation detail rather than the current ABI or
> behavior.
> 
> Remove the stale test and its build, run, and ignore entries.
> 
> ...
>
> --- a/tools/testing/selftests/mm/.gitignore
> +++ b/tools/testing/selftests/mm/.gitignore
> @@ -3,11 +3,9 @@ cow
>  hugepage-mmap
>  hugepage-mremap
>  hugepage-shm
> -hugepage-vmemmap
>  hugetlb-mmap
>  hugetlb-mremap
>  hugetlb-shm
> -hugetlb-vmemmap
>  hugetlb-madvise
>  hugetlb-read-hwpoison
>  hugetlb-soft-offline

We should leave these .gitignore entries in place.  Please see
https://lore.kernel.org/CAHk-=wiHK5_oBUdUiNAaevmN9f-ORe+QBqbRefAZaw-RbgEn3w@xxxxxxxxxxxxxx

I'll queue a -fix for this.