Re: [PATCH v3 3/3] mm: restructure memfd code

[Matthew Wilcox]

On Mon, Apr 09, 2018 at 04:05:05PM -0700, Mike Kravetz wrote:
> +/*
> + * We need a tag: a new tag would expand every radix_tree_node by 8 bytes,
> + * so reuse a tag which we firmly believe is never set or cleared on shmem.
> + */
> +#define SHMEM_TAG_PINNED        PAGECACHE_TAG_TOWRITE

Do we also firmly believe it's never used on hugetlbfs?