Re: [PATCH v2 3/4] elf: align ET_DYN base to max folio size for PTE coalescing

Matthew Wilcox
2026-03-20T17:47:34Z

On Sat, Mar 21, 2026 at 12:05:18AM +0800, WANG Rui wrote:
> >From experiments (with 16K base pages), mapping_max_folio_size() appears to
> depend on the filesystem. It returns 8M on ext4, while on btrfs it always
> falls back to PAGE_SIZE (it seems CONFIG_BTRFS_EXPERIMENTAL=y may change this).
> This looks overly conservative and ends up missing practical optimization
> opportunities.

btrfs only supports large folios with CONFIG_BTRFS_EXPERIMENTAL.
I mean, it's only been five years since it was added to XFS, can't rush
these things.