Matthew Wilcox (Oracle) [off-list ref] wrote:

Handle arbitrary-order folios being added to the LRU.  By definition,
all pages being added to the LRU were already head or base pages,
so define page wrappers around folio functions where the original
page functions involved calling compound_head() to manipulate flags,
but define folio wrappers around page functions where there's no need to
call compound_head().  The one thing that does change for those functions
is calling compound_nr() instead of thp_nr_pages(), in order to handle
arbitrary-sized folios.

Saves 783 bytes of kernel text; no functions grow.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Yu Zhao <redacted>

Reviewed-by: David Howells <dhowells@redhat.com>