Re: [PATCH v4 5/7] mm: thp: split huge page to any lower order pages (except order-1).

On 13.02.24 23:05, Luis Chamberlain wrote:

On Tue, Feb 13, 2024 at 04:55:18PM -0500, Zi Yan wrote:

...

From: Zi Yan ziy@nvidia.com Order-1 folio is not supported because _deferred_list, which is used by partially mapped folios, is stored in subpage 2 and an order-1 folio only has subpage 0 and 1.

The LBS patches has the patch from Matthew which enables and allowed us to successfully test order 1. So this restriction could be dropped if that gets merged.

For anon folios it will still be in place, so the restriction will only be dropped for !anon.