On Fri,  4 Jul 2025 12:24:54 +0200 David Hildenbrand [off-list ref] wrote:

In the future, as we decouple "struct page" from "struct folio", pages
that support "non-lru page migration" -- movable_ops page migration
such as memory balloons and zsmalloc -- will no longer be folios. They
will not have ->mapping, ->lru, and likely no refcount and no
page lock. But they will have a type and flags 🙂

This is the first part (other parts not written yet) of decoupling
movable_ops page migration from folio migration.

In this series, we get rid of the ->mapping usage, and start cleaning up
the code + separating it from folio migration.

Migration core will have to be further reworked to not treat movable_ops
pages like folios. This is the first step into that direction.

Heavily tested with virtio-balloon and lightly tested with zsmalloc
on x86-64. Cross-compile-tested.

Thanks, I added this to mm-new.  I suppressed the 1363 mm-commits
emails to avoid breaking the internet.