Linux MM adds THP co-maintainer, shifts more work off Morton's tree

Linux kernel memory management is taking another step away from Andrew Morton's long-standing single tree. David Hildenbrand has posted MAINTAINERS updates that start routing shared memory (shmem, tmpfs, and memfd) plus a slate of core MM subsystems through a dedicated core tree he co-maintains, with those pieces still feeding a common mm-next integration point. Morton will grab the series as a hotfix while he continues his own cleanup of MM entries in MAINTAINERS.

The subsystems now aimed at Hildenbrand's tree for ordinary patch pickup include memory ballooning, get-user-pages, kernel samepage merging, memory hotplug, page migration, NUMA placement, reverse mapping, transparent huge pages, and core MM itself. Hildenbrand stressed that the change only marks the start of that tree picking relevant material. Work that spans other components or raises serious conflicts will still need coordination with Morton's tree, and Morton stays listed under the generic memory-management entry so he remains CCed and can catch anything that falls through.

Hildenbrand added himself as a shared-memory maintainer mainly to pick patches, saying he will lean on Hugh Dickins and Baolin Wang for judgment on more involved or controversial bits. Further MM components are expected to move to other trees in later cycles. Controlled intake of the continuous stream of fixes, he wrote, has the highest priority.

In the same sweep, Zi Yan becomes a co-maintainer for transparent huge pages. Hildenbrand credited years of consistent THP contributions and said a single dedicated maintainer is no longer sustainable for such an active area.