I have "a few" projects I'm working on / intending to work on in the near future.

Folios is the big one. This has sub-projects: MM:

• Get large folio support in (5.18)
• Convert GUP to folios (5.18)
• Convert page_vma_mapped to folios
• Convert rmap to folios (depends on page_vma_mapped)
• Convert vmscan to folios (depends on rmap)
• Move split_huge_page() to non-THP code
• Get rid of all thp_size(), thp_order() and thp_nr_pages() calls (probably?)

FS:

• Adapt NFS to use large folios
• Adapt btrfs to use large folios
• Adapt CIFS to use large folios

Tangential to folios:

• Phyr
• Slab (Vlastimil took this over. merged 5.17)
• net pool as its own type
• pt pages as its own type
• zspage as its own type
• Can we make mapcount more sensible or disappear entirely?

Unrelated to folios:

• Maple Tree (Liam is doing most of the work)
• Shrinking struct mutex (Vishal has taken this on)
• Removing PG_private

• Synchronous ->readpage

• Broadcast readpage errors to all waiters

• Implement ->readahead for squashfs (Hsin-Yi)

• ImprovedReadaheadAlgorithm

• Make the last argument to read_mapping_page() / read_mapping_folio() a struct file ptr
• Slab Sevenths (Bill is attacking this one)
• NUMA-aware zero page (Bill is working on this one too)
• NUMA text pages in the page cache (Linus seems sceptical)
• Usercopy (5.18. With Kees)

  • If we check ->mapping for order-0 pages, is that a sure sign of individual allocation?

• Big Buckets (or integrate with Maple Tree)
• Readahead for compressed filesystems in general