All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH v2 00/17] mm: Introduce section-based vmemmap optimization for HugeTLB
@ 2026-07-20  9:31 Muchun Song
  2026-07-20  9:31 ` [PATCH v2 01/17] mm/sparse: relax struct mem_section size constraints Muchun Song
                   ` (16 more replies)
  0 siblings, 17 replies; 21+ messages in thread
From: Muchun Song @ 2026-07-20  9:31 UTC (permalink / raw)
  To: Andrew Morton, Oscar Salvador, David Hildenbrand
  Cc: Mike Rapoport, Vlastimil Babka, Lorenzo Stoakes, Michal Hocko,
	David Laight, linux-mm, linux-kernel, Muchun Song, Muchun Song

This series is split out from the earlier, larger series "mm: Generalize
HVO for HugeTLB and device DAX" [1]. While the parent series generalizes
vmemmap optimization across HugeTLB and device DAX, this subset addresses
a single, self-contained step: making the generic sparse-vmemmap code
section-based optimization aware and switching HugeTLB bootmem pages to
this path.

HugeTLB vmemmap optimization currently has its own early boot setup
path. It pre-populates optimized vmemmap mappings before the normal
sparse-vmemmap population code runs, and sparsemem carries
SPARSEMEM_VMEMMAP_PREINIT only to support that special case.

That makes the HugeTLB vmemmap optimization path harder to share with
other users of sparse-vmemmap optimization and leaves a fair amount of
HugeTLB-specific boot-time state in the generic memory initialization
flow.

This series introduces section-based vmemmap optimization support in
the sparse-vmemmap code and switches HugeTLB bootmem pages over to it.
Instead of having HugeTLB pre-populate optimized vmemmap mappings
itself, HugeTLB now records the compound page order in the corresponding
memory sections. The generic sparse-vmemmap population path can then
allocate or reuse shared tail vmemmap pages based on section metadata.

The patches are organized as follows:

  - patches 1-2 prepare sparsemem and vmemmap optimization metadata
  - patches 3-8 teach the common sparse-vmemmap paths to use that state
  - patches 9-10 switch HugeTLB bootmem optimization to the
    section-based path
  - patches 11-17 clean up sparsemem and HugeTLB bootmem code that is no
    longer needed after the conversion

This is intended to be the second smaller step toward the broader HVO
generalization. The device DAX conversion and the wider HVO
consolidation are left for follow-up series.

v2:
- Kept struct mem_section aligned after relaxing lookup constraints
  (suggested by David Laight).
- Folded section order tracking into the first user instead of keeping
  a standalone API-only patch (suggested by Mike Rapoport).
- Renamed the HVO order macros with a VMEMMAP_OPTIMIZATION prefix
  (suggested by Mike Rapoport).
- Moved pfn_to_zone() before the sparse-vmemmap optimization changes
  (suggested by Mike Rapoport).
- Kept vmemmap accounting and population logic in sparse-vmemmap.c
  (suggested by Mike Rapoport).
- Renamed the early sparsemem helper to sparse_sections_init()
  (suggested by Mike Rapoport).
- Fixed the !SPARSEMEM stub name so SPARSEMEM=n builds compile
  (reported by Sashiko).
- Guard section_order() with CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP so
  it returns 0 when HVO is disabled and lets the compiler optimize the
  code as much as possible (suggested by Mike Rapoport)
- Collected Acked-by tags from Mike Rapoport.

[1] https://lore.kernel.org/linux-mm/20260513130542.35604-1-songmuchun@bytedance.com/

Muchun Song (17):
  mm/sparse: relax struct mem_section size constraints
  mm/sparse-vmemmap: rename HVO order macros
  mm/mm_init: skip initializing shared vmemmap tail pages
  mm/sparse-vmemmap: initialize shared tail vmemmap pages on allocation
  mm/sparse-vmemmap: support section-based vmemmap accounting
  mm/mm_init: factor out pfn_to_zone()
  mm/sparse-vmemmap: move vmemmap_get_tail() before PTE population
  mm/sparse-vmemmap: support section-based vmemmap optimization
  mm/sparse: initialize memory sections earlier
  mm/hugetlb: switch HugeTLB to section-based vmemmap optimization
  mm/sparse-vmemmap: remove SPARSEMEM_VMEMMAP_PREINIT support
  mm/sparse: inline usemap allocation into sparse_init_nid()
  mm/sparse: remove section_map_size()
  mm/hugetlb: remove HUGE_BOOTMEM_HVO
  mm/hugetlb: remove HUGE_BOOTMEM_CMA
  mm/hugetlb: localize struct huge_bootmem_page
  mm/hugetlb: localize HUGE_BOOTMEM_ZONES_VALID

 arch/x86/Kconfig        |   1 -
 fs/Kconfig              |   1 -
 include/linux/hugetlb.h |   5 --
 include/linux/mm.h      |   4 -
 include/linux/mmzone.h  |  72 +++++++---------
 mm/Kconfig              |   5 --
 mm/hugetlb.c            |  64 ++++-----------
 mm/hugetlb_vmemmap.c    | 103 +----------------------
 mm/hugetlb_vmemmap.h    |  13 +--
 mm/internal.h           |   7 --
 mm/mm_init.c            |  62 ++++++++------
 mm/mm_init.h            |   1 +
 mm/sparse-vmemmap.c     | 176 +++++++++++++++++-----------------------
 mm/sparse.c             |  94 ++++-----------------
 mm/sparse.h             |  67 +++++++++++++++
 scripts/gdb/linux/mm.py |   6 +-
 16 files changed, 253 insertions(+), 428 deletions(-)


base-commit: 0718283ab28bc3907e10b61a6b4be6fefa1cbb2f
-- 
2.54.0


^ permalink raw reply	[flat|nested] 21+ messages in thread
end of thread, other threads:[~2026-07-20 11:11 UTC | newest]

Thread overview: 21+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-07-20  9:31 [PATCH v2 00/17] mm: Introduce section-based vmemmap optimization for HugeTLB Muchun Song
2026-07-20  9:31 ` [PATCH v2 01/17] mm/sparse: relax struct mem_section size constraints Muchun Song
2026-07-20  9:31 ` [PATCH v2 02/17] mm/sparse-vmemmap: rename HVO order macros Muchun Song
2026-07-20  9:31 ` [PATCH v2 03/17] mm/mm_init: skip initializing shared vmemmap tail pages Muchun Song
2026-07-20  9:31 ` [PATCH v2 04/17] mm/sparse-vmemmap: initialize shared tail vmemmap pages on allocation Muchun Song
2026-07-20  9:31 ` [PATCH v2 05/17] mm/sparse-vmemmap: support section-based vmemmap accounting Muchun Song
2026-07-20  9:31 ` [PATCH v2 06/17] mm/mm_init: factor out pfn_to_zone() Muchun Song
2026-07-20 11:04   ` Muchun Song
2026-07-20 11:05   ` Muchun Song
2026-07-20  9:31 ` [PATCH v2 07/17] mm/sparse-vmemmap: move vmemmap_get_tail() before PTE population Muchun Song
2026-07-20  9:31 ` [PATCH v2 08/17] mm/sparse-vmemmap: support section-based vmemmap optimization Muchun Song
2026-07-20 11:10   ` Muchun Song
2026-07-20  9:31 ` [PATCH v2 09/17] mm/sparse: initialize memory sections earlier Muchun Song
2026-07-20  9:31 ` [PATCH v2 10/17] mm/hugetlb: switch HugeTLB to section-based vmemmap optimization Muchun Song
2026-07-20  9:31 ` [PATCH v2 11/17] mm/sparse-vmemmap: remove SPARSEMEM_VMEMMAP_PREINIT support Muchun Song
2026-07-20  9:31 ` [PATCH v2 12/17] mm/sparse: inline usemap allocation into sparse_init_nid() Muchun Song
2026-07-20  9:31 ` [PATCH v2 13/17] mm/sparse: remove section_map_size() Muchun Song
2026-07-20  9:31 ` [PATCH v2 14/17] mm/hugetlb: remove HUGE_BOOTMEM_HVO Muchun Song
2026-07-20  9:31 ` [PATCH v2 15/17] mm/hugetlb: remove HUGE_BOOTMEM_CMA Muchun Song
2026-07-20  9:31 ` [PATCH v2 16/17] mm/hugetlb: localize struct huge_bootmem_page Muchun Song
2026-07-20  9:31 ` [PATCH v2 17/17] mm/hugetlb: localize HUGE_BOOTMEM_ZONES_VALID Muchun Song

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.