Re: [PATCH v4 00/21] Virtual Swap Space

[Nhat Pham]

On Wed, Mar 18, 2026 at 3:29 PM Nhat Pham <nphamcs@xxxxxxxxx> wrote:
>

[...]

Argh I copied my draft cover letter over the diffstat. My apologies -
here's the rest of the cover letter. Base commit is
05f7e89ab9731565d8a62e3b5d1ec206485eeb0b for your convenience (it's at
the bottom too - this should be 6.19).

Nhat Pham (21):
  mm/swap: decouple swap cache from physical swap infrastructure
  swap: rearrange the swap header file
  mm: swap: add an abstract API for locking out swapoff
  zswap: add new helpers for zswap entry operations
  mm/swap: add a new function to check if a swap entry is in swap
    cached.
  mm: swap: add a separate type for physical swap slots
  mm: create scaffolds for the new virtual swap implementation
  zswap: prepare zswap for swap virtualization
  mm: swap: allocate a virtual swap slot for each swapped out page
  swap: move swap cache to virtual swap descriptor
  zswap: move zswap entry management to the virtual swap descriptor
  swap: implement the swap_cgroup API using virtual swap
  swap: manage swap entry lifecycle at the virtual swap layer
  mm: swap: decouple virtual swap slot from backing store
  zswap: do not start zswap shrinker if there is no physical swap slots
  swap: do not unnecesarily pin readahead swap entries
  swapfile: remove zeromap bitmap
  memcg: swap: only charge physical swap slots
  swap: simplify swapoff using virtual swap
  swapfile: replace the swap map with bitmaps
  vswap: batch contiguous vswap free calls

 Documentation/mm/swap-table.rst |   69 --
 MAINTAINERS                     |    3 +-
 include/linux/cpuhotplug.h      |    1 +
 include/linux/memcontrol.h      |    6 +
 include/linux/mm_types.h        |   16 +
 include/linux/shmem_fs.h        |    7 +-
 include/linux/swap.h            |  185 ++-
 include/linux/swap_cgroup.h     |   13 -
 include/linux/swapops.h         |   25 +
 include/linux/zswap.h           |   17 +-
 kernel/power/swap.c             |    6 +-
 mm/Makefile                     |    5 +-
 mm/filemap.c                    |   14 +-
 mm/huge_memory.c                |   11 +-
 mm/internal.h                   |   24 +-
 mm/madvise.c                    |    2 +-
 mm/memcontrol-v1.c              |    6 +
 mm/memcontrol.c                 |  144 ++-
 mm/memory.c                     |  109 +-
 mm/migrate.c                    |   13 +-
 mm/mincore.c                    |   15 +-
 mm/page_io.c                    |   83 +-
 mm/shmem.c                      |  227 +---
 mm/swap.h                       |  179 +--
 mm/swap_cgroup.c                |  172 ---
 mm/swap_state.c                 |  306 +----
 mm/swap_table.h                 |   78 +-
 mm/swapfile.c                   | 1517 ++++-------------------
 mm/userfaultfd.c                |   18 +-
 mm/vmscan.c                     |   28 +-
 mm/vswap.c                      | 2008 +++++++++++++++++++++++++++++++
 mm/zswap.c                      |  142 +--
 32 files changed, 2942 insertions(+), 2507 deletions(-)
 delete mode 100644 Documentation/mm/swap-table.rst
 delete mode 100644 mm/swap_cgroup.c
 create mode 100644 mm/vswap.c


base-commit: 05f7e89ab9731565d8a62e3b5d1ec206485eeb0b

--
2.52.0