[PATCH v9 00/11] futex: Add support task local hash maps.

[Sebastian Andrzej Siewior]

Hi,

this is a follow up on
        https://lore.kernel.org/ZwVOMgBMxrw7BU9A@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

and adds support for task local futex_hash_bucket.

This is rebased of v8 ontop of PeterZ's futex_class. The complete tree
is at
	https://git.kernel.org/pub/scm/linux/kernel/git/bigeasy/staging.git/log/?h=futex_local_v9
	https://git.kernel.org/pub/scm/linux/kernel/git/bigeasy/staging.git futex_local_v9

v8…v9 https://lore.kernel.org/all/20250203135935.440018-1-bigeasy@xxxxxxxxxxxxx
  - Rebase on top PeterZ futex_class
  - A few patches vanished due to class rework.
  - struct futex_hash_bucket has now pointer to futex_private_hash
    instead of slot number
  - CONFIG_BASE_SMALL now removes support for the "futex local hash"
    instead of restricting it to to 2 slots.
  - Number of threads, used to determine the number of slots, is capped
    at num_online_cpus.

v7…v8 https://lore.kernel.org/all/20250123202446.610203-1-bigeasy@xxxxxxxxxxxxx/
  - Rebase on v6.14-rc1

Sebastian Andrzej Siewior (11):
  futex: fixup futex_wait_setup [fold futex: Move futex_queue() into
    futex_wait_setup()]
  futex: Create helper function to initialize a hash slot.
  futex: Add basic infrastructure for local task local hash.
  futex: Hash only the address for private futexes.
  futex: Allow automatic allocation of process wide futex hash.
  futex: Decrease the waiter count before the unlock operation.
  futex: Introduce futex_q_lockptr_lock().
  futex: Acquire a hash reference in futex_wait_multiple_setup().
  futex: Allow to re-allocate the private local hash.
  futex: Resize local futex hash table based on number of threads.
  futex: Use a hashmask instead of hashsize.

 include/linux/futex.h      |  32 ++-
 include/linux/mm_types.h   |   7 +-
 include/uapi/linux/prctl.h |   5 +
 kernel/fork.c              |  24 ++
 kernel/futex/core.c        | 450 +++++++++++++++++++++++++++++++++++--
 kernel/futex/futex.h       |  15 +-
 kernel/futex/pi.c          |  15 +-
 kernel/futex/requeue.c     |  29 ++-
 kernel/futex/waitwake.c    |  31 ++-
 kernel/sys.c               |   4 +
 10 files changed, 574 insertions(+), 38 deletions(-)

-- 
2.47.2