[PATCH 0/2] Implement numa node notifier

[Oscar Salvador]

Memory notifier is a tool that allow consumers to get notified whenever
memory gets onlined or offlined in the system.
Currently, there are 10 consumers of that, but 5 out of those 10 consumers
are only interested in getting notifications when a numa node has changed its
state.
That means going from memoryless to memory-aware of vice versa.

Which means that for every {online,offline}_pages operation they get
notified even though the numa node might not have changed its state.

The first patch implements a numa node notifier that does just that, and have
those consumers register in there, so they get notified only when they are
interested.

The second patch replaces 'status_change_normal{_normal}' fields within
memory_notify with a 'nid', as that is only what we need for memory
notifer and update the only user of it (page_ext).

Consumers that are only interested in numa node states change are:

 - memory-tier
 - slub
 - cpuset
 - hmat
 - cxl


Oscar Salvador (2):
  mm,memory_hotplug: Implement numa node notifier
  mm,memory_hotplug: Replace status_change_nid parameter in
    memory_notify

 drivers/acpi/numa/hmat.c  |  6 +--
 drivers/base/node.c       | 19 +++++++++
 drivers/cxl/core/region.c | 14 +++----
 drivers/cxl/cxl.h         |  4 +-
 include/linux/memory.h    | 37 ++++++++++++++++++
 kernel/cgroup/cpuset.c    |  2 +-
 mm/memory-tiers.c         |  8 ++--
 mm/memory_hotplug.c       | 82 +++++++++++++++++++++++++++++----------
 mm/page_ext.c             | 12 +-----
 mm/slub.c                 | 22 +++++------
 10 files changed, 146 insertions(+), 60 deletions(-)

-- 
2.49.0