[PATCH 0/9] mm: Use hotplug_memory_notifier() instead of register_hotmemory_notifier()

From: Liu Shixin
Date: Mon Sep 19 2022 - 03:58:20 EST


Patch f02c69680088 introduced register_hotmemory_notifier() to avoid a
compile problem with gcc-4.4.4:

When CONFIG_MEMORY_HOTPLUG=n, we don't want the memory-hotplug notifier
handlers to be included in the .o files, for space reasons.

The existing hotplug_memory_notifier() tries to handle this but testing
with gcc-4.4.4 shows that it doesn't work - the hotplug functions are
still present in the .o files.

Since patch 316346243be6 has already updated the minimum gcc version to 5.1.
The previous problem mentioned in patch f02c69680088 is not existed. So we
can now revert to use hotplug_memory_notifier() directly rather than
register_hotmemory_notifier().

Patch [1-6] replace register_hotmemory_notifier() with hotplug_memory_notifier()
for every caller.
Patch [7] remove unused register_hotmemory_notifier().
Patch [8] replace IPC_CALLBACK_PRI with MM_BATCH_CALLBACK_PRI.
Patch [9] collect all priority of hotplug memory callback into include/linux/memory.h
for easy reading.

Liu Shixin (9):
cgroup/cpuset: use hotplug_memory_notifier() directly
fs/proc/kcore.c: use hotplug_memory_notifier() directly
mm/slub.c: use hotplug_memory_notifier() directly
mm/mmap: use hotplug_memory_notifier() directly
mm/mm_init.c: use hotplug_memory_notifier() directly
ACPI: HMAT: use hotplug_memory_notifier() directly
memory: remove unused register_hotmemory_notifier()
memory: replace IPC_CALLBACK_PRI with MM_BATCH_CALLBACK_PRI
memory: clean up hotplug memory callback priority

drivers/acpi/numa/hmat.c | 7 +------
fs/proc/kcore.c | 7 +------
include/linux/memory-tiers.h | 1 -
include/linux/memory.h | 15 +++++++--------
kernel/cgroup/cpuset.c | 7 +------
mm/kasan/shadow.c | 2 +-
mm/ksm.c | 2 +-
mm/mm_init.c | 8 +-------
mm/mmap.c | 6 +-----
mm/page_ext.c | 2 +-
mm/slub.c | 7 +------
11 files changed, 16 insertions(+), 48 deletions(-)

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2.25.1