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. v1->v2: fix compile error of patch [4,5]. 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(-) -- 2.25.1