CONFIG_HOTPLUG=y
CONFIG_X86_NUMAQ=y
CONFIG_NUMA=y
CONFIG_MEMORY_HOTPLUG=y
CONFIG_MEMORY_HOTPLUG_SPARSE=y
CONFIG_HOTPLUG_CPU=y
CONFIG_ARCH_ENABLE_MEMORY_HOTPLUG=y
# Power management options (ACPI, APM)
# ACPI (Advanced Configuration and Power Interface) Support

==>

mm/built-in.o: In function `add_memory':
(.text+0x24235): undefined reference to `arch_add_memory'
drivers/built-in.o: In function `memory_block_change_state':
memory.c:(.text+0x75a1d): undefined reference to `remove_memory'
make: *** [.tmp_vmlinux1] Error 1

Full config attached.

---
~Randy