On Mon, 2011-05-02 at 23:19 +0200, Daniel Kiper wrote: > Memory hotplug code strictly depends on CONFIG_SPARSEMEM. > It means that code depending on CONFIG_FLATMEM in online_page() > is never compiled. Remove it because it is not needed anymore. It's subtle, but I don't think that's true. We had another hotplug mode for x86_64 before folks were comfortable turning SPARSEMEM on for the whole architecture. It was quite possible to have memory hotplug without sparsemem in that case. I think Keith Mannthey did some of that code if I remember right. But, I'm not sure how much of that stayed in distros versus made it upstream. In any case, you might want to chase down the X86_64_ACPI_NUMA bit to make sure it can't be used with FLATMEM ever. config MEMORY_HOTPLUG bool "Allow for memory hot-add" depends on SPARSEMEM || X86_64_ACPI_NUMA depends on HOTPLUG && ARCH_ENABLE_MEMORY_HOTPLUG depends on (IA64 || X86 || PPC_BOOK3S_64 || SUPERH || S390) -- Dave -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>