On Thu, 18 Nov 2010, Shaohui Zheng wrote: > in our draft patch, we re-setup nr_node_ids when CONFIG_ARCH_MEMORY_PROBE enabled > and mem=XXX was specified in grub. we set nr_node_ids as MAX_NUMNODES + 1, because > we do not know how many nodes will be hot-added through memory/probe interface. > it might be a little wasting of memory. > nr_node_ids need not be set to anything different at boot, the MEM_GOING_ONLINE callback should be used for anything (like the slab allocators) where a new node is introduced and needs to be dealt with accordingly; this is how regular memory hotplug works, we need no additional code in this regard because it's emulated. If a subsystem needs to change in response to a new node going online and doesn't as a result of using your emulator, that's a bug and either needs to be fixed or prohibited from use with CONFIG_MEMORY_HOTPLUG. (See the MEM_GOING_ONLINE callback in mm/slub.c, for instance, which deals only with the case of node hotplug.) -- 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 policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>