On Wed, 31 Oct 2012, Wen Congyang wrote: > From: Lai Jiangshan <laijs@xxxxxxxxxxxxxx> > > This patch is part3 of the following patchset: > https://lkml.org/lkml/2012/10/29/319 > > Part1 is here: > https://lkml.org/lkml/2012/10/31/30 > > Part2 is here: > http://marc.info/?l=linux-kernel&m=135166705909544&w=2 > > You can apply this patchset without the other parts. > > we need a node which only contains movable memory. This feature is very > important for node hotplug. So we will add a new nodemask > for all memory. N_MEMORY contains movable memory but N_HIGH_MEMORY > doesn't contain it. > > We don't remove N_HIGH_MEMORY because it can be used to search which > nodes contains memory that the kernel can use. > This doesn't describe why we need the new node state, unfortunately. It makes sense to boot with node(s) containing only ZONE_MOVABLE, but it doesn't show why we need a nodemask to specify such nodes and such information should be available from the kernel log or /proc/zoneinfo. Node hotplug should fail if all memory cannot be offlined, so why do we need another nodemask? Only offline the node if all memory is offlined. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>