On Fri, 16 Nov 2012 19:58:09 +0800 Wen Congyang <wency@xxxxxxxxxxxxxx> wrote: > From: Lai Jiangshan <laijs@xxxxxxxxxxxxxx> > > All are prepared, we can actually introduce N_MEMORY. > add CONFIG_MOVABLE_NODE make we can use it for movable-dedicated node This description is far too short on details. I grabbed this from the [0/n] email: : We need a node which only contains movable memory. This feature is very : important for node hotplug. If a node has normal/highmem, the memory may : be used by the kernel and can't be offlined. If the node only contains : movable memory, we can offline the memory and the node. which helps a bit, but it's still pretty thin. Why is this option made configurable? Why not enable it unconditionally? Please send a patch which adds the Kconfig help text for CONFIG_MOVABLE_NODE. Let's make that text nice and detailed. The name MOVABLE_NODE is not a good one. It means "a node which is movable", whereas the concept is actually "a node whcih contains only movable memory". I suppose we could change it to something like CONFIG_MOVABLE_MEMORY_ONLY_NODE or similar. But I suppose that CONFIG_MOVABLE_NODE is good enough, as long as it is well-described in associated comments or help text. This is not the case at present. > +#ifdef CONFIG_MOVABLE_NODE > + N_MEMORY, /* The node has memory(regular, high, movable) */ > +#else I think the comment should be "The node has only movable memory"? -- 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>