I have a P7 system that has no node0, but a node0 shows up in numactl --hardware, which has no cpus and no memory (and no PCI devices): numactl --hardware available: 4 nodes (0-3) node 0 cpus: node 0 size: 0 MB node 0 free: 0 MB node 1 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 node 1 size: 0 MB node 1 free: 0 MB node 2 cpus: node 2 size: 7935 MB node 2 free: 7716 MB node 3 cpus: node 3 size: 8395 MB node 3 free: 8015 MB node distances: node 0 1 2 3 0: 10 20 10 20 1: 20 10 20 20 2: 10 20 10 20 3: 20 20 20 10 This is because we statically initialize N_ONLINE to be [0] in mm/page_alloc.c: [N_ONLINE] = { { [0] = 1UL } }, I'm not sure what the architectural requirements are here, but at least on this test system, removing this initialization, it boots fine and is running. I've not yet tried stress tests, but it's survived the beginnings of kernbench so far. numactl --hardware available: 3 nodes (1-3) node 1 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 node 1 size: 0 MB node 1 free: 0 MB node 2 cpus: node 2 size: 7935 MB node 2 free: 7479 MB node 3 cpus: node 3 size: 8396 MB node 3 free: 8375 MB node distances: node 1 2 3 1: 10 20 20 2: 20 10 20 3: 20 20 10 Perhaps we could put in a ARCH_DOES_NOT_NEED_NODE0 and only define it on powerpc for now, conditionalizing the above initialization on that? Thanks, Nish -- 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>