On 05/21/2010 04:39 PM, KAMEZAWA Hiroyuki wrote:
On Fri, 21 May 2010 16:22:19 +0800 minskey guo<chaohong_guo@xxxxxxxxxxxxxxx> wrote:Yes. I can use cpu_to_mem(). only some little difference during CPU online: 1st cpu within memoryless node gets memory from current node or the node to which the cpu0 belongs, But I have a question about the patch: numa-slab-use-numa_mem_id-for-slab-local-memory-node.patch, @@ -2968,9 +2991,23 @@ static int __build_all_zonelists(void *d ... - for_each_possible_cpu(cpu) + for_each_possible_cpu(cpu) { setup_pageset(&per_cpu(boot_pageset, cpu), 0); ... +#ifdef CONFIG_HAVE_MEMORYLESS_NODES + if (cpu_online(cpu)) + cpu_to_mem(cpu) = local_memory_node(cpu_to_node(cpu)); +#endif
Look at the above code, int __build_all_zonelists(), cpu_to_mem(cpu) is set only when cpu is onlined. Suppose that a node with local memory, all memory segments are onlined first, and then, cpus within that node are onlined one by one, in this case, where does the cpu_to_mem(cpu) for the last cpu get its value ?
So, cpu_to_node(cpu) for possible cpus will have NUMA_NO_NODE(-1) or the number of the nearest node. IIUC, if SRAT is not broken, all pxm has its own node_id.
Thank you very much for the info, I have been thinking why node_id is (-1) in some cases. -minskey -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>