From: Yinghai Lu Date: Sat, 21 Nov 2009 08:23:37 +0000 (-0800) Subject: x86, numa: Use near(er) online node instead of roundrobin for NUMA X-Git-Tag: v2.6.33-rc1~374^2~10 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d9c2d5ac6af87b4491bff107113aaf16f6c2b2d9;p=pandora-kernel.git x86, numa: Use near(er) online node instead of roundrobin for NUMA CPU to node mapping is set via the following sequence: 1. numa_init_array(): Set up roundrobin from cpu to online node 2. init_cpu_to_node(): Set that according to apicid_to_node[] according to srat only handle the node that is online, and leave other cpu on node without ram (aka not online) to still roundrobin. 3. later call srat_detect_node for Intel/AMD, will use first_online node or nearby node. Problem is that setup_per_cpu_areas() is not called between 2 and 3, the per_cpu for cpu on node with ram is on different node, and could put that on node with two hops away. So try to optimize this and add find_near_online_node() and call init_cpu_to_node(). Signed-off-by: Yinghai Lu Cc: Tejun Heo Cc: Linus Torvalds Cc: Thomas Gleixner Cc: H. Peter Anvin Cc: Rusty Russell Cc: David Rientjes Cc: Andrew Morton LKML-Reference: <4B07A739.3030104@kernel.org> Signed-off-by: Ingo Molnar --- Reading git-diff-tree failed