From: Jiang Liu Date: Mon, 20 Jan 2014 02:31:54 +0000 (+0800) Subject: x86, acpi: Fix bug in associating hot-added CPUs with corresponding NUMA node X-Git-Tag: v3.15-rc1~179^2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=896dc5064083063981954f142e43548765199792;p=pandora-kernel.git x86, acpi: Fix bug in associating hot-added CPUs with corresponding NUMA node Current ACPI cpu hotplug driver fails to associate hot-added CPUs with corresponding NUMA node when doing socket online. The code path to associate CPU with NUMA node is as below: acpi_processor_add() ->acpi_processor_get_info() ->acpi_processor_hotadd_init() ->acpi_map_lsapic() ->_acpi_map_lsapic() ->acpi_map_cpu2node() cpu_subsys_online() ->try_online_node() ->node_set_online() When doing socket online, a new NUMA node is introduced in addition to hot-added CPU and memory device. And the new NUMA node is marked as online when onlining hot-added CPUs through sysfs interface /sys/devices/system/cpu/cpuxx/online. On the other hand, acpi_map_cpu2node() will only build the CPU to node map if corresponding NUMA node is already online, so it always fails to associate hot-added CPUs with corresponding NUMA node because the NUMA node is still in offline state. For the fix, we could safely remove the "node_online(node)" check in function acpi_map_cpu2node() because it's only called for hot-added CPUs by acpi_processor_hotadd_init(). Signed-off-by: Jiang Liu Link: http://lkml.kernel.org/r/1390185115-26850-1-git-send-email-jiang.liu@linux.intel.com Acked-by: Rafael J. Wysocki Signed-off-by: H. Peter Anvin --- Reading git-diff-tree failed