From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiang Liu Subject: [Patch v1] ACPI, x86: fix bug in associating hot-added CPUs with corresponding NUMA node Date: Mon, 20 Jan 2014 10:31:54 +0800 Message-ID: <1390185115-26850-1-git-send-email-jiang.liu@linux.intel.com> Return-path: Sender: linux-hotplug-owner@vger.kernel.org To: "Rafael J . Wysocki" , Toshi Kani , Yinghai Lu , Yijing Wang , Len Brown , Pavel Machek , "Rafael J. Wysocki" , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org Cc: Jiang Liu , linux-acpi@vger.kernel.org, linux-hotplug@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org List-Id: linux-pm@vger.kernel.org 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 --- arch/x86/kernel/acpi/boot.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index 6c0b43b..7625de9 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -614,10 +614,10 @@ static void acpi_map_cpu2node(acpi_handle handle, int cpu, int physid) int nid; nid = acpi_get_node(handle); - if (nid == -1 || !node_online(nid)) - return; - set_apicid_to_node(physid, nid); - numa_set_node(cpu, nid); + if (nid != -1) { + set_apicid_to_node(physid, nid); + numa_set_node(cpu, nid); + } #endif } -- 1.7.10.4