On Friday, February 07, 2014 05:17:45 PM Jiang Liu wrote: > > On 2014/2/5 8:14, Rafael J. Wysocki wrote: > > On Monday, January 20, 2014 10:31:54 AM Jiang Liu wrote: > >> 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 <jiang.liu@xxxxxxxxxxxxxxx> > > > > I wonder what the status here is? Did this patch go anywhere? > Hi Rafael, > It's still in review stage, hasn't been accepted by any > maintainer yet. OK Peter, are you fine with the patch below? Rafael > > > >> --- > >> 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 > >> } > >> > >> > > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html