From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> There is a potential race condition between cpu_subsys_online() and either acpi_processor_remove() or remove_memory() that execute try_offline_node(). Namely, it is possible that cpu_subsys_online() will run right after the CPUs NUMA node has been put offline and cpu_to_node() executed by it will return NUMA_NO_NODE (-1). In that case the CPU is gone and it doesn't make sense to call cpu_up() for it, so make cpu_subsys_online() return -ENODEV then. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Acked-by: Toshi Kani <toshi.kani@xxxxxx> --- Hi Greg, Can you please kindly queue up this one for 3.12? I've added the Toshi's ACK as he said it looked good to him. :-) Thanks, Rafael --- drivers/base/cpu.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) Index: linux-pm/drivers/base/cpu.c =================================================================== --- linux-pm.orig/drivers/base/cpu.c +++ linux-pm/drivers/base/cpu.c @@ -43,11 +43,14 @@ static int __ref cpu_subsys_online(struc struct cpu *cpu = container_of(dev, struct cpu, dev); int cpuid = dev->id; int from_nid, to_nid; - int ret; + int ret = -ENODEV; cpu_hotplug_driver_lock(); from_nid = cpu_to_node(cpuid); + if (from_nid == NUMA_NO_NODE) + goto out; + ret = cpu_up(cpuid); /* * When hot adding memory to memoryless node and enabling a cpu @@ -57,6 +60,7 @@ static int __ref cpu_subsys_online(struc if (from_nid != to_nid) change_cpu_under_node(cpu, from_nid, to_nid); + out: cpu_hotplug_driver_unlock(); return ret; } -- 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
