force offline the processor during hot-removal

The ACPI device node for the cpu has already been unregistered
when acpi_processor_handle_eject is called.
Thus we should offline the cpu and continue, rather than a failure here.
http://bugzilla.kernel.org/show_bug.cgi?id=9772

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

2 files changed, 4 insertions, 3 deletions

diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index 9dd0fa93b9e1..1c0008edccda 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -1014,9 +1014,9 @@ static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
 
 static int acpi_processor_handle_eject(struct acpi_processor *pr)
 {
-        if (cpu_online(pr->id)) {
-                return (-EINVAL);
-        }
+        if (cpu_online(pr->id))
+                cpu_down(pr->id);
+
         arch_unregister_cpu(pr->id);
         acpi_unmap_lsapic(pr->id);
         return (0);
diff --git a/kernel/cpu.c b/kernel/cpu.c
index b11f06dc149a..cfb1d43ab801 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -299,6 +299,7 @@ int __ref cpu_down(unsigned int cpu)
         cpu_maps_update_done();
         return err;
 }
+EXPORT_SYMBOL(cpu_down);
 #endif /*CONFIG_HOTPLUG_CPU*/
 
 /* Requires cpu_add_remove_lock to be held */