diff options
| -rw-r--r-- | arch/powerpc/platforms/pseries/hotplug-cpu.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c index 12cbffd3c2e3..ec478f8a98ff 100644 --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c @@ -271,6 +271,19 @@ static int dlpar_offline_cpu(struct device_node *dn) if (!cpu_online(cpu)) break; + /* + * device_offline() will return -EBUSY (via cpu_down()) if there + * is only one CPU left. Check it here to fail earlier and with a + * more informative error message, while also retaining the + * cpu_add_remove_lock to be sure that no CPUs are being + * online/offlined during this check. + */ + if (num_online_cpus() == 1) { + pr_warn("Unable to remove last online CPU %pOFn\n", dn); + rc = -EBUSY; + goto out_unlock; + } + cpu_maps_update_done(); rc = device_offline(get_cpu_device(cpu)); if (rc) @@ -283,6 +296,7 @@ static int dlpar_offline_cpu(struct device_node *dn) thread); } } +out_unlock: cpu_maps_update_done(); out: |