torture: Stop onoff task if there is only one cpu

If the whole system has only one cpu, that cpu won't be able to be
offlined, so there is no need onoff task is stil running.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

diff --git a/kernel/torture.c b/kernel/torture.c
index fb39a06bbef5062b8d3d242d911ac2616ac1eb74..75961b3decfe9489cfa08459a8efba8931a0343a 100644 (file)
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -194,6 +194,12 @@ torture_onoff(void *arg)
        for_each_online_cpu(cpu)
                maxcpu = cpu;
        WARN_ON(maxcpu < 0);
+
+       if (maxcpu == 0) {
+               VERBOSE_TOROUT_STRING("Only one CPU, so CPU-hotplug testing is disabled");
+               goto stop;
+       }
+
        if (onoff_holdoff > 0) {
                VERBOSE_TOROUT_STRING("torture_onoff begin holdoff");
                schedule_timeout_interruptible(onoff_holdoff);
@@ -209,6 +215,8 @@ torture_onoff(void *arg)
                                       &sum_online, &min_online, &max_online);
                schedule_timeout_interruptible(onoff_interval);
        }
+
+stop:
        torture_kthread_stopping("torture_onoff");
        return 0;
 }