torture: Clean up after torture-test CPU hotplugging

This commit puts all CPUs back online at the end of a torture test,
and also unconditionally puts them online at the beginning of the test,
rather than just in the case of built-in tests.  This allows torture tests
to behave in a predictable manner, whether built-in or based on modules.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

diff --git a/kernel/torture.c b/kernel/torture.c
index 93eeeb2b3d88cff7918d8e1c1ba1589998fe782c..507a20be69506a3ef5e2213ad27858c378c186de 100644 (file)
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -291,6 +291,26 @@ bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes,
 }
 EXPORT_SYMBOL_GPL(torture_online);
 
+/*
+ * Get everything online at the beginning and ends of tests.
+ */
+static void torture_online_all(char *phase)
+{
+       int cpu;
+       int ret;
+
+       for_each_possible_cpu(cpu) {
+               if (cpu_online(cpu))
+                       continue;
+               ret = add_cpu(cpu);
+               if (ret && verbose) {
+                       pr_alert("%s" TORTURE_FLAG
+                                "%s: %s online %d: errno %d\n",
+                                __func__, phase, torture_type, cpu, ret);
+               }
+       }
+}
+
 /*
  * Execute random CPU-hotplug operations at the interval specified
  * by the onoff_interval.
@@ -301,25 +321,12 @@ torture_onoff(void *arg)
        int cpu;
        int maxcpu = -1;
        DEFINE_TORTURE_RANDOM(rand);
-       int ret;
 
        VERBOSE_TOROUT_STRING("torture_onoff task started");
        for_each_online_cpu(cpu)
                maxcpu = cpu;
        WARN_ON(maxcpu < 0);
-       if (!IS_MODULE(CONFIG_TORTURE_TEST)) {
-               for_each_possible_cpu(cpu) {
-                       if (cpu_online(cpu))
-                               continue;
-                       ret = add_cpu(cpu);
-                       if (ret && verbose) {
-                               pr_alert("%s" TORTURE_FLAG
-                                        "%s: Initial online %d: errno %d\n",
-                                        __func__, torture_type, cpu, ret);
-                       }
-               }
-       }
-
+       torture_online_all("Initial");
        if (maxcpu == 0) {
                VERBOSE_TOROUT_STRING("Only one CPU, so CPU-hotplug testing is disabled");
                goto stop;
@@ -347,6 +354,7 @@ torture_onoff(void *arg)
 
 stop:
        torture_kthread_stopping("torture_onoff");
+       torture_online_all("Final");
        return 0;
 }