+/*
+ * Attempt to take a CPU offline. Return false if the CPU is already
+ * offline or if it is not subject to CPU-hotplug operations. The
+ * caller can detect other failures by looking at the statistics.
+ */
+bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes,
+ unsigned long *sum_offl, int *min_offl, int *max_offl)
+{
+ unsigned long delta;
+ int ret;
+ unsigned long starttime;
+
+ if (!cpu_online(cpu) || !cpu_is_hotpluggable(cpu))
+ return false;
+
+ if (verbose)
+ pr_alert("%s" TORTURE_FLAG
+ "torture_onoff task: offlining %d\n",
+ torture_type, cpu);
+ starttime = jiffies;
+ (*n_offl_attempts)++;
+ ret = cpu_down(cpu);
+ if (ret) {
+ if (verbose)
+ pr_alert("%s" TORTURE_FLAG
+ "torture_onoff task: offline %d failed: errno %d\n",
+ torture_type, cpu, ret);
+ } else {
+ if (verbose)
+ pr_alert("%s" TORTURE_FLAG
+ "torture_onoff task: offlined %d\n",
+ torture_type, cpu);
+ (*n_offl_successes)++;
+ delta = jiffies - starttime;
+ sum_offl += delta;
+ if (*min_offl < 0) {
+ *min_offl = delta;
+ *max_offl = delta;
+ }
+ if (*min_offl > delta)
+ *min_offl = delta;
+ if (*max_offl < delta)
+ *max_offl = delta;
+ }
+
+ return true;
+}
+EXPORT_SYMBOL_GPL(torture_offline);
+
+/*
+ * Attempt to bring a CPU online. Return false if the CPU is already
+ * online or if it is not subject to CPU-hotplug operations. The
+ * caller can detect other failures by looking at the statistics.
+ */
+bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes,
+ unsigned long *sum_onl, int *min_onl, int *max_onl)
+{
+ unsigned long delta;
+ int ret;
+ unsigned long starttime;
+
+ if (cpu_online(cpu) || !cpu_is_hotpluggable(cpu))
+ return false;
+
+ if (verbose)
+ pr_alert("%s" TORTURE_FLAG
+ "torture_onoff task: onlining %d\n",
+ torture_type, cpu);
+ starttime = jiffies;
+ (*n_onl_attempts)++;
+ ret = cpu_up(cpu);
+ if (ret) {
+ if (verbose)
+ pr_alert("%s" TORTURE_FLAG
+ "torture_onoff task: online %d failed: errno %d\n",
+ torture_type, cpu, ret);
+ } else {
+ if (verbose)
+ pr_alert("%s" TORTURE_FLAG
+ "torture_onoff task: onlined %d\n",
+ torture_type, cpu);
+ (*n_onl_successes)++;
+ delta = jiffies - starttime;
+ *sum_onl += delta;
+ if (*min_onl < 0) {
+ *min_onl = delta;
+ *max_onl = delta;
+ }
+ if (*min_onl > delta)
+ *min_onl = delta;
+ if (*max_onl < delta)
+ *max_onl = delta;
+ }
+
+ return true;
+}
+EXPORT_SYMBOL_GPL(torture_online);
+