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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2014-01-28 15:58:22 -0800
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2014-02-23 09:01:06 -0800
commit2e9e8081d2e7a4efb582a240aa7fee991bbbabb0 (patch)
tree21b3850bb6568d7bc61b432305c20b2423de24d7 /kernel/torture.c
parent3808dc9fab05913060626d7f0edd0f195cb9dcab (diff)
downloadlinux-2e9e8081d2e7a4efb582a240aa7fee991bbbabb0.tar.bz2
rcutorture: Abstract torture_onoff()
Because online/offline torturing is not specific to RCU, this commit abstracts it into the kernel/torture.c module to allow other torture tests to use it. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'kernel/torture.c')
-rw-r--r--kernel/torture.c186
1 files changed, 186 insertions, 0 deletions
diff --git a/kernel/torture.c b/kernel/torture.c
index 26058f20ee83..a7ec8a7d561e 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -54,6 +54,192 @@ EXPORT_SYMBOL_GPL(fullstop);
DEFINE_MUTEX(fullstop_mutex);
EXPORT_SYMBOL_GPL(fullstop_mutex);
+#ifdef CONFIG_HOTPLUG_CPU
+
+/*
+ * Variables for online-offline handling. Only present if CPU hotplug
+ * is enabled, otherwise does nothing.
+ */
+
+static struct task_struct *onoff_task;
+static long onoff_holdoff;
+static long onoff_interval;
+static long n_offline_attempts;
+static long n_offline_successes;
+static unsigned long sum_offline;
+static int min_offline = -1;
+static int max_offline;
+static long n_online_attempts;
+static long n_online_successes;
+static unsigned long sum_online;
+static int min_online = -1;
+static int max_online;
+
+/*
+ * Execute random CPU-hotplug operations at the interval specified
+ * by the onoff_interval.
+ */
+static int
+torture_onoff(void *arg)
+{
+ int cpu;
+ unsigned long delta;
+ int maxcpu = -1;
+ DEFINE_TORTURE_RANDOM(rand);
+ int ret;
+ unsigned long starttime;
+
+ VERBOSE_TOROUT_STRING("torture_onoff task started");
+ for_each_online_cpu(cpu)
+ maxcpu = cpu;
+ WARN_ON(maxcpu < 0);
+ if (onoff_holdoff > 0) {
+ VERBOSE_TOROUT_STRING("torture_onoff begin holdoff");
+ schedule_timeout_interruptible(onoff_holdoff);
+ VERBOSE_TOROUT_STRING("torture_onoff end holdoff");
+ }
+ while (!torture_must_stop()) {
+ cpu = (torture_random(&rand) >> 4) % (maxcpu + 1);
+ if (cpu_online(cpu) && cpu_is_hotpluggable(cpu)) {
+ if (verbose)
+ pr_alert("%s" TORTURE_FLAG
+ "torture_onoff task: offlining %d\n",
+ torture_type, cpu);
+ starttime = jiffies;
+ n_offline_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_offline_successes++;
+ delta = jiffies - starttime;
+ sum_offline += delta;
+ if (min_offline < 0) {
+ min_offline = delta;
+ max_offline = delta;
+ }
+ if (min_offline > delta)
+ min_offline = delta;
+ if (max_offline < delta)
+ max_offline = delta;
+ }
+ } else if (cpu_is_hotpluggable(cpu)) {
+ if (verbose)
+ pr_alert("%s" TORTURE_FLAG
+ "torture_onoff task: onlining %d\n",
+ torture_type, cpu);
+ starttime = jiffies;
+ n_online_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_online_successes++;
+ delta = jiffies - starttime;
+ sum_online += delta;
+ if (min_online < 0) {
+ min_online = delta;
+ max_online = delta;
+ }
+ if (min_online > delta)
+ min_online = delta;
+ if (max_online < delta)
+ max_online = delta;
+ }
+ }
+ schedule_timeout_interruptible(onoff_interval);
+ }
+ VERBOSE_TOROUT_STRING("torture_onoff task stopping");
+ return 0;
+}
+
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+
+/*
+ * Initiate online-offline handling.
+ */
+int torture_onoff_init(long ooholdoff, long oointerval)
+{
+#ifdef CONFIG_HOTPLUG_CPU
+ int ret;
+
+ onoff_holdoff = ooholdoff;
+ onoff_interval = oointerval;
+ if (onoff_interval <= 0)
+ return 0;
+ onoff_task = kthread_run(torture_onoff, NULL, "torture_onoff");
+ if (IS_ERR(onoff_task)) {
+ ret = PTR_ERR(onoff_task);
+ onoff_task = NULL;
+ return ret;
+ }
+ torture_shuffle_task_register(onoff_task);
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+ return 0;
+}
+EXPORT_SYMBOL_GPL(torture_onoff_init);
+
+/*
+ * Clean up after online/offline testing.
+ */
+void torture_onoff_cleanup(void)
+{
+#ifdef CONFIG_HOTPLUG_CPU
+ if (onoff_task == NULL)
+ return;
+ VERBOSE_TOROUT_STRING("Stopping torture_onoff task");
+ kthread_stop(onoff_task);
+ onoff_task = NULL;
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+}
+EXPORT_SYMBOL_GPL(torture_onoff_cleanup);
+
+/*
+ * Print online/offline testing statistics.
+ */
+char *torture_onoff_stats(char *page)
+{
+#ifdef CONFIG_HOTPLUG_CPU
+ page += sprintf(page,
+ "onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ",
+ n_online_successes, n_online_attempts,
+ n_offline_successes, n_offline_attempts,
+ min_online, max_online,
+ min_offline, max_offline,
+ sum_online, sum_offline, HZ);
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+ return page;
+}
+EXPORT_SYMBOL_GPL(torture_onoff_stats);
+
+/*
+ * Were all the online/offline operations successful?
+ */
+bool torture_onoff_failures(void)
+{
+#ifdef CONFIG_HOTPLUG_CPU
+ return n_online_successes != n_online_attempts ||
+ n_offline_successes != n_offline_attempts;
+#else /* #ifdef CONFIG_HOTPLUG_CPU */
+ return false;
+#endif /* #else #ifdef CONFIG_HOTPLUG_CPU */
+}
+EXPORT_SYMBOL_GPL(torture_onoff_failures);
+
#define TORTURE_RANDOM_MULT 39916801 /* prime */
#define TORTURE_RANDOM_ADD 479001701 /* prime */
#define TORTURE_RANDOM_REFRESH 10000