sched: Fix __schedule_bug() output when called from an interrupt
[linux-flexiantxendom0-3.2.10.git] / kernel / rcutorture.c
index 6a30ea3..a58ac28 100644 (file)
@@ -56,14 +56,16 @@ static int nreaders = -1;   /* # reader threads, defaults to 2*ncpus */
 static int nfakewriters = 4;   /* # fake writer threads */
 static int stat_interval;      /* Interval between stats, in seconds. */
                                /*  Defaults to "only at end of test". */
-static int verbose;            /* Print more debug info. */
-static int test_no_idle_hz;    /* Test RCU's support for tickless idle CPUs. */
+static bool verbose;           /* Print more debug info. */
+static bool test_no_idle_hz;   /* Test RCU's support for tickless idle CPUs. */
 static int shuffle_interval = 3; /* Interval between shuffles (in sec)*/
 static int stutter = 5;                /* Start/stop testing interval (in sec) */
 static int irqreader = 1;      /* RCU readers from irq (timers). */
-static int fqs_duration = 0;   /* Duration of bursts (us), 0 to disable. */
-static int fqs_holdoff = 0;    /* Hold time within burst (us). */
+static int fqs_duration;       /* Duration of bursts (us), 0 to disable. */
+static int fqs_holdoff;                /* Hold time within burst (us). */
 static int fqs_stutter = 3;    /* Wait time between bursts (s). */
+static int onoff_interval;     /* Wait time between CPU hotplugs, 0=disable. */
+static int shutdown_secs;      /* Shutdown time (s).  <=0 for no shutdown. */
 static int test_boost = 1;     /* Test RCU prio boost: 0=no, 1=maybe, 2=yes. */
 static int test_boost_interval = 7; /* Interval between boost tests, seconds. */
 static int test_boost_duration = 4; /* Duration of each boost test, seconds. */
@@ -73,7 +75,7 @@ module_param(nreaders, int, 0444);
 MODULE_PARM_DESC(nreaders, "Number of RCU reader threads");
 module_param(nfakewriters, int, 0444);
 MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads");
-module_param(stat_interval, int, 0444);
+module_param(stat_interval, int, 0644);
 MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s");
 module_param(verbose, bool, 0444);
 MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s");
@@ -91,6 +93,10 @@ module_param(fqs_holdoff, int, 0444);
 MODULE_PARM_DESC(fqs_holdoff, "Holdoff time within fqs bursts (us)");
 module_param(fqs_stutter, int, 0444);
 MODULE_PARM_DESC(fqs_stutter, "Wait time between fqs bursts (s)");
+module_param(onoff_interval, int, 0444);
+MODULE_PARM_DESC(onoff_interval, "Time between CPU hotplugs (s), 0=disable");
+module_param(shutdown_secs, int, 0444);
+MODULE_PARM_DESC(shutdown_secs, "Shutdown time (s), zero to disable.");
 module_param(test_boost, int, 0444);
 MODULE_PARM_DESC(test_boost, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
 module_param(test_boost_interval, int, 0444);
@@ -119,6 +125,10 @@ static struct task_struct *shuffler_task;
 static struct task_struct *stutter_task;
 static struct task_struct *fqs_task;
 static struct task_struct *boost_tasks[NR_CPUS];
+static struct task_struct *shutdown_task;
+#ifdef CONFIG_HOTPLUG_CPU
+static struct task_struct *onoff_task;
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
 
 #define RCU_TORTURE_PIPE_LEN 10
 
@@ -149,6 +159,10 @@ static long n_rcu_torture_boost_rterror;
 static long n_rcu_torture_boost_failure;
 static long n_rcu_torture_boosts;
 static long n_rcu_torture_timers;
+static long n_offline_attempts;
+static long n_offline_successes;
+static long n_online_attempts;
+static long n_online_successes;
 static struct list_head rcu_torture_removed;
 static cpumask_var_t shuffle_tmp_mask;
 
@@ -160,6 +174,8 @@ static int stutter_pause_test;
 #define RCUTORTURE_RUNNABLE_INIT 0
 #endif
 int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT;
+module_param(rcutorture_runnable, int, 0444);
+MODULE_PARM_DESC(rcutorture_runnable, "Start rcutorture at boot");
 
 #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU)
 #define rcu_can_boost() 1
@@ -167,6 +183,7 @@ int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT;
 #define rcu_can_boost() 0
 #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
 
+static unsigned long shutdown_time;    /* jiffies to system shutdown. */
 static unsigned long boost_starttime;  /* jiffies of next boost test start. */
 DEFINE_MUTEX(boost_mutex);             /* protect setting boost_starttime */
                                        /*  and boost task create/destroy. */
@@ -182,6 +199,9 @@ static int fullstop = FULLSTOP_RMMOD;
  */
 static DEFINE_MUTEX(fullstop_mutex);
 
+/* Forward reference. */
+static void rcu_torture_cleanup(void);
+
 /*
  * Detect and respond to a system shutdown.
  */
@@ -612,6 +632,30 @@ static struct rcu_torture_ops srcu_ops = {
        .name           = "srcu"
 };
 
+static int srcu_torture_read_lock_raw(void) __acquires(&srcu_ctl)
+{
+       return srcu_read_lock_raw(&srcu_ctl);
+}
+
+static void srcu_torture_read_unlock_raw(int idx) __releases(&srcu_ctl)
+{
+       srcu_read_unlock_raw(&srcu_ctl, idx);
+}
+
+static struct rcu_torture_ops srcu_raw_ops = {
+       .init           = srcu_torture_init,
+       .cleanup        = srcu_torture_cleanup,
+       .readlock       = srcu_torture_read_lock_raw,
+       .read_delay     = srcu_read_delay,
+       .readunlock     = srcu_torture_read_unlock_raw,
+       .completed      = srcu_torture_completed,
+       .deferred_free  = rcu_sync_torture_deferred_free,
+       .sync           = srcu_torture_synchronize,
+       .cb_barrier     = NULL,
+       .stats          = srcu_torture_stats,
+       .name           = "srcu_raw"
+};
+
 static void srcu_torture_synchronize_expedited(void)
 {
        synchronize_srcu_expedited(&srcu_ctl);
@@ -741,7 +785,7 @@ static int rcu_torture_boost(void *arg)
        do {
                /* Wait for the next test interval. */
                oldstarttime = boost_starttime;
-               while (jiffies - oldstarttime > ULONG_MAX / 2) {
+               while (ULONG_CMP_LT(jiffies, oldstarttime)) {
                        schedule_timeout_uninterruptible(1);
                        rcu_stutter_wait("rcu_torture_boost");
                        if (kthread_should_stop() ||
@@ -752,7 +796,7 @@ static int rcu_torture_boost(void *arg)
                /* Do one boost-test interval. */
                endtime = oldstarttime + test_boost_duration * HZ;
                call_rcu_time = jiffies;
-               while (jiffies - endtime > ULONG_MAX / 2) {
+               while (ULONG_CMP_LT(jiffies, endtime)) {
                        /* If we don't have a callback in flight, post one. */
                        if (!rbi.inflight) {
                                smp_mb(); /* RCU core before ->inflight = 1. */
@@ -779,7 +823,8 @@ static int rcu_torture_boost(void *arg)
                 * interval.  Besides, we are running at RT priority,
                 * so delays should be relatively rare.
                 */
-               while (oldstarttime == boost_starttime) {
+               while (oldstarttime == boost_starttime &&
+                      !kthread_should_stop()) {
                        if (mutex_trylock(&boost_mutex)) {
                                boost_starttime = jiffies +
                                                  test_boost_interval * HZ;
@@ -818,11 +863,13 @@ rcu_torture_fqs(void *arg)
        VERBOSE_PRINTK_STRING("rcu_torture_fqs task started");
        do {
                fqs_resume_time = jiffies + fqs_stutter * HZ;
-               while (jiffies - fqs_resume_time > LONG_MAX) {
+               while (ULONG_CMP_LT(jiffies, fqs_resume_time) &&
+                      !kthread_should_stop()) {
                        schedule_timeout_interruptible(1);
                }
                fqs_burst_remaining = fqs_duration;
-               while (fqs_burst_remaining > 0) {
+               while (fqs_burst_remaining > 0 &&
+                      !kthread_should_stop()) {
                        cur_ops->fqs();
                        udelay(fqs_holdoff);
                        fqs_burst_remaining -= fqs_holdoff;
@@ -910,6 +957,18 @@ rcu_torture_fakewriter(void *arg)
        return 0;
 }
 
+void rcutorture_trace_dump(void)
+{
+       static atomic_t beenhere = ATOMIC_INIT(0);
+
+       if (atomic_read(&beenhere))
+               return;
+       if (atomic_xchg(&beenhere, 1) != 0)
+               return;
+       do_trace_rcu_torture_read(cur_ops->name, (struct rcu_head *)~0UL);
+       ftrace_dump(DUMP_ALL);
+}
+
 /*
  * RCU torture reader from timer handler.  Dereferences rcu_torture_current,
  * incrementing the corresponding element of the pipeline array.  The
@@ -931,6 +990,7 @@ static void rcu_torture_timer(unsigned long unused)
                                  rcu_read_lock_bh_held() ||
                                  rcu_read_lock_sched_held() ||
                                  srcu_read_lock_held(&srcu_ctl));
+       do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu);
        if (p == NULL) {
                /* Leave because rcu_torture_writer is not yet underway */
                cur_ops->readunlock(idx);
@@ -948,6 +1008,8 @@ static void rcu_torture_timer(unsigned long unused)
                /* Should not happen, but... */
                pipe_count = RCU_TORTURE_PIPE_LEN;
        }
+       if (pipe_count > 1)
+               rcutorture_trace_dump();
        __this_cpu_inc(rcu_torture_count[pipe_count]);
        completed = cur_ops->completed() - completed;
        if (completed > RCU_TORTURE_PIPE_LEN) {
@@ -991,6 +1053,7 @@ rcu_torture_reader(void *arg)
                                          rcu_read_lock_bh_held() ||
                                          rcu_read_lock_sched_held() ||
                                          srcu_read_lock_held(&srcu_ctl));
+               do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu);
                if (p == NULL) {
                        /* Wait for rcu_torture_writer to get underway */
                        cur_ops->readunlock(idx);
@@ -1006,6 +1069,8 @@ rcu_torture_reader(void *arg)
                        /* Should not happen, but... */
                        pipe_count = RCU_TORTURE_PIPE_LEN;
                }
+               if (pipe_count > 1)
+                       rcutorture_trace_dump();
                __this_cpu_inc(rcu_torture_count[pipe_count]);
                completed = cur_ops->completed() - completed;
                if (completed > RCU_TORTURE_PIPE_LEN) {
@@ -1053,7 +1118,8 @@ rcu_torture_printk(char *page)
        cnt += sprintf(&page[cnt],
                       "rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d "
                       "rtmbe: %d rtbke: %ld rtbre: %ld "
-                      "rtbf: %ld rtb: %ld nt: %ld",
+                      "rtbf: %ld rtb: %ld nt: %ld "
+                      "onoff: %ld/%ld:%ld/%ld",
                       rcu_torture_current,
                       rcu_torture_current_version,
                       list_empty(&rcu_torture_freelist),
@@ -1065,7 +1131,11 @@ rcu_torture_printk(char *page)
                       n_rcu_torture_boost_rterror,
                       n_rcu_torture_boost_failure,
                       n_rcu_torture_boosts,
-                      n_rcu_torture_timers);
+                      n_rcu_torture_timers,
+                      n_online_successes,
+                      n_online_attempts,
+                      n_offline_successes,
+                      n_offline_attempts);
        if (atomic_read(&n_rcu_torture_mberror) != 0 ||
            n_rcu_torture_boost_ktrerror != 0 ||
            n_rcu_torture_boost_rterror != 0 ||
@@ -1229,12 +1299,14 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, char *tag)
                "shuffle_interval=%d stutter=%d irqreader=%d "
                "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
                "test_boost=%d/%d test_boost_interval=%d "
-               "test_boost_duration=%d\n",
+               "test_boost_duration=%d shutdown_secs=%d "
+               "onoff_interval=%d\n",
                torture_type, tag, nrealreaders, nfakewriters,
                stat_interval, verbose, test_no_idle_hz, shuffle_interval,
                stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter,
                test_boost, cur_ops->can_boost,
-               test_boost_interval, test_boost_duration);
+               test_boost_interval, test_boost_duration, shutdown_secs,
+               onoff_interval);
 }
 
 static struct notifier_block rcutorture_shutdown_nb = {
@@ -1284,6 +1356,131 @@ static int rcutorture_booster_init(int cpu)
        return 0;
 }
 
+/*
+ * Cause the rcutorture test to shutdown the system after the test has
+ * run for the time specified by the shutdown_secs module parameter.
+ */
+static int
+rcu_torture_shutdown(void *arg)
+{
+       long delta;
+       unsigned long jiffies_snap;
+
+       VERBOSE_PRINTK_STRING("rcu_torture_shutdown task started");
+       jiffies_snap = ACCESS_ONCE(jiffies);
+       while (ULONG_CMP_LT(jiffies_snap, shutdown_time) &&
+              !kthread_should_stop()) {
+               delta = shutdown_time - jiffies_snap;
+               if (verbose)
+                       printk(KERN_ALERT "%s" TORTURE_FLAG
+                              "rcu_torture_shutdown task: %lu "
+                              "jiffies remaining\n",
+                              torture_type, delta);
+               schedule_timeout_interruptible(delta);
+               jiffies_snap = ACCESS_ONCE(jiffies);
+       }
+       if (kthread_should_stop()) {
+               VERBOSE_PRINTK_STRING("rcu_torture_shutdown task stopping");
+               return 0;
+       }
+
+       /* OK, shut down the system. */
+
+       VERBOSE_PRINTK_STRING("rcu_torture_shutdown task shutting down system");
+       shutdown_task = NULL;   /* Avoid self-kill deadlock. */
+       rcu_torture_cleanup();  /* Get the success/failure message. */
+       kernel_power_off();     /* Shut down the system. */
+       return 0;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+/*
+ * Execute random CPU-hotplug operations at the interval specified
+ * by the onoff_interval.
+ */
+static int __cpuinit
+rcu_torture_onoff(void *arg)
+{
+       int cpu;
+       int maxcpu = -1;
+       DEFINE_RCU_RANDOM(rand);
+
+       VERBOSE_PRINTK_STRING("rcu_torture_onoff task started");
+       for_each_online_cpu(cpu)
+               maxcpu = cpu;
+       WARN_ON(maxcpu < 0);
+       while (!kthread_should_stop()) {
+               cpu = (rcu_random(&rand) >> 4) % (maxcpu + 1);
+               if (cpu_online(cpu) && cpu_is_hotpluggable(cpu)) {
+                       if (verbose)
+                               printk(KERN_ALERT "%s" TORTURE_FLAG
+                                      "rcu_torture_onoff task: offlining %d\n",
+                                      torture_type, cpu);
+                       n_offline_attempts++;
+                       if (cpu_down(cpu) == 0) {
+                               if (verbose)
+                                       printk(KERN_ALERT "%s" TORTURE_FLAG
+                                              "rcu_torture_onoff task: "
+                                              "offlined %d\n",
+                                              torture_type, cpu);
+                               n_offline_successes++;
+                       }
+               } else if (cpu_is_hotpluggable(cpu)) {
+                       if (verbose)
+                               printk(KERN_ALERT "%s" TORTURE_FLAG
+                                      "rcu_torture_onoff task: onlining %d\n",
+                                      torture_type, cpu);
+                       n_online_attempts++;
+                       if (cpu_up(cpu) == 0) {
+                               if (verbose)
+                                       printk(KERN_ALERT "%s" TORTURE_FLAG
+                                              "rcu_torture_onoff task: "
+                                              "onlined %d\n",
+                                              torture_type, cpu);
+                               n_online_successes++;
+                       }
+               }
+               schedule_timeout_interruptible(onoff_interval * HZ);
+       }
+       VERBOSE_PRINTK_STRING("rcu_torture_onoff task stopping");
+       return 0;
+}
+
+static int __cpuinit
+rcu_torture_onoff_init(void)
+{
+       if (onoff_interval <= 0)
+               return 0;
+       onoff_task = kthread_run(rcu_torture_onoff, NULL, "rcu_torture_onoff");
+       if (IS_ERR(onoff_task)) {
+               onoff_task = NULL;
+               return PTR_ERR(onoff_task);
+       }
+       return 0;
+}
+
+static void rcu_torture_onoff_cleanup(void)
+{
+       if (onoff_task == NULL)
+               return;
+       VERBOSE_PRINTK_STRING("Stopping rcu_torture_onoff task");
+       kthread_stop(onoff_task);
+}
+
+#else /* #ifdef CONFIG_HOTPLUG_CPU */
+
+static void
+rcu_torture_onoff_init(void)
+{
+}
+
+static void rcu_torture_onoff_cleanup(void)
+{
+}
+
+#endif /* #else #ifdef CONFIG_HOTPLUG_CPU */
+
 static int rcutorture_cpu_notify(struct notifier_block *self,
                                 unsigned long action, void *hcpu)
 {
@@ -1388,6 +1585,11 @@ rcu_torture_cleanup(void)
                for_each_possible_cpu(i)
                        rcutorture_booster_cleanup(i);
        }
+       if (shutdown_task != NULL) {
+               VERBOSE_PRINTK_STRING("Stopping rcu_torture_shutdown task");
+               kthread_stop(shutdown_task);
+       }
+       rcu_torture_onoff_cleanup();
 
        /* Wait for all RCU callbacks to fire.  */
 
@@ -1413,7 +1615,7 @@ rcu_torture_init(void)
        static struct rcu_torture_ops *torture_ops[] =
                { &rcu_ops, &rcu_sync_ops, &rcu_expedited_ops,
                  &rcu_bh_ops, &rcu_bh_sync_ops, &rcu_bh_expedited_ops,
-                 &srcu_ops, &srcu_expedited_ops,
+                 &srcu_ops, &srcu_raw_ops, &srcu_expedited_ops,
                  &sched_ops, &sched_sync_ops, &sched_expedited_ops, };
 
        mutex_lock(&fullstop_mutex);
@@ -1604,6 +1806,18 @@ rcu_torture_init(void)
                        }
                }
        }
+       if (shutdown_secs > 0) {
+               shutdown_time = jiffies + shutdown_secs * HZ;
+               shutdown_task = kthread_run(rcu_torture_shutdown, NULL,
+                                           "rcu_torture_shutdown");
+               if (IS_ERR(shutdown_task)) {
+                       firsterr = PTR_ERR(shutdown_task);
+                       VERBOSE_PRINTK_ERRSTRING("Failed to create shutdown");
+                       shutdown_task = NULL;
+                       goto unwind;
+               }
+       }
+       rcu_torture_onoff_init();
        register_reboot_notifier(&rcutorture_shutdown_nb);
        rcutorture_record_test_transition();
        mutex_unlock(&fullstop_mutex);