1 files changed, 166 insertions, 8 deletions

diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 33acc424667e..90b5b123f7a1 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -57,7 +57,9 @@ 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 int shuffle_interval = 5; /* Interval between shuffles (in sec)*/
+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 char *torture_type = "rcu"; /* What RCU implementation to torture. */
 
 module_param(nreaders, int, 0444);
@@ -72,6 +74,10 @@ module_param(test_no_idle_hz, bool, 0444);
 MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs");
 module_param(shuffle_interval, int, 0444);
 MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles");
+module_param(stutter, int, 0444);
+MODULE_PARM_DESC(stutter, "Number of seconds to run/halt test");
+module_param(irqreader, int, 0444);
+MODULE_PARM_DESC(irqreader, "Allow RCU readers from irq handlers");
 module_param(torture_type, charp, 0444);
 MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)");
 
@@ -91,6 +97,7 @@ static struct task_struct **fakewriter_tasks;
 static struct task_struct **reader_tasks;
 static struct task_struct *stats_task;
 static struct task_struct *shuffler_task;
+static struct task_struct *stutter_task;
 
 #define RCU_TORTURE_PIPE_LEN 10
 
@@ -117,8 +124,18 @@ static atomic_t n_rcu_torture_alloc_fail;
 static atomic_t n_rcu_torture_free;
 static atomic_t n_rcu_torture_mberror;
 static atomic_t n_rcu_torture_error;
+static long n_rcu_torture_timers = 0;
 static struct list_head rcu_torture_removed;
 
+static int stutter_pause_test = 0;
+
+#if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
+#define RCUTORTURE_RUNNABLE_INIT 1
+#else
+#define RCUTORTURE_RUNNABLE_INIT 0
+#endif
+int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT;
+
 /*
  * Allocate an element from the rcu_tortures pool.
  */
@@ -179,6 +196,16 @@ rcu_random(struct rcu_random_state *rrsp)
         return swahw32(rrsp->rrs_state);
 }
 
+static void
+rcu_stutter_wait(void)
+{
+        while (stutter_pause_test || !rcutorture_runnable)
+                if (rcutorture_runnable)
+                        schedule_timeout_interruptible(1);
+                else
+                        schedule_timeout_interruptible(round_jiffies_relative(HZ));
+}
+
 /*
  * Operations vector for selecting different types of tests.
  */
@@ -192,7 +219,9 @@ struct rcu_torture_ops {
         int (*completed)(void);
         void (*deferredfree)(struct rcu_torture *p);
         void (*sync)(void);
+        void (*cb_barrier)(void);
         int (*stats)(char *page);
+        int irqcapable;
         char *name;
 };
 static struct rcu_torture_ops *cur_ops = NULL;
@@ -265,7 +294,9 @@ static struct rcu_torture_ops rcu_ops = {
         .completed = rcu_torture_completed,
         .deferredfree = rcu_torture_deferred_free,
         .sync = synchronize_rcu,
+        .cb_barrier = rcu_barrier,
         .stats = NULL,
+        .irqcapable = 1,
         .name = "rcu"
 };
 
@@ -304,7 +335,9 @@ static struct rcu_torture_ops rcu_sync_ops = {
         .completed = rcu_torture_completed,
         .deferredfree = rcu_sync_torture_deferred_free,
         .sync = synchronize_rcu,
+        .cb_barrier = NULL,
         .stats = NULL,
+        .irqcapable = 1,
         .name = "rcu_sync"
 };
 
@@ -364,7 +397,9 @@ static struct rcu_torture_ops rcu_bh_ops = {
         .completed = rcu_bh_torture_completed,
         .deferredfree = rcu_bh_torture_deferred_free,
         .sync = rcu_bh_torture_synchronize,
+        .cb_barrier = rcu_barrier_bh,
         .stats = NULL,
+        .irqcapable = 1,
         .name = "rcu_bh"
 };
 
@@ -377,7 +412,9 @@ static struct rcu_torture_ops rcu_bh_sync_ops = {
         .completed = rcu_bh_torture_completed,
         .deferredfree = rcu_sync_torture_deferred_free,
         .sync = rcu_bh_torture_synchronize,
+        .cb_barrier = NULL,
         .stats = NULL,
+        .irqcapable = 1,
         .name = "rcu_bh_sync"
 };
 
@@ -458,6 +495,7 @@ static struct rcu_torture_ops srcu_ops = {
         .completed = srcu_torture_completed,
         .deferredfree = rcu_sync_torture_deferred_free,
         .sync = srcu_torture_synchronize,
+        .cb_barrier = NULL,
         .stats = srcu_torture_stats,
         .name = "srcu"
 };
@@ -482,6 +520,11 @@ static int sched_torture_completed(void)
         return 0;
 }
 
+static void rcu_sched_torture_deferred_free(struct rcu_torture *p)
+{
+        call_rcu_sched(&p->rtort_rcu, rcu_torture_cb);
+}
+
 static void sched_torture_synchronize(void)
 {
         synchronize_sched();
@@ -494,12 +537,28 @@ static struct rcu_torture_ops sched_ops = {
         .readdelay = rcu_read_delay,  /* just reuse rcu's version. */
         .readunlock = sched_torture_read_unlock,
         .completed = sched_torture_completed,
-        .deferredfree = rcu_sync_torture_deferred_free,
+        .deferredfree = rcu_sched_torture_deferred_free,
         .sync = sched_torture_synchronize,
+        .cb_barrier = rcu_barrier_sched,
         .stats = NULL,
+        .irqcapable = 1,
         .name = "sched"
 };
 
+static struct rcu_torture_ops sched_ops_sync = {
+        .init = rcu_sync_torture_init,
+        .cleanup = NULL,
+        .readlock = sched_torture_read_lock,
+        .readdelay = rcu_read_delay,  /* just reuse rcu's version. */
+        .readunlock = sched_torture_read_unlock,
+        .completed = sched_torture_completed,
+        .deferredfree = rcu_sync_torture_deferred_free,
+        .sync = sched_torture_synchronize,
+        .cb_barrier = NULL,
+        .stats = NULL,
+        .name = "sched_sync"
+};
+
 /*
  * RCU torture writer kthread.  Repeatedly substitutes a new structure
  * for that pointed to by rcu_torture_current, freeing the old structure
@@ -537,6 +596,7 @@ rcu_torture_writer(void *arg)
                 }
                 rcu_torture_current_version++;
                 oldbatch = cur_ops->completed();
+                rcu_stutter_wait();
         } while (!kthread_should_stop() && !fullstop);
         VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping");
         while (!kthread_should_stop())
@@ -560,6 +620,7 @@ rcu_torture_fakewriter(void *arg)
                 schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10);
                 udelay(rcu_random(&rand) & 0x3ff);
                 cur_ops->sync();
+                rcu_stutter_wait();
         } while (!kthread_should_stop() && !fullstop);
 
         VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping");
@@ -569,6 +630,52 @@ rcu_torture_fakewriter(void *arg)
 }
 
 /*
+ * RCU torture reader from timer handler.  Dereferences rcu_torture_current,
+ * incrementing the corresponding element of the pipeline array.  The
+ * counter in the element should never be greater than 1, otherwise, the
+ * RCU implementation is broken.
+ */
+static void rcu_torture_timer(unsigned long unused)
+{
+        int idx;
+        int completed;
+        static DEFINE_RCU_RANDOM(rand);
+        static DEFINE_SPINLOCK(rand_lock);
+        struct rcu_torture *p;
+        int pipe_count;
+
+        idx = cur_ops->readlock();
+        completed = cur_ops->completed();
+        p = rcu_dereference(rcu_torture_current);
+        if (p == NULL) {
+                /* Leave because rcu_torture_writer is not yet underway */
+                cur_ops->readunlock(idx);
+                return;
+        }
+        if (p->rtort_mbtest == 0)
+                atomic_inc(&n_rcu_torture_mberror);
+        spin_lock(&rand_lock);
+        cur_ops->readdelay(&rand);
+        n_rcu_torture_timers++;
+        spin_unlock(&rand_lock);
+        preempt_disable();
+        pipe_count = p->rtort_pipe_count;
+        if (pipe_count > RCU_TORTURE_PIPE_LEN) {
+                /* Should not happen, but... */
+                pipe_count = RCU_TORTURE_PIPE_LEN;
+        }
+        ++__get_cpu_var(rcu_torture_count)[pipe_count];
+        completed = cur_ops->completed() - completed;
+        if (completed > RCU_TORTURE_PIPE_LEN) {
+                /* Should not happen, but... */
+                completed = RCU_TORTURE_PIPE_LEN;
+        }
+        ++__get_cpu_var(rcu_torture_batch)[completed];
+        preempt_enable();
+        cur_ops->readunlock(idx);
+}
+
+/*
  * RCU torture reader kthread.  Repeatedly dereferences rcu_torture_current,
  * incrementing the corresponding element of the pipeline array.  The
  * counter in the element should never be greater than 1, otherwise, the
@@ -582,11 +689,18 @@ rcu_torture_reader(void *arg)
         DEFINE_RCU_RANDOM(rand);
         struct rcu_torture *p;
         int pipe_count;
+        struct timer_list t;
 
         VERBOSE_PRINTK_STRING("rcu_torture_reader task started");
         set_user_nice(current, 19);
+        if (irqreader && cur_ops->irqcapable)
+                setup_timer_on_stack(&t, rcu_torture_timer, 0);
 
         do {
+                if (irqreader && cur_ops->irqcapable) {
+                        if (!timer_pending(&t))
+                                mod_timer(&t, 1);
+                }
                 idx = cur_ops->readlock();
                 completed = cur_ops->completed();
                 p = rcu_dereference(rcu_torture_current);
@@ -615,8 +729,11 @@ rcu_torture_reader(void *arg)
                 preempt_enable();
                 cur_ops->readunlock(idx);
                 schedule();
+                rcu_stutter_wait();
         } while (!kthread_should_stop() && !fullstop);
         VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping");
+        if (irqreader && cur_ops->irqcapable)
+                del_timer_sync(&t);
         while (!kthread_should_stop())
                 schedule_timeout_uninterruptible(1);
         return 0;
@@ -647,20 +764,22 @@ rcu_torture_printk(char *page)
         cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG);
         cnt += sprintf(&page[cnt],
                        "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d "
-                       "rtmbe: %d",
+                       "rtmbe: %d nt: %ld",
                        rcu_torture_current,
                        rcu_torture_current_version,
                        list_empty(&rcu_torture_freelist),
                        atomic_read(&n_rcu_torture_alloc),
                        atomic_read(&n_rcu_torture_alloc_fail),
                        atomic_read(&n_rcu_torture_free),
-                       atomic_read(&n_rcu_torture_mberror));
+                       atomic_read(&n_rcu_torture_mberror),
+                       n_rcu_torture_timers);
         if (atomic_read(&n_rcu_torture_mberror) != 0)
                 cnt += sprintf(&page[cnt], " !!!");
         cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG);
         if (i > 1) {
                 cnt += sprintf(&page[cnt], "!!! ");
                 atomic_inc(&n_rcu_torture_error);
+                WARN_ON_ONCE(1);
         }
         cnt += sprintf(&page[cnt], "Reader Pipe: ");
         for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
@@ -785,15 +904,34 @@ rcu_torture_shuffle(void *arg)
         return 0;
 }
 
+/* Cause the rcutorture test to "stutter", starting and stopping all
+ * threads periodically.
+ */
+static int
+rcu_torture_stutter(void *arg)
+{
+        VERBOSE_PRINTK_STRING("rcu_torture_stutter task started");
+        do {
+                schedule_timeout_interruptible(stutter * HZ);
+                stutter_pause_test = 1;
+                if (!kthread_should_stop())
+                        schedule_timeout_interruptible(stutter * HZ);
+                stutter_pause_test = 0;
+        } while (!kthread_should_stop());
+        VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping");
+        return 0;
+}
+
 static inline void
 rcu_torture_print_module_parms(char *tag)
 {
         printk(KERN_ALERT "%s" TORTURE_FLAG
                 "--- %s: nreaders=%d nfakewriters=%d "
                 "stat_interval=%d verbose=%d test_no_idle_hz=%d "
-                "shuffle_interval = %d\n",
+                "shuffle_interval=%d stutter=%d irqreader=%d\n",
                 torture_type, tag, nrealreaders, nfakewriters,
-                stat_interval, verbose, test_no_idle_hz, shuffle_interval);
+                stat_interval, verbose, test_no_idle_hz, shuffle_interval,
+                stutter, irqreader);
 }
 
 static void
@@ -802,6 +940,11 @@ rcu_torture_cleanup(void)
         int i;
 
         fullstop = 1;
+        if (stutter_task) {
+                VERBOSE_PRINTK_STRING("Stopping rcu_torture_stutter task");
+                kthread_stop(stutter_task);
+        }
+        stutter_task = NULL;
         if (shuffler_task) {
                 VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task");
                 kthread_stop(shuffler_task);
@@ -848,7 +991,9 @@ rcu_torture_cleanup(void)
         stats_task = NULL;
 
         /* Wait for all RCU callbacks to fire.  */
-        rcu_barrier();
+
+        if (cur_ops->cb_barrier != NULL)
+                cur_ops->cb_barrier();
 
         rcu_torture_stats_print();  /* -After- the stats thread is stopped! */
 
@@ -868,7 +1013,7 @@ rcu_torture_init(void)
         int firsterr = 0;
         static struct rcu_torture_ops *torture_ops[] =
                 { &rcu_ops, &rcu_sync_ops, &rcu_bh_ops, &rcu_bh_sync_ops,
-                  &srcu_ops, &sched_ops, };
+                  &srcu_ops, &sched_ops, &sched_ops_sync, };
 
         /* Process args and tell the world that the torturer is on the job. */
         for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
@@ -988,6 +1133,19 @@ rcu_torture_init(void)
                         goto unwind;
                 }
         }
+        if (stutter < 0)
+                stutter = 0;
+        if (stutter) {
+                /* Create the stutter thread */
+                stutter_task = kthread_run(rcu_torture_stutter, NULL,
+                                          "rcu_torture_stutter");
+                if (IS_ERR(stutter_task)) {
+                        firsterr = PTR_ERR(stutter_task);
+                        VERBOSE_PRINTK_ERRSTRING("Failed to create stutter");
+                        stutter_task = NULL;
+                        goto unwind;
+                }
+        }
         return 0;
 
 unwind: