Freezer: make kernel threads nonfreezable by default
[safe/jmp/linux-2.6] / kernel / rcutorture.c
index e045021..ddff332 100644 (file)
@@ -40,6 +40,7 @@
 #include <linux/moduleparam.h>
 #include <linux/percpu.h>
 #include <linux/notifier.h>
+#include <linux/freezer.h>
 #include <linux/cpu.h>
 #include <linux/random.h>
 #include <linux/delay.h>
@@ -58,21 +59,21 @@ static int stat_interval;   /* Interval between stats, in seconds. */
 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 char *torture_type = "rcu"; /* What to torture: rcu, rcu_bh, srcu. */
+static char *torture_type = "rcu"; /* What RCU implementation to torture. */
 
-module_param(nreaders, int, 0);
+module_param(nreaders, int, 0444);
 MODULE_PARM_DESC(nreaders, "Number of RCU reader threads");
-module_param(nfakewriters, int, 0);
+module_param(nfakewriters, int, 0444);
 MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads");
-module_param(stat_interval, int, 0);
+module_param(stat_interval, int, 0444);
 MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s");
-module_param(verbose, bool, 0);
+module_param(verbose, bool, 0444);
 MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s");
-module_param(test_no_idle_hz, bool, 0);
+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, 0);
+module_param(shuffle_interval, int, 0444);
 MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles");
-module_param(torture_type, charp, 0);
+module_param(torture_type, charp, 0444);
 MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)");
 
 #define TORTURE_FLAG "-torture:"
@@ -117,6 +118,7 @@ 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 struct list_head rcu_torture_removed;
 
 /*
  * Allocate an element from the rcu_tortures pool.
@@ -270,6 +272,45 @@ static struct rcu_torture_ops rcu_ops = {
        .name = "rcu"
 };
 
+static void rcu_sync_torture_deferred_free(struct rcu_torture *p)
+{
+       int i;
+       struct rcu_torture *rp;
+       struct rcu_torture *rp1;
+
+       cur_ops->sync();
+       list_add(&p->rtort_free, &rcu_torture_removed);
+       list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) {
+               i = rp->rtort_pipe_count;
+               if (i > RCU_TORTURE_PIPE_LEN)
+                       i = RCU_TORTURE_PIPE_LEN;
+               atomic_inc(&rcu_torture_wcount[i]);
+               if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
+                       rp->rtort_mbtest = 0;
+                       list_del(&rp->rtort_free);
+                       rcu_torture_free(rp);
+               }
+       }
+}
+
+static void rcu_sync_torture_init(void)
+{
+       INIT_LIST_HEAD(&rcu_torture_removed);
+}
+
+static struct rcu_torture_ops rcu_sync_ops = {
+       .init = rcu_sync_torture_init,
+       .cleanup = NULL,
+       .readlock = rcu_torture_read_lock,
+       .readdelay = rcu_read_delay,
+       .readunlock = rcu_torture_read_unlock,
+       .completed = rcu_torture_completed,
+       .deferredfree = rcu_sync_torture_deferred_free,
+       .sync = synchronize_rcu,
+       .stats = NULL,
+       .name = "rcu_sync"
+};
+
 /*
  * Definitions for rcu_bh torture testing.
  */
@@ -330,17 +371,29 @@ static struct rcu_torture_ops rcu_bh_ops = {
        .name = "rcu_bh"
 };
 
+static struct rcu_torture_ops rcu_bh_sync_ops = {
+       .init = rcu_sync_torture_init,
+       .cleanup = NULL,
+       .readlock = rcu_bh_torture_read_lock,
+       .readdelay = rcu_read_delay,  /* just reuse rcu's version. */
+       .readunlock = rcu_bh_torture_read_unlock,
+       .completed = rcu_bh_torture_completed,
+       .deferredfree = rcu_sync_torture_deferred_free,
+       .sync = rcu_bh_torture_synchronize,
+       .stats = NULL,
+       .name = "rcu_bh_sync"
+};
+
 /*
  * Definitions for srcu torture testing.
  */
 
 static struct srcu_struct srcu_ctl;
-static struct list_head srcu_removed;
 
 static void srcu_torture_init(void)
 {
        init_srcu_struct(&srcu_ctl);
-       INIT_LIST_HEAD(&srcu_removed);
+       rcu_sync_torture_init();
 }
 
 static void srcu_torture_cleanup(void)
@@ -349,7 +402,7 @@ static void srcu_torture_cleanup(void)
        cleanup_srcu_struct(&srcu_ctl);
 }
 
-static int srcu_torture_read_lock(void)
+static int srcu_torture_read_lock(void) __acquires(&srcu_ctl)
 {
        return srcu_read_lock(&srcu_ctl);
 }
@@ -367,7 +420,7 @@ static void srcu_read_delay(struct rcu_random_state *rrsp)
                schedule_timeout_interruptible(longdelay);
 }
 
-static void srcu_torture_read_unlock(int idx)
+static void srcu_torture_read_unlock(int idx) __releases(&srcu_ctl)
 {
        srcu_read_unlock(&srcu_ctl, idx);
 }
@@ -377,27 +430,6 @@ static int srcu_torture_completed(void)
        return srcu_batches_completed(&srcu_ctl);
 }
 
-static void srcu_torture_deferred_free(struct rcu_torture *p)
-{
-       int i;
-       struct rcu_torture *rp;
-       struct rcu_torture *rp1;
-
-       synchronize_srcu(&srcu_ctl);
-       list_add(&p->rtort_free, &srcu_removed);
-       list_for_each_entry_safe(rp, rp1, &srcu_removed, rtort_free) {
-               i = rp->rtort_pipe_count;
-               if (i > RCU_TORTURE_PIPE_LEN)
-                       i = RCU_TORTURE_PIPE_LEN;
-               atomic_inc(&rcu_torture_wcount[i]);
-               if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
-                       rp->rtort_mbtest = 0;
-                       list_del(&rp->rtort_free);
-                       rcu_torture_free(rp);
-               }
-       }
-}
-
 static void srcu_torture_synchronize(void)
 {
        synchronize_srcu(&srcu_ctl);
@@ -427,14 +459,49 @@ static struct rcu_torture_ops srcu_ops = {
        .readdelay = srcu_read_delay,
        .readunlock = srcu_torture_read_unlock,
        .completed = srcu_torture_completed,
-       .deferredfree = srcu_torture_deferred_free,
+       .deferredfree = rcu_sync_torture_deferred_free,
        .sync = srcu_torture_synchronize,
        .stats = srcu_torture_stats,
        .name = "srcu"
 };
 
-static struct rcu_torture_ops *torture_ops[] =
-       { &rcu_ops, &rcu_bh_ops, &srcu_ops, NULL };
+/*
+ * Definitions for sched torture testing.
+ */
+
+static int sched_torture_read_lock(void)
+{
+       preempt_disable();
+       return 0;
+}
+
+static void sched_torture_read_unlock(int idx)
+{
+       preempt_enable();
+}
+
+static int sched_torture_completed(void)
+{
+       return 0;
+}
+
+static void sched_torture_synchronize(void)
+{
+       synchronize_sched();
+}
+
+static struct rcu_torture_ops sched_ops = {
+       .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,
+       .stats = NULL,
+       .name = "sched"
+};
 
 /*
  * RCU torture writer kthread.  Repeatedly substitutes a new structure
@@ -463,7 +530,7 @@ rcu_torture_writer(void *arg)
                rp->rtort_mbtest = 1;
                rcu_assign_pointer(rcu_torture_current, rp);
                smp_wmb();
-               if (old_rp != NULL) {
+               if (old_rp) {
                        i = old_rp->rtort_pipe_count;
                        if (i > RCU_TORTURE_PIPE_LEN)
                                i = RCU_TORTURE_PIPE_LEN;
@@ -612,7 +679,7 @@ rcu_torture_printk(char *page)
                               atomic_read(&rcu_torture_wcount[i]));
        }
        cnt += sprintf(&page[cnt], "\n");
-       if (cur_ops->stats != NULL)
+       if (cur_ops->stats)
                cnt += cur_ops->stats(&page[cnt]);
        return cnt;
 }
@@ -676,13 +743,13 @@ static void rcu_torture_shuffle_tasks(void)
 
        set_cpus_allowed(current, tmp_mask);
 
-       if (reader_tasks != NULL) {
+       if (reader_tasks) {
                for (i = 0; i < nrealreaders; i++)
                        if (reader_tasks[i])
                                set_cpus_allowed(reader_tasks[i], tmp_mask);
        }
 
-       if (fakewriter_tasks != NULL) {
+       if (fakewriter_tasks) {
                for (i = 0; i < nfakewriters; i++)
                        if (fakewriter_tasks[i])
                                set_cpus_allowed(fakewriter_tasks[i], tmp_mask);
@@ -735,21 +802,21 @@ rcu_torture_cleanup(void)
        int i;
 
        fullstop = 1;
-       if (shuffler_task != NULL) {
+       if (shuffler_task) {
                VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task");
                kthread_stop(shuffler_task);
        }
        shuffler_task = NULL;
 
-       if (writer_task != NULL) {
+       if (writer_task) {
                VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task");
                kthread_stop(writer_task);
        }
        writer_task = NULL;
 
-       if (reader_tasks != NULL) {
+       if (reader_tasks) {
                for (i = 0; i < nrealreaders; i++) {
-                       if (reader_tasks[i] != NULL) {
+                       if (reader_tasks[i]) {
                                VERBOSE_PRINTK_STRING(
                                        "Stopping rcu_torture_reader task");
                                kthread_stop(reader_tasks[i]);
@@ -761,9 +828,9 @@ rcu_torture_cleanup(void)
        }
        rcu_torture_current = NULL;
 
-       if (fakewriter_tasks != NULL) {
+       if (fakewriter_tasks) {
                for (i = 0; i < nfakewriters; i++) {
-                       if (fakewriter_tasks[i] != NULL) {
+                       if (fakewriter_tasks[i]) {
                                VERBOSE_PRINTK_STRING(
                                        "Stopping rcu_torture_fakewriter task");
                                kthread_stop(fakewriter_tasks[i]);
@@ -774,7 +841,7 @@ rcu_torture_cleanup(void)
                fakewriter_tasks = NULL;
        }
 
-       if (stats_task != NULL) {
+       if (stats_task) {
                VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task");
                kthread_stop(stats_task);
        }
@@ -785,7 +852,7 @@ rcu_torture_cleanup(void)
 
        rcu_torture_stats_print();  /* -After- the stats thread is stopped! */
 
-       if (cur_ops->cleanup != NULL)
+       if (cur_ops->cleanup)
                cur_ops->cleanup();
        if (atomic_read(&n_rcu_torture_error))
                rcu_torture_print_module_parms("End of test: FAILURE");
@@ -793,27 +860,28 @@ rcu_torture_cleanup(void)
                rcu_torture_print_module_parms("End of test: SUCCESS");
 }
 
-static int
+static int __init
 rcu_torture_init(void)
 {
        int i;
        int cpu;
        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, };
 
        /* Process args and tell the world that the torturer is on the job. */
-
-       for (i = 0; cur_ops = torture_ops[i], cur_ops != NULL; i++) {
+       for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
                cur_ops = torture_ops[i];
-               if (strcmp(torture_type, cur_ops->name) == 0) {
+               if (strcmp(torture_type, cur_ops->name) == 0)
                        break;
-               }
        }
-       if (cur_ops == NULL) {
+       if (i == ARRAY_SIZE(torture_ops)) {
                printk(KERN_ALERT "rcutorture: invalid torture type: \"%s\"\n",
                       torture_type);
                return (-EINVAL);
        }
-       if (cur_ops->init != NULL)
+       if (cur_ops->init)
                cur_ops->init(); /* no "goto unwind" prior to this point!!! */
 
        if (nreaders >= 0)
@@ -826,7 +894,7 @@ rcu_torture_init(void)
        /* Set up the freelist. */
 
        INIT_LIST_HEAD(&rcu_torture_freelist);
-       for (i = 0; i < sizeof(rcu_tortures) / sizeof(rcu_tortures[0]); i++) {
+       for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) {
                rcu_tortures[i].rtort_mbtest = 0;
                list_add_tail(&rcu_tortures[i].rtort_free,
                              &rcu_torture_freelist);