Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull RCU updates from Ingo Molnar:
 "Main changes:

   - Torture-test changes, including refactoring of rcutorture and
     introduction of a vestigial locktorture.

   - Real-time latency fixes.

   - Documentation updates.

   - Miscellaneous fixes"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (77 commits)
  rcu: Provide grace-period piggybacking API
  rcu: Ensure kernel/rcu/rcu.h can be sourced/used stand-alone
  rcu: Fix sparse warning for rcu_expedited from kernel/ksysfs.c
  notifier: Substitute rcu_access_pointer() for rcu_dereference_raw()
  Documentation/memory-barriers.txt: Clarify release/acquire ordering
  rcutorture: Save kvm.sh output to log
  rcutorture: Add a lock_busted to test the test
  rcutorture: Place kvm-test-1-run.sh output into res directory
  rcutorture: Rename TREE_RCU-Kconfig.txt
  locktorture: Add kvm-recheck.sh plug-in for locktorture
  rcutorture: Gracefully handle NULL cleanup hooks
  locktorture: Add vestigial locktorture configuration
  rcutorture: Introduce "rcu" directory level underneath configs
  rcutorture: Rename kvm-test-1-rcu.sh
  rcutorture: Remove RCU dependencies from ver_functions.sh API
  rcutorture: Create CFcommon file for common Kconfig parameters
  rcutorture: Create config files for scripted test-the-test testing
  rcutorture: Add an rcu_busted to test the test
  locktorture: Add a lock-torture kernel module
  rcutorture: Abstract kvm-recheck.sh
  ...

17 files changed, 1491 insertions, 828 deletions

diff --git a/kernel/Makefile b/kernel/Makefile
index bc010ee272b6..5c0e7666811d 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -93,6 +93,7 @@ obj-$(CONFIG_PADATA) += padata.o
 obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
 obj-$(CONFIG_JUMP_LABEL) += jump_label.o
 obj-$(CONFIG_CONTEXT_TRACKING) += context_tracking.o
+obj-$(CONFIG_TORTURE_TEST) += torture.o
 
 $(obj)/configs.o: $(obj)/config_data.h
 
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index d945a949760f..e660964086e2 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -19,6 +19,8 @@
 #include <linux/sched.h>
 #include <linux/capability.h>
 
+#include <linux/rcupdate.h>	/* rcu_expedited */
+
 #define KERNEL_ATTR_RO(_name) \
 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
 
diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile
index 2a9ee96ecf00..306a76b51e0f 100644
--- a/kernel/locking/Makefile
+++ b/kernel/locking/Makefile
@@ -23,3 +23,4 @@ obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
 obj-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
 obj-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem-xadd.o
 obj-$(CONFIG_PERCPU_RWSEM) += percpu-rwsem.o
+obj-$(CONFIG_LOCK_TORTURE_TEST) += locktorture.o
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
new file mode 100644
index 000000000000..f26b1a18e34e
--- /dev/null
+++ b/kernel/locking/locktorture.c
@@ -0,0 +1,452 @@
+/*
+ * Module-based torture test facility for locking
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
+ *
+ * Copyright (C) IBM Corporation, 2014
+ *
+ * Author: Paul E. McKenney <paulmck@us.ibm.com>
+ *	Based on kernel/rcu/torture.c.
+ */
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kthread.h>
+#include <linux/err.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/atomic.h>
+#include <linux/bitops.h>
+#include <linux/completion.h>
+#include <linux/moduleparam.h>
+#include <linux/percpu.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/freezer.h>
+#include <linux/cpu.h>
+#include <linux/delay.h>
+#include <linux/stat.h>
+#include <linux/slab.h>
+#include <linux/trace_clock.h>
+#include <asm/byteorder.h>
+#include <linux/torture.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>");
+
+torture_param(int, nwriters_stress, -1,
+	     "Number of write-locking stress-test threads");
+torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
+torture_param(int, onoff_interval, 0,
+	     "Time between CPU hotplugs (s), 0=disable");
+torture_param(int, shuffle_interval, 3,
+	     "Number of jiffies between shuffles, 0=disable");
+torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable.");
+torture_param(int, stat_interval, 60,
+	     "Number of seconds between stats printk()s");
+torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable");
+torture_param(bool, verbose, true,
+	     "Enable verbose debugging printk()s");
+
+static char *torture_type = "spin_lock";
+module_param(torture_type, charp, 0444);
+MODULE_PARM_DESC(torture_type,
+		 "Type of lock to torture (spin_lock, spin_lock_irq, ...)");
+
+static atomic_t n_lock_torture_errors;
+
+static struct task_struct *stats_task;
+static struct task_struct **writer_tasks;
+
+static int nrealwriters_stress;
+static bool lock_is_write_held;
+
+struct lock_writer_stress_stats {
+	long n_write_lock_fail;
+	long n_write_lock_acquired;
+};
+static struct lock_writer_stress_stats *lwsa;
+
+#if defined(MODULE) || defined(CONFIG_LOCK_TORTURE_TEST_RUNNABLE)
+#define LOCKTORTURE_RUNNABLE_INIT 1
+#else
+#define LOCKTORTURE_RUNNABLE_INIT 0
+#endif
+int locktorture_runnable = LOCKTORTURE_RUNNABLE_INIT;
+module_param(locktorture_runnable, int, 0444);
+MODULE_PARM_DESC(locktorture_runnable, "Start locktorture at boot");
+
+/* Forward reference. */
+static void lock_torture_cleanup(void);
+
+/*
+ * Operations vector for selecting different types of tests.
+ */
+struct lock_torture_ops {
+	void (*init)(void);
+	int (*writelock)(void);
+	void (*write_delay)(struct torture_random_state *trsp);
+	void (*writeunlock)(void);
+	unsigned long flags;
+	const char *name;
+};
+
+static struct lock_torture_ops *cur_ops;
+
+/*
+ * Definitions for lock torture testing.
+ */
+
+static int torture_lock_busted_write_lock(void)
+{
+	return 0;  /* BUGGY, do not use in real life!!! */
+}
+
+static void torture_lock_busted_write_delay(struct torture_random_state *trsp)
+{
+	const unsigned long longdelay_us = 100;
+
+	/* We want a long delay occasionally to force massive contention.  */
+	if (!(torture_random(trsp) %
+	      (nrealwriters_stress * 2000 * longdelay_us)))
+		mdelay(longdelay_us);
+#ifdef CONFIG_PREEMPT
+	if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))
+		preempt_schedule();  /* Allow test to be preempted. */
+#endif
+}
+
+static void torture_lock_busted_write_unlock(void)
+{
+	  /* BUGGY, do not use in real life!!! */
+}
+
+static struct lock_torture_ops lock_busted_ops = {
+	.writelock	= torture_lock_busted_write_lock,
+	.write_delay	= torture_lock_busted_write_delay,
+	.writeunlock	= torture_lock_busted_write_unlock,
+	.name		= "lock_busted"
+};
+
+static DEFINE_SPINLOCK(torture_spinlock);
+
+static int torture_spin_lock_write_lock(void) __acquires(torture_spinlock)
+{
+	spin_lock(&torture_spinlock);
+	return 0;
+}
+
+static void torture_spin_lock_write_delay(struct torture_random_state *trsp)
+{
+	const unsigned long shortdelay_us = 2;
+	const unsigned long longdelay_us = 100;
+
+	/* We want a short delay mostly to emulate likely code, and
+	 * we want a long delay occasionally to force massive contention.
+	 */
+	if (!(torture_random(trsp) %
+	      (nrealwriters_stress * 2000 * longdelay_us)))
+		mdelay(longdelay_us);
+	if (!(torture_random(trsp) %
+	      (nrealwriters_stress * 2 * shortdelay_us)))
+		udelay(shortdelay_us);
+#ifdef CONFIG_PREEMPT
+	if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))
+		preempt_schedule();  /* Allow test to be preempted. */
+#endif
+}
+
+static void torture_spin_lock_write_unlock(void) __releases(torture_spinlock)
+{
+	spin_unlock(&torture_spinlock);
+}
+
+static struct lock_torture_ops spin_lock_ops = {
+	.writelock	= torture_spin_lock_write_lock,
+	.write_delay	= torture_spin_lock_write_delay,
+	.writeunlock	= torture_spin_lock_write_unlock,
+	.name		= "spin_lock"
+};
+
+static int torture_spin_lock_write_lock_irq(void)
+__acquires(torture_spinlock_irq)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&torture_spinlock, flags);
+	cur_ops->flags = flags;
+	return 0;
+}
+
+static void torture_lock_spin_write_unlock_irq(void)
+__releases(torture_spinlock)
+{
+	spin_unlock_irqrestore(&torture_spinlock, cur_ops->flags);
+}
+
+static struct lock_torture_ops spin_lock_irq_ops = {
+	.writelock	= torture_spin_lock_write_lock_irq,
+	.write_delay	= torture_spin_lock_write_delay,
+	.writeunlock	= torture_lock_spin_write_unlock_irq,
+	.name		= "spin_lock_irq"
+};
+
+/*
+ * Lock torture writer kthread.  Repeatedly acquires and releases
+ * the lock, checking for duplicate acquisitions.
+ */
+static int lock_torture_writer(void *arg)
+{
+	struct lock_writer_stress_stats *lwsp = arg;
+	static DEFINE_TORTURE_RANDOM(rand);
+
+	VERBOSE_TOROUT_STRING("lock_torture_writer task started");
+	set_user_nice(current, 19);
+
+	do {
+		schedule_timeout_uninterruptible(1);
+		cur_ops->writelock();
+		if (WARN_ON_ONCE(lock_is_write_held))
+			lwsp->n_write_lock_fail++;
+		lock_is_write_held = 1;
+		lwsp->n_write_lock_acquired++;
+		cur_ops->write_delay(&rand);
+		lock_is_write_held = 0;
+		cur_ops->writeunlock();
+		stutter_wait("lock_torture_writer");
+	} while (!torture_must_stop());
+	torture_kthread_stopping("lock_torture_writer");
+	return 0;
+}
+
+/*
+ * Create an lock-torture-statistics message in the specified buffer.
+ */
+static void lock_torture_printk(char *page)
+{
+	bool fail = 0;
+	int i;
+	long max = 0;
+	long min = lwsa[0].n_write_lock_acquired;
+	long long sum = 0;
+
+	for (i = 0; i < nrealwriters_stress; i++) {
+		if (lwsa[i].n_write_lock_fail)
+			fail = true;
+		sum += lwsa[i].n_write_lock_acquired;
+		if (max < lwsa[i].n_write_lock_fail)
+			max = lwsa[i].n_write_lock_fail;
+		if (min > lwsa[i].n_write_lock_fail)
+			min = lwsa[i].n_write_lock_fail;
+	}
+	page += sprintf(page, "%s%s ", torture_type, TORTURE_FLAG);
+	page += sprintf(page,
+			"Writes:  Total: %lld  Max/Min: %ld/%ld %s  Fail: %d %s\n",
+			sum, max, min, max / 2 > min ? "???" : "",
+			fail, fail ? "!!!" : "");
+	if (fail)
+		atomic_inc(&n_lock_torture_errors);
+}
+
+/*
+ * Print torture statistics.  Caller must ensure that there is only one
+ * call to this function at a given time!!!  This is normally accomplished
+ * by relying on the module system to only have one copy of the module
+ * loaded, and then by giving the lock_torture_stats kthread full control
+ * (or the init/cleanup functions when lock_torture_stats thread is not
+ * running).
+ */
+static void lock_torture_stats_print(void)
+{
+	int size = nrealwriters_stress * 200 + 8192;
+	char *buf;
+
+	buf = kmalloc(size, GFP_KERNEL);
+	if (!buf) {
+		pr_err("lock_torture_stats_print: Out of memory, need: %d",
+		       size);
+		return;
+	}
+	lock_torture_printk(buf);
+	pr_alert("%s", buf);
+	kfree(buf);
+}
+
+/*
+ * Periodically prints torture statistics, if periodic statistics printing
+ * was specified via the stat_interval module parameter.
+ *
+ * No need to worry about fullstop here, since this one doesn't reference
+ * volatile state or register callbacks.
+ */
+static int lock_torture_stats(void *arg)
+{
+	VERBOSE_TOROUT_STRING("lock_torture_stats task started");
+	do {
+		schedule_timeout_interruptible(stat_interval * HZ);
+		lock_torture_stats_print();
+		torture_shutdown_absorb("lock_torture_stats");
+	} while (!torture_must_stop());
+	torture_kthread_stopping("lock_torture_stats");
+	return 0;
+}
+
+static inline void
+lock_torture_print_module_parms(struct lock_torture_ops *cur_ops,
+				const char *tag)
+{
+	pr_alert("%s" TORTURE_FLAG
+		 "--- %s: nwriters_stress=%d stat_interval=%d verbose=%d shuffle_interval=%d stutter=%d shutdown_secs=%d onoff_interval=%d onoff_holdoff=%d\n",
+		 torture_type, tag, nrealwriters_stress, stat_interval, verbose,
+		 shuffle_interval, stutter, shutdown_secs,
+		 onoff_interval, onoff_holdoff);
+}
+
+static void lock_torture_cleanup(void)
+{
+	int i;
+
+	if (torture_cleanup())
+		return;
+
+	if (writer_tasks) {
+		for (i = 0; i < nrealwriters_stress; i++)
+			torture_stop_kthread(lock_torture_writer,
+					     writer_tasks[i]);
+		kfree(writer_tasks);
+		writer_tasks = NULL;
+	}
+
+	torture_stop_kthread(lock_torture_stats, stats_task);
+	lock_torture_stats_print();  /* -After- the stats thread is stopped! */
+
+	if (atomic_read(&n_lock_torture_errors))
+		lock_torture_print_module_parms(cur_ops,
+						"End of test: FAILURE");
+	else if (torture_onoff_failures())
+		lock_torture_print_module_parms(cur_ops,
+						"End of test: LOCK_HOTPLUG");
+	else
+		lock_torture_print_module_parms(cur_ops,
+						"End of test: SUCCESS");
+}
+
+static int __init lock_torture_init(void)
+{
+	int i;
+	int firsterr = 0;
+	static struct lock_torture_ops *torture_ops[] = {
+		&lock_busted_ops, &spin_lock_ops, &spin_lock_irq_ops,
+	};
+
+	torture_init_begin(torture_type, verbose, &locktorture_runnable);
+
+	/* Process args and tell the world that the torturer is on the job. */
+	for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
+		cur_ops = torture_ops[i];
+		if (strcmp(torture_type, cur_ops->name) == 0)
+			break;
+	}
+	if (i == ARRAY_SIZE(torture_ops)) {
+		pr_alert("lock-torture: invalid torture type: \"%s\"\n",
+			 torture_type);
+		pr_alert("lock-torture types:");
+		for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
+			pr_alert(" %s", torture_ops[i]->name);
+		pr_alert("\n");
+		torture_init_end();
+		return -EINVAL;
+	}
+	if (cur_ops->init)
+		cur_ops->init(); /* no "goto unwind" prior to this point!!! */
+
+	if (nwriters_stress >= 0)
+		nrealwriters_stress = nwriters_stress;
+	else
+		nrealwriters_stress = 2 * num_online_cpus();
+	lock_torture_print_module_parms(cur_ops, "Start of test");
+
+	/* Initialize the statistics so that each run gets its own numbers. */
+
+	lock_is_write_held = 0;
+	lwsa = kmalloc(sizeof(*lwsa) * nrealwriters_stress, GFP_KERNEL);
+	if (lwsa == NULL) {
+		VERBOSE_TOROUT_STRING("lwsa: Out of memory");
+		firsterr = -ENOMEM;
+		goto unwind;
+	}
+	for (i = 0; i < nrealwriters_stress; i++) {
+		lwsa[i].n_write_lock_fail = 0;
+		lwsa[i].n_write_lock_acquired = 0;
+	}
+
+	/* Start up the kthreads. */
+
+	if (onoff_interval > 0) {
+		firsterr = torture_onoff_init(onoff_holdoff * HZ,
+					      onoff_interval * HZ);
+		if (firsterr)
+			goto unwind;
+	}
+	if (shuffle_interval > 0) {
+		firsterr = torture_shuffle_init(shuffle_interval);
+		if (firsterr)
+			goto unwind;
+	}
+	if (shutdown_secs > 0) {
+		firsterr = torture_shutdown_init(shutdown_secs,
+						 lock_torture_cleanup);
+		if (firsterr)
+			goto unwind;
+	}
+	if (stutter > 0) {
+		firsterr = torture_stutter_init(stutter);
+		if (firsterr)
+			goto unwind;
+	}
+
+	writer_tasks = kzalloc(nrealwriters_stress * sizeof(writer_tasks[0]),
+			       GFP_KERNEL);
+	if (writer_tasks == NULL) {
+		VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory");
+		firsterr = -ENOMEM;
+		goto unwind;
+	}
+	for (i = 0; i < nrealwriters_stress; i++) {
+		firsterr = torture_create_kthread(lock_torture_writer, &lwsa[i],
+						  writer_tasks[i]);
+		if (firsterr)
+			goto unwind;
+	}
+	if (stat_interval > 0) {
+		firsterr = torture_create_kthread(lock_torture_stats, NULL,
+						  stats_task);
+		if (firsterr)
+			goto unwind;
+	}
+	torture_init_end();
+	return 0;
+
+unwind:
+	torture_init_end();
+	lock_torture_cleanup();
+	return firsterr;
+}
+
+module_init(lock_torture_init);
+module_exit(lock_torture_cleanup);
diff --git a/kernel/notifier.c b/kernel/notifier.c
index 2d5cc4ccff7f..db4c8b08a50c 100644
--- a/kernel/notifier.c
+++ b/kernel/notifier.c
@@ -309,7 +309,7 @@ int __blocking_notifier_call_chain(struct blocking_notifier_head *nh,
 	 * racy then it does not matter what the result of the test
 	 * is, we re-check the list after having taken the lock anyway:
 	 */
-	if (rcu_dereference_raw(nh->head)) {
+	if (rcu_access_pointer(nh->head)) {
 		down_read(&nh->rwsem);
 		ret = notifier_call_chain(&nh->head, val, v, nr_to_call,
 					nr_calls);
diff --git a/kernel/rcu/Makefile b/kernel/rcu/Makefile
index 01e9ec37a3e3..807ccfbf69b3 100644
--- a/kernel/rcu/Makefile
+++ b/kernel/rcu/Makefile
@@ -1,5 +1,5 @@
 obj-y += update.o srcu.o
-obj-$(CONFIG_RCU_TORTURE_TEST) += torture.o
+obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
 obj-$(CONFIG_TREE_RCU) += tree.o
 obj-$(CONFIG_TREE_PREEMPT_RCU) += tree.o
 obj-$(CONFIG_TREE_RCU_TRACE) += tree_trace.o
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index 79c3877e9c5b..bfda2726ca45 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -12,8 +12,8 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
  *
  * Copyright IBM Corporation, 2011
  *
@@ -23,6 +23,7 @@
 #ifndef __LINUX_RCU_H
 #define __LINUX_RCU_H
 
+#include <trace/events/rcu.h>
 #ifdef CONFIG_RCU_TRACE
 #define RCU_TRACE(stmt) stmt
 #else /* #ifdef CONFIG_RCU_TRACE */
@@ -116,8 +117,6 @@ static inline bool __rcu_reclaim(const char *rn, struct rcu_head *head)
 	}
 }
 
-extern int rcu_expedited;
-
 #ifdef CONFIG_RCU_STALL_COMMON
 
 extern int rcu_cpu_stall_suppress;
diff --git a/kernel/rcu/torture.c b/kernel/rcu/rcutorture.c
index 732f8ae3086a..f59d48597dde 100644
--- a/kernel/rcu/torture.c
+++ b/kernel/rcu/rcutorture.c
@@ -12,8 +12,8 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
  *
  * Copyright (C) IBM Corporation, 2005, 2006
  *
@@ -48,110 +48,58 @@
 #include <linux/slab.h>
 #include <linux/trace_clock.h>
 #include <asm/byteorder.h>
+#include <linux/torture.h>
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and Josh Triplett <josh@freedesktop.org>");
 
-MODULE_ALIAS("rcutorture");
-#ifdef MODULE_PARAM_PREFIX
-#undef MODULE_PARAM_PREFIX
-#endif
-#define MODULE_PARAM_PREFIX "rcutorture."
-
-static int fqs_duration;
-module_param(fqs_duration, int, 0444);
-MODULE_PARM_DESC(fqs_duration, "Duration of fqs bursts (us), 0 to disable");
-static int fqs_holdoff;
-module_param(fqs_holdoff, int, 0444);
-MODULE_PARM_DESC(fqs_holdoff, "Holdoff time within fqs bursts (us)");
-static int fqs_stutter = 3;
-module_param(fqs_stutter, int, 0444);
-MODULE_PARM_DESC(fqs_stutter, "Wait time between fqs bursts (s)");
-static bool gp_exp;
-module_param(gp_exp, bool, 0444);
-MODULE_PARM_DESC(gp_exp, "Use expedited GP wait primitives");
-static bool gp_normal;
-module_param(gp_normal, bool, 0444);
-MODULE_PARM_DESC(gp_normal, "Use normal (non-expedited) GP wait primitives");
-static int irqreader = 1;
-module_param(irqreader, int, 0444);
-MODULE_PARM_DESC(irqreader, "Allow RCU readers from irq handlers");
-static int n_barrier_cbs;
-module_param(n_barrier_cbs, int, 0444);
-MODULE_PARM_DESC(n_barrier_cbs, "# of callbacks/kthreads for barrier testing");
-static int nfakewriters = 4;
-module_param(nfakewriters, int, 0444);
-MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads");
-static int nreaders = -1;
-module_param(nreaders, int, 0444);
-MODULE_PARM_DESC(nreaders, "Number of RCU reader threads");
-static int object_debug;
-module_param(object_debug, int, 0444);
-MODULE_PARM_DESC(object_debug, "Enable debug-object double call_rcu() testing");
-static int onoff_holdoff;
-module_param(onoff_holdoff, int, 0444);
-MODULE_PARM_DESC(onoff_holdoff, "Time after boot before CPU hotplugs (s)");
-static int onoff_interval;
-module_param(onoff_interval, int, 0444);
-MODULE_PARM_DESC(onoff_interval, "Time between CPU hotplugs (s), 0=disable");
-static int shuffle_interval = 3;
-module_param(shuffle_interval, int, 0444);
-MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles");
-static int shutdown_secs;
-module_param(shutdown_secs, int, 0444);
-MODULE_PARM_DESC(shutdown_secs, "Shutdown time (s), <= zero to disable.");
-static int stall_cpu;
-module_param(stall_cpu, int, 0444);
-MODULE_PARM_DESC(stall_cpu, "Stall duration (s), zero to disable.");
-static int stall_cpu_holdoff = 10;
-module_param(stall_cpu_holdoff, int, 0444);
-MODULE_PARM_DESC(stall_cpu_holdoff, "Time to wait before starting stall (s).");
-static int stat_interval = 60;
-module_param(stat_interval, int, 0644);
-MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s");
-static int stutter = 5;
-module_param(stutter, int, 0444);
-MODULE_PARM_DESC(stutter, "Number of seconds to run/halt test");
-static int test_boost = 1;
-module_param(test_boost, int, 0444);
-MODULE_PARM_DESC(test_boost, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
-static int test_boost_duration = 4;
-module_param(test_boost_duration, int, 0444);
-MODULE_PARM_DESC(test_boost_duration, "Duration of each boost test, seconds.");
-static int test_boost_interval = 7;
-module_param(test_boost_interval, int, 0444);
-MODULE_PARM_DESC(test_boost_interval, "Interval between boost tests, seconds.");
-static bool test_no_idle_hz = true;
-module_param(test_no_idle_hz, bool, 0444);
-MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs");
+
+torture_param(int, fqs_duration, 0,
+	      "Duration of fqs bursts (us), 0 to disable");
+torture_param(int, fqs_holdoff, 0, "Holdoff time within fqs bursts (us)");
+torture_param(int, fqs_stutter, 3, "Wait time between fqs bursts (s)");
+torture_param(bool, gp_exp, false, "Use expedited GP wait primitives");
+torture_param(bool, gp_normal, false,
+	     "Use normal (non-expedited) GP wait primitives");
+torture_param(int, irqreader, 1, "Allow RCU readers from irq handlers");
+torture_param(int, n_barrier_cbs, 0,
+	     "# of callbacks/kthreads for barrier testing");
+torture_param(int, nfakewriters, 4, "Number of RCU fake writer threads");
+torture_param(int, nreaders, -1, "Number of RCU reader threads");
+torture_param(int, object_debug, 0,
+	     "Enable debug-object double call_rcu() testing");
+torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
+torture_param(int, onoff_interval, 0,
+	     "Time between CPU hotplugs (s), 0=disable");
+torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles");
+torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable.");
+torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable.");
+torture_param(int, stall_cpu_holdoff, 10,
+	     "Time to wait before starting stall (s).");
+torture_param(int, stat_interval, 60,
+	     "Number of seconds between stats printk()s");
+torture_param(int, stutter, 5, "Number of seconds to run/halt test");
+torture_param(int, test_boost, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
+torture_param(int, test_boost_duration, 4,
+	     "Duration of each boost test, seconds.");
+torture_param(int, test_boost_interval, 7,
+	     "Interval between boost tests, seconds.");
+torture_param(bool, test_no_idle_hz, true,
+	     "Test support for tickless idle CPUs");
+torture_param(bool, verbose, true,
+	     "Enable verbose debugging printk()s");
+
 static char *torture_type = "rcu";
 module_param(torture_type, charp, 0444);
 MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, ...)");
-static bool verbose;
-module_param(verbose, bool, 0444);
-MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s");
-
-#define TORTURE_FLAG "-torture:"
-#define PRINTK_STRING(s) \
-	do { pr_alert("%s" TORTURE_FLAG s "\n", torture_type); } while (0)
-#define VERBOSE_PRINTK_STRING(s) \
-	do { if (verbose) pr_alert("%s" TORTURE_FLAG s "\n", torture_type); } while (0)
-#define VERBOSE_PRINTK_ERRSTRING(s) \
-	do { if (verbose) pr_alert("%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0)
 
 static int nrealreaders;
 static struct task_struct *writer_task;
 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;
 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 */
 static struct task_struct *stall_task;
 static struct task_struct **barrier_cbs_tasks;
 static struct task_struct *barrier_task;
@@ -170,10 +118,10 @@ static struct rcu_torture __rcu *rcu_torture_current;
 static unsigned long rcu_torture_current_version;
 static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
 static DEFINE_SPINLOCK(rcu_torture_lock);
-static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) =
-	{ 0 };
-static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) =
-	{ 0 };
+static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1],
+		      rcu_torture_count) = { 0 };
+static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1],
+		      rcu_torture_batch) = { 0 };
 static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
 static atomic_t n_rcu_torture_alloc;
 static atomic_t n_rcu_torture_alloc_fail;
@@ -186,22 +134,9 @@ 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 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;
 static long n_barrier_attempts;
 static long n_barrier_successes;
 static struct list_head rcu_torture_removed;
-static cpumask_var_t shuffle_tmp_mask;
-
-static int stutter_pause_test;
 
 #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
 #define RCUTORTURE_RUNNABLE_INIT 1
@@ -232,7 +167,6 @@ static u64 notrace rcu_trace_clock_local(void)
 }
 #endif /* #else #ifdef CONFIG_RCU_TRACE */
 
-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. */
@@ -242,51 +176,6 @@ static atomic_t barrier_cbs_invoked;	/* Barrier callbacks invoked. */
 static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */
 static DECLARE_WAIT_QUEUE_HEAD(barrier_wq);
 
-/* Mediate rmmod and system shutdown.  Concurrent rmmod & shutdown illegal! */
-
-#define FULLSTOP_DONTSTOP 0	/* Normal operation. */
-#define FULLSTOP_SHUTDOWN 1	/* System shutdown with rcutorture running. */
-#define FULLSTOP_RMMOD    2	/* Normal rmmod of rcutorture. */
-static int fullstop = FULLSTOP_RMMOD;
-/*
- * Protect fullstop transitions and spawning of kthreads.
- */
-static DEFINE_MUTEX(fullstop_mutex);
-
-/* Forward reference. */
-static void rcu_torture_cleanup(void);
-
-/*
- * Detect and respond to a system shutdown.
- */
-static int
-rcutorture_shutdown_notify(struct notifier_block *unused1,
-			   unsigned long unused2, void *unused3)
-{
-	mutex_lock(&fullstop_mutex);
-	if (fullstop == FULLSTOP_DONTSTOP)
-		fullstop = FULLSTOP_SHUTDOWN;
-	else
-		pr_warn(/* but going down anyway, so... */
-		       "Concurrent 'rmmod rcutorture' and shutdown illegal!\n");
-	mutex_unlock(&fullstop_mutex);
-	return NOTIFY_DONE;
-}
-
-/*
- * Absorb kthreads into a kernel function that won't return, so that
- * they won't ever access module text or data again.
- */
-static void rcutorture_shutdown_absorb(const char *title)
-{
-	if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) {
-		pr_notice(
-		       "rcutorture thread %s parking due to system shutdown\n",
-		       title);
-		schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT);
-	}
-}
-
 /*
  * Allocate an element from the rcu_tortures pool.
  */
@@ -320,44 +209,6 @@ rcu_torture_free(struct rcu_torture *p)
 	spin_unlock_bh(&rcu_torture_lock);
 }
 
-struct rcu_random_state {
-	unsigned long rrs_state;
-	long rrs_count;
-};
-
-#define RCU_RANDOM_MULT 39916801  /* prime */
-#define RCU_RANDOM_ADD	479001701 /* prime */
-#define RCU_RANDOM_REFRESH 10000
-
-#define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 }
-
-/*
- * Crude but fast random-number generator.  Uses a linear congruential
- * generator, with occasional help from cpu_clock().
- */
-static unsigned long
-rcu_random(struct rcu_random_state *rrsp)
-{
-	if (--rrsp->rrs_count < 0) {
-		rrsp->rrs_state += (unsigned long)local_clock();
-		rrsp->rrs_count = RCU_RANDOM_REFRESH;
-	}
-	rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD;
-	return swahw32(rrsp->rrs_state);
-}
-
-static void
-rcu_stutter_wait(const char *title)
-{
-	while (stutter_pause_test || !rcutorture_runnable) {
-		if (rcutorture_runnable)
-			schedule_timeout_interruptible(1);
-		else
-			schedule_timeout_interruptible(round_jiffies_relative(HZ));
-		rcutorture_shutdown_absorb(title);
-	}
-}
-
 /*
  * Operations vector for selecting different types of tests.
  */
@@ -365,7 +216,7 @@ rcu_stutter_wait(const char *title)
 struct rcu_torture_ops {
 	void (*init)(void);
 	int (*readlock)(void);
-	void (*read_delay)(struct rcu_random_state *rrsp);
+	void (*read_delay)(struct torture_random_state *rrsp);
 	void (*readunlock)(int idx);
 	int (*completed)(void);
 	void (*deferred_free)(struct rcu_torture *p);<