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Paul E. McKenneya241ec62005-10-30 15:03:12 -08001/*
Paul E. McKenney29766f12006-06-27 02:54:02 -07002 * Read-Copy Update module-based torture test facility
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 *
Josh Triplettb772e1d2006-10-04 02:17:13 -070018 * Copyright (C) IBM Corporation, 2005, 2006
Paul E. McKenneya241ec62005-10-30 15:03:12 -080019 *
20 * Authors: Paul E. McKenney <paulmck@us.ibm.com>
Josh Triplettb772e1d2006-10-04 02:17:13 -070021 * Josh Triplett <josh@freedesktop.org>
Paul E. McKenneya241ec62005-10-30 15:03:12 -080022 *
23 * See also: Documentation/RCU/torture.txt
24 */
25#include <linux/types.h>
26#include <linux/kernel.h>
27#include <linux/init.h>
28#include <linux/module.h>
29#include <linux/kthread.h>
30#include <linux/err.h>
31#include <linux/spinlock.h>
32#include <linux/smp.h>
33#include <linux/rcupdate.h>
34#include <linux/interrupt.h>
35#include <linux/sched.h>
36#include <asm/atomic.h>
37#include <linux/bitops.h>
Paul E. McKenneya241ec62005-10-30 15:03:12 -080038#include <linux/completion.h>
39#include <linux/moduleparam.h>
40#include <linux/percpu.h>
41#include <linux/notifier.h>
Paul E. McKenney343e9092008-12-15 16:13:07 -080042#include <linux/reboot.h>
Rafael J. Wysocki83144182007-07-17 04:03:35 -070043#include <linux/freezer.h>
Paul E. McKenneya241ec62005-10-30 15:03:12 -080044#include <linux/cpu.h>
Paul E. McKenneya241ec62005-10-30 15:03:12 -080045#include <linux/delay.h>
Paul E. McKenneya241ec62005-10-30 15:03:12 -080046#include <linux/stat.h>
Paul E. McKenneyb2896d22006-10-04 02:17:03 -070047#include <linux/srcu.h>
Robert P. J. Day1aeb2722008-04-29 00:59:25 -070048#include <linux/slab.h>
Harvey Harrisonf07767f2008-10-20 10:23:38 -070049#include <asm/byteorder.h>
Paul E. McKenneya241ec62005-10-30 15:03:12 -080050
51MODULE_LICENSE("GPL");
Josh Triplettb772e1d2006-10-04 02:17:13 -070052MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and "
53 "Josh Triplett <josh@freedesktop.org>");
Paul E. McKenneya241ec62005-10-30 15:03:12 -080054
Josh Triplett48022112006-10-03 23:26:16 +020055static int nreaders = -1; /* # reader threads, defaults to 2*ncpus */
Josh Triplettb772e1d2006-10-04 02:17:13 -070056static int nfakewriters = 4; /* # fake writer threads */
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -080057static int stat_interval; /* Interval between stats, in seconds. */
Paul E. McKenneya241ec62005-10-30 15:03:12 -080058 /* Defaults to "only at end of test". */
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -080059static int verbose; /* Print more debug info. */
60static int test_no_idle_hz; /* Test RCU's support for tickless idle CPUs. */
Paul E. McKenneyd120f652008-06-18 05:21:44 -070061static int shuffle_interval = 3; /* Interval between shuffles (in sec)*/
62static int stutter = 5; /* Start/stop testing interval (in sec) */
Paul E. McKenney0729fbf2008-06-25 12:24:52 -070063static int irqreader = 1; /* RCU readers from irq (timers). */
Josh Triplett20d2e422006-10-04 02:17:15 -070064static char *torture_type = "rcu"; /* What RCU implementation to torture. */
Paul E. McKenneya241ec62005-10-30 15:03:12 -080065
Josh Triplettd6ad6712007-03-06 01:42:13 -080066module_param(nreaders, int, 0444);
Paul E. McKenneya241ec62005-10-30 15:03:12 -080067MODULE_PARM_DESC(nreaders, "Number of RCU reader threads");
Josh Triplettd6ad6712007-03-06 01:42:13 -080068module_param(nfakewriters, int, 0444);
Josh Triplettb772e1d2006-10-04 02:17:13 -070069MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads");
Josh Triplettd6ad6712007-03-06 01:42:13 -080070module_param(stat_interval, int, 0444);
Paul E. McKenneya241ec62005-10-30 15:03:12 -080071MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s");
Josh Triplettd6ad6712007-03-06 01:42:13 -080072module_param(verbose, bool, 0444);
Paul E. McKenneya241ec62005-10-30 15:03:12 -080073MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s");
Josh Triplettd6ad6712007-03-06 01:42:13 -080074module_param(test_no_idle_hz, bool, 0444);
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -080075MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs");
Josh Triplettd6ad6712007-03-06 01:42:13 -080076module_param(shuffle_interval, int, 0444);
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -080077MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles");
Paul E. McKenneyd120f652008-06-18 05:21:44 -070078module_param(stutter, int, 0444);
79MODULE_PARM_DESC(stutter, "Number of seconds to run/halt test");
Paul E. McKenney0729fbf2008-06-25 12:24:52 -070080module_param(irqreader, int, 0444);
81MODULE_PARM_DESC(irqreader, "Allow RCU readers from irq handlers");
Josh Triplettd6ad6712007-03-06 01:42:13 -080082module_param(torture_type, charp, 0444);
Paul E. McKenneyb2896d22006-10-04 02:17:03 -070083MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)");
Paul E. McKenney72e9bb52006-06-27 02:54:03 -070084
85#define TORTURE_FLAG "-torture:"
Paul E. McKenneya241ec62005-10-30 15:03:12 -080086#define PRINTK_STRING(s) \
Paul E. McKenney72e9bb52006-06-27 02:54:03 -070087 do { printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0)
Paul E. McKenneya241ec62005-10-30 15:03:12 -080088#define VERBOSE_PRINTK_STRING(s) \
Paul E. McKenney72e9bb52006-06-27 02:54:03 -070089 do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0)
Paul E. McKenneya241ec62005-10-30 15:03:12 -080090#define VERBOSE_PRINTK_ERRSTRING(s) \
Paul E. McKenney72e9bb52006-06-27 02:54:03 -070091 do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0)
Paul E. McKenneya241ec62005-10-30 15:03:12 -080092
93static char printk_buf[4096];
94
95static int nrealreaders;
96static struct task_struct *writer_task;
Josh Triplettb772e1d2006-10-04 02:17:13 -070097static struct task_struct **fakewriter_tasks;
Paul E. McKenneya241ec62005-10-30 15:03:12 -080098static struct task_struct **reader_tasks;
99static struct task_struct *stats_task;
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800100static struct task_struct *shuffler_task;
Paul E. McKenneyd120f652008-06-18 05:21:44 -0700101static struct task_struct *stutter_task;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800102
103#define RCU_TORTURE_PIPE_LEN 10
104
105struct rcu_torture {
106 struct rcu_head rtort_rcu;
107 int rtort_pipe_count;
108 struct list_head rtort_free;
Paul E. McKenney996417d2005-11-18 01:10:50 -0800109 int rtort_mbtest;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800110};
111
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800112static LIST_HEAD(rcu_torture_freelist);
113static struct rcu_torture *rcu_torture_current = NULL;
114static long rcu_torture_current_version = 0;
115static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
116static DEFINE_SPINLOCK(rcu_torture_lock);
117static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) =
118 { 0 };
119static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) =
120 { 0 };
121static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700122static atomic_t n_rcu_torture_alloc;
123static atomic_t n_rcu_torture_alloc_fail;
124static atomic_t n_rcu_torture_free;
125static atomic_t n_rcu_torture_mberror;
126static atomic_t n_rcu_torture_error;
Paul E. McKenney0729fbf2008-06-25 12:24:52 -0700127static long n_rcu_torture_timers = 0;
Josh Triplette3033732006-10-04 02:17:14 -0700128static struct list_head rcu_torture_removed;
Rusty Russell73d0a4b2009-03-30 22:05:16 -0600129static cpumask_var_t shuffle_tmp_mask;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800130
Paul E. McKenneyd120f652008-06-18 05:21:44 -0700131static int stutter_pause_test = 0;
132
Paul E. McKenney31a72bc2008-06-18 09:26:49 -0700133#if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
134#define RCUTORTURE_RUNNABLE_INIT 1
135#else
136#define RCUTORTURE_RUNNABLE_INIT 0
137#endif
138int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT;
139
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800140/* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */
141
142#define FULLSTOP_DONTSTOP 0 /* Normal operation. */
143#define FULLSTOP_SHUTDOWN 1 /* System shutdown with rcutorture running. */
144#define FULLSTOP_RMMOD 2 /* Normal rmmod of rcutorture. */
145static int fullstop = FULLSTOP_RMMOD;
146DEFINE_MUTEX(fullstop_mutex); /* Protect fullstop transitions and spawning */
147 /* of kthreads. */
Paul E. McKenney343e9092008-12-15 16:13:07 -0800148
149/*
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800150 * Detect and respond to a system shutdown.
Paul E. McKenney343e9092008-12-15 16:13:07 -0800151 */
152static int
153rcutorture_shutdown_notify(struct notifier_block *unused1,
154 unsigned long unused2, void *unused3)
155{
Paul E. McKenneyc59ab972009-01-04 18:28:27 -0800156 mutex_lock(&fullstop_mutex);
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800157 if (fullstop == FULLSTOP_DONTSTOP)
Paul E. McKenneyc59ab972009-01-04 18:28:27 -0800158 fullstop = FULLSTOP_SHUTDOWN;
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800159 else
160 printk(KERN_WARNING /* but going down anyway, so... */
161 "Concurrent 'rmmod rcutorture' and shutdown illegal!\n");
Paul E. McKenneyc59ab972009-01-04 18:28:27 -0800162 mutex_unlock(&fullstop_mutex);
Paul E. McKenney343e9092008-12-15 16:13:07 -0800163 return NOTIFY_DONE;
164}
165
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800166/*
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800167 * Absorb kthreads into a kernel function that won't return, so that
168 * they won't ever access module text or data again.
169 */
170static void rcutorture_shutdown_absorb(char *title)
171{
172 if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) {
173 printk(KERN_NOTICE
174 "rcutorture thread %s parking due to system shutdown\n",
175 title);
176 schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT);
177 }
178}
179
180/*
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800181 * Allocate an element from the rcu_tortures pool.
182 */
Adrian Bunk97a41e22006-01-08 01:02:17 -0800183static struct rcu_torture *
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800184rcu_torture_alloc(void)
185{
186 struct list_head *p;
187
Ingo Molnaradac1662006-01-25 19:50:12 +0100188 spin_lock_bh(&rcu_torture_lock);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800189 if (list_empty(&rcu_torture_freelist)) {
190 atomic_inc(&n_rcu_torture_alloc_fail);
Ingo Molnaradac1662006-01-25 19:50:12 +0100191 spin_unlock_bh(&rcu_torture_lock);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800192 return NULL;
193 }
194 atomic_inc(&n_rcu_torture_alloc);
195 p = rcu_torture_freelist.next;
196 list_del_init(p);
Ingo Molnaradac1662006-01-25 19:50:12 +0100197 spin_unlock_bh(&rcu_torture_lock);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800198 return container_of(p, struct rcu_torture, rtort_free);
199}
200
201/*
202 * Free an element to the rcu_tortures pool.
203 */
204static void
205rcu_torture_free(struct rcu_torture *p)
206{
207 atomic_inc(&n_rcu_torture_free);
Ingo Molnaradac1662006-01-25 19:50:12 +0100208 spin_lock_bh(&rcu_torture_lock);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800209 list_add_tail(&p->rtort_free, &rcu_torture_freelist);
Ingo Molnaradac1662006-01-25 19:50:12 +0100210 spin_unlock_bh(&rcu_torture_lock);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800211}
212
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800213struct rcu_random_state {
214 unsigned long rrs_state;
Josh Triplett75cfef32006-10-04 02:17:12 -0700215 long rrs_count;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800216};
217
218#define RCU_RANDOM_MULT 39916801 /* prime */
219#define RCU_RANDOM_ADD 479001701 /* prime */
220#define RCU_RANDOM_REFRESH 10000
221
222#define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 }
223
224/*
225 * Crude but fast random-number generator. Uses a linear congruential
Paul E. McKenneyc17ac852007-10-16 23:27:19 -0700226 * generator, with occasional help from cpu_clock().
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800227 */
Josh Triplett75cfef32006-10-04 02:17:12 -0700228static unsigned long
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800229rcu_random(struct rcu_random_state *rrsp)
230{
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800231 if (--rrsp->rrs_count < 0) {
Paul E. McKenneyc17ac852007-10-16 23:27:19 -0700232 rrsp->rrs_state +=
233 (unsigned long)cpu_clock(raw_smp_processor_id());
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800234 rrsp->rrs_count = RCU_RANDOM_REFRESH;
235 }
236 rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD;
237 return swahw32(rrsp->rrs_state);
238}
239
Paul E. McKenneyd120f652008-06-18 05:21:44 -0700240static void
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800241rcu_stutter_wait(char *title)
Paul E. McKenneyd120f652008-06-18 05:21:44 -0700242{
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800243 while (stutter_pause_test || !rcutorture_runnable) {
Paul E. McKenneye3d7be22008-06-22 13:06:38 -0700244 if (rcutorture_runnable)
245 schedule_timeout_interruptible(1);
246 else
Paul E. McKenney3ccf79f2008-06-22 14:02:55 -0700247 schedule_timeout_interruptible(round_jiffies_relative(HZ));
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800248 rcutorture_shutdown_absorb(title);
Paul E. McKenney343e9092008-12-15 16:13:07 -0800249 }
Paul E. McKenneyd120f652008-06-18 05:21:44 -0700250}
251
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800252/*
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700253 * Operations vector for selecting different types of tests.
254 */
255
256struct rcu_torture_ops {
257 void (*init)(void);
258 void (*cleanup)(void);
259 int (*readlock)(void);
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700260 void (*readdelay)(struct rcu_random_state *rrsp);
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700261 void (*readunlock)(int idx);
262 int (*completed)(void);
263 void (*deferredfree)(struct rcu_torture *p);
Josh Triplettb772e1d2006-10-04 02:17:13 -0700264 void (*sync)(void);
Paul E. McKenney23269742008-05-12 21:21:05 +0200265 void (*cb_barrier)(void);
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700266 int (*stats)(char *page);
Paul E. McKenney0729fbf2008-06-25 12:24:52 -0700267 int irqcapable;
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700268 char *name;
269};
270static struct rcu_torture_ops *cur_ops = NULL;
271
272/*
273 * Definitions for rcu torture testing.
274 */
275
Josh Tripletta49a4af2006-09-29 01:59:30 -0700276static int rcu_torture_read_lock(void) __acquires(RCU)
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700277{
278 rcu_read_lock();
279 return 0;
280}
281
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700282static void rcu_read_delay(struct rcu_random_state *rrsp)
283{
284 long delay;
285 const long longdelay = 200;
286
287 /* We want there to be long-running readers, but not all the time. */
288
289 delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay);
290 if (!delay)
291 udelay(longdelay);
292}
293
Josh Tripletta49a4af2006-09-29 01:59:30 -0700294static void rcu_torture_read_unlock(int idx) __releases(RCU)
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700295{
296 rcu_read_unlock();
297}
298
299static int rcu_torture_completed(void)
300{
301 return rcu_batches_completed();
302}
303
304static void
305rcu_torture_cb(struct rcu_head *p)
306{
307 int i;
308 struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu);
309
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800310 if (fullstop != FULLSTOP_DONTSTOP) {
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700311 /* Test is ending, just drop callbacks on the floor. */
312 /* The next initialization will pick up the pieces. */
313 return;
314 }
315 i = rp->rtort_pipe_count;
316 if (i > RCU_TORTURE_PIPE_LEN)
317 i = RCU_TORTURE_PIPE_LEN;
318 atomic_inc(&rcu_torture_wcount[i]);
319 if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
320 rp->rtort_mbtest = 0;
321 rcu_torture_free(rp);
322 } else
323 cur_ops->deferredfree(rp);
324}
325
326static void rcu_torture_deferred_free(struct rcu_torture *p)
327{
328 call_rcu(&p->rtort_rcu, rcu_torture_cb);
329}
330
331static struct rcu_torture_ops rcu_ops = {
332 .init = NULL,
333 .cleanup = NULL,
334 .readlock = rcu_torture_read_lock,
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700335 .readdelay = rcu_read_delay,
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700336 .readunlock = rcu_torture_read_unlock,
337 .completed = rcu_torture_completed,
338 .deferredfree = rcu_torture_deferred_free,
Josh Triplettb772e1d2006-10-04 02:17:13 -0700339 .sync = synchronize_rcu,
Paul E. McKenney23269742008-05-12 21:21:05 +0200340 .cb_barrier = rcu_barrier,
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700341 .stats = NULL,
Paul E. McKenney0729fbf2008-06-25 12:24:52 -0700342 .irqcapable = 1,
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700343 .name = "rcu"
344};
345
Josh Triplette3033732006-10-04 02:17:14 -0700346static void rcu_sync_torture_deferred_free(struct rcu_torture *p)
347{
348 int i;
349 struct rcu_torture *rp;
350 struct rcu_torture *rp1;
351
352 cur_ops->sync();
353 list_add(&p->rtort_free, &rcu_torture_removed);
354 list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) {
355 i = rp->rtort_pipe_count;
356 if (i > RCU_TORTURE_PIPE_LEN)
357 i = RCU_TORTURE_PIPE_LEN;
358 atomic_inc(&rcu_torture_wcount[i]);
359 if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
360 rp->rtort_mbtest = 0;
361 list_del(&rp->rtort_free);
362 rcu_torture_free(rp);
363 }
364 }
365}
366
367static void rcu_sync_torture_init(void)
368{
369 INIT_LIST_HEAD(&rcu_torture_removed);
370}
371
Josh Triplett20d2e422006-10-04 02:17:15 -0700372static struct rcu_torture_ops rcu_sync_ops = {
373 .init = rcu_sync_torture_init,
374 .cleanup = NULL,
375 .readlock = rcu_torture_read_lock,
376 .readdelay = rcu_read_delay,
377 .readunlock = rcu_torture_read_unlock,
378 .completed = rcu_torture_completed,
379 .deferredfree = rcu_sync_torture_deferred_free,
380 .sync = synchronize_rcu,
Paul E. McKenney23269742008-05-12 21:21:05 +0200381 .cb_barrier = NULL,
Josh Triplett20d2e422006-10-04 02:17:15 -0700382 .stats = NULL,
Paul E. McKenney0729fbf2008-06-25 12:24:52 -0700383 .irqcapable = 1,
Josh Triplett20d2e422006-10-04 02:17:15 -0700384 .name = "rcu_sync"
385};
386
Paul E. McKenneyc32e0662006-06-27 02:54:04 -0700387/*
388 * Definitions for rcu_bh torture testing.
389 */
390
Josh Tripletta49a4af2006-09-29 01:59:30 -0700391static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH)
Paul E. McKenneyc32e0662006-06-27 02:54:04 -0700392{
393 rcu_read_lock_bh();
394 return 0;
395}
396
Josh Tripletta49a4af2006-09-29 01:59:30 -0700397static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH)
Paul E. McKenneyc32e0662006-06-27 02:54:04 -0700398{
399 rcu_read_unlock_bh();
400}
401
402static int rcu_bh_torture_completed(void)
403{
404 return rcu_batches_completed_bh();
405}
406
407static void rcu_bh_torture_deferred_free(struct rcu_torture *p)
408{
409 call_rcu_bh(&p->rtort_rcu, rcu_torture_cb);
410}
411
Josh Triplettb772e1d2006-10-04 02:17:13 -0700412struct rcu_bh_torture_synchronize {
413 struct rcu_head head;
414 struct completion completion;
415};
416
417static void rcu_bh_torture_wakeme_after_cb(struct rcu_head *head)
418{
419 struct rcu_bh_torture_synchronize *rcu;
420
421 rcu = container_of(head, struct rcu_bh_torture_synchronize, head);
422 complete(&rcu->completion);
423}
424
425static void rcu_bh_torture_synchronize(void)
426{
427 struct rcu_bh_torture_synchronize rcu;
428
429 init_completion(&rcu.completion);
430 call_rcu_bh(&rcu.head, rcu_bh_torture_wakeme_after_cb);
431 wait_for_completion(&rcu.completion);
432}
433
Paul E. McKenneyc32e0662006-06-27 02:54:04 -0700434static struct rcu_torture_ops rcu_bh_ops = {
435 .init = NULL,
436 .cleanup = NULL,
437 .readlock = rcu_bh_torture_read_lock,
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700438 .readdelay = rcu_read_delay, /* just reuse rcu's version. */
Paul E. McKenneyc32e0662006-06-27 02:54:04 -0700439 .readunlock = rcu_bh_torture_read_unlock,
440 .completed = rcu_bh_torture_completed,
441 .deferredfree = rcu_bh_torture_deferred_free,
Josh Triplettb772e1d2006-10-04 02:17:13 -0700442 .sync = rcu_bh_torture_synchronize,
Paul E. McKenney23269742008-05-12 21:21:05 +0200443 .cb_barrier = rcu_barrier_bh,
Paul E. McKenneyc32e0662006-06-27 02:54:04 -0700444 .stats = NULL,
Paul E. McKenney0729fbf2008-06-25 12:24:52 -0700445 .irqcapable = 1,
Paul E. McKenneyc32e0662006-06-27 02:54:04 -0700446 .name = "rcu_bh"
447};
448
Josh Triplett11a14702006-10-04 02:17:16 -0700449static struct rcu_torture_ops rcu_bh_sync_ops = {
450 .init = rcu_sync_torture_init,
451 .cleanup = NULL,
452 .readlock = rcu_bh_torture_read_lock,
453 .readdelay = rcu_read_delay, /* just reuse rcu's version. */
454 .readunlock = rcu_bh_torture_read_unlock,
455 .completed = rcu_bh_torture_completed,
456 .deferredfree = rcu_sync_torture_deferred_free,
457 .sync = rcu_bh_torture_synchronize,
Paul E. McKenney23269742008-05-12 21:21:05 +0200458 .cb_barrier = NULL,
Josh Triplett11a14702006-10-04 02:17:16 -0700459 .stats = NULL,
Paul E. McKenney0729fbf2008-06-25 12:24:52 -0700460 .irqcapable = 1,
Josh Triplett11a14702006-10-04 02:17:16 -0700461 .name = "rcu_bh_sync"
462};
463
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700464/*
465 * Definitions for srcu torture testing.
466 */
467
468static struct srcu_struct srcu_ctl;
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700469
470static void srcu_torture_init(void)
471{
472 init_srcu_struct(&srcu_ctl);
Josh Triplette3033732006-10-04 02:17:14 -0700473 rcu_sync_torture_init();
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700474}
475
476static void srcu_torture_cleanup(void)
477{
478 synchronize_srcu(&srcu_ctl);
479 cleanup_srcu_struct(&srcu_ctl);
480}
481
Josh Triplett012d3ca2006-12-06 20:40:19 -0800482static int srcu_torture_read_lock(void) __acquires(&srcu_ctl)
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700483{
484 return srcu_read_lock(&srcu_ctl);
485}
486
487static void srcu_read_delay(struct rcu_random_state *rrsp)
488{
489 long delay;
490 const long uspertick = 1000000 / HZ;
491 const long longdelay = 10;
492
493 /* We want there to be long-running readers, but not all the time. */
494
495 delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick);
496 if (!delay)
497 schedule_timeout_interruptible(longdelay);
498}
499
Josh Triplett012d3ca2006-12-06 20:40:19 -0800500static void srcu_torture_read_unlock(int idx) __releases(&srcu_ctl)
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700501{
502 srcu_read_unlock(&srcu_ctl, idx);
503}
504
505static int srcu_torture_completed(void)
506{
507 return srcu_batches_completed(&srcu_ctl);
508}
509
Josh Triplettb772e1d2006-10-04 02:17:13 -0700510static void srcu_torture_synchronize(void)
511{
512 synchronize_srcu(&srcu_ctl);
513}
514
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700515static int srcu_torture_stats(char *page)
516{
517 int cnt = 0;
518 int cpu;
519 int idx = srcu_ctl.completed & 0x1;
520
521 cnt += sprintf(&page[cnt], "%s%s per-CPU(idx=%d):",
522 torture_type, TORTURE_FLAG, idx);
523 for_each_possible_cpu(cpu) {
524 cnt += sprintf(&page[cnt], " %d(%d,%d)", cpu,
525 per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[!idx],
526 per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[idx]);
527 }
528 cnt += sprintf(&page[cnt], "\n");
529 return cnt;
530}
531
532static struct rcu_torture_ops srcu_ops = {
533 .init = srcu_torture_init,
534 .cleanup = srcu_torture_cleanup,
535 .readlock = srcu_torture_read_lock,
536 .readdelay = srcu_read_delay,
537 .readunlock = srcu_torture_read_unlock,
538 .completed = srcu_torture_completed,
Josh Triplette3033732006-10-04 02:17:14 -0700539 .deferredfree = rcu_sync_torture_deferred_free,
Josh Triplettb772e1d2006-10-04 02:17:13 -0700540 .sync = srcu_torture_synchronize,
Paul E. McKenney23269742008-05-12 21:21:05 +0200541 .cb_barrier = NULL,
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700542 .stats = srcu_torture_stats,
543 .name = "srcu"
544};
545
Josh Triplett4b6c2cc2006-10-04 02:17:16 -0700546/*
547 * Definitions for sched torture testing.
548 */
549
550static int sched_torture_read_lock(void)
551{
552 preempt_disable();
553 return 0;
554}
555
556static void sched_torture_read_unlock(int idx)
557{
558 preempt_enable();
559}
560
561static int sched_torture_completed(void)
562{
563 return 0;
564}
565
Paul E. McKenney23269742008-05-12 21:21:05 +0200566static void rcu_sched_torture_deferred_free(struct rcu_torture *p)
567{
568 call_rcu_sched(&p->rtort_rcu, rcu_torture_cb);
569}
570
Josh Triplett4b6c2cc2006-10-04 02:17:16 -0700571static void sched_torture_synchronize(void)
572{
573 synchronize_sched();
574}
575
576static struct rcu_torture_ops sched_ops = {
577 .init = rcu_sync_torture_init,
578 .cleanup = NULL,
579 .readlock = sched_torture_read_lock,
580 .readdelay = rcu_read_delay, /* just reuse rcu's version. */
581 .readunlock = sched_torture_read_unlock,
582 .completed = sched_torture_completed,
Paul E. McKenney23269742008-05-12 21:21:05 +0200583 .deferredfree = rcu_sched_torture_deferred_free,
Josh Triplett4b6c2cc2006-10-04 02:17:16 -0700584 .sync = sched_torture_synchronize,
Paul E. McKenney23269742008-05-12 21:21:05 +0200585 .cb_barrier = rcu_barrier_sched,
Josh Triplett4b6c2cc2006-10-04 02:17:16 -0700586 .stats = NULL,
Paul E. McKenney0729fbf2008-06-25 12:24:52 -0700587 .irqcapable = 1,
Josh Triplett4b6c2cc2006-10-04 02:17:16 -0700588 .name = "sched"
589};
590
Paul E. McKenney23269742008-05-12 21:21:05 +0200591static struct rcu_torture_ops sched_ops_sync = {
592 .init = rcu_sync_torture_init,
593 .cleanup = NULL,
594 .readlock = sched_torture_read_lock,
595 .readdelay = rcu_read_delay, /* just reuse rcu's version. */
596 .readunlock = sched_torture_read_unlock,
597 .completed = sched_torture_completed,
598 .deferredfree = rcu_sync_torture_deferred_free,
599 .sync = sched_torture_synchronize,
600 .cb_barrier = NULL,
601 .stats = NULL,
602 .name = "sched_sync"
603};
604
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700605/*
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800606 * RCU torture writer kthread. Repeatedly substitutes a new structure
607 * for that pointed to by rcu_torture_current, freeing the old structure
608 * after a series of grace periods (the "pipeline").
609 */
610static int
611rcu_torture_writer(void *arg)
612{
613 int i;
614 long oldbatch = rcu_batches_completed();
615 struct rcu_torture *rp;
616 struct rcu_torture *old_rp;
617 static DEFINE_RCU_RANDOM(rand);
618
619 VERBOSE_PRINTK_STRING("rcu_torture_writer task started");
Ingo Molnardbdf65b2005-11-13 16:07:22 -0800620 set_user_nice(current, 19);
621
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800622 do {
623 schedule_timeout_uninterruptible(1);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800624 if ((rp = rcu_torture_alloc()) == NULL)
625 continue;
626 rp->rtort_pipe_count = 0;
627 udelay(rcu_random(&rand) & 0x3ff);
628 old_rp = rcu_torture_current;
Paul E. McKenney996417d2005-11-18 01:10:50 -0800629 rp->rtort_mbtest = 1;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800630 rcu_assign_pointer(rcu_torture_current, rp);
631 smp_wmb();
Josh Triplettc8e5b162007-05-08 00:33:20 -0700632 if (old_rp) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800633 i = old_rp->rtort_pipe_count;
634 if (i > RCU_TORTURE_PIPE_LEN)
635 i = RCU_TORTURE_PIPE_LEN;
636 atomic_inc(&rcu_torture_wcount[i]);
637 old_rp->rtort_pipe_count++;
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700638 cur_ops->deferredfree(old_rp);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800639 }
640 rcu_torture_current_version++;
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700641 oldbatch = cur_ops->completed();
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800642 rcu_stutter_wait("rcu_torture_writer");
643 } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800644 VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping");
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800645 rcutorture_shutdown_absorb("rcu_torture_writer");
646 while (!kthread_should_stop())
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800647 schedule_timeout_uninterruptible(1);
648 return 0;
649}
650
651/*
Josh Triplettb772e1d2006-10-04 02:17:13 -0700652 * RCU torture fake writer kthread. Repeatedly calls sync, with a random
653 * delay between calls.
654 */
655static int
656rcu_torture_fakewriter(void *arg)
657{
658 DEFINE_RCU_RANDOM(rand);
659
660 VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task started");
661 set_user_nice(current, 19);
662
663 do {
664 schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10);
665 udelay(rcu_random(&rand) & 0x3ff);
666 cur_ops->sync();
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800667 rcu_stutter_wait("rcu_torture_fakewriter");
668 } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
Josh Triplettb772e1d2006-10-04 02:17:13 -0700669
670 VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping");
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800671 rcutorture_shutdown_absorb("rcu_torture_fakewriter");
672 while (!kthread_should_stop())
Josh Triplettb772e1d2006-10-04 02:17:13 -0700673 schedule_timeout_uninterruptible(1);
674 return 0;
675}
676
677/*
Paul E. McKenney0729fbf2008-06-25 12:24:52 -0700678 * RCU torture reader from timer handler. Dereferences rcu_torture_current,
679 * incrementing the corresponding element of the pipeline array. The
680 * counter in the element should never be greater than 1, otherwise, the
681 * RCU implementation is broken.
682 */
683static void rcu_torture_timer(unsigned long unused)
684{
685 int idx;
686 int completed;
687 static DEFINE_RCU_RANDOM(rand);
688 static DEFINE_SPINLOCK(rand_lock);
689 struct rcu_torture *p;
690 int pipe_count;
691
692 idx = cur_ops->readlock();
693 completed = cur_ops->completed();
694 p = rcu_dereference(rcu_torture_current);
695 if (p == NULL) {
696 /* Leave because rcu_torture_writer is not yet underway */
697 cur_ops->readunlock(idx);
698 return;
699 }
700 if (p->rtort_mbtest == 0)
701 atomic_inc(&n_rcu_torture_mberror);
702 spin_lock(&rand_lock);
703 cur_ops->readdelay(&rand);
704 n_rcu_torture_timers++;
705 spin_unlock(&rand_lock);
706 preempt_disable();
707 pipe_count = p->rtort_pipe_count;
708 if (pipe_count > RCU_TORTURE_PIPE_LEN) {
709 /* Should not happen, but... */
710 pipe_count = RCU_TORTURE_PIPE_LEN;
711 }
712 ++__get_cpu_var(rcu_torture_count)[pipe_count];
713 completed = cur_ops->completed() - completed;
714 if (completed > RCU_TORTURE_PIPE_LEN) {
715 /* Should not happen, but... */
716 completed = RCU_TORTURE_PIPE_LEN;
717 }
718 ++__get_cpu_var(rcu_torture_batch)[completed];
719 preempt_enable();
720 cur_ops->readunlock(idx);
721}
722
723/*
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800724 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current,
725 * incrementing the corresponding element of the pipeline array. The
726 * counter in the element should never be greater than 1, otherwise, the
727 * RCU implementation is broken.
728 */
729static int
730rcu_torture_reader(void *arg)
731{
732 int completed;
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700733 int idx;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800734 DEFINE_RCU_RANDOM(rand);
735 struct rcu_torture *p;
736 int pipe_count;
Paul E. McKenney0729fbf2008-06-25 12:24:52 -0700737 struct timer_list t;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800738
739 VERBOSE_PRINTK_STRING("rcu_torture_reader task started");
Ingo Molnardbdf65b2005-11-13 16:07:22 -0800740 set_user_nice(current, 19);
Paul E. McKenney0729fbf2008-06-25 12:24:52 -0700741 if (irqreader && cur_ops->irqcapable)
742 setup_timer_on_stack(&t, rcu_torture_timer, 0);
Ingo Molnardbdf65b2005-11-13 16:07:22 -0800743
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800744 do {
Paul E. McKenney0729fbf2008-06-25 12:24:52 -0700745 if (irqreader && cur_ops->irqcapable) {
746 if (!timer_pending(&t))
747 mod_timer(&t, 1);
748 }
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700749 idx = cur_ops->readlock();
750 completed = cur_ops->completed();
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800751 p = rcu_dereference(rcu_torture_current);
752 if (p == NULL) {
753 /* Wait for rcu_torture_writer to get underway */
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700754 cur_ops->readunlock(idx);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800755 schedule_timeout_interruptible(HZ);
756 continue;
757 }
Paul E. McKenney996417d2005-11-18 01:10:50 -0800758 if (p->rtort_mbtest == 0)
759 atomic_inc(&n_rcu_torture_mberror);
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700760 cur_ops->readdelay(&rand);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800761 preempt_disable();
762 pipe_count = p->rtort_pipe_count;
763 if (pipe_count > RCU_TORTURE_PIPE_LEN) {
764 /* Should not happen, but... */
765 pipe_count = RCU_TORTURE_PIPE_LEN;
766 }
767 ++__get_cpu_var(rcu_torture_count)[pipe_count];
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700768 completed = cur_ops->completed() - completed;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800769 if (completed > RCU_TORTURE_PIPE_LEN) {
770 /* Should not happen, but... */
771 completed = RCU_TORTURE_PIPE_LEN;
772 }
773 ++__get_cpu_var(rcu_torture_batch)[completed];
774 preempt_enable();
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700775 cur_ops->readunlock(idx);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800776 schedule();
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800777 rcu_stutter_wait("rcu_torture_reader");
778 } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800779 VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping");
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800780 rcutorture_shutdown_absorb("rcu_torture_reader");
Paul E. McKenney0729fbf2008-06-25 12:24:52 -0700781 if (irqreader && cur_ops->irqcapable)
782 del_timer_sync(&t);
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800783 while (!kthread_should_stop())
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800784 schedule_timeout_uninterruptible(1);
785 return 0;
786}
787
788/*
789 * Create an RCU-torture statistics message in the specified buffer.
790 */
791static int
792rcu_torture_printk(char *page)
793{
794 int cnt = 0;
795 int cpu;
796 int i;
797 long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
798 long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
799
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -0800800 for_each_possible_cpu(cpu) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800801 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
802 pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i];
803 batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i];
804 }
805 }
806 for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) {
807 if (pipesummary[i] != 0)
808 break;
809 }
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700810 cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800811 cnt += sprintf(&page[cnt],
Paul E. McKenney996417d2005-11-18 01:10:50 -0800812 "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d "
Paul E. McKenney0729fbf2008-06-25 12:24:52 -0700813 "rtmbe: %d nt: %ld",
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800814 rcu_torture_current,
815 rcu_torture_current_version,
816 list_empty(&rcu_torture_freelist),
817 atomic_read(&n_rcu_torture_alloc),
818 atomic_read(&n_rcu_torture_alloc_fail),
Paul E. McKenney996417d2005-11-18 01:10:50 -0800819 atomic_read(&n_rcu_torture_free),
Paul E. McKenney0729fbf2008-06-25 12:24:52 -0700820 atomic_read(&n_rcu_torture_mberror),
821 n_rcu_torture_timers);
Paul E. McKenney996417d2005-11-18 01:10:50 -0800822 if (atomic_read(&n_rcu_torture_mberror) != 0)
823 cnt += sprintf(&page[cnt], " !!!");
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700824 cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG);
Paul E. McKenney996417d2005-11-18 01:10:50 -0800825 if (i > 1) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800826 cnt += sprintf(&page[cnt], "!!! ");
Paul E. McKenney996417d2005-11-18 01:10:50 -0800827 atomic_inc(&n_rcu_torture_error);
Ingo Molnar5af970a2008-06-18 10:09:48 +0200828 WARN_ON_ONCE(1);
Paul E. McKenney996417d2005-11-18 01:10:50 -0800829 }
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800830 cnt += sprintf(&page[cnt], "Reader Pipe: ");
831 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
832 cnt += sprintf(&page[cnt], " %ld", pipesummary[i]);
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700833 cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800834 cnt += sprintf(&page[cnt], "Reader Batch: ");
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700835 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800836 cnt += sprintf(&page[cnt], " %ld", batchsummary[i]);
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700837 cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800838 cnt += sprintf(&page[cnt], "Free-Block Circulation: ");
839 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
840 cnt += sprintf(&page[cnt], " %d",
841 atomic_read(&rcu_torture_wcount[i]));
842 }
843 cnt += sprintf(&page[cnt], "\n");
Josh Triplettc8e5b162007-05-08 00:33:20 -0700844 if (cur_ops->stats)
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700845 cnt += cur_ops->stats(&page[cnt]);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800846 return cnt;
847}
848
849/*
850 * Print torture statistics. Caller must ensure that there is only
851 * one call to this function at a given time!!! This is normally
852 * accomplished by relying on the module system to only have one copy
853 * of the module loaded, and then by giving the rcu_torture_stats
854 * kthread full control (or the init/cleanup functions when rcu_torture_stats
855 * thread is not running).
856 */
857static void
858rcu_torture_stats_print(void)
859{
860 int cnt;
861
862 cnt = rcu_torture_printk(printk_buf);
863 printk(KERN_ALERT "%s", printk_buf);
864}
865
866/*
867 * Periodically prints torture statistics, if periodic statistics printing
868 * was specified via the stat_interval module parameter.
869 *
870 * No need to worry about fullstop here, since this one doesn't reference
871 * volatile state or register callbacks.
872 */
873static int
874rcu_torture_stats(void *arg)
875{
876 VERBOSE_PRINTK_STRING("rcu_torture_stats task started");
877 do {
878 schedule_timeout_interruptible(stat_interval * HZ);
879 rcu_torture_stats_print();
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800880 rcutorture_shutdown_absorb("rcu_torture_stats");
881 } while (!kthread_should_stop());
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800882 VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping");
883 return 0;
884}
885
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800886static int rcu_idle_cpu; /* Force all torture tasks off this CPU */
887
888/* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case
889 * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs.
890 */
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700891static void rcu_torture_shuffle_tasks(void)
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800892{
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800893 int i;
894
Rusty Russell73d0a4b2009-03-30 22:05:16 -0600895 cpumask_setall(shuffle_tmp_mask);
Gautham R Shenoy86ef5c92008-01-25 21:08:02 +0100896 get_online_cpus();
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800897
898 /* No point in shuffling if there is only one online CPU (ex: UP) */
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800899 if (num_online_cpus() == 1) {
900 put_online_cpus();
901 return;
902 }
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800903
904 if (rcu_idle_cpu != -1)
Rusty Russell73d0a4b2009-03-30 22:05:16 -0600905 cpumask_clear_cpu(rcu_idle_cpu, shuffle_tmp_mask);
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800906
Rusty Russell73d0a4b2009-03-30 22:05:16 -0600907 set_cpus_allowed_ptr(current, shuffle_tmp_mask);
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800908
Josh Triplettc8e5b162007-05-08 00:33:20 -0700909 if (reader_tasks) {
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800910 for (i = 0; i < nrealreaders; i++)
911 if (reader_tasks[i])
Mike Travisf70316d2008-04-04 18:11:06 -0700912 set_cpus_allowed_ptr(reader_tasks[i],
Rusty Russell73d0a4b2009-03-30 22:05:16 -0600913 shuffle_tmp_mask);
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800914 }
915
Josh Triplettc8e5b162007-05-08 00:33:20 -0700916 if (fakewriter_tasks) {
Josh Triplettb772e1d2006-10-04 02:17:13 -0700917 for (i = 0; i < nfakewriters; i++)
918 if (fakewriter_tasks[i])
Mike Travisf70316d2008-04-04 18:11:06 -0700919 set_cpus_allowed_ptr(fakewriter_tasks[i],
Rusty Russell73d0a4b2009-03-30 22:05:16 -0600920 shuffle_tmp_mask);
Josh Triplettb772e1d2006-10-04 02:17:13 -0700921 }
922
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800923 if (writer_task)
Rusty Russell73d0a4b2009-03-30 22:05:16 -0600924 set_cpus_allowed_ptr(writer_task, shuffle_tmp_mask);
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800925
926 if (stats_task)
Rusty Russell73d0a4b2009-03-30 22:05:16 -0600927 set_cpus_allowed_ptr(stats_task, shuffle_tmp_mask);
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800928
929 if (rcu_idle_cpu == -1)
930 rcu_idle_cpu = num_online_cpus() - 1;
931 else
932 rcu_idle_cpu--;
933
Gautham R Shenoy86ef5c92008-01-25 21:08:02 +0100934 put_online_cpus();
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800935}
936
937/* Shuffle tasks across CPUs, with the intent of allowing each CPU in the
938 * system to become idle at a time and cut off its timer ticks. This is meant
939 * to test the support for such tickless idle CPU in RCU.
940 */
941static int
942rcu_torture_shuffle(void *arg)
943{
944 VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started");
945 do {
946 schedule_timeout_interruptible(shuffle_interval * HZ);
947 rcu_torture_shuffle_tasks();
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800948 rcutorture_shutdown_absorb("rcu_torture_shuffle");
949 } while (!kthread_should_stop());
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800950 VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping");
951 return 0;
952}
953
Paul E. McKenneyd120f652008-06-18 05:21:44 -0700954/* Cause the rcutorture test to "stutter", starting and stopping all
955 * threads periodically.
956 */
957static int
958rcu_torture_stutter(void *arg)
959{
960 VERBOSE_PRINTK_STRING("rcu_torture_stutter task started");
961 do {
962 schedule_timeout_interruptible(stutter * HZ);
963 stutter_pause_test = 1;
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800964 if (!kthread_should_stop())
Paul E. McKenneyd120f652008-06-18 05:21:44 -0700965 schedule_timeout_interruptible(stutter * HZ);
966 stutter_pause_test = 0;
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800967 rcutorture_shutdown_absorb("rcu_torture_stutter");
968 } while (!kthread_should_stop());
Paul E. McKenneyd120f652008-06-18 05:21:44 -0700969 VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping");
970 return 0;
971}
972
Paul E. McKenney95c38322006-03-24 03:15:58 -0800973static inline void
974rcu_torture_print_module_parms(char *tag)
975{
Josh Triplettb772e1d2006-10-04 02:17:13 -0700976 printk(KERN_ALERT "%s" TORTURE_FLAG
977 "--- %s: nreaders=%d nfakewriters=%d "
Paul E. McKenney95c38322006-03-24 03:15:58 -0800978 "stat_interval=%d verbose=%d test_no_idle_hz=%d "
Paul E. McKenney0729fbf2008-06-25 12:24:52 -0700979 "shuffle_interval=%d stutter=%d irqreader=%d\n",
Josh Triplettb772e1d2006-10-04 02:17:13 -0700980 torture_type, tag, nrealreaders, nfakewriters,
Paul E. McKenneyd120f652008-06-18 05:21:44 -0700981 stat_interval, verbose, test_no_idle_hz, shuffle_interval,
Paul E. McKenney0729fbf2008-06-25 12:24:52 -0700982 stutter, irqreader);
Paul E. McKenney95c38322006-03-24 03:15:58 -0800983}
984
Paul E. McKenney343e9092008-12-15 16:13:07 -0800985static struct notifier_block rcutorture_nb = {
986 .notifier_call = rcutorture_shutdown_notify,
987};
988
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800989static void
990rcu_torture_cleanup(void)
991{
992 int i;
993
Paul E. McKenney343e9092008-12-15 16:13:07 -0800994 mutex_lock(&fullstop_mutex);
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800995 if (fullstop == FULLSTOP_SHUTDOWN) {
996 printk(KERN_WARNING /* but going down anyway, so... */
997 "Concurrent 'rmmod rcutorture' and shutdown illegal!\n");
Paul E. McKenney343e9092008-12-15 16:13:07 -0800998 mutex_unlock(&fullstop_mutex);
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -0800999 schedule_timeout_uninterruptible(10);
Paul E. McKenney343e9092008-12-15 16:13:07 -08001000 if (cur_ops->cb_barrier != NULL)
1001 cur_ops->cb_barrier();
1002 return;
1003 }
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -08001004 fullstop = FULLSTOP_RMMOD;
Paul E. McKenney343e9092008-12-15 16:13:07 -08001005 mutex_unlock(&fullstop_mutex);
1006 unregister_reboot_notifier(&rcutorture_nb);
Paul E. McKenneyd120f652008-06-18 05:21:44 -07001007 if (stutter_task) {
1008 VERBOSE_PRINTK_STRING("Stopping rcu_torture_stutter task");
1009 kthread_stop(stutter_task);
1010 }
1011 stutter_task = NULL;
Josh Triplettc8e5b162007-05-08 00:33:20 -07001012 if (shuffler_task) {
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -08001013 VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task");
1014 kthread_stop(shuffler_task);
Rusty Russell73d0a4b2009-03-30 22:05:16 -06001015 free_cpumask_var(shuffle_tmp_mask);
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -08001016 }
1017 shuffler_task = NULL;
1018
Josh Triplettc8e5b162007-05-08 00:33:20 -07001019 if (writer_task) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001020 VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task");
1021 kthread_stop(writer_task);
1022 }
1023 writer_task = NULL;
1024
Josh Triplettc8e5b162007-05-08 00:33:20 -07001025 if (reader_tasks) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001026 for (i = 0; i < nrealreaders; i++) {
Josh Triplettc8e5b162007-05-08 00:33:20 -07001027 if (reader_tasks[i]) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001028 VERBOSE_PRINTK_STRING(
1029 "Stopping rcu_torture_reader task");
1030 kthread_stop(reader_tasks[i]);
1031 }
1032 reader_tasks[i] = NULL;
1033 }
1034 kfree(reader_tasks);
1035 reader_tasks = NULL;
1036 }
1037 rcu_torture_current = NULL;
1038
Josh Triplettc8e5b162007-05-08 00:33:20 -07001039 if (fakewriter_tasks) {
Josh Triplettb772e1d2006-10-04 02:17:13 -07001040 for (i = 0; i < nfakewriters; i++) {
Josh Triplettc8e5b162007-05-08 00:33:20 -07001041 if (fakewriter_tasks[i]) {
Josh Triplettb772e1d2006-10-04 02:17:13 -07001042 VERBOSE_PRINTK_STRING(
1043 "Stopping rcu_torture_fakewriter task");
1044 kthread_stop(fakewriter_tasks[i]);
1045 }
1046 fakewriter_tasks[i] = NULL;
1047 }
1048 kfree(fakewriter_tasks);
1049 fakewriter_tasks = NULL;
1050 }
1051
Josh Triplettc8e5b162007-05-08 00:33:20 -07001052 if (stats_task) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001053 VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task");
1054 kthread_stop(stats_task);
1055 }
1056 stats_task = NULL;
1057
1058 /* Wait for all RCU callbacks to fire. */
Paul E. McKenney23269742008-05-12 21:21:05 +02001059
1060 if (cur_ops->cb_barrier != NULL)
1061 cur_ops->cb_barrier();
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001062
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001063 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
Paul E. McKenney72e9bb52006-06-27 02:54:03 -07001064
Josh Triplettc8e5b162007-05-08 00:33:20 -07001065 if (cur_ops->cleanup)
Paul E. McKenney72e9bb52006-06-27 02:54:03 -07001066 cur_ops->cleanup();
Paul E. McKenney95c38322006-03-24 03:15:58 -08001067 if (atomic_read(&n_rcu_torture_error))
1068 rcu_torture_print_module_parms("End of test: FAILURE");
1069 else
1070 rcu_torture_print_module_parms("End of test: SUCCESS");
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001071}
1072
Josh Triplett6f8bc5002007-05-08 00:25:24 -07001073static int __init
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001074rcu_torture_init(void)
1075{
1076 int i;
1077 int cpu;
1078 int firsterr = 0;
Josh Triplettade5fb82007-05-08 00:33:22 -07001079 static struct rcu_torture_ops *torture_ops[] =
1080 { &rcu_ops, &rcu_sync_ops, &rcu_bh_ops, &rcu_bh_sync_ops,
Paul E. McKenney23269742008-05-12 21:21:05 +02001081 &srcu_ops, &sched_ops, &sched_ops_sync, };
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001082
Paul E. McKenney343e9092008-12-15 16:13:07 -08001083 mutex_lock(&fullstop_mutex);
1084
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001085 /* Process args and tell the world that the torturer is on the job. */
Josh Triplettade5fb82007-05-08 00:33:22 -07001086 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
Paul E. McKenney72e9bb52006-06-27 02:54:03 -07001087 cur_ops = torture_ops[i];
Josh Triplettade5fb82007-05-08 00:33:22 -07001088 if (strcmp(torture_type, cur_ops->name) == 0)
Paul E. McKenney72e9bb52006-06-27 02:54:03 -07001089 break;
Paul E. McKenney72e9bb52006-06-27 02:54:03 -07001090 }
Josh Triplettade5fb82007-05-08 00:33:22 -07001091 if (i == ARRAY_SIZE(torture_ops)) {
Paul E. McKenney72e9bb52006-06-27 02:54:03 -07001092 printk(KERN_ALERT "rcutorture: invalid torture type: \"%s\"\n",
1093 torture_type);
Paul E. McKenney343e9092008-12-15 16:13:07 -08001094 mutex_unlock(&fullstop_mutex);
Paul E. McKenney72e9bb52006-06-27 02:54:03 -07001095 return (-EINVAL);
1096 }
Josh Triplettc8e5b162007-05-08 00:33:20 -07001097 if (cur_ops->init)
Paul E. McKenney72e9bb52006-06-27 02:54:03 -07001098 cur_ops->init(); /* no "goto unwind" prior to this point!!! */
1099
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001100 if (nreaders >= 0)
1101 nrealreaders = nreaders;
1102 else
1103 nrealreaders = 2 * num_online_cpus();
Paul E. McKenney95c38322006-03-24 03:15:58 -08001104 rcu_torture_print_module_parms("Start of test");
Paul E. McKenneyc9d557c2009-01-07 14:33:30 -08001105 fullstop = FULLSTOP_DONTSTOP;
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001106
1107 /* Set up the freelist. */
1108
1109 INIT_LIST_HEAD(&rcu_torture_freelist);
Ahmed S. Darwish788e7702007-05-08 00:33:14 -07001110 for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) {
Paul E. McKenney996417d2005-11-18 01:10:50 -08001111 rcu_tortures[i].rtort_mbtest = 0;
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001112 list_add_tail(&rcu_tortures[i].rtort_free,
1113 &rcu_torture_freelist);
1114 }
1115
1116 /* Initialize the statistics so that each run gets its own numbers. */
1117
1118 rcu_torture_current = NULL;
1119 rcu_torture_current_version = 0;
1120 atomic_set(&n_rcu_torture_alloc, 0);
1121 atomic_set(&n_rcu_torture_alloc_fail, 0);
1122 atomic_set(&n_rcu_torture_free, 0);
Paul E. McKenney996417d2005-11-18 01:10:50 -08001123 atomic_set(&n_rcu_torture_mberror, 0);
1124 atomic_set(&n_rcu_torture_error, 0);
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001125 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1126 atomic_set(&rcu_torture_wcount[i], 0);
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -08001127 for_each_possible_cpu(cpu) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001128 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1129 per_cpu(rcu_torture_count, cpu)[i] = 0;
1130 per_cpu(rcu_torture_batch, cpu)[i] = 0;
1131 }
1132 }
1133
1134 /* Start up the kthreads. */
1135
1136 VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task");
1137 writer_task = kthread_run(rcu_torture_writer, NULL,
1138 "rcu_torture_writer");
1139 if (IS_ERR(writer_task)) {
1140 firsterr = PTR_ERR(writer_task);
1141 VERBOSE_PRINTK_ERRSTRING("Failed to create writer");
1142 writer_task = NULL;
1143 goto unwind;
1144 }
Josh Triplettb772e1d2006-10-04 02:17:13 -07001145 fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]),
1146 GFP_KERNEL);
1147 if (fakewriter_tasks == NULL) {
1148 VERBOSE_PRINTK_ERRSTRING("out of memory");
1149 firsterr = -ENOMEM;
1150 goto unwind;
1151 }
1152 for (i = 0; i < nfakewriters; i++) {
1153 VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task");
1154 fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL,
1155 "rcu_torture_fakewriter");
1156 if (IS_ERR(fakewriter_tasks[i])) {
1157 firsterr = PTR_ERR(fakewriter_tasks[i]);
1158 VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter");
1159 fakewriter_tasks[i] = NULL;
1160 goto unwind;
1161 }
1162 }
Josh Triplett2860aab2006-10-04 02:17:11 -07001163 reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]),
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001164 GFP_KERNEL);
1165 if (reader_tasks == NULL) {
1166 VERBOSE_PRINTK_ERRSTRING("out of memory");
1167 firsterr = -ENOMEM;
1168 goto unwind;
1169 }
1170 for (i = 0; i < nrealreaders; i++) {
1171 VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task");
1172 reader_tasks[i] = kthread_run(rcu_torture_reader, NULL,
1173 "rcu_torture_reader");
1174 if (IS_ERR(reader_tasks[i])) {
1175 firsterr = PTR_ERR(reader_tasks[i]);
1176 VERBOSE_PRINTK_ERRSTRING("Failed to create reader");
1177 reader_tasks[i] = NULL;
1178 goto unwind;
1179 }
1180 }
1181 if (stat_interval > 0) {
1182 VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task");
1183 stats_task = kthread_run(rcu_torture_stats, NULL,
1184 "rcu_torture_stats");
1185 if (IS_ERR(stats_task)) {
1186 firsterr = PTR_ERR(stats_task);
1187 VERBOSE_PRINTK_ERRSTRING("Failed to create stats");
1188 stats_task = NULL;
1189 goto unwind;
1190 }
1191 }
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -08001192 if (test_no_idle_hz) {
1193 rcu_idle_cpu = num_online_cpus() - 1;
Rusty Russell73d0a4b2009-03-30 22:05:16 -06001194
1195 if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) {
1196 firsterr = -ENOMEM;
1197 VERBOSE_PRINTK_ERRSTRING("Failed to alloc mask");
1198 goto unwind;
1199 }
1200
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -08001201 /* Create the shuffler thread */
1202 shuffler_task = kthread_run(rcu_torture_shuffle, NULL,
1203 "rcu_torture_shuffle");
1204 if (IS_ERR(shuffler_task)) {
Rusty Russell73d0a4b2009-03-30 22:05:16 -06001205 free_cpumask_var(shuffle_tmp_mask);
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -08001206 firsterr = PTR_ERR(shuffler_task);
1207 VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler");
1208 shuffler_task = NULL;
1209 goto unwind;
1210 }
1211 }
Paul E. McKenneyd120f652008-06-18 05:21:44 -07001212 if (stutter < 0)
1213 stutter = 0;
1214 if (stutter) {
1215 /* Create the stutter thread */
1216 stutter_task = kthread_run(rcu_torture_stutter, NULL,
1217 "rcu_torture_stutter");
1218 if (IS_ERR(stutter_task)) {
1219 firsterr = PTR_ERR(stutter_task);
1220 VERBOSE_PRINTK_ERRSTRING("Failed to create stutter");
1221 stutter_task = NULL;
1222 goto unwind;
1223 }
1224 }
Paul E. McKenney343e9092008-12-15 16:13:07 -08001225 register_reboot_notifier(&rcutorture_nb);
1226 mutex_unlock(&fullstop_mutex);
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001227 return 0;
1228
1229unwind:
Paul E. McKenney343e9092008-12-15 16:13:07 -08001230 mutex_unlock(&fullstop_mutex);
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001231 rcu_torture_cleanup();
1232 return firsterr;
1233}
1234
1235module_init(rcu_torture_init);
1236module_exit(rcu_torture_cleanup);