blob: ddff33247785aa95a95f00356f9909dde2ff3196 [file] [log] [blame]
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>
38#include <linux/module.h>
39#include <linux/completion.h>
40#include <linux/moduleparam.h>
41#include <linux/percpu.h>
42#include <linux/notifier.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>
45#include <linux/random.h>
46#include <linux/delay.h>
47#include <linux/byteorder/swabb.h>
48#include <linux/stat.h>
Paul E. McKenneyb2896d22006-10-04 02:17:03 -070049#include <linux/srcu.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. */
61static int shuffle_interval = 5; /* Interval between shuffles (in sec)*/
Josh Triplett20d2e422006-10-04 02:17:15 -070062static char *torture_type = "rcu"; /* What RCU implementation to torture. */
Paul E. McKenneya241ec62005-10-30 15:03:12 -080063
Josh Triplettd6ad6712007-03-06 01:42:13 -080064module_param(nreaders, int, 0444);
Paul E. McKenneya241ec62005-10-30 15:03:12 -080065MODULE_PARM_DESC(nreaders, "Number of RCU reader threads");
Josh Triplettd6ad6712007-03-06 01:42:13 -080066module_param(nfakewriters, int, 0444);
Josh Triplettb772e1d2006-10-04 02:17:13 -070067MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads");
Josh Triplettd6ad6712007-03-06 01:42:13 -080068module_param(stat_interval, int, 0444);
Paul E. McKenneya241ec62005-10-30 15:03:12 -080069MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s");
Josh Triplettd6ad6712007-03-06 01:42:13 -080070module_param(verbose, bool, 0444);
Paul E. McKenneya241ec62005-10-30 15:03:12 -080071MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s");
Josh Triplettd6ad6712007-03-06 01:42:13 -080072module_param(test_no_idle_hz, bool, 0444);
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -080073MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs");
Josh Triplettd6ad6712007-03-06 01:42:13 -080074module_param(shuffle_interval, int, 0444);
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -080075MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles");
Josh Triplettd6ad6712007-03-06 01:42:13 -080076module_param(torture_type, charp, 0444);
Paul E. McKenneyb2896d22006-10-04 02:17:03 -070077MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)");
Paul E. McKenney72e9bb52006-06-27 02:54:03 -070078
79#define TORTURE_FLAG "-torture:"
Paul E. McKenneya241ec62005-10-30 15:03:12 -080080#define PRINTK_STRING(s) \
Paul E. McKenney72e9bb52006-06-27 02:54:03 -070081 do { printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0)
Paul E. McKenneya241ec62005-10-30 15:03:12 -080082#define VERBOSE_PRINTK_STRING(s) \
Paul E. McKenney72e9bb52006-06-27 02:54:03 -070083 do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0)
Paul E. McKenneya241ec62005-10-30 15:03:12 -080084#define VERBOSE_PRINTK_ERRSTRING(s) \
Paul E. McKenney72e9bb52006-06-27 02:54:03 -070085 do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0)
Paul E. McKenneya241ec62005-10-30 15:03:12 -080086
87static char printk_buf[4096];
88
89static int nrealreaders;
90static struct task_struct *writer_task;
Josh Triplettb772e1d2006-10-04 02:17:13 -070091static struct task_struct **fakewriter_tasks;
Paul E. McKenneya241ec62005-10-30 15:03:12 -080092static struct task_struct **reader_tasks;
93static struct task_struct *stats_task;
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -080094static struct task_struct *shuffler_task;
Paul E. McKenneya241ec62005-10-30 15:03:12 -080095
96#define RCU_TORTURE_PIPE_LEN 10
97
98struct rcu_torture {
99 struct rcu_head rtort_rcu;
100 int rtort_pipe_count;
101 struct list_head rtort_free;
Paul E. McKenney996417d2005-11-18 01:10:50 -0800102 int rtort_mbtest;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800103};
104
105static int fullstop = 0; /* stop generating callbacks at test end. */
106static LIST_HEAD(rcu_torture_freelist);
107static struct rcu_torture *rcu_torture_current = NULL;
108static long rcu_torture_current_version = 0;
109static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
110static DEFINE_SPINLOCK(rcu_torture_lock);
111static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) =
112 { 0 };
113static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) =
114 { 0 };
115static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700116static atomic_t n_rcu_torture_alloc;
117static atomic_t n_rcu_torture_alloc_fail;
118static atomic_t n_rcu_torture_free;
119static atomic_t n_rcu_torture_mberror;
120static atomic_t n_rcu_torture_error;
Josh Triplette3033732006-10-04 02:17:14 -0700121static struct list_head rcu_torture_removed;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800122
123/*
124 * Allocate an element from the rcu_tortures pool.
125 */
Adrian Bunk97a41e22006-01-08 01:02:17 -0800126static struct rcu_torture *
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800127rcu_torture_alloc(void)
128{
129 struct list_head *p;
130
Ingo Molnaradac1662006-01-25 19:50:12 +0100131 spin_lock_bh(&rcu_torture_lock);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800132 if (list_empty(&rcu_torture_freelist)) {
133 atomic_inc(&n_rcu_torture_alloc_fail);
Ingo Molnaradac1662006-01-25 19:50:12 +0100134 spin_unlock_bh(&rcu_torture_lock);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800135 return NULL;
136 }
137 atomic_inc(&n_rcu_torture_alloc);
138 p = rcu_torture_freelist.next;
139 list_del_init(p);
Ingo Molnaradac1662006-01-25 19:50:12 +0100140 spin_unlock_bh(&rcu_torture_lock);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800141 return container_of(p, struct rcu_torture, rtort_free);
142}
143
144/*
145 * Free an element to the rcu_tortures pool.
146 */
147static void
148rcu_torture_free(struct rcu_torture *p)
149{
150 atomic_inc(&n_rcu_torture_free);
Ingo Molnaradac1662006-01-25 19:50:12 +0100151 spin_lock_bh(&rcu_torture_lock);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800152 list_add_tail(&p->rtort_free, &rcu_torture_freelist);
Ingo Molnaradac1662006-01-25 19:50:12 +0100153 spin_unlock_bh(&rcu_torture_lock);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800154}
155
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800156struct rcu_random_state {
157 unsigned long rrs_state;
Josh Triplett75cfef32006-10-04 02:17:12 -0700158 long rrs_count;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800159};
160
161#define RCU_RANDOM_MULT 39916801 /* prime */
162#define RCU_RANDOM_ADD 479001701 /* prime */
163#define RCU_RANDOM_REFRESH 10000
164
165#define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 }
166
167/*
168 * Crude but fast random-number generator. Uses a linear congruential
169 * generator, with occasional help from get_random_bytes().
170 */
Josh Triplett75cfef32006-10-04 02:17:12 -0700171static unsigned long
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800172rcu_random(struct rcu_random_state *rrsp)
173{
174 long refresh;
175
176 if (--rrsp->rrs_count < 0) {
177 get_random_bytes(&refresh, sizeof(refresh));
178 rrsp->rrs_state += refresh;
179 rrsp->rrs_count = RCU_RANDOM_REFRESH;
180 }
181 rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD;
182 return swahw32(rrsp->rrs_state);
183}
184
185/*
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700186 * Operations vector for selecting different types of tests.
187 */
188
189struct rcu_torture_ops {
190 void (*init)(void);
191 void (*cleanup)(void);
192 int (*readlock)(void);
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700193 void (*readdelay)(struct rcu_random_state *rrsp);
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700194 void (*readunlock)(int idx);
195 int (*completed)(void);
196 void (*deferredfree)(struct rcu_torture *p);
Josh Triplettb772e1d2006-10-04 02:17:13 -0700197 void (*sync)(void);
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700198 int (*stats)(char *page);
199 char *name;
200};
201static struct rcu_torture_ops *cur_ops = NULL;
202
203/*
204 * Definitions for rcu torture testing.
205 */
206
Josh Tripletta49a4af2006-09-29 01:59:30 -0700207static int rcu_torture_read_lock(void) __acquires(RCU)
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700208{
209 rcu_read_lock();
210 return 0;
211}
212
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700213static void rcu_read_delay(struct rcu_random_state *rrsp)
214{
215 long delay;
216 const long longdelay = 200;
217
218 /* We want there to be long-running readers, but not all the time. */
219
220 delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay);
221 if (!delay)
222 udelay(longdelay);
223}
224
Josh Tripletta49a4af2006-09-29 01:59:30 -0700225static void rcu_torture_read_unlock(int idx) __releases(RCU)
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700226{
227 rcu_read_unlock();
228}
229
230static int rcu_torture_completed(void)
231{
232 return rcu_batches_completed();
233}
234
235static void
236rcu_torture_cb(struct rcu_head *p)
237{
238 int i;
239 struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu);
240
241 if (fullstop) {
242 /* Test is ending, just drop callbacks on the floor. */
243 /* The next initialization will pick up the pieces. */
244 return;
245 }
246 i = rp->rtort_pipe_count;
247 if (i > RCU_TORTURE_PIPE_LEN)
248 i = RCU_TORTURE_PIPE_LEN;
249 atomic_inc(&rcu_torture_wcount[i]);
250 if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
251 rp->rtort_mbtest = 0;
252 rcu_torture_free(rp);
253 } else
254 cur_ops->deferredfree(rp);
255}
256
257static void rcu_torture_deferred_free(struct rcu_torture *p)
258{
259 call_rcu(&p->rtort_rcu, rcu_torture_cb);
260}
261
262static struct rcu_torture_ops rcu_ops = {
263 .init = NULL,
264 .cleanup = NULL,
265 .readlock = rcu_torture_read_lock,
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700266 .readdelay = rcu_read_delay,
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700267 .readunlock = rcu_torture_read_unlock,
268 .completed = rcu_torture_completed,
269 .deferredfree = rcu_torture_deferred_free,
Josh Triplettb772e1d2006-10-04 02:17:13 -0700270 .sync = synchronize_rcu,
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700271 .stats = NULL,
272 .name = "rcu"
273};
274
Josh Triplette3033732006-10-04 02:17:14 -0700275static void rcu_sync_torture_deferred_free(struct rcu_torture *p)
276{
277 int i;
278 struct rcu_torture *rp;
279 struct rcu_torture *rp1;
280
281 cur_ops->sync();
282 list_add(&p->rtort_free, &rcu_torture_removed);
283 list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) {
284 i = rp->rtort_pipe_count;
285 if (i > RCU_TORTURE_PIPE_LEN)
286 i = RCU_TORTURE_PIPE_LEN;
287 atomic_inc(&rcu_torture_wcount[i]);
288 if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
289 rp->rtort_mbtest = 0;
290 list_del(&rp->rtort_free);
291 rcu_torture_free(rp);
292 }
293 }
294}
295
296static void rcu_sync_torture_init(void)
297{
298 INIT_LIST_HEAD(&rcu_torture_removed);
299}
300
Josh Triplett20d2e422006-10-04 02:17:15 -0700301static struct rcu_torture_ops rcu_sync_ops = {
302 .init = rcu_sync_torture_init,
303 .cleanup = NULL,
304 .readlock = rcu_torture_read_lock,
305 .readdelay = rcu_read_delay,
306 .readunlock = rcu_torture_read_unlock,
307 .completed = rcu_torture_completed,
308 .deferredfree = rcu_sync_torture_deferred_free,
309 .sync = synchronize_rcu,
310 .stats = NULL,
311 .name = "rcu_sync"
312};
313
Paul E. McKenneyc32e0662006-06-27 02:54:04 -0700314/*
315 * Definitions for rcu_bh torture testing.
316 */
317
Josh Tripletta49a4af2006-09-29 01:59:30 -0700318static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH)
Paul E. McKenneyc32e0662006-06-27 02:54:04 -0700319{
320 rcu_read_lock_bh();
321 return 0;
322}
323
Josh Tripletta49a4af2006-09-29 01:59:30 -0700324static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH)
Paul E. McKenneyc32e0662006-06-27 02:54:04 -0700325{
326 rcu_read_unlock_bh();
327}
328
329static int rcu_bh_torture_completed(void)
330{
331 return rcu_batches_completed_bh();
332}
333
334static void rcu_bh_torture_deferred_free(struct rcu_torture *p)
335{
336 call_rcu_bh(&p->rtort_rcu, rcu_torture_cb);
337}
338
Josh Triplettb772e1d2006-10-04 02:17:13 -0700339struct rcu_bh_torture_synchronize {
340 struct rcu_head head;
341 struct completion completion;
342};
343
344static void rcu_bh_torture_wakeme_after_cb(struct rcu_head *head)
345{
346 struct rcu_bh_torture_synchronize *rcu;
347
348 rcu = container_of(head, struct rcu_bh_torture_synchronize, head);
349 complete(&rcu->completion);
350}
351
352static void rcu_bh_torture_synchronize(void)
353{
354 struct rcu_bh_torture_synchronize rcu;
355
356 init_completion(&rcu.completion);
357 call_rcu_bh(&rcu.head, rcu_bh_torture_wakeme_after_cb);
358 wait_for_completion(&rcu.completion);
359}
360
Paul E. McKenneyc32e0662006-06-27 02:54:04 -0700361static struct rcu_torture_ops rcu_bh_ops = {
362 .init = NULL,
363 .cleanup = NULL,
364 .readlock = rcu_bh_torture_read_lock,
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700365 .readdelay = rcu_read_delay, /* just reuse rcu's version. */
Paul E. McKenneyc32e0662006-06-27 02:54:04 -0700366 .readunlock = rcu_bh_torture_read_unlock,
367 .completed = rcu_bh_torture_completed,
368 .deferredfree = rcu_bh_torture_deferred_free,
Josh Triplettb772e1d2006-10-04 02:17:13 -0700369 .sync = rcu_bh_torture_synchronize,
Paul E. McKenneyc32e0662006-06-27 02:54:04 -0700370 .stats = NULL,
371 .name = "rcu_bh"
372};
373
Josh Triplett11a14702006-10-04 02:17:16 -0700374static struct rcu_torture_ops rcu_bh_sync_ops = {
375 .init = rcu_sync_torture_init,
376 .cleanup = NULL,
377 .readlock = rcu_bh_torture_read_lock,
378 .readdelay = rcu_read_delay, /* just reuse rcu's version. */
379 .readunlock = rcu_bh_torture_read_unlock,
380 .completed = rcu_bh_torture_completed,
381 .deferredfree = rcu_sync_torture_deferred_free,
382 .sync = rcu_bh_torture_synchronize,
383 .stats = NULL,
384 .name = "rcu_bh_sync"
385};
386
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700387/*
388 * Definitions for srcu torture testing.
389 */
390
391static struct srcu_struct srcu_ctl;
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700392
393static void srcu_torture_init(void)
394{
395 init_srcu_struct(&srcu_ctl);
Josh Triplette3033732006-10-04 02:17:14 -0700396 rcu_sync_torture_init();
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700397}
398
399static void srcu_torture_cleanup(void)
400{
401 synchronize_srcu(&srcu_ctl);
402 cleanup_srcu_struct(&srcu_ctl);
403}
404
Josh Triplett012d3ca2006-12-06 20:40:19 -0800405static int srcu_torture_read_lock(void) __acquires(&srcu_ctl)
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700406{
407 return srcu_read_lock(&srcu_ctl);
408}
409
410static void srcu_read_delay(struct rcu_random_state *rrsp)
411{
412 long delay;
413 const long uspertick = 1000000 / HZ;
414 const long longdelay = 10;
415
416 /* We want there to be long-running readers, but not all the time. */
417
418 delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick);
419 if (!delay)
420 schedule_timeout_interruptible(longdelay);
421}
422
Josh Triplett012d3ca2006-12-06 20:40:19 -0800423static void srcu_torture_read_unlock(int idx) __releases(&srcu_ctl)
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700424{
425 srcu_read_unlock(&srcu_ctl, idx);
426}
427
428static int srcu_torture_completed(void)
429{
430 return srcu_batches_completed(&srcu_ctl);
431}
432
Josh Triplettb772e1d2006-10-04 02:17:13 -0700433static void srcu_torture_synchronize(void)
434{
435 synchronize_srcu(&srcu_ctl);
436}
437
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700438static int srcu_torture_stats(char *page)
439{
440 int cnt = 0;
441 int cpu;
442 int idx = srcu_ctl.completed & 0x1;
443
444 cnt += sprintf(&page[cnt], "%s%s per-CPU(idx=%d):",
445 torture_type, TORTURE_FLAG, idx);
446 for_each_possible_cpu(cpu) {
447 cnt += sprintf(&page[cnt], " %d(%d,%d)", cpu,
448 per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[!idx],
449 per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[idx]);
450 }
451 cnt += sprintf(&page[cnt], "\n");
452 return cnt;
453}
454
455static struct rcu_torture_ops srcu_ops = {
456 .init = srcu_torture_init,
457 .cleanup = srcu_torture_cleanup,
458 .readlock = srcu_torture_read_lock,
459 .readdelay = srcu_read_delay,
460 .readunlock = srcu_torture_read_unlock,
461 .completed = srcu_torture_completed,
Josh Triplette3033732006-10-04 02:17:14 -0700462 .deferredfree = rcu_sync_torture_deferred_free,
Josh Triplettb772e1d2006-10-04 02:17:13 -0700463 .sync = srcu_torture_synchronize,
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700464 .stats = srcu_torture_stats,
465 .name = "srcu"
466};
467
Josh Triplett4b6c2cc2006-10-04 02:17:16 -0700468/*
469 * Definitions for sched torture testing.
470 */
471
472static int sched_torture_read_lock(void)
473{
474 preempt_disable();
475 return 0;
476}
477
478static void sched_torture_read_unlock(int idx)
479{
480 preempt_enable();
481}
482
483static int sched_torture_completed(void)
484{
485 return 0;
486}
487
488static void sched_torture_synchronize(void)
489{
490 synchronize_sched();
491}
492
493static struct rcu_torture_ops sched_ops = {
494 .init = rcu_sync_torture_init,
495 .cleanup = NULL,
496 .readlock = sched_torture_read_lock,
497 .readdelay = rcu_read_delay, /* just reuse rcu's version. */
498 .readunlock = sched_torture_read_unlock,
499 .completed = sched_torture_completed,
500 .deferredfree = rcu_sync_torture_deferred_free,
501 .sync = sched_torture_synchronize,
502 .stats = NULL,
503 .name = "sched"
504};
505
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700506/*
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800507 * RCU torture writer kthread. Repeatedly substitutes a new structure
508 * for that pointed to by rcu_torture_current, freeing the old structure
509 * after a series of grace periods (the "pipeline").
510 */
511static int
512rcu_torture_writer(void *arg)
513{
514 int i;
515 long oldbatch = rcu_batches_completed();
516 struct rcu_torture *rp;
517 struct rcu_torture *old_rp;
518 static DEFINE_RCU_RANDOM(rand);
519
520 VERBOSE_PRINTK_STRING("rcu_torture_writer task started");
Ingo Molnardbdf65b2005-11-13 16:07:22 -0800521 set_user_nice(current, 19);
522
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800523 do {
524 schedule_timeout_uninterruptible(1);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800525 if ((rp = rcu_torture_alloc()) == NULL)
526 continue;
527 rp->rtort_pipe_count = 0;
528 udelay(rcu_random(&rand) & 0x3ff);
529 old_rp = rcu_torture_current;
Paul E. McKenney996417d2005-11-18 01:10:50 -0800530 rp->rtort_mbtest = 1;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800531 rcu_assign_pointer(rcu_torture_current, rp);
532 smp_wmb();
Josh Triplettc8e5b162007-05-08 00:33:20 -0700533 if (old_rp) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800534 i = old_rp->rtort_pipe_count;
535 if (i > RCU_TORTURE_PIPE_LEN)
536 i = RCU_TORTURE_PIPE_LEN;
537 atomic_inc(&rcu_torture_wcount[i]);
538 old_rp->rtort_pipe_count++;
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700539 cur_ops->deferredfree(old_rp);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800540 }
541 rcu_torture_current_version++;
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700542 oldbatch = cur_ops->completed();
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800543 } while (!kthread_should_stop() && !fullstop);
544 VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping");
545 while (!kthread_should_stop())
546 schedule_timeout_uninterruptible(1);
547 return 0;
548}
549
550/*
Josh Triplettb772e1d2006-10-04 02:17:13 -0700551 * RCU torture fake writer kthread. Repeatedly calls sync, with a random
552 * delay between calls.
553 */
554static int
555rcu_torture_fakewriter(void *arg)
556{
557 DEFINE_RCU_RANDOM(rand);
558
559 VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task started");
560 set_user_nice(current, 19);
561
562 do {
563 schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10);
564 udelay(rcu_random(&rand) & 0x3ff);
565 cur_ops->sync();
566 } while (!kthread_should_stop() && !fullstop);
567
568 VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping");
569 while (!kthread_should_stop())
570 schedule_timeout_uninterruptible(1);
571 return 0;
572}
573
574/*
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800575 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current,
576 * incrementing the corresponding element of the pipeline array. The
577 * counter in the element should never be greater than 1, otherwise, the
578 * RCU implementation is broken.
579 */
580static int
581rcu_torture_reader(void *arg)
582{
583 int completed;
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700584 int idx;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800585 DEFINE_RCU_RANDOM(rand);
586 struct rcu_torture *p;
587 int pipe_count;
588
589 VERBOSE_PRINTK_STRING("rcu_torture_reader task started");
Ingo Molnardbdf65b2005-11-13 16:07:22 -0800590 set_user_nice(current, 19);
591
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800592 do {
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700593 idx = cur_ops->readlock();
594 completed = cur_ops->completed();
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800595 p = rcu_dereference(rcu_torture_current);
596 if (p == NULL) {
597 /* Wait for rcu_torture_writer to get underway */
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700598 cur_ops->readunlock(idx);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800599 schedule_timeout_interruptible(HZ);
600 continue;
601 }
Paul E. McKenney996417d2005-11-18 01:10:50 -0800602 if (p->rtort_mbtest == 0)
603 atomic_inc(&n_rcu_torture_mberror);
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700604 cur_ops->readdelay(&rand);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800605 preempt_disable();
606 pipe_count = p->rtort_pipe_count;
607 if (pipe_count > RCU_TORTURE_PIPE_LEN) {
608 /* Should not happen, but... */
609 pipe_count = RCU_TORTURE_PIPE_LEN;
610 }
611 ++__get_cpu_var(rcu_torture_count)[pipe_count];
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700612 completed = cur_ops->completed() - completed;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800613 if (completed > RCU_TORTURE_PIPE_LEN) {
614 /* Should not happen, but... */
615 completed = RCU_TORTURE_PIPE_LEN;
616 }
617 ++__get_cpu_var(rcu_torture_batch)[completed];
618 preempt_enable();
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700619 cur_ops->readunlock(idx);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800620 schedule();
621 } while (!kthread_should_stop() && !fullstop);
622 VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping");
623 while (!kthread_should_stop())
624 schedule_timeout_uninterruptible(1);
625 return 0;
626}
627
628/*
629 * Create an RCU-torture statistics message in the specified buffer.
630 */
631static int
632rcu_torture_printk(char *page)
633{
634 int cnt = 0;
635 int cpu;
636 int i;
637 long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
638 long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
639
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -0800640 for_each_possible_cpu(cpu) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800641 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
642 pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i];
643 batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i];
644 }
645 }
646 for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) {
647 if (pipesummary[i] != 0)
648 break;
649 }
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700650 cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800651 cnt += sprintf(&page[cnt],
Paul E. McKenney996417d2005-11-18 01:10:50 -0800652 "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d "
653 "rtmbe: %d",
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800654 rcu_torture_current,
655 rcu_torture_current_version,
656 list_empty(&rcu_torture_freelist),
657 atomic_read(&n_rcu_torture_alloc),
658 atomic_read(&n_rcu_torture_alloc_fail),
Paul E. McKenney996417d2005-11-18 01:10:50 -0800659 atomic_read(&n_rcu_torture_free),
660 atomic_read(&n_rcu_torture_mberror));
661 if (atomic_read(&n_rcu_torture_mberror) != 0)
662 cnt += sprintf(&page[cnt], " !!!");
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700663 cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG);
Paul E. McKenney996417d2005-11-18 01:10:50 -0800664 if (i > 1) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800665 cnt += sprintf(&page[cnt], "!!! ");
Paul E. McKenney996417d2005-11-18 01:10:50 -0800666 atomic_inc(&n_rcu_torture_error);
667 }
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800668 cnt += sprintf(&page[cnt], "Reader Pipe: ");
669 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
670 cnt += sprintf(&page[cnt], " %ld", pipesummary[i]);
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700671 cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800672 cnt += sprintf(&page[cnt], "Reader Batch: ");
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700673 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800674 cnt += sprintf(&page[cnt], " %ld", batchsummary[i]);
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700675 cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800676 cnt += sprintf(&page[cnt], "Free-Block Circulation: ");
677 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
678 cnt += sprintf(&page[cnt], " %d",
679 atomic_read(&rcu_torture_wcount[i]));
680 }
681 cnt += sprintf(&page[cnt], "\n");
Josh Triplettc8e5b162007-05-08 00:33:20 -0700682 if (cur_ops->stats)
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700683 cnt += cur_ops->stats(&page[cnt]);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800684 return cnt;
685}
686
687/*
688 * Print torture statistics. Caller must ensure that there is only
689 * one call to this function at a given time!!! This is normally
690 * accomplished by relying on the module system to only have one copy
691 * of the module loaded, and then by giving the rcu_torture_stats
692 * kthread full control (or the init/cleanup functions when rcu_torture_stats
693 * thread is not running).
694 */
695static void
696rcu_torture_stats_print(void)
697{
698 int cnt;
699
700 cnt = rcu_torture_printk(printk_buf);
701 printk(KERN_ALERT "%s", printk_buf);
702}
703
704/*
705 * Periodically prints torture statistics, if periodic statistics printing
706 * was specified via the stat_interval module parameter.
707 *
708 * No need to worry about fullstop here, since this one doesn't reference
709 * volatile state or register callbacks.
710 */
711static int
712rcu_torture_stats(void *arg)
713{
714 VERBOSE_PRINTK_STRING("rcu_torture_stats task started");
715 do {
716 schedule_timeout_interruptible(stat_interval * HZ);
717 rcu_torture_stats_print();
718 } while (!kthread_should_stop());
719 VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping");
720 return 0;
721}
722
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800723static int rcu_idle_cpu; /* Force all torture tasks off this CPU */
724
725/* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case
726 * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs.
727 */
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700728static void rcu_torture_shuffle_tasks(void)
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800729{
730 cpumask_t tmp_mask = CPU_MASK_ALL;
731 int i;
732
733 lock_cpu_hotplug();
734
735 /* No point in shuffling if there is only one online CPU (ex: UP) */
736 if (num_online_cpus() == 1) {
737 unlock_cpu_hotplug();
738 return;
739 }
740
741 if (rcu_idle_cpu != -1)
742 cpu_clear(rcu_idle_cpu, tmp_mask);
743
744 set_cpus_allowed(current, tmp_mask);
745
Josh Triplettc8e5b162007-05-08 00:33:20 -0700746 if (reader_tasks) {
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800747 for (i = 0; i < nrealreaders; i++)
748 if (reader_tasks[i])
749 set_cpus_allowed(reader_tasks[i], tmp_mask);
750 }
751
Josh Triplettc8e5b162007-05-08 00:33:20 -0700752 if (fakewriter_tasks) {
Josh Triplettb772e1d2006-10-04 02:17:13 -0700753 for (i = 0; i < nfakewriters; i++)
754 if (fakewriter_tasks[i])
755 set_cpus_allowed(fakewriter_tasks[i], tmp_mask);
756 }
757
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800758 if (writer_task)
759 set_cpus_allowed(writer_task, tmp_mask);
760
761 if (stats_task)
762 set_cpus_allowed(stats_task, tmp_mask);
763
764 if (rcu_idle_cpu == -1)
765 rcu_idle_cpu = num_online_cpus() - 1;
766 else
767 rcu_idle_cpu--;
768
769 unlock_cpu_hotplug();
770}
771
772/* Shuffle tasks across CPUs, with the intent of allowing each CPU in the
773 * system to become idle at a time and cut off its timer ticks. This is meant
774 * to test the support for such tickless idle CPU in RCU.
775 */
776static int
777rcu_torture_shuffle(void *arg)
778{
779 VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started");
780 do {
781 schedule_timeout_interruptible(shuffle_interval * HZ);
782 rcu_torture_shuffle_tasks();
783 } while (!kthread_should_stop());
784 VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping");
785 return 0;
786}
787
Paul E. McKenney95c38322006-03-24 03:15:58 -0800788static inline void
789rcu_torture_print_module_parms(char *tag)
790{
Josh Triplettb772e1d2006-10-04 02:17:13 -0700791 printk(KERN_ALERT "%s" TORTURE_FLAG
792 "--- %s: nreaders=%d nfakewriters=%d "
Paul E. McKenney95c38322006-03-24 03:15:58 -0800793 "stat_interval=%d verbose=%d test_no_idle_hz=%d "
794 "shuffle_interval = %d\n",
Josh Triplettb772e1d2006-10-04 02:17:13 -0700795 torture_type, tag, nrealreaders, nfakewriters,
796 stat_interval, verbose, test_no_idle_hz, shuffle_interval);
Paul E. McKenney95c38322006-03-24 03:15:58 -0800797}
798
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800799static void
800rcu_torture_cleanup(void)
801{
802 int i;
803
804 fullstop = 1;
Josh Triplettc8e5b162007-05-08 00:33:20 -0700805 if (shuffler_task) {
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800806 VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task");
807 kthread_stop(shuffler_task);
808 }
809 shuffler_task = NULL;
810
Josh Triplettc8e5b162007-05-08 00:33:20 -0700811 if (writer_task) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800812 VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task");
813 kthread_stop(writer_task);
814 }
815 writer_task = NULL;
816
Josh Triplettc8e5b162007-05-08 00:33:20 -0700817 if (reader_tasks) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800818 for (i = 0; i < nrealreaders; i++) {
Josh Triplettc8e5b162007-05-08 00:33:20 -0700819 if (reader_tasks[i]) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800820 VERBOSE_PRINTK_STRING(
821 "Stopping rcu_torture_reader task");
822 kthread_stop(reader_tasks[i]);
823 }
824 reader_tasks[i] = NULL;
825 }
826 kfree(reader_tasks);
827 reader_tasks = NULL;
828 }
829 rcu_torture_current = NULL;
830
Josh Triplettc8e5b162007-05-08 00:33:20 -0700831 if (fakewriter_tasks) {
Josh Triplettb772e1d2006-10-04 02:17:13 -0700832 for (i = 0; i < nfakewriters; i++) {
Josh Triplettc8e5b162007-05-08 00:33:20 -0700833 if (fakewriter_tasks[i]) {
Josh Triplettb772e1d2006-10-04 02:17:13 -0700834 VERBOSE_PRINTK_STRING(
835 "Stopping rcu_torture_fakewriter task");
836 kthread_stop(fakewriter_tasks[i]);
837 }
838 fakewriter_tasks[i] = NULL;
839 }
840 kfree(fakewriter_tasks);
841 fakewriter_tasks = NULL;
842 }
843
Josh Triplettc8e5b162007-05-08 00:33:20 -0700844 if (stats_task) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800845 VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task");
846 kthread_stop(stats_task);
847 }
848 stats_task = NULL;
849
850 /* Wait for all RCU callbacks to fire. */
Srivatsa Vaddagiri89d46b82005-12-12 00:37:06 -0800851 rcu_barrier();
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800852
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800853 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700854
Josh Triplettc8e5b162007-05-08 00:33:20 -0700855 if (cur_ops->cleanup)
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700856 cur_ops->cleanup();
Paul E. McKenney95c38322006-03-24 03:15:58 -0800857 if (atomic_read(&n_rcu_torture_error))
858 rcu_torture_print_module_parms("End of test: FAILURE");
859 else
860 rcu_torture_print_module_parms("End of test: SUCCESS");
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800861}
862
Josh Triplett6f8bc5002007-05-08 00:25:24 -0700863static int __init
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800864rcu_torture_init(void)
865{
866 int i;
867 int cpu;
868 int firsterr = 0;
Josh Triplettade5fb82007-05-08 00:33:22 -0700869 static struct rcu_torture_ops *torture_ops[] =
870 { &rcu_ops, &rcu_sync_ops, &rcu_bh_ops, &rcu_bh_sync_ops,
871 &srcu_ops, &sched_ops, };
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800872
873 /* Process args and tell the world that the torturer is on the job. */
Josh Triplettade5fb82007-05-08 00:33:22 -0700874 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700875 cur_ops = torture_ops[i];
Josh Triplettade5fb82007-05-08 00:33:22 -0700876 if (strcmp(torture_type, cur_ops->name) == 0)
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700877 break;
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700878 }
Josh Triplettade5fb82007-05-08 00:33:22 -0700879 if (i == ARRAY_SIZE(torture_ops)) {
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700880 printk(KERN_ALERT "rcutorture: invalid torture type: \"%s\"\n",
881 torture_type);
882 return (-EINVAL);
883 }
Josh Triplettc8e5b162007-05-08 00:33:20 -0700884 if (cur_ops->init)
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700885 cur_ops->init(); /* no "goto unwind" prior to this point!!! */
886
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800887 if (nreaders >= 0)
888 nrealreaders = nreaders;
889 else
890 nrealreaders = 2 * num_online_cpus();
Paul E. McKenney95c38322006-03-24 03:15:58 -0800891 rcu_torture_print_module_parms("Start of test");
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800892 fullstop = 0;
893
894 /* Set up the freelist. */
895
896 INIT_LIST_HEAD(&rcu_torture_freelist);
Ahmed S. Darwish788e7702007-05-08 00:33:14 -0700897 for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) {
Paul E. McKenney996417d2005-11-18 01:10:50 -0800898 rcu_tortures[i].rtort_mbtest = 0;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800899 list_add_tail(&rcu_tortures[i].rtort_free,
900 &rcu_torture_freelist);
901 }
902
903 /* Initialize the statistics so that each run gets its own numbers. */
904
905 rcu_torture_current = NULL;
906 rcu_torture_current_version = 0;
907 atomic_set(&n_rcu_torture_alloc, 0);
908 atomic_set(&n_rcu_torture_alloc_fail, 0);
909 atomic_set(&n_rcu_torture_free, 0);
Paul E. McKenney996417d2005-11-18 01:10:50 -0800910 atomic_set(&n_rcu_torture_mberror, 0);
911 atomic_set(&n_rcu_torture_error, 0);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800912 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
913 atomic_set(&rcu_torture_wcount[i], 0);
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -0800914 for_each_possible_cpu(cpu) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800915 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
916 per_cpu(rcu_torture_count, cpu)[i] = 0;
917 per_cpu(rcu_torture_batch, cpu)[i] = 0;
918 }
919 }
920
921 /* Start up the kthreads. */
922
923 VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task");
924 writer_task = kthread_run(rcu_torture_writer, NULL,
925 "rcu_torture_writer");
926 if (IS_ERR(writer_task)) {
927 firsterr = PTR_ERR(writer_task);
928 VERBOSE_PRINTK_ERRSTRING("Failed to create writer");
929 writer_task = NULL;
930 goto unwind;
931 }
Josh Triplettb772e1d2006-10-04 02:17:13 -0700932 fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]),
933 GFP_KERNEL);
934 if (fakewriter_tasks == NULL) {
935 VERBOSE_PRINTK_ERRSTRING("out of memory");
936 firsterr = -ENOMEM;
937 goto unwind;
938 }
939 for (i = 0; i < nfakewriters; i++) {
940 VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task");
941 fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL,
942 "rcu_torture_fakewriter");
943 if (IS_ERR(fakewriter_tasks[i])) {
944 firsterr = PTR_ERR(fakewriter_tasks[i]);
945 VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter");
946 fakewriter_tasks[i] = NULL;
947 goto unwind;
948 }
949 }
Josh Triplett2860aab2006-10-04 02:17:11 -0700950 reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]),
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800951 GFP_KERNEL);
952 if (reader_tasks == NULL) {
953 VERBOSE_PRINTK_ERRSTRING("out of memory");
954 firsterr = -ENOMEM;
955 goto unwind;
956 }
957 for (i = 0; i < nrealreaders; i++) {
958 VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task");
959 reader_tasks[i] = kthread_run(rcu_torture_reader, NULL,
960 "rcu_torture_reader");
961 if (IS_ERR(reader_tasks[i])) {
962 firsterr = PTR_ERR(reader_tasks[i]);
963 VERBOSE_PRINTK_ERRSTRING("Failed to create reader");
964 reader_tasks[i] = NULL;
965 goto unwind;
966 }
967 }
968 if (stat_interval > 0) {
969 VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task");
970 stats_task = kthread_run(rcu_torture_stats, NULL,
971 "rcu_torture_stats");
972 if (IS_ERR(stats_task)) {
973 firsterr = PTR_ERR(stats_task);
974 VERBOSE_PRINTK_ERRSTRING("Failed to create stats");
975 stats_task = NULL;
976 goto unwind;
977 }
978 }
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -0800979 if (test_no_idle_hz) {
980 rcu_idle_cpu = num_online_cpus() - 1;
981 /* Create the shuffler thread */
982 shuffler_task = kthread_run(rcu_torture_shuffle, NULL,
983 "rcu_torture_shuffle");
984 if (IS_ERR(shuffler_task)) {
985 firsterr = PTR_ERR(shuffler_task);
986 VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler");
987 shuffler_task = NULL;
988 goto unwind;
989 }
990 }
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800991 return 0;
992
993unwind:
994 rcu_torture_cleanup();
995 return firsterr;
996}
997
998module_init(rcu_torture_init);
999module_exit(rcu_torture_cleanup);