2 * Read-Copy Update module-based torture test facility
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.
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.
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.
18 * Copyright (C) IBM Corporation, 2005, 2006
20 * Authors: Paul E. McKenney <paulmck@us.ibm.com>
21 * Josh Triplett <josh@freedesktop.org>
23 * See also: Documentation/RCU/torture.txt
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/completion.h>
39 #include <linux/moduleparam.h>
40 #include <linux/percpu.h>
41 #include <linux/notifier.h>
42 #include <linux/reboot.h>
43 #include <linux/freezer.h>
44 #include <linux/cpu.h>
45 #include <linux/delay.h>
46 #include <linux/stat.h>
47 #include <linux/srcu.h>
48 #include <linux/slab.h>
49 #include <asm/byteorder.h>
51 MODULE_LICENSE("GPL");
52 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and "
53 "Josh Triplett <josh@freedesktop.org>");
55 static int nreaders
= -1; /* # reader threads, defaults to 2*ncpus */
56 static int nfakewriters
= 4; /* # fake writer threads */
57 static int stat_interval
; /* Interval between stats, in seconds. */
58 /* Defaults to "only at end of test". */
59 static int verbose
; /* Print more debug info. */
60 static int test_no_idle_hz
; /* Test RCU's support for tickless idle CPUs. */
61 static int shuffle_interval
= 3; /* Interval between shuffles (in sec)*/
62 static int stutter
= 5; /* Start/stop testing interval (in sec) */
63 static int irqreader
= 1; /* RCU readers from irq (timers). */
64 static char *torture_type
= "rcu"; /* What RCU implementation to torture. */
66 module_param(nreaders
, int, 0444);
67 MODULE_PARM_DESC(nreaders
, "Number of RCU reader threads");
68 module_param(nfakewriters
, int, 0444);
69 MODULE_PARM_DESC(nfakewriters
, "Number of RCU fake writer threads");
70 module_param(stat_interval
, int, 0444);
71 MODULE_PARM_DESC(stat_interval
, "Number of seconds between stats printk()s");
72 module_param(verbose
, bool, 0444);
73 MODULE_PARM_DESC(verbose
, "Enable verbose debugging printk()s");
74 module_param(test_no_idle_hz
, bool, 0444);
75 MODULE_PARM_DESC(test_no_idle_hz
, "Test support for tickless idle CPUs");
76 module_param(shuffle_interval
, int, 0444);
77 MODULE_PARM_DESC(shuffle_interval
, "Number of seconds between shuffles");
78 module_param(stutter
, int, 0444);
79 MODULE_PARM_DESC(stutter
, "Number of seconds to run/halt test");
80 module_param(irqreader
, int, 0444);
81 MODULE_PARM_DESC(irqreader
, "Allow RCU readers from irq handlers");
82 module_param(torture_type
, charp
, 0444);
83 MODULE_PARM_DESC(torture_type
, "Type of RCU to torture (rcu, rcu_bh, srcu)");
85 #define TORTURE_FLAG "-torture:"
86 #define PRINTK_STRING(s) \
87 do { printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0)
88 #define VERBOSE_PRINTK_STRING(s) \
89 do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0)
90 #define VERBOSE_PRINTK_ERRSTRING(s) \
91 do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0)
93 static char printk_buf
[4096];
95 static int nrealreaders
;
96 static struct task_struct
*writer_task
;
97 static struct task_struct
**fakewriter_tasks
;
98 static struct task_struct
**reader_tasks
;
99 static struct task_struct
*stats_task
;
100 static struct task_struct
*shuffler_task
;
101 static struct task_struct
*stutter_task
;
103 #define RCU_TORTURE_PIPE_LEN 10
106 struct rcu_head rtort_rcu
;
107 int rtort_pipe_count
;
108 struct list_head rtort_free
;
112 static LIST_HEAD(rcu_torture_freelist
);
113 static struct rcu_torture
*rcu_torture_current
= NULL
;
114 static long rcu_torture_current_version
= 0;
115 static struct rcu_torture rcu_tortures
[10 * RCU_TORTURE_PIPE_LEN
];
116 static DEFINE_SPINLOCK(rcu_torture_lock
);
117 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN
+ 1], rcu_torture_count
) =
119 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN
+ 1], rcu_torture_batch
) =
121 static atomic_t rcu_torture_wcount
[RCU_TORTURE_PIPE_LEN
+ 1];
122 static atomic_t n_rcu_torture_alloc
;
123 static atomic_t n_rcu_torture_alloc_fail
;
124 static atomic_t n_rcu_torture_free
;
125 static atomic_t n_rcu_torture_mberror
;
126 static atomic_t n_rcu_torture_error
;
127 static long n_rcu_torture_timers
= 0;
128 static struct list_head rcu_torture_removed
;
130 static int stutter_pause_test
= 0;
132 #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
133 #define RCUTORTURE_RUNNABLE_INIT 1
135 #define RCUTORTURE_RUNNABLE_INIT 0
137 int rcutorture_runnable
= RCUTORTURE_RUNNABLE_INIT
;
139 #define FULLSTOP_SHUTDOWN 1 /* Bail due to system shutdown/panic. */
140 #define FULLSTOP_CLEANUP 2 /* Orderly shutdown. */
141 static int fullstop
; /* stop generating callbacks at test end. */
142 DEFINE_MUTEX(fullstop_mutex
); /* protect fullstop transitions and */
143 /* spawning of kthreads. */
146 * Detect and respond to a signal-based shutdown.
149 rcutorture_shutdown_notify(struct notifier_block
*unused1
,
150 unsigned long unused2
, void *unused3
)
154 mutex_lock(&fullstop_mutex
);
156 fullstop
= FULLSTOP_SHUTDOWN
;
157 mutex_unlock(&fullstop_mutex
);
162 * Allocate an element from the rcu_tortures pool.
164 static struct rcu_torture
*
165 rcu_torture_alloc(void)
169 spin_lock_bh(&rcu_torture_lock
);
170 if (list_empty(&rcu_torture_freelist
)) {
171 atomic_inc(&n_rcu_torture_alloc_fail
);
172 spin_unlock_bh(&rcu_torture_lock
);
175 atomic_inc(&n_rcu_torture_alloc
);
176 p
= rcu_torture_freelist
.next
;
178 spin_unlock_bh(&rcu_torture_lock
);
179 return container_of(p
, struct rcu_torture
, rtort_free
);
183 * Free an element to the rcu_tortures pool.
186 rcu_torture_free(struct rcu_torture
*p
)
188 atomic_inc(&n_rcu_torture_free
);
189 spin_lock_bh(&rcu_torture_lock
);
190 list_add_tail(&p
->rtort_free
, &rcu_torture_freelist
);
191 spin_unlock_bh(&rcu_torture_lock
);
194 struct rcu_random_state
{
195 unsigned long rrs_state
;
199 #define RCU_RANDOM_MULT 39916801 /* prime */
200 #define RCU_RANDOM_ADD 479001701 /* prime */
201 #define RCU_RANDOM_REFRESH 10000
203 #define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 }
206 * Crude but fast random-number generator. Uses a linear congruential
207 * generator, with occasional help from cpu_clock().
210 rcu_random(struct rcu_random_state
*rrsp
)
212 if (--rrsp
->rrs_count
< 0) {
214 (unsigned long)cpu_clock(raw_smp_processor_id());
215 rrsp
->rrs_count
= RCU_RANDOM_REFRESH
;
217 rrsp
->rrs_state
= rrsp
->rrs_state
* RCU_RANDOM_MULT
+ RCU_RANDOM_ADD
;
218 return swahw32(rrsp
->rrs_state
);
222 rcu_stutter_wait(void)
224 while ((stutter_pause_test
|| !rcutorture_runnable
) && !fullstop
) {
225 if (rcutorture_runnable
)
226 schedule_timeout_interruptible(1);
228 schedule_timeout_interruptible(round_jiffies_relative(HZ
));
233 * Operations vector for selecting different types of tests.
236 struct rcu_torture_ops
{
238 void (*cleanup
)(void);
239 int (*readlock
)(void);
240 void (*readdelay
)(struct rcu_random_state
*rrsp
);
241 void (*readunlock
)(int idx
);
242 int (*completed
)(void);
243 void (*deferredfree
)(struct rcu_torture
*p
);
245 void (*cb_barrier
)(void);
246 int (*stats
)(char *page
);
250 static struct rcu_torture_ops
*cur_ops
= NULL
;
253 * Definitions for rcu torture testing.
256 static int rcu_torture_read_lock(void) __acquires(RCU
)
262 static void rcu_read_delay(struct rcu_random_state
*rrsp
)
265 const long longdelay
= 200;
267 /* We want there to be long-running readers, but not all the time. */
269 delay
= rcu_random(rrsp
) % (nrealreaders
* 2 * longdelay
);
274 static void rcu_torture_read_unlock(int idx
) __releases(RCU
)
279 static int rcu_torture_completed(void)
281 return rcu_batches_completed();
285 rcu_torture_cb(struct rcu_head
*p
)
288 struct rcu_torture
*rp
= container_of(p
, struct rcu_torture
, rtort_rcu
);
291 /* Test is ending, just drop callbacks on the floor. */
292 /* The next initialization will pick up the pieces. */
295 i
= rp
->rtort_pipe_count
;
296 if (i
> RCU_TORTURE_PIPE_LEN
)
297 i
= RCU_TORTURE_PIPE_LEN
;
298 atomic_inc(&rcu_torture_wcount
[i
]);
299 if (++rp
->rtort_pipe_count
>= RCU_TORTURE_PIPE_LEN
) {
300 rp
->rtort_mbtest
= 0;
301 rcu_torture_free(rp
);
303 cur_ops
->deferredfree(rp
);
306 static void rcu_torture_deferred_free(struct rcu_torture
*p
)
308 call_rcu(&p
->rtort_rcu
, rcu_torture_cb
);
311 static struct rcu_torture_ops rcu_ops
= {
314 .readlock
= rcu_torture_read_lock
,
315 .readdelay
= rcu_read_delay
,
316 .readunlock
= rcu_torture_read_unlock
,
317 .completed
= rcu_torture_completed
,
318 .deferredfree
= rcu_torture_deferred_free
,
319 .sync
= synchronize_rcu
,
320 .cb_barrier
= rcu_barrier
,
326 static void rcu_sync_torture_deferred_free(struct rcu_torture
*p
)
329 struct rcu_torture
*rp
;
330 struct rcu_torture
*rp1
;
333 list_add(&p
->rtort_free
, &rcu_torture_removed
);
334 list_for_each_entry_safe(rp
, rp1
, &rcu_torture_removed
, rtort_free
) {
335 i
= rp
->rtort_pipe_count
;
336 if (i
> RCU_TORTURE_PIPE_LEN
)
337 i
= RCU_TORTURE_PIPE_LEN
;
338 atomic_inc(&rcu_torture_wcount
[i
]);
339 if (++rp
->rtort_pipe_count
>= RCU_TORTURE_PIPE_LEN
) {
340 rp
->rtort_mbtest
= 0;
341 list_del(&rp
->rtort_free
);
342 rcu_torture_free(rp
);
347 static void rcu_sync_torture_init(void)
349 INIT_LIST_HEAD(&rcu_torture_removed
);
352 static struct rcu_torture_ops rcu_sync_ops
= {
353 .init
= rcu_sync_torture_init
,
355 .readlock
= rcu_torture_read_lock
,
356 .readdelay
= rcu_read_delay
,
357 .readunlock
= rcu_torture_read_unlock
,
358 .completed
= rcu_torture_completed
,
359 .deferredfree
= rcu_sync_torture_deferred_free
,
360 .sync
= synchronize_rcu
,
368 * Definitions for rcu_bh torture testing.
371 static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH
)
377 static void rcu_bh_torture_read_unlock(int idx
) __releases(RCU_BH
)
379 rcu_read_unlock_bh();
382 static int rcu_bh_torture_completed(void)
384 return rcu_batches_completed_bh();
387 static void rcu_bh_torture_deferred_free(struct rcu_torture
*p
)
389 call_rcu_bh(&p
->rtort_rcu
, rcu_torture_cb
);
392 struct rcu_bh_torture_synchronize
{
393 struct rcu_head head
;
394 struct completion completion
;
397 static void rcu_bh_torture_wakeme_after_cb(struct rcu_head
*head
)
399 struct rcu_bh_torture_synchronize
*rcu
;
401 rcu
= container_of(head
, struct rcu_bh_torture_synchronize
, head
);
402 complete(&rcu
->completion
);
405 static void rcu_bh_torture_synchronize(void)
407 struct rcu_bh_torture_synchronize rcu
;
409 init_completion(&rcu
.completion
);
410 call_rcu_bh(&rcu
.head
, rcu_bh_torture_wakeme_after_cb
);
411 wait_for_completion(&rcu
.completion
);
414 static struct rcu_torture_ops rcu_bh_ops
= {
417 .readlock
= rcu_bh_torture_read_lock
,
418 .readdelay
= rcu_read_delay
, /* just reuse rcu's version. */
419 .readunlock
= rcu_bh_torture_read_unlock
,
420 .completed
= rcu_bh_torture_completed
,
421 .deferredfree
= rcu_bh_torture_deferred_free
,
422 .sync
= rcu_bh_torture_synchronize
,
423 .cb_barrier
= rcu_barrier_bh
,
429 static struct rcu_torture_ops rcu_bh_sync_ops
= {
430 .init
= rcu_sync_torture_init
,
432 .readlock
= rcu_bh_torture_read_lock
,
433 .readdelay
= rcu_read_delay
, /* just reuse rcu's version. */
434 .readunlock
= rcu_bh_torture_read_unlock
,
435 .completed
= rcu_bh_torture_completed
,
436 .deferredfree
= rcu_sync_torture_deferred_free
,
437 .sync
= rcu_bh_torture_synchronize
,
441 .name
= "rcu_bh_sync"
445 * Definitions for srcu torture testing.
448 static struct srcu_struct srcu_ctl
;
450 static void srcu_torture_init(void)
452 init_srcu_struct(&srcu_ctl
);
453 rcu_sync_torture_init();
456 static void srcu_torture_cleanup(void)
458 synchronize_srcu(&srcu_ctl
);
459 cleanup_srcu_struct(&srcu_ctl
);
462 static int srcu_torture_read_lock(void) __acquires(&srcu_ctl
)
464 return srcu_read_lock(&srcu_ctl
);
467 static void srcu_read_delay(struct rcu_random_state
*rrsp
)
470 const long uspertick
= 1000000 / HZ
;
471 const long longdelay
= 10;
473 /* We want there to be long-running readers, but not all the time. */
475 delay
= rcu_random(rrsp
) % (nrealreaders
* 2 * longdelay
* uspertick
);
477 schedule_timeout_interruptible(longdelay
);
480 static void srcu_torture_read_unlock(int idx
) __releases(&srcu_ctl
)
482 srcu_read_unlock(&srcu_ctl
, idx
);
485 static int srcu_torture_completed(void)
487 return srcu_batches_completed(&srcu_ctl
);
490 static void srcu_torture_synchronize(void)
492 synchronize_srcu(&srcu_ctl
);
495 static int srcu_torture_stats(char *page
)
499 int idx
= srcu_ctl
.completed
& 0x1;
501 cnt
+= sprintf(&page
[cnt
], "%s%s per-CPU(idx=%d):",
502 torture_type
, TORTURE_FLAG
, idx
);
503 for_each_possible_cpu(cpu
) {
504 cnt
+= sprintf(&page
[cnt
], " %d(%d,%d)", cpu
,
505 per_cpu_ptr(srcu_ctl
.per_cpu_ref
, cpu
)->c
[!idx
],
506 per_cpu_ptr(srcu_ctl
.per_cpu_ref
, cpu
)->c
[idx
]);
508 cnt
+= sprintf(&page
[cnt
], "\n");
512 static struct rcu_torture_ops srcu_ops
= {
513 .init
= srcu_torture_init
,
514 .cleanup
= srcu_torture_cleanup
,
515 .readlock
= srcu_torture_read_lock
,
516 .readdelay
= srcu_read_delay
,
517 .readunlock
= srcu_torture_read_unlock
,
518 .completed
= srcu_torture_completed
,
519 .deferredfree
= rcu_sync_torture_deferred_free
,
520 .sync
= srcu_torture_synchronize
,
522 .stats
= srcu_torture_stats
,
527 * Definitions for sched torture testing.
530 static int sched_torture_read_lock(void)
536 static void sched_torture_read_unlock(int idx
)
541 static int sched_torture_completed(void)
546 static void rcu_sched_torture_deferred_free(struct rcu_torture
*p
)
548 call_rcu_sched(&p
->rtort_rcu
, rcu_torture_cb
);
551 static void sched_torture_synchronize(void)
556 static struct rcu_torture_ops sched_ops
= {
557 .init
= rcu_sync_torture_init
,
559 .readlock
= sched_torture_read_lock
,
560 .readdelay
= rcu_read_delay
, /* just reuse rcu's version. */
561 .readunlock
= sched_torture_read_unlock
,
562 .completed
= sched_torture_completed
,
563 .deferredfree
= rcu_sched_torture_deferred_free
,
564 .sync
= sched_torture_synchronize
,
565 .cb_barrier
= rcu_barrier_sched
,
571 static struct rcu_torture_ops sched_ops_sync
= {
572 .init
= rcu_sync_torture_init
,
574 .readlock
= sched_torture_read_lock
,
575 .readdelay
= rcu_read_delay
, /* just reuse rcu's version. */
576 .readunlock
= sched_torture_read_unlock
,
577 .completed
= sched_torture_completed
,
578 .deferredfree
= rcu_sync_torture_deferred_free
,
579 .sync
= sched_torture_synchronize
,
586 * RCU torture writer kthread. Repeatedly substitutes a new structure
587 * for that pointed to by rcu_torture_current, freeing the old structure
588 * after a series of grace periods (the "pipeline").
591 rcu_torture_writer(void *arg
)
594 long oldbatch
= rcu_batches_completed();
595 struct rcu_torture
*rp
;
596 struct rcu_torture
*old_rp
;
597 static DEFINE_RCU_RANDOM(rand
);
599 VERBOSE_PRINTK_STRING("rcu_torture_writer task started");
600 set_user_nice(current
, 19);
603 schedule_timeout_uninterruptible(1);
604 if ((rp
= rcu_torture_alloc()) == NULL
)
606 rp
->rtort_pipe_count
= 0;
607 udelay(rcu_random(&rand
) & 0x3ff);
608 old_rp
= rcu_torture_current
;
609 rp
->rtort_mbtest
= 1;
610 rcu_assign_pointer(rcu_torture_current
, rp
);
613 i
= old_rp
->rtort_pipe_count
;
614 if (i
> RCU_TORTURE_PIPE_LEN
)
615 i
= RCU_TORTURE_PIPE_LEN
;
616 atomic_inc(&rcu_torture_wcount
[i
]);
617 old_rp
->rtort_pipe_count
++;
618 cur_ops
->deferredfree(old_rp
);
620 rcu_torture_current_version
++;
621 oldbatch
= cur_ops
->completed();
623 } while (!kthread_should_stop() && !fullstop
);
624 VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping");
625 while (!kthread_should_stop() && fullstop
!= FULLSTOP_SHUTDOWN
)
626 schedule_timeout_uninterruptible(1);
631 * RCU torture fake writer kthread. Repeatedly calls sync, with a random
632 * delay between calls.
635 rcu_torture_fakewriter(void *arg
)
637 DEFINE_RCU_RANDOM(rand
);
639 VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task started");
640 set_user_nice(current
, 19);
643 schedule_timeout_uninterruptible(1 + rcu_random(&rand
)%10);
644 udelay(rcu_random(&rand
) & 0x3ff);
647 } while (!kthread_should_stop() && !fullstop
);
649 VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping");
650 while (!kthread_should_stop() && fullstop
!= FULLSTOP_SHUTDOWN
)
651 schedule_timeout_uninterruptible(1);
656 * RCU torture reader from timer handler. Dereferences rcu_torture_current,
657 * incrementing the corresponding element of the pipeline array. The
658 * counter in the element should never be greater than 1, otherwise, the
659 * RCU implementation is broken.
661 static void rcu_torture_timer(unsigned long unused
)
665 static DEFINE_RCU_RANDOM(rand
);
666 static DEFINE_SPINLOCK(rand_lock
);
667 struct rcu_torture
*p
;
670 idx
= cur_ops
->readlock();
671 completed
= cur_ops
->completed();
672 p
= rcu_dereference(rcu_torture_current
);
674 /* Leave because rcu_torture_writer is not yet underway */
675 cur_ops
->readunlock(idx
);
678 if (p
->rtort_mbtest
== 0)
679 atomic_inc(&n_rcu_torture_mberror
);
680 spin_lock(&rand_lock
);
681 cur_ops
->readdelay(&rand
);
682 n_rcu_torture_timers
++;
683 spin_unlock(&rand_lock
);
685 pipe_count
= p
->rtort_pipe_count
;
686 if (pipe_count
> RCU_TORTURE_PIPE_LEN
) {
687 /* Should not happen, but... */
688 pipe_count
= RCU_TORTURE_PIPE_LEN
;
690 ++__get_cpu_var(rcu_torture_count
)[pipe_count
];
691 completed
= cur_ops
->completed() - completed
;
692 if (completed
> RCU_TORTURE_PIPE_LEN
) {
693 /* Should not happen, but... */
694 completed
= RCU_TORTURE_PIPE_LEN
;
696 ++__get_cpu_var(rcu_torture_batch
)[completed
];
698 cur_ops
->readunlock(idx
);
702 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current,
703 * incrementing the corresponding element of the pipeline array. The
704 * counter in the element should never be greater than 1, otherwise, the
705 * RCU implementation is broken.
708 rcu_torture_reader(void *arg
)
712 DEFINE_RCU_RANDOM(rand
);
713 struct rcu_torture
*p
;
717 VERBOSE_PRINTK_STRING("rcu_torture_reader task started");
718 set_user_nice(current
, 19);
719 if (irqreader
&& cur_ops
->irqcapable
)
720 setup_timer_on_stack(&t
, rcu_torture_timer
, 0);
723 if (irqreader
&& cur_ops
->irqcapable
) {
724 if (!timer_pending(&t
))
727 idx
= cur_ops
->readlock();
728 completed
= cur_ops
->completed();
729 p
= rcu_dereference(rcu_torture_current
);
731 /* Wait for rcu_torture_writer to get underway */
732 cur_ops
->readunlock(idx
);
733 schedule_timeout_interruptible(HZ
);
736 if (p
->rtort_mbtest
== 0)
737 atomic_inc(&n_rcu_torture_mberror
);
738 cur_ops
->readdelay(&rand
);
740 pipe_count
= p
->rtort_pipe_count
;
741 if (pipe_count
> RCU_TORTURE_PIPE_LEN
) {
742 /* Should not happen, but... */
743 pipe_count
= RCU_TORTURE_PIPE_LEN
;
745 ++__get_cpu_var(rcu_torture_count
)[pipe_count
];
746 completed
= cur_ops
->completed() - completed
;
747 if (completed
> RCU_TORTURE_PIPE_LEN
) {
748 /* Should not happen, but... */
749 completed
= RCU_TORTURE_PIPE_LEN
;
751 ++__get_cpu_var(rcu_torture_batch
)[completed
];
753 cur_ops
->readunlock(idx
);
756 } while (!kthread_should_stop() && !fullstop
);
757 VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping");
758 if (irqreader
&& cur_ops
->irqcapable
)
760 while (!kthread_should_stop() && fullstop
!= FULLSTOP_SHUTDOWN
)
761 schedule_timeout_uninterruptible(1);
766 * Create an RCU-torture statistics message in the specified buffer.
769 rcu_torture_printk(char *page
)
774 long pipesummary
[RCU_TORTURE_PIPE_LEN
+ 1] = { 0 };
775 long batchsummary
[RCU_TORTURE_PIPE_LEN
+ 1] = { 0 };
777 for_each_possible_cpu(cpu
) {
778 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++) {
779 pipesummary
[i
] += per_cpu(rcu_torture_count
, cpu
)[i
];
780 batchsummary
[i
] += per_cpu(rcu_torture_batch
, cpu
)[i
];
783 for (i
= RCU_TORTURE_PIPE_LEN
- 1; i
>= 0; i
--) {
784 if (pipesummary
[i
] != 0)
787 cnt
+= sprintf(&page
[cnt
], "%s%s ", torture_type
, TORTURE_FLAG
);
788 cnt
+= sprintf(&page
[cnt
],
789 "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d "
792 rcu_torture_current_version
,
793 list_empty(&rcu_torture_freelist
),
794 atomic_read(&n_rcu_torture_alloc
),
795 atomic_read(&n_rcu_torture_alloc_fail
),
796 atomic_read(&n_rcu_torture_free
),
797 atomic_read(&n_rcu_torture_mberror
),
798 n_rcu_torture_timers
);
799 if (atomic_read(&n_rcu_torture_mberror
) != 0)
800 cnt
+= sprintf(&page
[cnt
], " !!!");
801 cnt
+= sprintf(&page
[cnt
], "\n%s%s ", torture_type
, TORTURE_FLAG
);
803 cnt
+= sprintf(&page
[cnt
], "!!! ");
804 atomic_inc(&n_rcu_torture_error
);
807 cnt
+= sprintf(&page
[cnt
], "Reader Pipe: ");
808 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++)
809 cnt
+= sprintf(&page
[cnt
], " %ld", pipesummary
[i
]);
810 cnt
+= sprintf(&page
[cnt
], "\n%s%s ", torture_type
, TORTURE_FLAG
);
811 cnt
+= sprintf(&page
[cnt
], "Reader Batch: ");
812 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++)
813 cnt
+= sprintf(&page
[cnt
], " %ld", batchsummary
[i
]);
814 cnt
+= sprintf(&page
[cnt
], "\n%s%s ", torture_type
, TORTURE_FLAG
);
815 cnt
+= sprintf(&page
[cnt
], "Free-Block Circulation: ");
816 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++) {
817 cnt
+= sprintf(&page
[cnt
], " %d",
818 atomic_read(&rcu_torture_wcount
[i
]));
820 cnt
+= sprintf(&page
[cnt
], "\n");
822 cnt
+= cur_ops
->stats(&page
[cnt
]);
827 * Print torture statistics. Caller must ensure that there is only
828 * one call to this function at a given time!!! This is normally
829 * accomplished by relying on the module system to only have one copy
830 * of the module loaded, and then by giving the rcu_torture_stats
831 * kthread full control (or the init/cleanup functions when rcu_torture_stats
832 * thread is not running).
835 rcu_torture_stats_print(void)
839 cnt
= rcu_torture_printk(printk_buf
);
840 printk(KERN_ALERT
"%s", printk_buf
);
844 * Periodically prints torture statistics, if periodic statistics printing
845 * was specified via the stat_interval module parameter.
847 * No need to worry about fullstop here, since this one doesn't reference
848 * volatile state or register callbacks.
851 rcu_torture_stats(void *arg
)
853 VERBOSE_PRINTK_STRING("rcu_torture_stats task started");
855 schedule_timeout_interruptible(stat_interval
* HZ
);
856 rcu_torture_stats_print();
857 } while (!kthread_should_stop() && !fullstop
);
858 VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping");
862 static int rcu_idle_cpu
; /* Force all torture tasks off this CPU */
864 /* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case
865 * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs.
867 static void rcu_torture_shuffle_tasks(void)
869 cpumask_var_t tmp_mask
;
872 if (!alloc_cpumask_var(&tmp_mask
, GFP_KERNEL
))
875 cpumask_setall(tmp_mask
);
878 /* No point in shuffling if there is only one online CPU (ex: UP) */
879 if (num_online_cpus() == 1)
882 if (rcu_idle_cpu
!= -1)
883 cpumask_clear_cpu(rcu_idle_cpu
, tmp_mask
);
885 set_cpus_allowed_ptr(current
, tmp_mask
);
888 for (i
= 0; i
< nrealreaders
; i
++)
890 set_cpus_allowed_ptr(reader_tasks
[i
],
894 if (fakewriter_tasks
) {
895 for (i
= 0; i
< nfakewriters
; i
++)
896 if (fakewriter_tasks
[i
])
897 set_cpus_allowed_ptr(fakewriter_tasks
[i
],
902 set_cpus_allowed_ptr(writer_task
, tmp_mask
);
905 set_cpus_allowed_ptr(stats_task
, tmp_mask
);
907 if (rcu_idle_cpu
== -1)
908 rcu_idle_cpu
= num_online_cpus() - 1;
914 free_cpumask_var(tmp_mask
);
917 /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the
918 * system to become idle at a time and cut off its timer ticks. This is meant
919 * to test the support for such tickless idle CPU in RCU.
922 rcu_torture_shuffle(void *arg
)
924 VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started");
926 schedule_timeout_interruptible(shuffle_interval
* HZ
);
927 rcu_torture_shuffle_tasks();
928 } while (!kthread_should_stop() && !fullstop
);
929 VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping");
933 /* Cause the rcutorture test to "stutter", starting and stopping all
934 * threads periodically.
937 rcu_torture_stutter(void *arg
)
939 VERBOSE_PRINTK_STRING("rcu_torture_stutter task started");
941 schedule_timeout_interruptible(stutter
* HZ
);
942 stutter_pause_test
= 1;
943 if (!kthread_should_stop() && !fullstop
)
944 schedule_timeout_interruptible(stutter
* HZ
);
945 stutter_pause_test
= 0;
946 } while (!kthread_should_stop() && !fullstop
);
947 VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping");
952 rcu_torture_print_module_parms(char *tag
)
954 printk(KERN_ALERT
"%s" TORTURE_FLAG
955 "--- %s: nreaders=%d nfakewriters=%d "
956 "stat_interval=%d verbose=%d test_no_idle_hz=%d "
957 "shuffle_interval=%d stutter=%d irqreader=%d\n",
958 torture_type
, tag
, nrealreaders
, nfakewriters
,
959 stat_interval
, verbose
, test_no_idle_hz
, shuffle_interval
,
963 static struct notifier_block rcutorture_nb
= {
964 .notifier_call
= rcutorture_shutdown_notify
,
968 rcu_torture_cleanup(void)
972 mutex_lock(&fullstop_mutex
);
974 /* If being signaled, let it happen, then exit. */
975 mutex_unlock(&fullstop_mutex
);
976 schedule_timeout_interruptible(10 * HZ
);
977 if (cur_ops
->cb_barrier
!= NULL
)
978 cur_ops
->cb_barrier();
981 fullstop
= FULLSTOP_CLEANUP
;
982 mutex_unlock(&fullstop_mutex
);
983 unregister_reboot_notifier(&rcutorture_nb
);
985 VERBOSE_PRINTK_STRING("Stopping rcu_torture_stutter task");
986 kthread_stop(stutter_task
);
990 VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task");
991 kthread_stop(shuffler_task
);
993 shuffler_task
= NULL
;
996 VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task");
997 kthread_stop(writer_task
);
1002 for (i
= 0; i
< nrealreaders
; i
++) {
1003 if (reader_tasks
[i
]) {
1004 VERBOSE_PRINTK_STRING(
1005 "Stopping rcu_torture_reader task");
1006 kthread_stop(reader_tasks
[i
]);
1008 reader_tasks
[i
] = NULL
;
1010 kfree(reader_tasks
);
1011 reader_tasks
= NULL
;
1013 rcu_torture_current
= NULL
;
1015 if (fakewriter_tasks
) {
1016 for (i
= 0; i
< nfakewriters
; i
++) {
1017 if (fakewriter_tasks
[i
]) {
1018 VERBOSE_PRINTK_STRING(
1019 "Stopping rcu_torture_fakewriter task");
1020 kthread_stop(fakewriter_tasks
[i
]);
1022 fakewriter_tasks
[i
] = NULL
;
1024 kfree(fakewriter_tasks
);
1025 fakewriter_tasks
= NULL
;
1029 VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task");
1030 kthread_stop(stats_task
);
1034 /* Wait for all RCU callbacks to fire. */
1036 if (cur_ops
->cb_barrier
!= NULL
)
1037 cur_ops
->cb_barrier();
1039 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
1041 if (cur_ops
->cleanup
)
1043 if (atomic_read(&n_rcu_torture_error
))
1044 rcu_torture_print_module_parms("End of test: FAILURE");
1046 rcu_torture_print_module_parms("End of test: SUCCESS");
1050 rcu_torture_init(void)
1055 static struct rcu_torture_ops
*torture_ops
[] =
1056 { &rcu_ops
, &rcu_sync_ops
, &rcu_bh_ops
, &rcu_bh_sync_ops
,
1057 &srcu_ops
, &sched_ops
, &sched_ops_sync
, };
1059 mutex_lock(&fullstop_mutex
);
1061 /* Process args and tell the world that the torturer is on the job. */
1062 for (i
= 0; i
< ARRAY_SIZE(torture_ops
); i
++) {
1063 cur_ops
= torture_ops
[i
];
1064 if (strcmp(torture_type
, cur_ops
->name
) == 0)
1067 if (i
== ARRAY_SIZE(torture_ops
)) {
1068 printk(KERN_ALERT
"rcutorture: invalid torture type: \"%s\"\n",
1070 mutex_unlock(&fullstop_mutex
);
1074 cur_ops
->init(); /* no "goto unwind" prior to this point!!! */
1077 nrealreaders
= nreaders
;
1079 nrealreaders
= 2 * num_online_cpus();
1080 rcu_torture_print_module_parms("Start of test");
1083 /* Set up the freelist. */
1085 INIT_LIST_HEAD(&rcu_torture_freelist
);
1086 for (i
= 0; i
< ARRAY_SIZE(rcu_tortures
); i
++) {
1087 rcu_tortures
[i
].rtort_mbtest
= 0;
1088 list_add_tail(&rcu_tortures
[i
].rtort_free
,
1089 &rcu_torture_freelist
);
1092 /* Initialize the statistics so that each run gets its own numbers. */
1094 rcu_torture_current
= NULL
;
1095 rcu_torture_current_version
= 0;
1096 atomic_set(&n_rcu_torture_alloc
, 0);
1097 atomic_set(&n_rcu_torture_alloc_fail
, 0);
1098 atomic_set(&n_rcu_torture_free
, 0);
1099 atomic_set(&n_rcu_torture_mberror
, 0);
1100 atomic_set(&n_rcu_torture_error
, 0);
1101 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++)
1102 atomic_set(&rcu_torture_wcount
[i
], 0);
1103 for_each_possible_cpu(cpu
) {
1104 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++) {
1105 per_cpu(rcu_torture_count
, cpu
)[i
] = 0;
1106 per_cpu(rcu_torture_batch
, cpu
)[i
] = 0;
1110 /* Start up the kthreads. */
1112 VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task");
1113 writer_task
= kthread_run(rcu_torture_writer
, NULL
,
1114 "rcu_torture_writer");
1115 if (IS_ERR(writer_task
)) {
1116 firsterr
= PTR_ERR(writer_task
);
1117 VERBOSE_PRINTK_ERRSTRING("Failed to create writer");
1121 fakewriter_tasks
= kzalloc(nfakewriters
* sizeof(fakewriter_tasks
[0]),
1123 if (fakewriter_tasks
== NULL
) {
1124 VERBOSE_PRINTK_ERRSTRING("out of memory");
1128 for (i
= 0; i
< nfakewriters
; i
++) {
1129 VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task");
1130 fakewriter_tasks
[i
] = kthread_run(rcu_torture_fakewriter
, NULL
,
1131 "rcu_torture_fakewriter");
1132 if (IS_ERR(fakewriter_tasks
[i
])) {
1133 firsterr
= PTR_ERR(fakewriter_tasks
[i
]);
1134 VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter");
1135 fakewriter_tasks
[i
] = NULL
;
1139 reader_tasks
= kzalloc(nrealreaders
* sizeof(reader_tasks
[0]),
1141 if (reader_tasks
== NULL
) {
1142 VERBOSE_PRINTK_ERRSTRING("out of memory");
1146 for (i
= 0; i
< nrealreaders
; i
++) {
1147 VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task");
1148 reader_tasks
[i
] = kthread_run(rcu_torture_reader
, NULL
,
1149 "rcu_torture_reader");
1150 if (IS_ERR(reader_tasks
[i
])) {
1151 firsterr
= PTR_ERR(reader_tasks
[i
]);
1152 VERBOSE_PRINTK_ERRSTRING("Failed to create reader");
1153 reader_tasks
[i
] = NULL
;
1157 if (stat_interval
> 0) {
1158 VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task");
1159 stats_task
= kthread_run(rcu_torture_stats
, NULL
,
1160 "rcu_torture_stats");
1161 if (IS_ERR(stats_task
)) {
1162 firsterr
= PTR_ERR(stats_task
);
1163 VERBOSE_PRINTK_ERRSTRING("Failed to create stats");
1168 if (test_no_idle_hz
) {
1169 rcu_idle_cpu
= num_online_cpus() - 1;
1170 /* Create the shuffler thread */
1171 shuffler_task
= kthread_run(rcu_torture_shuffle
, NULL
,
1172 "rcu_torture_shuffle");
1173 if (IS_ERR(shuffler_task
)) {
1174 firsterr
= PTR_ERR(shuffler_task
);
1175 VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler");
1176 shuffler_task
= NULL
;
1183 /* Create the stutter thread */
1184 stutter_task
= kthread_run(rcu_torture_stutter
, NULL
,
1185 "rcu_torture_stutter");
1186 if (IS_ERR(stutter_task
)) {
1187 firsterr
= PTR_ERR(stutter_task
);
1188 VERBOSE_PRINTK_ERRSTRING("Failed to create stutter");
1189 stutter_task
= NULL
;
1193 register_reboot_notifier(&rcutorture_nb
);
1194 mutex_unlock(&fullstop_mutex
);
1198 mutex_unlock(&fullstop_mutex
);
1199 rcu_torture_cleanup();
1203 module_init(rcu_torture_init
);
1204 module_exit(rcu_torture_cleanup
);