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, you can access it online at
16 * http://www.gnu.org/licenses/gpl-2.0.html.
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 <linux/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 <linux/trace_clock.h>
50 #include <asm/byteorder.h>
51 #include <linux/torture.h>
53 MODULE_LICENSE("GPL");
54 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and Josh Triplett <josh@freedesktop.org>");
57 torture_param(int, fqs_duration
, 0,
58 "Duration of fqs bursts (us), 0 to disable");
59 torture_param(int, fqs_holdoff
, 0, "Holdoff time within fqs bursts (us)");
60 torture_param(int, fqs_stutter
, 3, "Wait time between fqs bursts (s)");
61 torture_param(bool, gp_exp
, false, "Use expedited GP wait primitives");
62 torture_param(bool, gp_normal
, false,
63 "Use normal (non-expedited) GP wait primitives");
64 torture_param(int, irqreader
, 1, "Allow RCU readers from irq handlers");
65 torture_param(int, n_barrier_cbs
, 0,
66 "# of callbacks/kthreads for barrier testing");
67 torture_param(int, nfakewriters
, 4, "Number of RCU fake writer threads");
68 torture_param(int, nreaders
, -1, "Number of RCU reader threads");
69 torture_param(int, object_debug
, 0,
70 "Enable debug-object double call_rcu() testing");
71 torture_param(int, onoff_holdoff
, 0, "Time after boot before CPU hotplugs (s)");
72 torture_param(int, onoff_interval
, 0,
73 "Time between CPU hotplugs (s), 0=disable");
74 torture_param(int, shuffle_interval
, 3, "Number of seconds between shuffles");
75 torture_param(int, shutdown_secs
, 0, "Shutdown time (s), <= zero to disable.");
76 torture_param(int, stall_cpu
, 0, "Stall duration (s), zero to disable.");
77 torture_param(int, stall_cpu_holdoff
, 10,
78 "Time to wait before starting stall (s).");
79 torture_param(int, stat_interval
, 60,
80 "Number of seconds between stats printk()s");
81 torture_param(int, stutter
, 5, "Number of seconds to run/halt test");
82 torture_param(int, test_boost
, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
83 torture_param(int, test_boost_duration
, 4,
84 "Duration of each boost test, seconds.");
85 torture_param(int, test_boost_interval
, 7,
86 "Interval between boost tests, seconds.");
87 torture_param(bool, test_no_idle_hz
, true,
88 "Test support for tickless idle CPUs");
89 torture_param(bool, verbose
, true,
90 "Enable verbose debugging printk()s");
92 static char *torture_type
= "rcu";
93 module_param(torture_type
, charp
, 0444);
94 MODULE_PARM_DESC(torture_type
, "Type of RCU to torture (rcu, rcu_bh, ...)");
96 static int nrealreaders
;
97 static struct task_struct
*writer_task
;
98 static struct task_struct
**fakewriter_tasks
;
99 static struct task_struct
**reader_tasks
;
100 static struct task_struct
*stats_task
;
101 static struct task_struct
*fqs_task
;
102 static struct task_struct
*boost_tasks
[NR_CPUS
];
103 static struct task_struct
*stall_task
;
104 static struct task_struct
**barrier_cbs_tasks
;
105 static struct task_struct
*barrier_task
;
107 #define RCU_TORTURE_PIPE_LEN 10
110 struct rcu_head rtort_rcu
;
111 int rtort_pipe_count
;
112 struct list_head rtort_free
;
116 static LIST_HEAD(rcu_torture_freelist
);
117 static struct rcu_torture __rcu
*rcu_torture_current
;
118 static unsigned long rcu_torture_current_version
;
119 static struct rcu_torture rcu_tortures
[10 * RCU_TORTURE_PIPE_LEN
];
120 static DEFINE_SPINLOCK(rcu_torture_lock
);
121 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN
+ 1],
122 rcu_torture_count
) = { 0 };
123 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN
+ 1],
124 rcu_torture_batch
) = { 0 };
125 static atomic_t rcu_torture_wcount
[RCU_TORTURE_PIPE_LEN
+ 1];
126 static atomic_t n_rcu_torture_alloc
;
127 static atomic_t n_rcu_torture_alloc_fail
;
128 static atomic_t n_rcu_torture_free
;
129 static atomic_t n_rcu_torture_mberror
;
130 static atomic_t n_rcu_torture_error
;
131 static long n_rcu_torture_barrier_error
;
132 static long n_rcu_torture_boost_ktrerror
;
133 static long n_rcu_torture_boost_rterror
;
134 static long n_rcu_torture_boost_failure
;
135 static long n_rcu_torture_boosts
;
136 static long n_rcu_torture_timers
;
137 static long n_barrier_attempts
;
138 static long n_barrier_successes
;
139 static struct list_head rcu_torture_removed
;
141 static int rcu_torture_writer_state
;
142 #define RTWS_FIXED_DELAY 0
144 #define RTWS_REPLACE 2
145 #define RTWS_DEF_FREE 3
146 #define RTWS_EXP_SYNC 4
147 #define RTWS_STUTTER 5
148 #define RTWS_STOPPING 6
150 #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
151 #define RCUTORTURE_RUNNABLE_INIT 1
153 #define RCUTORTURE_RUNNABLE_INIT 0
155 int rcutorture_runnable
= RCUTORTURE_RUNNABLE_INIT
;
156 module_param(rcutorture_runnable
, int, 0444);
157 MODULE_PARM_DESC(rcutorture_runnable
, "Start rcutorture at boot");
159 #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU)
160 #define rcu_can_boost() 1
161 #else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
162 #define rcu_can_boost() 0
163 #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
165 #ifdef CONFIG_RCU_TRACE
166 static u64 notrace
rcu_trace_clock_local(void)
168 u64 ts
= trace_clock_local();
169 unsigned long __maybe_unused ts_rem
= do_div(ts
, NSEC_PER_USEC
);
172 #else /* #ifdef CONFIG_RCU_TRACE */
173 static u64 notrace
rcu_trace_clock_local(void)
177 #endif /* #else #ifdef CONFIG_RCU_TRACE */
179 static unsigned long boost_starttime
; /* jiffies of next boost test start. */
180 DEFINE_MUTEX(boost_mutex
); /* protect setting boost_starttime */
181 /* and boost task create/destroy. */
182 static atomic_t barrier_cbs_count
; /* Barrier callbacks registered. */
183 static bool barrier_phase
; /* Test phase. */
184 static atomic_t barrier_cbs_invoked
; /* Barrier callbacks invoked. */
185 static wait_queue_head_t
*barrier_cbs_wq
; /* Coordinate barrier testing. */
186 static DECLARE_WAIT_QUEUE_HEAD(barrier_wq
);
189 * Allocate an element from the rcu_tortures pool.
191 static struct rcu_torture
*
192 rcu_torture_alloc(void)
196 spin_lock_bh(&rcu_torture_lock
);
197 if (list_empty(&rcu_torture_freelist
)) {
198 atomic_inc(&n_rcu_torture_alloc_fail
);
199 spin_unlock_bh(&rcu_torture_lock
);
202 atomic_inc(&n_rcu_torture_alloc
);
203 p
= rcu_torture_freelist
.next
;
205 spin_unlock_bh(&rcu_torture_lock
);
206 return container_of(p
, struct rcu_torture
, rtort_free
);
210 * Free an element to the rcu_tortures pool.
213 rcu_torture_free(struct rcu_torture
*p
)
215 atomic_inc(&n_rcu_torture_free
);
216 spin_lock_bh(&rcu_torture_lock
);
217 list_add_tail(&p
->rtort_free
, &rcu_torture_freelist
);
218 spin_unlock_bh(&rcu_torture_lock
);
222 * Operations vector for selecting different types of tests.
225 struct rcu_torture_ops
{
228 int (*readlock
)(void);
229 void (*read_delay
)(struct torture_random_state
*rrsp
);
230 void (*readunlock
)(int idx
);
231 int (*completed
)(void);
232 void (*deferred_free
)(struct rcu_torture
*p
);
234 void (*exp_sync
)(void);
235 void (*call
)(struct rcu_head
*head
, void (*func
)(struct rcu_head
*rcu
));
236 void (*cb_barrier
)(void);
238 void (*stats
)(char *page
);
244 static struct rcu_torture_ops
*cur_ops
;
247 * Definitions for rcu torture testing.
250 static int rcu_torture_read_lock(void) __acquires(RCU
)
256 static void rcu_read_delay(struct torture_random_state
*rrsp
)
258 const unsigned long shortdelay_us
= 200;
259 const unsigned long longdelay_ms
= 50;
261 /* We want a short delay sometimes to make a reader delay the grace
262 * period, and we want a long delay occasionally to trigger
263 * force_quiescent_state. */
265 if (!(torture_random(rrsp
) % (nrealreaders
* 2000 * longdelay_ms
)))
266 mdelay(longdelay_ms
);
267 if (!(torture_random(rrsp
) % (nrealreaders
* 2 * shortdelay_us
)))
268 udelay(shortdelay_us
);
269 #ifdef CONFIG_PREEMPT
270 if (!preempt_count() &&
271 !(torture_random(rrsp
) % (nrealreaders
* 20000)))
272 preempt_schedule(); /* No QS if preempt_disable() in effect */
276 static void rcu_torture_read_unlock(int idx
) __releases(RCU
)
281 static int rcu_torture_completed(void)
283 return rcu_batches_completed();
287 rcu_torture_cb(struct rcu_head
*p
)
290 struct rcu_torture
*rp
= container_of(p
, struct rcu_torture
, rtort_rcu
);
292 if (torture_must_stop_irq()) {
293 /* Test is ending, just drop callbacks on the floor. */
294 /* The next initialization will pick up the pieces. */
297 i
= rp
->rtort_pipe_count
;
298 if (i
> RCU_TORTURE_PIPE_LEN
)
299 i
= RCU_TORTURE_PIPE_LEN
;
300 atomic_inc(&rcu_torture_wcount
[i
]);
301 if (++rp
->rtort_pipe_count
>= RCU_TORTURE_PIPE_LEN
) {
302 rp
->rtort_mbtest
= 0;
303 rcu_torture_free(rp
);
305 cur_ops
->deferred_free(rp
);
309 static int rcu_no_completed(void)
314 static void rcu_torture_deferred_free(struct rcu_torture
*p
)
316 call_rcu(&p
->rtort_rcu
, rcu_torture_cb
);
319 static void rcu_sync_torture_init(void)
321 INIT_LIST_HEAD(&rcu_torture_removed
);
324 static struct rcu_torture_ops rcu_ops
= {
326 .init
= rcu_sync_torture_init
,
327 .readlock
= rcu_torture_read_lock
,
328 .read_delay
= rcu_read_delay
,
329 .readunlock
= rcu_torture_read_unlock
,
330 .completed
= rcu_torture_completed
,
331 .deferred_free
= rcu_torture_deferred_free
,
332 .sync
= synchronize_rcu
,
333 .exp_sync
= synchronize_rcu_expedited
,
335 .cb_barrier
= rcu_barrier
,
336 .fqs
= rcu_force_quiescent_state
,
339 .can_boost
= rcu_can_boost(),
344 * Definitions for rcu_bh torture testing.
347 static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH
)
353 static void rcu_bh_torture_read_unlock(int idx
) __releases(RCU_BH
)
355 rcu_read_unlock_bh();
358 static int rcu_bh_torture_completed(void)
360 return rcu_batches_completed_bh();
363 static void rcu_bh_torture_deferred_free(struct rcu_torture
*p
)
365 call_rcu_bh(&p
->rtort_rcu
, rcu_torture_cb
);
368 static struct rcu_torture_ops rcu_bh_ops
= {
369 .ttype
= RCU_BH_FLAVOR
,
370 .init
= rcu_sync_torture_init
,
371 .readlock
= rcu_bh_torture_read_lock
,
372 .read_delay
= rcu_read_delay
, /* just reuse rcu's version. */
373 .readunlock
= rcu_bh_torture_read_unlock
,
374 .completed
= rcu_bh_torture_completed
,
375 .deferred_free
= rcu_bh_torture_deferred_free
,
376 .sync
= synchronize_rcu_bh
,
377 .exp_sync
= synchronize_rcu_bh_expedited
,
379 .cb_barrier
= rcu_barrier_bh
,
380 .fqs
= rcu_bh_force_quiescent_state
,
387 * Don't even think about trying any of these in real life!!!
388 * The names includes "busted", and they really means it!
389 * The only purpose of these functions is to provide a buggy RCU
390 * implementation to make sure that rcutorture correctly emits
391 * buggy-RCU error messages.
393 static void rcu_busted_torture_deferred_free(struct rcu_torture
*p
)
395 /* This is a deliberate bug for testing purposes only! */
396 rcu_torture_cb(&p
->rtort_rcu
);
399 static void synchronize_rcu_busted(void)
401 /* This is a deliberate bug for testing purposes only! */
405 call_rcu_busted(struct rcu_head
*head
, void (*func
)(struct rcu_head
*rcu
))
407 /* This is a deliberate bug for testing purposes only! */
411 static struct rcu_torture_ops rcu_busted_ops
= {
412 .ttype
= INVALID_RCU_FLAVOR
,
413 .init
= rcu_sync_torture_init
,
414 .readlock
= rcu_torture_read_lock
,
415 .read_delay
= rcu_read_delay
, /* just reuse rcu's version. */
416 .readunlock
= rcu_torture_read_unlock
,
417 .completed
= rcu_no_completed
,
418 .deferred_free
= rcu_busted_torture_deferred_free
,
419 .sync
= synchronize_rcu_busted
,
420 .exp_sync
= synchronize_rcu_busted
,
421 .call
= call_rcu_busted
,
430 * Definitions for srcu torture testing.
433 DEFINE_STATIC_SRCU(srcu_ctl
);
435 static int srcu_torture_read_lock(void) __acquires(&srcu_ctl
)
437 return srcu_read_lock(&srcu_ctl
);
440 static void srcu_read_delay(struct torture_random_state
*rrsp
)
443 const long uspertick
= 1000000 / HZ
;
444 const long longdelay
= 10;
446 /* We want there to be long-running readers, but not all the time. */
448 delay
= torture_random(rrsp
) %
449 (nrealreaders
* 2 * longdelay
* uspertick
);
451 schedule_timeout_interruptible(longdelay
);
453 rcu_read_delay(rrsp
);
456 static void srcu_torture_read_unlock(int idx
) __releases(&srcu_ctl
)
458 srcu_read_unlock(&srcu_ctl
, idx
);
461 static int srcu_torture_completed(void)
463 return srcu_batches_completed(&srcu_ctl
);
466 static void srcu_torture_deferred_free(struct rcu_torture
*rp
)
468 call_srcu(&srcu_ctl
, &rp
->rtort_rcu
, rcu_torture_cb
);
471 static void srcu_torture_synchronize(void)
473 synchronize_srcu(&srcu_ctl
);
476 static void srcu_torture_call(struct rcu_head
*head
,
477 void (*func
)(struct rcu_head
*head
))
479 call_srcu(&srcu_ctl
, head
, func
);
482 static void srcu_torture_barrier(void)
484 srcu_barrier(&srcu_ctl
);
487 static void srcu_torture_stats(char *page
)
490 int idx
= srcu_ctl
.completed
& 0x1;
492 page
+= sprintf(page
, "%s%s per-CPU(idx=%d):",
493 torture_type
, TORTURE_FLAG
, idx
);
494 for_each_possible_cpu(cpu
) {
495 page
+= sprintf(page
, " %d(%lu,%lu)", cpu
,
496 per_cpu_ptr(srcu_ctl
.per_cpu_ref
, cpu
)->c
[!idx
],
497 per_cpu_ptr(srcu_ctl
.per_cpu_ref
, cpu
)->c
[idx
]);
502 static void srcu_torture_synchronize_expedited(void)
504 synchronize_srcu_expedited(&srcu_ctl
);
507 static struct rcu_torture_ops srcu_ops
= {
508 .ttype
= SRCU_FLAVOR
,
509 .init
= rcu_sync_torture_init
,
510 .readlock
= srcu_torture_read_lock
,
511 .read_delay
= srcu_read_delay
,
512 .readunlock
= srcu_torture_read_unlock
,
513 .completed
= srcu_torture_completed
,
514 .deferred_free
= srcu_torture_deferred_free
,
515 .sync
= srcu_torture_synchronize
,
516 .exp_sync
= srcu_torture_synchronize_expedited
,
517 .call
= srcu_torture_call
,
518 .cb_barrier
= srcu_torture_barrier
,
519 .stats
= srcu_torture_stats
,
524 * Definitions for sched torture testing.
527 static int sched_torture_read_lock(void)
533 static void sched_torture_read_unlock(int idx
)
538 static void rcu_sched_torture_deferred_free(struct rcu_torture
*p
)
540 call_rcu_sched(&p
->rtort_rcu
, rcu_torture_cb
);
543 static struct rcu_torture_ops sched_ops
= {
544 .ttype
= RCU_SCHED_FLAVOR
,
545 .init
= rcu_sync_torture_init
,
546 .readlock
= sched_torture_read_lock
,
547 .read_delay
= rcu_read_delay
, /* just reuse rcu's version. */
548 .readunlock
= sched_torture_read_unlock
,
549 .completed
= rcu_no_completed
,
550 .deferred_free
= rcu_sched_torture_deferred_free
,
551 .sync
= synchronize_sched
,
552 .exp_sync
= synchronize_sched_expedited
,
553 .call
= call_rcu_sched
,
554 .cb_barrier
= rcu_barrier_sched
,
555 .fqs
= rcu_sched_force_quiescent_state
,
562 * RCU torture priority-boost testing. Runs one real-time thread per
563 * CPU for moderate bursts, repeatedly registering RCU callbacks and
564 * spinning waiting for them to be invoked. If a given callback takes
565 * too long to be invoked, we assume that priority inversion has occurred.
568 struct rcu_boost_inflight
{
573 static void rcu_torture_boost_cb(struct rcu_head
*head
)
575 struct rcu_boost_inflight
*rbip
=
576 container_of(head
, struct rcu_boost_inflight
, rcu
);
578 smp_mb(); /* Ensure RCU-core accesses precede clearing ->inflight */
582 static int rcu_torture_boost(void *arg
)
584 unsigned long call_rcu_time
;
585 unsigned long endtime
;
586 unsigned long oldstarttime
;
587 struct rcu_boost_inflight rbi
= { .inflight
= 0 };
588 struct sched_param sp
;
590 VERBOSE_TOROUT_STRING("rcu_torture_boost started");
592 /* Set real-time priority. */
593 sp
.sched_priority
= 1;
594 if (sched_setscheduler(current
, SCHED_FIFO
, &sp
) < 0) {
595 VERBOSE_TOROUT_STRING("rcu_torture_boost RT prio failed!");
596 n_rcu_torture_boost_rterror
++;
599 init_rcu_head_on_stack(&rbi
.rcu
);
600 /* Each pass through the following loop does one boost-test cycle. */
602 /* Wait for the next test interval. */
603 oldstarttime
= boost_starttime
;
604 while (ULONG_CMP_LT(jiffies
, oldstarttime
)) {
605 schedule_timeout_interruptible(oldstarttime
- jiffies
);
606 stutter_wait("rcu_torture_boost");
607 if (torture_must_stop())
611 /* Do one boost-test interval. */
612 endtime
= oldstarttime
+ test_boost_duration
* HZ
;
613 call_rcu_time
= jiffies
;
614 while (ULONG_CMP_LT(jiffies
, endtime
)) {
615 /* If we don't have a callback in flight, post one. */
617 smp_mb(); /* RCU core before ->inflight = 1. */
619 call_rcu(&rbi
.rcu
, rcu_torture_boost_cb
);
620 if (jiffies
- call_rcu_time
>
621 test_boost_duration
* HZ
- HZ
/ 2) {
622 VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed");
623 n_rcu_torture_boost_failure
++;
625 call_rcu_time
= jiffies
;
628 stutter_wait("rcu_torture_boost");
629 if (torture_must_stop())
634 * Set the start time of the next test interval.
635 * Yes, this is vulnerable to long delays, but such
636 * delays simply cause a false negative for the next
637 * interval. Besides, we are running at RT priority,
638 * so delays should be relatively rare.
640 while (oldstarttime
== boost_starttime
&&
641 !kthread_should_stop()) {
642 if (mutex_trylock(&boost_mutex
)) {
643 boost_starttime
= jiffies
+
644 test_boost_interval
* HZ
;
645 n_rcu_torture_boosts
++;
646 mutex_unlock(&boost_mutex
);
649 schedule_timeout_uninterruptible(1);
652 /* Go do the stutter. */
653 checkwait
: stutter_wait("rcu_torture_boost");
654 } while (!torture_must_stop());
656 /* Clean up and exit. */
657 while (!kthread_should_stop() || rbi
.inflight
) {
658 torture_shutdown_absorb("rcu_torture_boost");
659 schedule_timeout_uninterruptible(1);
661 smp_mb(); /* order accesses to ->inflight before stack-frame death. */
662 destroy_rcu_head_on_stack(&rbi
.rcu
);
663 torture_kthread_stopping("rcu_torture_boost");
668 * RCU torture force-quiescent-state kthread. Repeatedly induces
669 * bursts of calls to force_quiescent_state(), increasing the probability
670 * of occurrence of some important types of race conditions.
673 rcu_torture_fqs(void *arg
)
675 unsigned long fqs_resume_time
;
676 int fqs_burst_remaining
;
678 VERBOSE_TOROUT_STRING("rcu_torture_fqs task started");
680 fqs_resume_time
= jiffies
+ fqs_stutter
* HZ
;
681 while (ULONG_CMP_LT(jiffies
, fqs_resume_time
) &&
682 !kthread_should_stop()) {
683 schedule_timeout_interruptible(1);
685 fqs_burst_remaining
= fqs_duration
;
686 while (fqs_burst_remaining
> 0 &&
687 !kthread_should_stop()) {
690 fqs_burst_remaining
-= fqs_holdoff
;
692 stutter_wait("rcu_torture_fqs");
693 } while (!torture_must_stop());
694 torture_kthread_stopping("rcu_torture_fqs");
699 * RCU torture writer kthread. Repeatedly substitutes a new structure
700 * for that pointed to by rcu_torture_current, freeing the old structure
701 * after a series of grace periods (the "pipeline").
704 rcu_torture_writer(void *arg
)
708 struct rcu_torture
*rp
;
709 struct rcu_torture
*rp1
;
710 struct rcu_torture
*old_rp
;
711 static DEFINE_TORTURE_RANDOM(rand
);
713 VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
714 set_user_nice(current
, MAX_NICE
);
717 rcu_torture_writer_state
= RTWS_FIXED_DELAY
;
718 schedule_timeout_uninterruptible(1);
719 rp
= rcu_torture_alloc();
722 rp
->rtort_pipe_count
= 0;
723 rcu_torture_writer_state
= RTWS_DELAY
;
724 udelay(torture_random(&rand
) & 0x3ff);
725 rcu_torture_writer_state
= RTWS_REPLACE
;
726 old_rp
= rcu_dereference_check(rcu_torture_current
,
727 current
== writer_task
);
728 rp
->rtort_mbtest
= 1;
729 rcu_assign_pointer(rcu_torture_current
, rp
);
730 smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */
732 i
= old_rp
->rtort_pipe_count
;
733 if (i
> RCU_TORTURE_PIPE_LEN
)
734 i
= RCU_TORTURE_PIPE_LEN
;
735 atomic_inc(&rcu_torture_wcount
[i
]);
736 old_rp
->rtort_pipe_count
++;
737 if (gp_normal
== gp_exp
)
738 exp
= !!(torture_random(&rand
) & 0x80);
742 rcu_torture_writer_state
= RTWS_DEF_FREE
;
743 cur_ops
->deferred_free(old_rp
);
745 rcu_torture_writer_state
= RTWS_EXP_SYNC
;
747 list_add(&old_rp
->rtort_free
,
748 &rcu_torture_removed
);
749 list_for_each_entry_safe(rp
, rp1
,
750 &rcu_torture_removed
,
752 i
= rp
->rtort_pipe_count
;
753 if (i
> RCU_TORTURE_PIPE_LEN
)
754 i
= RCU_TORTURE_PIPE_LEN
;
755 atomic_inc(&rcu_torture_wcount
[i
]);
756 if (++rp
->rtort_pipe_count
>=
757 RCU_TORTURE_PIPE_LEN
) {
758 rp
->rtort_mbtest
= 0;
759 list_del(&rp
->rtort_free
);
760 rcu_torture_free(rp
);
765 rcutorture_record_progress(++rcu_torture_current_version
);
766 rcu_torture_writer_state
= RTWS_STUTTER
;
767 stutter_wait("rcu_torture_writer");
768 } while (!torture_must_stop());
769 rcu_torture_writer_state
= RTWS_STOPPING
;
770 torture_kthread_stopping("rcu_torture_writer");
775 * RCU torture fake writer kthread. Repeatedly calls sync, with a random
776 * delay between calls.
779 rcu_torture_fakewriter(void *arg
)
781 DEFINE_TORTURE_RANDOM(rand
);
783 VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started");
784 set_user_nice(current
, MAX_NICE
);
787 schedule_timeout_uninterruptible(1 + torture_random(&rand
)%10);
788 udelay(torture_random(&rand
) & 0x3ff);
789 if (cur_ops
->cb_barrier
!= NULL
&&
790 torture_random(&rand
) % (nfakewriters
* 8) == 0) {
791 cur_ops
->cb_barrier();
792 } else if (gp_normal
== gp_exp
) {
793 if (torture_random(&rand
) & 0x80)
797 } else if (gp_normal
) {
802 stutter_wait("rcu_torture_fakewriter");
803 } while (!torture_must_stop());
805 torture_kthread_stopping("rcu_torture_fakewriter");
809 void rcutorture_trace_dump(void)
811 static atomic_t beenhere
= ATOMIC_INIT(0);
813 if (atomic_read(&beenhere
))
815 if (atomic_xchg(&beenhere
, 1) != 0)
817 ftrace_dump(DUMP_ALL
);
821 * RCU torture reader from timer handler. Dereferences rcu_torture_current,
822 * incrementing the corresponding element of the pipeline array. The
823 * counter in the element should never be greater than 1, otherwise, the
824 * RCU implementation is broken.
826 static void rcu_torture_timer(unsigned long unused
)
831 static DEFINE_TORTURE_RANDOM(rand
);
832 static DEFINE_SPINLOCK(rand_lock
);
833 struct rcu_torture
*p
;
835 unsigned long long ts
;
837 idx
= cur_ops
->readlock();
838 completed
= cur_ops
->completed();
839 ts
= rcu_trace_clock_local();
840 p
= rcu_dereference_check(rcu_torture_current
,
841 rcu_read_lock_bh_held() ||
842 rcu_read_lock_sched_held() ||
843 srcu_read_lock_held(&srcu_ctl
));
845 /* Leave because rcu_torture_writer is not yet underway */
846 cur_ops
->readunlock(idx
);
849 if (p
->rtort_mbtest
== 0)
850 atomic_inc(&n_rcu_torture_mberror
);
851 spin_lock(&rand_lock
);
852 cur_ops
->read_delay(&rand
);
853 n_rcu_torture_timers
++;
854 spin_unlock(&rand_lock
);
856 pipe_count
= p
->rtort_pipe_count
;
857 if (pipe_count
> RCU_TORTURE_PIPE_LEN
) {
858 /* Should not happen, but... */
859 pipe_count
= RCU_TORTURE_PIPE_LEN
;
861 completed_end
= cur_ops
->completed();
862 if (pipe_count
> 1) {
863 do_trace_rcu_torture_read(cur_ops
->name
, &p
->rtort_rcu
, ts
,
864 completed
, completed_end
);
865 rcutorture_trace_dump();
867 __this_cpu_inc(rcu_torture_count
[pipe_count
]);
868 completed
= completed_end
- completed
;
869 if (completed
> RCU_TORTURE_PIPE_LEN
) {
870 /* Should not happen, but... */
871 completed
= RCU_TORTURE_PIPE_LEN
;
873 __this_cpu_inc(rcu_torture_batch
[completed
]);
875 cur_ops
->readunlock(idx
);
879 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current,
880 * incrementing the corresponding element of the pipeline array. The
881 * counter in the element should never be greater than 1, otherwise, the
882 * RCU implementation is broken.
885 rcu_torture_reader(void *arg
)
890 DEFINE_TORTURE_RANDOM(rand
);
891 struct rcu_torture
*p
;
894 unsigned long long ts
;
896 VERBOSE_TOROUT_STRING("rcu_torture_reader task started");
897 set_user_nice(current
, MAX_NICE
);
898 if (irqreader
&& cur_ops
->irq_capable
)
899 setup_timer_on_stack(&t
, rcu_torture_timer
, 0);
902 if (irqreader
&& cur_ops
->irq_capable
) {
903 if (!timer_pending(&t
))
904 mod_timer(&t
, jiffies
+ 1);
906 idx
= cur_ops
->readlock();
907 completed
= cur_ops
->completed();
908 ts
= rcu_trace_clock_local();
909 p
= rcu_dereference_check(rcu_torture_current
,
910 rcu_read_lock_bh_held() ||
911 rcu_read_lock_sched_held() ||
912 srcu_read_lock_held(&srcu_ctl
));
914 /* Wait for rcu_torture_writer to get underway */
915 cur_ops
->readunlock(idx
);
916 schedule_timeout_interruptible(HZ
);
919 if (p
->rtort_mbtest
== 0)
920 atomic_inc(&n_rcu_torture_mberror
);
921 cur_ops
->read_delay(&rand
);
923 pipe_count
= p
->rtort_pipe_count
;
924 if (pipe_count
> RCU_TORTURE_PIPE_LEN
) {
925 /* Should not happen, but... */
926 pipe_count
= RCU_TORTURE_PIPE_LEN
;
928 completed_end
= cur_ops
->completed();
929 if (pipe_count
> 1) {
930 do_trace_rcu_torture_read(cur_ops
->name
, &p
->rtort_rcu
,
931 ts
, completed
, completed_end
);
932 rcutorture_trace_dump();
934 __this_cpu_inc(rcu_torture_count
[pipe_count
]);
935 completed
= completed_end
- completed
;
936 if (completed
> RCU_TORTURE_PIPE_LEN
) {
937 /* Should not happen, but... */
938 completed
= RCU_TORTURE_PIPE_LEN
;
940 __this_cpu_inc(rcu_torture_batch
[completed
]);
942 cur_ops
->readunlock(idx
);
944 stutter_wait("rcu_torture_reader");
945 } while (!torture_must_stop());
946 if (irqreader
&& cur_ops
->irq_capable
)
948 torture_kthread_stopping("rcu_torture_reader");
953 * Create an RCU-torture statistics message in the specified buffer.
956 rcu_torture_printk(char *page
)
960 long pipesummary
[RCU_TORTURE_PIPE_LEN
+ 1] = { 0 };
961 long batchsummary
[RCU_TORTURE_PIPE_LEN
+ 1] = { 0 };
962 static unsigned long rtcv_snap
= ULONG_MAX
;
964 for_each_possible_cpu(cpu
) {
965 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++) {
966 pipesummary
[i
] += per_cpu(rcu_torture_count
, cpu
)[i
];
967 batchsummary
[i
] += per_cpu(rcu_torture_batch
, cpu
)[i
];
970 for (i
= RCU_TORTURE_PIPE_LEN
- 1; i
>= 0; i
--) {
971 if (pipesummary
[i
] != 0)
974 page
+= sprintf(page
, "%s%s ", torture_type
, TORTURE_FLAG
);
975 page
+= sprintf(page
,
976 "rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
978 rcu_torture_current_version
,
979 list_empty(&rcu_torture_freelist
),
980 atomic_read(&n_rcu_torture_alloc
),
981 atomic_read(&n_rcu_torture_alloc_fail
),
982 atomic_read(&n_rcu_torture_free
));
983 page
+= sprintf(page
, "rtmbe: %d rtbke: %ld rtbre: %ld ",
984 atomic_read(&n_rcu_torture_mberror
),
985 n_rcu_torture_boost_ktrerror
,
986 n_rcu_torture_boost_rterror
);
987 page
+= sprintf(page
, "rtbf: %ld rtb: %ld nt: %ld ",
988 n_rcu_torture_boost_failure
,
989 n_rcu_torture_boosts
,
990 n_rcu_torture_timers
);
991 page
= torture_onoff_stats(page
);
992 page
+= sprintf(page
, "barrier: %ld/%ld:%ld",
995 n_rcu_torture_barrier_error
);
996 page
+= sprintf(page
, "\n%s%s ", torture_type
, TORTURE_FLAG
);
997 if (atomic_read(&n_rcu_torture_mberror
) != 0 ||
998 n_rcu_torture_barrier_error
!= 0 ||
999 n_rcu_torture_boost_ktrerror
!= 0 ||
1000 n_rcu_torture_boost_rterror
!= 0 ||
1001 n_rcu_torture_boost_failure
!= 0 ||
1003 page
+= sprintf(page
, "!!! ");
1004 atomic_inc(&n_rcu_torture_error
);
1007 page
+= sprintf(page
, "Reader Pipe: ");
1008 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++)
1009 page
+= sprintf(page
, " %ld", pipesummary
[i
]);
1010 page
+= sprintf(page
, "\n%s%s ", torture_type
, TORTURE_FLAG
);
1011 page
+= sprintf(page
, "Reader Batch: ");
1012 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++)
1013 page
+= sprintf(page
, " %ld", batchsummary
[i
]);
1014 page
+= sprintf(page
, "\n%s%s ", torture_type
, TORTURE_FLAG
);
1015 page
+= sprintf(page
, "Free-Block Circulation: ");
1016 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++) {
1017 page
+= sprintf(page
, " %d",
1018 atomic_read(&rcu_torture_wcount
[i
]));
1020 page
+= sprintf(page
, "\n");
1022 cur_ops
->stats(page
);
1023 if (rtcv_snap
== rcu_torture_current_version
&&
1024 rcu_torture_current
!= NULL
) {
1025 int __maybe_unused flags
;
1026 unsigned long __maybe_unused gpnum
;
1027 unsigned long __maybe_unused completed
;
1029 rcutorture_get_gp_data(cur_ops
->ttype
,
1030 &flags
, &gpnum
, &completed
);
1031 page
+= sprintf(page
,
1032 "??? Writer stall state %d g%lu c%lu f%#x\n",
1033 rcu_torture_writer_state
,
1034 gpnum
, completed
, flags
);
1036 rtcv_snap
= rcu_torture_current_version
;
1040 * Print torture statistics. Caller must ensure that there is only
1041 * one call to this function at a given time!!! This is normally
1042 * accomplished by relying on the module system to only have one copy
1043 * of the module loaded, and then by giving the rcu_torture_stats
1044 * kthread full control (or the init/cleanup functions when rcu_torture_stats
1045 * thread is not running).
1048 rcu_torture_stats_print(void)
1050 int size
= nr_cpu_ids
* 200 + 8192;
1053 buf
= kmalloc(size
, GFP_KERNEL
);
1055 pr_err("rcu-torture: Out of memory, need: %d", size
);
1058 rcu_torture_printk(buf
);
1059 pr_alert("%s", buf
);
1064 * Periodically prints torture statistics, if periodic statistics printing
1065 * was specified via the stat_interval module parameter.
1068 rcu_torture_stats(void *arg
)
1070 VERBOSE_TOROUT_STRING("rcu_torture_stats task started");
1072 schedule_timeout_interruptible(stat_interval
* HZ
);
1073 rcu_torture_stats_print();
1074 torture_shutdown_absorb("rcu_torture_stats");
1075 } while (!torture_must_stop());
1076 torture_kthread_stopping("rcu_torture_stats");
1081 rcu_torture_print_module_parms(struct rcu_torture_ops
*cur_ops
, const char *tag
)
1083 pr_alert("%s" TORTURE_FLAG
1084 "--- %s: nreaders=%d nfakewriters=%d "
1085 "stat_interval=%d verbose=%d test_no_idle_hz=%d "
1086 "shuffle_interval=%d stutter=%d irqreader=%d "
1087 "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
1088 "test_boost=%d/%d test_boost_interval=%d "
1089 "test_boost_duration=%d shutdown_secs=%d "
1090 "stall_cpu=%d stall_cpu_holdoff=%d "
1092 "onoff_interval=%d onoff_holdoff=%d\n",
1093 torture_type
, tag
, nrealreaders
, nfakewriters
,
1094 stat_interval
, verbose
, test_no_idle_hz
, shuffle_interval
,
1095 stutter
, irqreader
, fqs_duration
, fqs_holdoff
, fqs_stutter
,
1096 test_boost
, cur_ops
->can_boost
,
1097 test_boost_interval
, test_boost_duration
, shutdown_secs
,
1098 stall_cpu
, stall_cpu_holdoff
,
1100 onoff_interval
, onoff_holdoff
);
1103 static void rcutorture_booster_cleanup(int cpu
)
1105 struct task_struct
*t
;
1107 if (boost_tasks
[cpu
] == NULL
)
1109 mutex_lock(&boost_mutex
);
1110 t
= boost_tasks
[cpu
];
1111 boost_tasks
[cpu
] = NULL
;
1112 mutex_unlock(&boost_mutex
);
1114 /* This must be outside of the mutex, otherwise deadlock! */
1115 torture_stop_kthread(rcu_torture_boost
, t
);
1118 static int rcutorture_booster_init(int cpu
)
1122 if (boost_tasks
[cpu
] != NULL
)
1123 return 0; /* Already created, nothing more to do. */
1125 /* Don't allow time recalculation while creating a new task. */
1126 mutex_lock(&boost_mutex
);
1127 VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task");
1128 boost_tasks
[cpu
] = kthread_create_on_node(rcu_torture_boost
, NULL
,
1130 "rcu_torture_boost");
1131 if (IS_ERR(boost_tasks
[cpu
])) {
1132 retval
= PTR_ERR(boost_tasks
[cpu
]);
1133 VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed");
1134 n_rcu_torture_boost_ktrerror
++;
1135 boost_tasks
[cpu
] = NULL
;
1136 mutex_unlock(&boost_mutex
);
1139 kthread_bind(boost_tasks
[cpu
], cpu
);
1140 wake_up_process(boost_tasks
[cpu
]);
1141 mutex_unlock(&boost_mutex
);
1146 * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then
1147 * induces a CPU stall for the time specified by stall_cpu.
1149 static int rcu_torture_stall(void *args
)
1151 unsigned long stop_at
;
1153 VERBOSE_TOROUT_STRING("rcu_torture_stall task started");
1154 if (stall_cpu_holdoff
> 0) {
1155 VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff");
1156 schedule_timeout_interruptible(stall_cpu_holdoff
* HZ
);
1157 VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff");
1159 if (!kthread_should_stop()) {
1160 stop_at
= get_seconds() + stall_cpu
;
1161 /* RCU CPU stall is expected behavior in following code. */
1162 pr_alert("rcu_torture_stall start.\n");
1165 while (ULONG_CMP_LT(get_seconds(), stop_at
))
1166 continue; /* Induce RCU CPU stall warning. */
1169 pr_alert("rcu_torture_stall end.\n");
1171 torture_shutdown_absorb("rcu_torture_stall");
1172 while (!kthread_should_stop())
1173 schedule_timeout_interruptible(10 * HZ
);
1177 /* Spawn CPU-stall kthread, if stall_cpu specified. */
1178 static int __init
rcu_torture_stall_init(void)
1182 return torture_create_kthread(rcu_torture_stall
, NULL
, stall_task
);
1185 /* Callback function for RCU barrier testing. */
1186 void rcu_torture_barrier_cbf(struct rcu_head
*rcu
)
1188 atomic_inc(&barrier_cbs_invoked
);
1191 /* kthread function to register callbacks used to test RCU barriers. */
1192 static int rcu_torture_barrier_cbs(void *arg
)
1194 long myid
= (long)arg
;
1197 struct rcu_head rcu
;
1199 init_rcu_head_on_stack(&rcu
);
1200 VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started");
1201 set_user_nice(current
, MAX_NICE
);
1203 wait_event(barrier_cbs_wq
[myid
],
1205 ACCESS_ONCE(barrier_phase
)) != lastphase
||
1206 torture_must_stop());
1207 lastphase
= newphase
;
1208 smp_mb(); /* ensure barrier_phase load before ->call(). */
1209 if (torture_must_stop())
1211 cur_ops
->call(&rcu
, rcu_torture_barrier_cbf
);
1212 if (atomic_dec_and_test(&barrier_cbs_count
))
1213 wake_up(&barrier_wq
);
1214 } while (!torture_must_stop());
1215 cur_ops
->cb_barrier();
1216 destroy_rcu_head_on_stack(&rcu
);
1217 torture_kthread_stopping("rcu_torture_barrier_cbs");
1221 /* kthread function to drive and coordinate RCU barrier testing. */
1222 static int rcu_torture_barrier(void *arg
)
1226 VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting");
1228 atomic_set(&barrier_cbs_invoked
, 0);
1229 atomic_set(&barrier_cbs_count
, n_barrier_cbs
);
1230 smp_mb(); /* Ensure barrier_phase after prior assignments. */
1231 barrier_phase
= !barrier_phase
;
1232 for (i
= 0; i
< n_barrier_cbs
; i
++)
1233 wake_up(&barrier_cbs_wq
[i
]);
1234 wait_event(barrier_wq
,
1235 atomic_read(&barrier_cbs_count
) == 0 ||
1236 torture_must_stop());
1237 if (torture_must_stop())
1239 n_barrier_attempts
++;
1240 cur_ops
->cb_barrier(); /* Implies smp_mb() for wait_event(). */
1241 if (atomic_read(&barrier_cbs_invoked
) != n_barrier_cbs
) {
1242 n_rcu_torture_barrier_error
++;
1245 n_barrier_successes
++;
1246 schedule_timeout_interruptible(HZ
/ 10);
1247 } while (!torture_must_stop());
1248 torture_kthread_stopping("rcu_torture_barrier");
1252 /* Initialize RCU barrier testing. */
1253 static int rcu_torture_barrier_init(void)
1258 if (n_barrier_cbs
== 0)
1260 if (cur_ops
->call
== NULL
|| cur_ops
->cb_barrier
== NULL
) {
1261 pr_alert("%s" TORTURE_FLAG
1262 " Call or barrier ops missing for %s,\n",
1263 torture_type
, cur_ops
->name
);
1264 pr_alert("%s" TORTURE_FLAG
1265 " RCU barrier testing omitted from run.\n",
1269 atomic_set(&barrier_cbs_count
, 0);
1270 atomic_set(&barrier_cbs_invoked
, 0);
1272 kzalloc(n_barrier_cbs
* sizeof(barrier_cbs_tasks
[0]),
1275 kzalloc(n_barrier_cbs
* sizeof(barrier_cbs_wq
[0]),
1277 if (barrier_cbs_tasks
== NULL
|| !barrier_cbs_wq
)
1279 for (i
= 0; i
< n_barrier_cbs
; i
++) {
1280 init_waitqueue_head(&barrier_cbs_wq
[i
]);
1281 ret
= torture_create_kthread(rcu_torture_barrier_cbs
,
1283 barrier_cbs_tasks
[i
]);
1287 return torture_create_kthread(rcu_torture_barrier
, NULL
, barrier_task
);
1290 /* Clean up after RCU barrier testing. */
1291 static void rcu_torture_barrier_cleanup(void)
1295 torture_stop_kthread(rcu_torture_barrier
, barrier_task
);
1296 if (barrier_cbs_tasks
!= NULL
) {
1297 for (i
= 0; i
< n_barrier_cbs
; i
++)
1298 torture_stop_kthread(rcu_torture_barrier_cbs
,
1299 barrier_cbs_tasks
[i
]);
1300 kfree(barrier_cbs_tasks
);
1301 barrier_cbs_tasks
= NULL
;
1303 if (barrier_cbs_wq
!= NULL
) {
1304 kfree(barrier_cbs_wq
);
1305 barrier_cbs_wq
= NULL
;
1309 static int rcutorture_cpu_notify(struct notifier_block
*self
,
1310 unsigned long action
, void *hcpu
)
1312 long cpu
= (long)hcpu
;
1316 case CPU_DOWN_FAILED
:
1317 (void)rcutorture_booster_init(cpu
);
1319 case CPU_DOWN_PREPARE
:
1320 rcutorture_booster_cleanup(cpu
);
1328 static struct notifier_block rcutorture_cpu_nb
= {
1329 .notifier_call
= rcutorture_cpu_notify
,
1333 rcu_torture_cleanup(void)
1337 rcutorture_record_test_transition();
1338 if (torture_cleanup()) {
1339 if (cur_ops
->cb_barrier
!= NULL
)
1340 cur_ops
->cb_barrier();
1344 rcu_torture_barrier_cleanup();
1345 torture_stop_kthread(rcu_torture_stall
, stall_task
);
1346 torture_stop_kthread(rcu_torture_writer
, writer_task
);
1349 for (i
= 0; i
< nrealreaders
; i
++)
1350 torture_stop_kthread(rcu_torture_reader
,
1352 kfree(reader_tasks
);
1354 rcu_torture_current
= NULL
;
1356 if (fakewriter_tasks
) {
1357 for (i
= 0; i
< nfakewriters
; i
++) {
1358 torture_stop_kthread(rcu_torture_fakewriter
,
1359 fakewriter_tasks
[i
]);
1361 kfree(fakewriter_tasks
);
1362 fakewriter_tasks
= NULL
;
1365 torture_stop_kthread(rcu_torture_stats
, stats_task
);
1366 torture_stop_kthread(rcu_torture_fqs
, fqs_task
);
1367 if ((test_boost
== 1 && cur_ops
->can_boost
) ||
1369 unregister_cpu_notifier(&rcutorture_cpu_nb
);
1370 for_each_possible_cpu(i
)
1371 rcutorture_booster_cleanup(i
);
1374 /* Wait for all RCU callbacks to fire. */
1376 if (cur_ops
->cb_barrier
!= NULL
)
1377 cur_ops
->cb_barrier();
1379 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
1381 if (atomic_read(&n_rcu_torture_error
) || n_rcu_torture_barrier_error
)
1382 rcu_torture_print_module_parms(cur_ops
, "End of test: FAILURE");
1383 else if (torture_onoff_failures())
1384 rcu_torture_print_module_parms(cur_ops
,
1385 "End of test: RCU_HOTPLUG");
1387 rcu_torture_print_module_parms(cur_ops
, "End of test: SUCCESS");
1390 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
1391 static void rcu_torture_leak_cb(struct rcu_head
*rhp
)
1395 static void rcu_torture_err_cb(struct rcu_head
*rhp
)
1398 * This -might- happen due to race conditions, but is unlikely.
1399 * The scenario that leads to this happening is that the
1400 * first of the pair of duplicate callbacks is queued,
1401 * someone else starts a grace period that includes that
1402 * callback, then the second of the pair must wait for the
1403 * next grace period. Unlikely, but can happen. If it
1404 * does happen, the debug-objects subsystem won't have splatted.
1406 pr_alert("rcutorture: duplicated callback was invoked.\n");
1408 #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1411 * Verify that double-free causes debug-objects to complain, but only
1412 * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test
1413 * cannot be carried out.
1415 static void rcu_test_debug_objects(void)
1417 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
1418 struct rcu_head rh1
;
1419 struct rcu_head rh2
;
1421 init_rcu_head_on_stack(&rh1
);
1422 init_rcu_head_on_stack(&rh2
);
1423 pr_alert("rcutorture: WARN: Duplicate call_rcu() test starting.\n");
1425 /* Try to queue the rh2 pair of callbacks for the same grace period. */
1426 preempt_disable(); /* Prevent preemption from interrupting test. */
1427 rcu_read_lock(); /* Make it impossible to finish a grace period. */
1428 call_rcu(&rh1
, rcu_torture_leak_cb
); /* Start grace period. */
1429 local_irq_disable(); /* Make it harder to start a new grace period. */
1430 call_rcu(&rh2
, rcu_torture_leak_cb
);
1431 call_rcu(&rh2
, rcu_torture_err_cb
); /* Duplicate callback. */
1436 /* Wait for them all to get done so we can safely return. */
1438 pr_alert("rcutorture: WARN: Duplicate call_rcu() test complete.\n");
1439 destroy_rcu_head_on_stack(&rh1
);
1440 destroy_rcu_head_on_stack(&rh2
);
1441 #else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1442 pr_alert("rcutorture: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n");
1443 #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1447 rcu_torture_init(void)
1452 static struct rcu_torture_ops
*torture_ops
[] = {
1453 &rcu_ops
, &rcu_bh_ops
, &rcu_busted_ops
, &srcu_ops
, &sched_ops
,
1456 torture_init_begin(torture_type
, verbose
, &rcutorture_runnable
);
1458 /* Process args and tell the world that the torturer is on the job. */
1459 for (i
= 0; i
< ARRAY_SIZE(torture_ops
); i
++) {
1460 cur_ops
= torture_ops
[i
];
1461 if (strcmp(torture_type
, cur_ops
->name
) == 0)
1464 if (i
== ARRAY_SIZE(torture_ops
)) {
1465 pr_alert("rcu-torture: invalid torture type: \"%s\"\n",
1467 pr_alert("rcu-torture types:");
1468 for (i
= 0; i
< ARRAY_SIZE(torture_ops
); i
++)
1469 pr_alert(" %s", torture_ops
[i
]->name
);
1474 if (cur_ops
->fqs
== NULL
&& fqs_duration
!= 0) {
1475 pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n");
1479 cur_ops
->init(); /* no "goto unwind" prior to this point!!! */
1482 nrealreaders
= nreaders
;
1484 nrealreaders
= 2 * num_online_cpus();
1485 rcu_torture_print_module_parms(cur_ops
, "Start of test");
1487 /* Set up the freelist. */
1489 INIT_LIST_HEAD(&rcu_torture_freelist
);
1490 for (i
= 0; i
< ARRAY_SIZE(rcu_tortures
); i
++) {
1491 rcu_tortures
[i
].rtort_mbtest
= 0;
1492 list_add_tail(&rcu_tortures
[i
].rtort_free
,
1493 &rcu_torture_freelist
);
1496 /* Initialize the statistics so that each run gets its own numbers. */
1498 rcu_torture_current
= NULL
;
1499 rcu_torture_current_version
= 0;
1500 atomic_set(&n_rcu_torture_alloc
, 0);
1501 atomic_set(&n_rcu_torture_alloc_fail
, 0);
1502 atomic_set(&n_rcu_torture_free
, 0);
1503 atomic_set(&n_rcu_torture_mberror
, 0);
1504 atomic_set(&n_rcu_torture_error
, 0);
1505 n_rcu_torture_barrier_error
= 0;
1506 n_rcu_torture_boost_ktrerror
= 0;
1507 n_rcu_torture_boost_rterror
= 0;
1508 n_rcu_torture_boost_failure
= 0;
1509 n_rcu_torture_boosts
= 0;
1510 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++)
1511 atomic_set(&rcu_torture_wcount
[i
], 0);
1512 for_each_possible_cpu(cpu
) {
1513 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++) {
1514 per_cpu(rcu_torture_count
, cpu
)[i
] = 0;
1515 per_cpu(rcu_torture_batch
, cpu
)[i
] = 0;
1519 /* Start up the kthreads. */
1521 firsterr
= torture_create_kthread(rcu_torture_writer
, NULL
,
1525 fakewriter_tasks
= kzalloc(nfakewriters
* sizeof(fakewriter_tasks
[0]),
1527 if (fakewriter_tasks
== NULL
) {
1528 VERBOSE_TOROUT_ERRSTRING("out of memory");
1532 for (i
= 0; i
< nfakewriters
; i
++) {
1533 firsterr
= torture_create_kthread(rcu_torture_fakewriter
,
1534 NULL
, fakewriter_tasks
[i
]);
1538 reader_tasks
= kzalloc(nrealreaders
* sizeof(reader_tasks
[0]),
1540 if (reader_tasks
== NULL
) {
1541 VERBOSE_TOROUT_ERRSTRING("out of memory");
1545 for (i
= 0; i
< nrealreaders
; i
++) {
1546 firsterr
= torture_create_kthread(rcu_torture_reader
, NULL
,
1551 if (stat_interval
> 0) {
1552 firsterr
= torture_create_kthread(rcu_torture_stats
, NULL
,
1557 if (test_no_idle_hz
) {
1558 firsterr
= torture_shuffle_init(shuffle_interval
* HZ
);
1565 firsterr
= torture_stutter_init(stutter
* HZ
);
1569 if (fqs_duration
< 0)
1572 /* Create the fqs thread */
1573 torture_create_kthread(rcu_torture_fqs
, NULL
, fqs_task
);
1577 if (test_boost_interval
< 1)
1578 test_boost_interval
= 1;
1579 if (test_boost_duration
< 2)
1580 test_boost_duration
= 2;
1581 if ((test_boost
== 1 && cur_ops
->can_boost
) ||
1584 boost_starttime
= jiffies
+ test_boost_interval
* HZ
;
1585 register_cpu_notifier(&rcutorture_cpu_nb
);
1586 for_each_possible_cpu(i
) {
1587 if (cpu_is_offline(i
))
1588 continue; /* Heuristic: CPU can go offline. */
1589 firsterr
= rcutorture_booster_init(i
);
1594 firsterr
= torture_shutdown_init(shutdown_secs
, rcu_torture_cleanup
);
1597 firsterr
= torture_onoff_init(onoff_holdoff
* HZ
, onoff_interval
* HZ
);
1600 firsterr
= rcu_torture_stall_init();
1603 firsterr
= rcu_torture_barrier_init();
1607 rcu_test_debug_objects();
1608 rcutorture_record_test_transition();
1614 rcu_torture_cleanup();
1618 module_init(rcu_torture_init
);
1619 module_exit(rcu_torture_cleanup
);