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@joshtriplett.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/signal.h>
36 #include <uapi/linux/sched/types.h>
37 #include <linux/atomic.h>
38 #include <linux/bitops.h>
39 #include <linux/completion.h>
40 #include <linux/moduleparam.h>
41 #include <linux/percpu.h>
42 #include <linux/notifier.h>
43 #include <linux/reboot.h>
44 #include <linux/freezer.h>
45 #include <linux/cpu.h>
46 #include <linux/delay.h>
47 #include <linux/stat.h>
48 #include <linux/srcu.h>
49 #include <linux/slab.h>
50 #include <linux/trace_clock.h>
51 #include <asm/byteorder.h>
52 #include <linux/torture.h>
53 #include <linux/vmalloc.h>
57 MODULE_LICENSE("GPL");
58 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and Josh Triplett <josh@joshtriplett.org>");
61 torture_param(int, cbflood_inter_holdoff
, HZ
,
62 "Holdoff between floods (jiffies)");
63 torture_param(int, cbflood_intra_holdoff
, 1,
64 "Holdoff between bursts (jiffies)");
65 torture_param(int, cbflood_n_burst
, 3, "# bursts in flood, zero to disable");
66 torture_param(int, cbflood_n_per_burst
, 20000,
67 "# callbacks per burst in flood");
68 torture_param(int, fqs_duration
, 0,
69 "Duration of fqs bursts (us), 0 to disable");
70 torture_param(int, fqs_holdoff
, 0, "Holdoff time within fqs bursts (us)");
71 torture_param(int, fqs_stutter
, 3, "Wait time between fqs bursts (s)");
72 torture_param(bool, gp_cond
, false, "Use conditional/async GP wait primitives");
73 torture_param(bool, gp_exp
, false, "Use expedited GP wait primitives");
74 torture_param(bool, gp_normal
, false,
75 "Use normal (non-expedited) GP wait primitives");
76 torture_param(bool, gp_sync
, false, "Use synchronous GP wait primitives");
77 torture_param(int, irqreader
, 1, "Allow RCU readers from irq handlers");
78 torture_param(int, n_barrier_cbs
, 0,
79 "# of callbacks/kthreads for barrier testing");
80 torture_param(int, nfakewriters
, 4, "Number of RCU fake writer threads");
81 torture_param(int, nreaders
, -1, "Number of RCU reader threads");
82 torture_param(int, object_debug
, 0,
83 "Enable debug-object double call_rcu() testing");
84 torture_param(int, onoff_holdoff
, 0, "Time after boot before CPU hotplugs (s)");
85 torture_param(int, onoff_interval
, 0,
86 "Time between CPU hotplugs (s), 0=disable");
87 torture_param(int, shuffle_interval
, 3, "Number of seconds between shuffles");
88 torture_param(int, shutdown_secs
, 0, "Shutdown time (s), <= zero to disable.");
89 torture_param(int, stall_cpu
, 0, "Stall duration (s), zero to disable.");
90 torture_param(int, stall_cpu_holdoff
, 10,
91 "Time to wait before starting stall (s).");
92 torture_param(int, stat_interval
, 60,
93 "Number of seconds between stats printk()s");
94 torture_param(int, stutter
, 5, "Number of seconds to run/halt test");
95 torture_param(int, test_boost
, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
96 torture_param(int, test_boost_duration
, 4,
97 "Duration of each boost test, seconds.");
98 torture_param(int, test_boost_interval
, 7,
99 "Interval between boost tests, seconds.");
100 torture_param(bool, test_no_idle_hz
, true,
101 "Test support for tickless idle CPUs");
102 torture_param(bool, verbose
, true,
103 "Enable verbose debugging printk()s");
105 static char *torture_type
= "rcu";
106 module_param(torture_type
, charp
, 0444);
107 MODULE_PARM_DESC(torture_type
, "Type of RCU to torture (rcu, rcu_bh, ...)");
109 static int nrealreaders
;
110 static int ncbflooders
;
111 static struct task_struct
*writer_task
;
112 static struct task_struct
**fakewriter_tasks
;
113 static struct task_struct
**reader_tasks
;
114 static struct task_struct
*stats_task
;
115 static struct task_struct
**cbflood_task
;
116 static struct task_struct
*fqs_task
;
117 static struct task_struct
*boost_tasks
[NR_CPUS
];
118 static struct task_struct
*stall_task
;
119 static struct task_struct
**barrier_cbs_tasks
;
120 static struct task_struct
*barrier_task
;
122 #define RCU_TORTURE_PIPE_LEN 10
125 struct rcu_head rtort_rcu
;
126 int rtort_pipe_count
;
127 struct list_head rtort_free
;
131 static LIST_HEAD(rcu_torture_freelist
);
132 static struct rcu_torture __rcu
*rcu_torture_current
;
133 static unsigned long rcu_torture_current_version
;
134 static struct rcu_torture rcu_tortures
[10 * RCU_TORTURE_PIPE_LEN
];
135 static DEFINE_SPINLOCK(rcu_torture_lock
);
136 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN
+ 1], rcu_torture_count
);
137 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN
+ 1], rcu_torture_batch
);
138 static atomic_t rcu_torture_wcount
[RCU_TORTURE_PIPE_LEN
+ 1];
139 static atomic_t n_rcu_torture_alloc
;
140 static atomic_t n_rcu_torture_alloc_fail
;
141 static atomic_t n_rcu_torture_free
;
142 static atomic_t n_rcu_torture_mberror
;
143 static atomic_t n_rcu_torture_error
;
144 static long n_rcu_torture_barrier_error
;
145 static long n_rcu_torture_boost_ktrerror
;
146 static long n_rcu_torture_boost_rterror
;
147 static long n_rcu_torture_boost_failure
;
148 static long n_rcu_torture_boosts
;
149 static long n_rcu_torture_timers
;
150 static long n_barrier_attempts
;
151 static long n_barrier_successes
;
152 static atomic_long_t n_cbfloods
;
153 static struct list_head rcu_torture_removed
;
155 static int rcu_torture_writer_state
;
156 #define RTWS_FIXED_DELAY 0
158 #define RTWS_REPLACE 2
159 #define RTWS_DEF_FREE 3
160 #define RTWS_EXP_SYNC 4
161 #define RTWS_COND_GET 5
162 #define RTWS_COND_SYNC 6
164 #define RTWS_STUTTER 8
165 #define RTWS_STOPPING 9
166 static const char * const rcu_torture_writer_state_names
[] = {
179 static const char *rcu_torture_writer_state_getname(void)
181 unsigned int i
= READ_ONCE(rcu_torture_writer_state
);
183 if (i
>= ARRAY_SIZE(rcu_torture_writer_state_names
))
185 return rcu_torture_writer_state_names
[i
];
188 static int torture_runnable
= IS_ENABLED(MODULE
);
189 module_param(torture_runnable
, int, 0444);
190 MODULE_PARM_DESC(torture_runnable
, "Start rcutorture at boot");
192 #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU)
193 #define rcu_can_boost() 1
194 #else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
195 #define rcu_can_boost() 0
196 #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
198 #ifdef CONFIG_RCU_TRACE
199 static u64 notrace
rcu_trace_clock_local(void)
201 u64 ts
= trace_clock_local();
202 unsigned long __maybe_unused ts_rem
= do_div(ts
, NSEC_PER_USEC
);
205 #else /* #ifdef CONFIG_RCU_TRACE */
206 static u64 notrace
rcu_trace_clock_local(void)
210 #endif /* #else #ifdef CONFIG_RCU_TRACE */
212 static unsigned long boost_starttime
; /* jiffies of next boost test start. */
213 static DEFINE_MUTEX(boost_mutex
); /* protect setting boost_starttime */
214 /* and boost task create/destroy. */
215 static atomic_t barrier_cbs_count
; /* Barrier callbacks registered. */
216 static bool barrier_phase
; /* Test phase. */
217 static atomic_t barrier_cbs_invoked
; /* Barrier callbacks invoked. */
218 static wait_queue_head_t
*barrier_cbs_wq
; /* Coordinate barrier testing. */
219 static DECLARE_WAIT_QUEUE_HEAD(barrier_wq
);
222 * Allocate an element from the rcu_tortures pool.
224 static struct rcu_torture
*
225 rcu_torture_alloc(void)
229 spin_lock_bh(&rcu_torture_lock
);
230 if (list_empty(&rcu_torture_freelist
)) {
231 atomic_inc(&n_rcu_torture_alloc_fail
);
232 spin_unlock_bh(&rcu_torture_lock
);
235 atomic_inc(&n_rcu_torture_alloc
);
236 p
= rcu_torture_freelist
.next
;
238 spin_unlock_bh(&rcu_torture_lock
);
239 return container_of(p
, struct rcu_torture
, rtort_free
);
243 * Free an element to the rcu_tortures pool.
246 rcu_torture_free(struct rcu_torture
*p
)
248 atomic_inc(&n_rcu_torture_free
);
249 spin_lock_bh(&rcu_torture_lock
);
250 list_add_tail(&p
->rtort_free
, &rcu_torture_freelist
);
251 spin_unlock_bh(&rcu_torture_lock
);
255 * Operations vector for selecting different types of tests.
258 struct rcu_torture_ops
{
261 void (*cleanup
)(void);
262 int (*readlock
)(void);
263 void (*read_delay
)(struct torture_random_state
*rrsp
);
264 void (*readunlock
)(int idx
);
265 unsigned long (*started
)(void);
266 unsigned long (*completed
)(void);
267 void (*deferred_free
)(struct rcu_torture
*p
);
269 void (*exp_sync
)(void);
270 unsigned long (*get_state
)(void);
271 void (*cond_sync
)(unsigned long oldstate
);
272 call_rcu_func_t call
;
273 void (*cb_barrier
)(void);
281 static struct rcu_torture_ops
*cur_ops
;
284 * Definitions for rcu torture testing.
287 static int rcu_torture_read_lock(void) __acquires(RCU
)
293 static void rcu_read_delay(struct torture_random_state
*rrsp
)
295 unsigned long started
;
296 unsigned long completed
;
297 const unsigned long shortdelay_us
= 200;
298 const unsigned long longdelay_ms
= 50;
299 unsigned long long ts
;
301 /* We want a short delay sometimes to make a reader delay the grace
302 * period, and we want a long delay occasionally to trigger
303 * force_quiescent_state. */
305 if (!(torture_random(rrsp
) % (nrealreaders
* 2000 * longdelay_ms
))) {
306 started
= cur_ops
->completed();
307 ts
= rcu_trace_clock_local();
308 mdelay(longdelay_ms
);
309 completed
= cur_ops
->completed();
310 do_trace_rcu_torture_read(cur_ops
->name
, NULL
, ts
,
313 if (!(torture_random(rrsp
) % (nrealreaders
* 2 * shortdelay_us
)))
314 udelay(shortdelay_us
);
315 #ifdef CONFIG_PREEMPT
316 if (!preempt_count() &&
317 !(torture_random(rrsp
) % (nrealreaders
* 20000)))
318 preempt_schedule(); /* No QS if preempt_disable() in effect */
322 static void rcu_torture_read_unlock(int idx
) __releases(RCU
)
328 * Update callback in the pipe. This should be invoked after a grace period.
331 rcu_torture_pipe_update_one(struct rcu_torture
*rp
)
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;
347 * Update all callbacks in the pipe. Suitable for synchronous grace-period
351 rcu_torture_pipe_update(struct rcu_torture
*old_rp
)
353 struct rcu_torture
*rp
;
354 struct rcu_torture
*rp1
;
357 list_add(&old_rp
->rtort_free
, &rcu_torture_removed
);
358 list_for_each_entry_safe(rp
, rp1
, &rcu_torture_removed
, rtort_free
) {
359 if (rcu_torture_pipe_update_one(rp
)) {
360 list_del(&rp
->rtort_free
);
361 rcu_torture_free(rp
);
367 rcu_torture_cb(struct rcu_head
*p
)
369 struct rcu_torture
*rp
= container_of(p
, struct rcu_torture
, rtort_rcu
);
371 if (torture_must_stop_irq()) {
372 /* Test is ending, just drop callbacks on the floor. */
373 /* The next initialization will pick up the pieces. */
376 if (rcu_torture_pipe_update_one(rp
))
377 rcu_torture_free(rp
);
379 cur_ops
->deferred_free(rp
);
382 static unsigned long rcu_no_completed(void)
387 static void rcu_torture_deferred_free(struct rcu_torture
*p
)
389 call_rcu(&p
->rtort_rcu
, rcu_torture_cb
);
392 static void rcu_sync_torture_init(void)
394 INIT_LIST_HEAD(&rcu_torture_removed
);
397 static struct rcu_torture_ops rcu_ops
= {
399 .init
= rcu_sync_torture_init
,
400 .readlock
= rcu_torture_read_lock
,
401 .read_delay
= rcu_read_delay
,
402 .readunlock
= rcu_torture_read_unlock
,
403 .started
= rcu_batches_started
,
404 .completed
= rcu_batches_completed
,
405 .deferred_free
= rcu_torture_deferred_free
,
406 .sync
= synchronize_rcu
,
407 .exp_sync
= synchronize_rcu_expedited
,
408 .get_state
= get_state_synchronize_rcu
,
409 .cond_sync
= cond_synchronize_rcu
,
411 .cb_barrier
= rcu_barrier
,
412 .fqs
= rcu_force_quiescent_state
,
415 .can_boost
= rcu_can_boost(),
420 * Definitions for rcu_bh torture testing.
423 static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH
)
429 static void rcu_bh_torture_read_unlock(int idx
) __releases(RCU_BH
)
431 rcu_read_unlock_bh();
434 static void rcu_bh_torture_deferred_free(struct rcu_torture
*p
)
436 call_rcu_bh(&p
->rtort_rcu
, rcu_torture_cb
);
439 static struct rcu_torture_ops rcu_bh_ops
= {
440 .ttype
= RCU_BH_FLAVOR
,
441 .init
= rcu_sync_torture_init
,
442 .readlock
= rcu_bh_torture_read_lock
,
443 .read_delay
= rcu_read_delay
, /* just reuse rcu's version. */
444 .readunlock
= rcu_bh_torture_read_unlock
,
445 .started
= rcu_batches_started_bh
,
446 .completed
= rcu_batches_completed_bh
,
447 .deferred_free
= rcu_bh_torture_deferred_free
,
448 .sync
= synchronize_rcu_bh
,
449 .exp_sync
= synchronize_rcu_bh_expedited
,
451 .cb_barrier
= rcu_barrier_bh
,
452 .fqs
= rcu_bh_force_quiescent_state
,
459 * Don't even think about trying any of these in real life!!!
460 * The names includes "busted", and they really means it!
461 * The only purpose of these functions is to provide a buggy RCU
462 * implementation to make sure that rcutorture correctly emits
463 * buggy-RCU error messages.
465 static void rcu_busted_torture_deferred_free(struct rcu_torture
*p
)
467 /* This is a deliberate bug for testing purposes only! */
468 rcu_torture_cb(&p
->rtort_rcu
);
471 static void synchronize_rcu_busted(void)
473 /* This is a deliberate bug for testing purposes only! */
477 call_rcu_busted(struct rcu_head
*head
, rcu_callback_t func
)
479 /* This is a deliberate bug for testing purposes only! */
483 static struct rcu_torture_ops rcu_busted_ops
= {
484 .ttype
= INVALID_RCU_FLAVOR
,
485 .init
= rcu_sync_torture_init
,
486 .readlock
= rcu_torture_read_lock
,
487 .read_delay
= rcu_read_delay
, /* just reuse rcu's version. */
488 .readunlock
= rcu_torture_read_unlock
,
489 .started
= rcu_no_completed
,
490 .completed
= rcu_no_completed
,
491 .deferred_free
= rcu_busted_torture_deferred_free
,
492 .sync
= synchronize_rcu_busted
,
493 .exp_sync
= synchronize_rcu_busted
,
494 .call
= call_rcu_busted
,
503 * Definitions for srcu torture testing.
506 DEFINE_STATIC_SRCU(srcu_ctl
);
507 static struct srcu_struct srcu_ctld
;
508 static struct srcu_struct
*srcu_ctlp
= &srcu_ctl
;
510 static int srcu_torture_read_lock(void) __acquires(srcu_ctlp
)
512 return srcu_read_lock(srcu_ctlp
);
515 static void srcu_read_delay(struct torture_random_state
*rrsp
)
518 const long uspertick
= 1000000 / HZ
;
519 const long longdelay
= 10;
521 /* We want there to be long-running readers, but not all the time. */
523 delay
= torture_random(rrsp
) %
524 (nrealreaders
* 2 * longdelay
* uspertick
);
526 schedule_timeout_interruptible(longdelay
);
528 rcu_read_delay(rrsp
);
531 static void srcu_torture_read_unlock(int idx
) __releases(srcu_ctlp
)
533 srcu_read_unlock(srcu_ctlp
, idx
);
536 static unsigned long srcu_torture_completed(void)
538 return srcu_batches_completed(srcu_ctlp
);
541 static void srcu_torture_deferred_free(struct rcu_torture
*rp
)
543 call_srcu(srcu_ctlp
, &rp
->rtort_rcu
, rcu_torture_cb
);
546 static void srcu_torture_synchronize(void)
548 synchronize_srcu(srcu_ctlp
);
551 static void srcu_torture_call(struct rcu_head
*head
,
554 call_srcu(srcu_ctlp
, head
, func
);
557 static void srcu_torture_barrier(void)
559 srcu_barrier(srcu_ctlp
);
562 static void srcu_torture_stats(void)
564 int __maybe_unused cpu
;
567 #ifdef CONFIG_TREE_SRCU
568 idx
= srcu_ctlp
->srcu_idx
& 0x1;
569 pr_alert("%s%s Tree SRCU per-CPU(idx=%d):",
570 torture_type
, TORTURE_FLAG
, idx
);
571 for_each_possible_cpu(cpu
) {
572 unsigned long l0
, l1
;
573 unsigned long u0
, u1
;
575 struct srcu_data
*counts
;
577 counts
= per_cpu_ptr(srcu_ctlp
->sda
, cpu
);
578 u0
= counts
->srcu_unlock_count
[!idx
];
579 u1
= counts
->srcu_unlock_count
[idx
];
582 * Make sure that a lock is always counted if the corresponding
587 l0
= counts
->srcu_lock_count
[!idx
];
588 l1
= counts
->srcu_lock_count
[idx
];
592 pr_cont(" %d(%ld,%ld)", cpu
, c0
, c1
);
595 #elif defined(CONFIG_TINY_SRCU)
596 idx
= READ_ONCE(srcu_ctlp
->srcu_idx
) & 0x1;
597 pr_alert("%s%s Tiny SRCU per-CPU(idx=%d): (%hd,%hd)\n",
598 torture_type
, TORTURE_FLAG
, idx
,
599 READ_ONCE(srcu_ctlp
->srcu_lock_nesting
[!idx
]),
600 READ_ONCE(srcu_ctlp
->srcu_lock_nesting
[idx
]));
604 static void srcu_torture_synchronize_expedited(void)
606 synchronize_srcu_expedited(srcu_ctlp
);
609 static struct rcu_torture_ops srcu_ops
= {
610 .ttype
= SRCU_FLAVOR
,
611 .init
= rcu_sync_torture_init
,
612 .readlock
= srcu_torture_read_lock
,
613 .read_delay
= srcu_read_delay
,
614 .readunlock
= srcu_torture_read_unlock
,
616 .completed
= srcu_torture_completed
,
617 .deferred_free
= srcu_torture_deferred_free
,
618 .sync
= srcu_torture_synchronize
,
619 .exp_sync
= srcu_torture_synchronize_expedited
,
620 .call
= srcu_torture_call
,
621 .cb_barrier
= srcu_torture_barrier
,
622 .stats
= srcu_torture_stats
,
626 static void srcu_torture_init(void)
628 rcu_sync_torture_init();
629 WARN_ON(init_srcu_struct(&srcu_ctld
));
630 srcu_ctlp
= &srcu_ctld
;
633 static void srcu_torture_cleanup(void)
635 cleanup_srcu_struct(&srcu_ctld
);
636 srcu_ctlp
= &srcu_ctl
; /* In case of a later rcutorture run. */
639 /* As above, but dynamically allocated. */
640 static struct rcu_torture_ops srcud_ops
= {
641 .ttype
= SRCU_FLAVOR
,
642 .init
= srcu_torture_init
,
643 .cleanup
= srcu_torture_cleanup
,
644 .readlock
= srcu_torture_read_lock
,
645 .read_delay
= srcu_read_delay
,
646 .readunlock
= srcu_torture_read_unlock
,
648 .completed
= srcu_torture_completed
,
649 .deferred_free
= srcu_torture_deferred_free
,
650 .sync
= srcu_torture_synchronize
,
651 .exp_sync
= srcu_torture_synchronize_expedited
,
652 .call
= srcu_torture_call
,
653 .cb_barrier
= srcu_torture_barrier
,
654 .stats
= srcu_torture_stats
,
659 * Definitions for sched torture testing.
662 static int sched_torture_read_lock(void)
668 static void sched_torture_read_unlock(int idx
)
673 static void rcu_sched_torture_deferred_free(struct rcu_torture
*p
)
675 call_rcu_sched(&p
->rtort_rcu
, rcu_torture_cb
);
678 static struct rcu_torture_ops sched_ops
= {
679 .ttype
= RCU_SCHED_FLAVOR
,
680 .init
= rcu_sync_torture_init
,
681 .readlock
= sched_torture_read_lock
,
682 .read_delay
= rcu_read_delay
, /* just reuse rcu's version. */
683 .readunlock
= sched_torture_read_unlock
,
684 .started
= rcu_batches_started_sched
,
685 .completed
= rcu_batches_completed_sched
,
686 .deferred_free
= rcu_sched_torture_deferred_free
,
687 .sync
= synchronize_sched
,
688 .exp_sync
= synchronize_sched_expedited
,
689 .get_state
= get_state_synchronize_sched
,
690 .cond_sync
= cond_synchronize_sched
,
691 .call
= call_rcu_sched
,
692 .cb_barrier
= rcu_barrier_sched
,
693 .fqs
= rcu_sched_force_quiescent_state
,
699 #ifdef CONFIG_TASKS_RCU
702 * Definitions for RCU-tasks torture testing.
705 static int tasks_torture_read_lock(void)
710 static void tasks_torture_read_unlock(int idx
)
714 static void rcu_tasks_torture_deferred_free(struct rcu_torture
*p
)
716 call_rcu_tasks(&p
->rtort_rcu
, rcu_torture_cb
);
719 static struct rcu_torture_ops tasks_ops
= {
720 .ttype
= RCU_TASKS_FLAVOR
,
721 .init
= rcu_sync_torture_init
,
722 .readlock
= tasks_torture_read_lock
,
723 .read_delay
= rcu_read_delay
, /* just reuse rcu's version. */
724 .readunlock
= tasks_torture_read_unlock
,
725 .started
= rcu_no_completed
,
726 .completed
= rcu_no_completed
,
727 .deferred_free
= rcu_tasks_torture_deferred_free
,
728 .sync
= synchronize_rcu_tasks
,
729 .exp_sync
= synchronize_rcu_tasks
,
730 .call
= call_rcu_tasks
,
731 .cb_barrier
= rcu_barrier_tasks
,
738 #define RCUTORTURE_TASKS_OPS &tasks_ops,
740 static bool __maybe_unused
torturing_tasks(void)
742 return cur_ops
== &tasks_ops
;
745 #else /* #ifdef CONFIG_TASKS_RCU */
747 #define RCUTORTURE_TASKS_OPS
749 static bool __maybe_unused
torturing_tasks(void)
754 #endif /* #else #ifdef CONFIG_TASKS_RCU */
757 * RCU torture priority-boost testing. Runs one real-time thread per
758 * CPU for moderate bursts, repeatedly registering RCU callbacks and
759 * spinning waiting for them to be invoked. If a given callback takes
760 * too long to be invoked, we assume that priority inversion has occurred.
763 struct rcu_boost_inflight
{
768 static void rcu_torture_boost_cb(struct rcu_head
*head
)
770 struct rcu_boost_inflight
*rbip
=
771 container_of(head
, struct rcu_boost_inflight
, rcu
);
773 /* Ensure RCU-core accesses precede clearing ->inflight */
774 smp_store_release(&rbip
->inflight
, 0);
777 static int rcu_torture_boost(void *arg
)
779 unsigned long call_rcu_time
;
780 unsigned long endtime
;
781 unsigned long oldstarttime
;
782 struct rcu_boost_inflight rbi
= { .inflight
= 0 };
783 struct sched_param sp
;
785 VERBOSE_TOROUT_STRING("rcu_torture_boost started");
787 /* Set real-time priority. */
788 sp
.sched_priority
= 1;
789 if (sched_setscheduler(current
, SCHED_FIFO
, &sp
) < 0) {
790 VERBOSE_TOROUT_STRING("rcu_torture_boost RT prio failed!");
791 n_rcu_torture_boost_rterror
++;
794 init_rcu_head_on_stack(&rbi
.rcu
);
795 /* Each pass through the following loop does one boost-test cycle. */
797 /* Wait for the next test interval. */
798 oldstarttime
= boost_starttime
;
799 while (ULONG_CMP_LT(jiffies
, oldstarttime
)) {
800 schedule_timeout_interruptible(oldstarttime
- jiffies
);
801 stutter_wait("rcu_torture_boost");
802 if (torture_must_stop())
806 /* Do one boost-test interval. */
807 endtime
= oldstarttime
+ test_boost_duration
* HZ
;
808 call_rcu_time
= jiffies
;
809 while (ULONG_CMP_LT(jiffies
, endtime
)) {
810 /* If we don't have a callback in flight, post one. */
811 if (!smp_load_acquire(&rbi
.inflight
)) {
812 /* RCU core before ->inflight = 1. */
813 smp_store_release(&rbi
.inflight
, 1);
814 call_rcu(&rbi
.rcu
, rcu_torture_boost_cb
);
815 if (jiffies
- call_rcu_time
>
816 test_boost_duration
* HZ
- HZ
/ 2) {
817 VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed");
818 n_rcu_torture_boost_failure
++;
820 call_rcu_time
= jiffies
;
822 stutter_wait("rcu_torture_boost");
823 if (torture_must_stop())
828 * Set the start time of the next test interval.
829 * Yes, this is vulnerable to long delays, but such
830 * delays simply cause a false negative for the next
831 * interval. Besides, we are running at RT priority,
832 * so delays should be relatively rare.
834 while (oldstarttime
== boost_starttime
&&
835 !kthread_should_stop()) {
836 if (mutex_trylock(&boost_mutex
)) {
837 boost_starttime
= jiffies
+
838 test_boost_interval
* HZ
;
839 n_rcu_torture_boosts
++;
840 mutex_unlock(&boost_mutex
);
843 schedule_timeout_uninterruptible(1);
846 /* Go do the stutter. */
847 checkwait
: stutter_wait("rcu_torture_boost");
848 } while (!torture_must_stop());
850 /* Clean up and exit. */
851 while (!kthread_should_stop() || smp_load_acquire(&rbi
.inflight
)) {
852 torture_shutdown_absorb("rcu_torture_boost");
853 schedule_timeout_uninterruptible(1);
855 destroy_rcu_head_on_stack(&rbi
.rcu
);
856 torture_kthread_stopping("rcu_torture_boost");
860 static void rcu_torture_cbflood_cb(struct rcu_head
*rhp
)
865 * RCU torture callback-flood kthread. Repeatedly induces bursts of calls
866 * to call_rcu() or analogous, increasing the probability of occurrence
867 * of callback-overflow corner cases.
870 rcu_torture_cbflood(void *arg
)
875 struct rcu_head
*rhp
;
877 if (cbflood_n_per_burst
> 0 &&
878 cbflood_inter_holdoff
> 0 &&
879 cbflood_intra_holdoff
> 0 &&
881 cur_ops
->cb_barrier
) {
882 rhp
= vmalloc(sizeof(*rhp
) *
883 cbflood_n_burst
* cbflood_n_per_burst
);
887 VERBOSE_TOROUT_STRING("rcu_torture_cbflood disabled: Bad args or OOM");
890 VERBOSE_TOROUT_STRING("rcu_torture_cbflood task started");
892 schedule_timeout_interruptible(cbflood_inter_holdoff
);
893 atomic_long_inc(&n_cbfloods
);
894 WARN_ON(signal_pending(current
));
895 for (i
= 0; i
< cbflood_n_burst
; i
++) {
896 for (j
= 0; j
< cbflood_n_per_burst
; j
++) {
897 cur_ops
->call(&rhp
[i
* cbflood_n_per_burst
+ j
],
898 rcu_torture_cbflood_cb
);
900 schedule_timeout_interruptible(cbflood_intra_holdoff
);
901 WARN_ON(signal_pending(current
));
903 cur_ops
->cb_barrier();
904 stutter_wait("rcu_torture_cbflood");
905 } while (!torture_must_stop());
908 torture_kthread_stopping("rcu_torture_cbflood");
913 * RCU torture force-quiescent-state kthread. Repeatedly induces
914 * bursts of calls to force_quiescent_state(), increasing the probability
915 * of occurrence of some important types of race conditions.
918 rcu_torture_fqs(void *arg
)
920 unsigned long fqs_resume_time
;
921 int fqs_burst_remaining
;
923 VERBOSE_TOROUT_STRING("rcu_torture_fqs task started");
925 fqs_resume_time
= jiffies
+ fqs_stutter
* HZ
;
926 while (ULONG_CMP_LT(jiffies
, fqs_resume_time
) &&
927 !kthread_should_stop()) {
928 schedule_timeout_interruptible(1);
930 fqs_burst_remaining
= fqs_duration
;
931 while (fqs_burst_remaining
> 0 &&
932 !kthread_should_stop()) {
935 fqs_burst_remaining
-= fqs_holdoff
;
937 stutter_wait("rcu_torture_fqs");
938 } while (!torture_must_stop());
939 torture_kthread_stopping("rcu_torture_fqs");
944 * RCU torture writer kthread. Repeatedly substitutes a new structure
945 * for that pointed to by rcu_torture_current, freeing the old structure
946 * after a series of grace periods (the "pipeline").
949 rcu_torture_writer(void *arg
)
951 bool can_expedite
= !rcu_gp_is_expedited() && !rcu_gp_is_normal();
953 unsigned long gp_snap
;
954 bool gp_cond1
= gp_cond
, gp_exp1
= gp_exp
, gp_normal1
= gp_normal
;
955 bool gp_sync1
= gp_sync
;
957 struct rcu_torture
*rp
;
958 struct rcu_torture
*old_rp
;
959 static DEFINE_TORTURE_RANDOM(rand
);
960 int synctype
[] = { RTWS_DEF_FREE
, RTWS_EXP_SYNC
,
961 RTWS_COND_GET
, RTWS_SYNC
};
964 VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
966 pr_alert("%s" TORTURE_FLAG
967 " GP expediting controlled from boot/sysfs for %s,\n",
968 torture_type
, cur_ops
->name
);
969 pr_alert("%s" TORTURE_FLAG
970 " Disabled dynamic grace-period expediting.\n",
974 /* Initialize synctype[] array. If none set, take default. */
975 if (!gp_cond1
&& !gp_exp1
&& !gp_normal1
&& !gp_sync1
)
976 gp_cond1
= gp_exp1
= gp_normal1
= gp_sync1
= true;
977 if (gp_cond1
&& cur_ops
->get_state
&& cur_ops
->cond_sync
)
978 synctype
[nsynctypes
++] = RTWS_COND_GET
;
979 else if (gp_cond
&& (!cur_ops
->get_state
|| !cur_ops
->cond_sync
))
980 pr_alert("rcu_torture_writer: gp_cond without primitives.\n");
981 if (gp_exp1
&& cur_ops
->exp_sync
)
982 synctype
[nsynctypes
++] = RTWS_EXP_SYNC
;
983 else if (gp_exp
&& !cur_ops
->exp_sync
)
984 pr_alert("rcu_torture_writer: gp_exp without primitives.\n");
985 if (gp_normal1
&& cur_ops
->deferred_free
)
986 synctype
[nsynctypes
++] = RTWS_DEF_FREE
;
987 else if (gp_normal
&& !cur_ops
->deferred_free
)
988 pr_alert("rcu_torture_writer: gp_normal without primitives.\n");
989 if (gp_sync1
&& cur_ops
->sync
)
990 synctype
[nsynctypes
++] = RTWS_SYNC
;
991 else if (gp_sync
&& !cur_ops
->sync
)
992 pr_alert("rcu_torture_writer: gp_sync without primitives.\n");
993 if (WARN_ONCE(nsynctypes
== 0,
994 "rcu_torture_writer: No update-side primitives.\n")) {
996 * No updates primitives, so don't try updating.
997 * The resulting test won't be testing much, hence the
1000 rcu_torture_writer_state
= RTWS_STOPPING
;
1001 torture_kthread_stopping("rcu_torture_writer");
1005 rcu_torture_writer_state
= RTWS_FIXED_DELAY
;
1006 schedule_timeout_uninterruptible(1);
1007 rp
= rcu_torture_alloc();
1010 rp
->rtort_pipe_count
= 0;
1011 rcu_torture_writer_state
= RTWS_DELAY
;
1012 udelay(torture_random(&rand
) & 0x3ff);
1013 rcu_torture_writer_state
= RTWS_REPLACE
;
1014 old_rp
= rcu_dereference_check(rcu_torture_current
,
1015 current
== writer_task
);
1016 rp
->rtort_mbtest
= 1;
1017 rcu_assign_pointer(rcu_torture_current
, rp
);
1018 smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */
1020 i
= old_rp
->rtort_pipe_count
;
1021 if (i
> RCU_TORTURE_PIPE_LEN
)
1022 i
= RCU_TORTURE_PIPE_LEN
;
1023 atomic_inc(&rcu_torture_wcount
[i
]);
1024 old_rp
->rtort_pipe_count
++;
1025 switch (synctype
[torture_random(&rand
) % nsynctypes
]) {
1027 rcu_torture_writer_state
= RTWS_DEF_FREE
;
1028 cur_ops
->deferred_free(old_rp
);
1031 rcu_torture_writer_state
= RTWS_EXP_SYNC
;
1032 cur_ops
->exp_sync();
1033 rcu_torture_pipe_update(old_rp
);
1036 rcu_torture_writer_state
= RTWS_COND_GET
;
1037 gp_snap
= cur_ops
->get_state();
1038 i
= torture_random(&rand
) % 16;
1040 schedule_timeout_interruptible(i
);
1041 udelay(torture_random(&rand
) % 1000);
1042 rcu_torture_writer_state
= RTWS_COND_SYNC
;
1043 cur_ops
->cond_sync(gp_snap
);
1044 rcu_torture_pipe_update(old_rp
);
1047 rcu_torture_writer_state
= RTWS_SYNC
;
1049 rcu_torture_pipe_update(old_rp
);
1056 rcutorture_record_progress(++rcu_torture_current_version
);
1057 /* Cycle through nesting levels of rcu_expedite_gp() calls. */
1059 !(torture_random(&rand
) & 0xff & (!!expediting
- 1))) {
1060 WARN_ON_ONCE(expediting
== 0 && rcu_gp_is_expedited());
1061 if (expediting
>= 0)
1064 rcu_unexpedite_gp();
1065 if (++expediting
> 3)
1066 expediting
= -expediting
;
1068 rcu_torture_writer_state
= RTWS_STUTTER
;
1069 stutter_wait("rcu_torture_writer");
1070 } while (!torture_must_stop());
1071 /* Reset expediting back to unexpedited. */
1073 expediting
= -expediting
;
1074 while (can_expedite
&& expediting
++ < 0)
1075 rcu_unexpedite_gp();
1076 WARN_ON_ONCE(can_expedite
&& rcu_gp_is_expedited());
1077 rcu_torture_writer_state
= RTWS_STOPPING
;
1078 torture_kthread_stopping("rcu_torture_writer");
1083 * RCU torture fake writer kthread. Repeatedly calls sync, with a random
1084 * delay between calls.
1087 rcu_torture_fakewriter(void *arg
)
1089 DEFINE_TORTURE_RANDOM(rand
);
1091 VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started");
1092 set_user_nice(current
, MAX_NICE
);
1095 schedule_timeout_uninterruptible(1 + torture_random(&rand
)%10);
1096 udelay(torture_random(&rand
) & 0x3ff);
1097 if (cur_ops
->cb_barrier
!= NULL
&&
1098 torture_random(&rand
) % (nfakewriters
* 8) == 0) {
1099 cur_ops
->cb_barrier();
1100 } else if (gp_normal
== gp_exp
) {
1101 if (torture_random(&rand
) & 0x80)
1104 cur_ops
->exp_sync();
1105 } else if (gp_normal
) {
1108 cur_ops
->exp_sync();
1110 stutter_wait("rcu_torture_fakewriter");
1111 } while (!torture_must_stop());
1113 torture_kthread_stopping("rcu_torture_fakewriter");
1118 * RCU torture reader from timer handler. Dereferences rcu_torture_current,
1119 * incrementing the corresponding element of the pipeline array. The
1120 * counter in the element should never be greater than 1, otherwise, the
1121 * RCU implementation is broken.
1123 static void rcu_torture_timer(unsigned long unused
)
1126 unsigned long started
;
1127 unsigned long completed
;
1128 static DEFINE_TORTURE_RANDOM(rand
);
1129 static DEFINE_SPINLOCK(rand_lock
);
1130 struct rcu_torture
*p
;
1132 unsigned long long ts
;
1134 idx
= cur_ops
->readlock();
1135 if (cur_ops
->started
)
1136 started
= cur_ops
->started();
1138 started
= cur_ops
->completed();
1139 ts
= rcu_trace_clock_local();
1140 p
= rcu_dereference_check(rcu_torture_current
,
1141 rcu_read_lock_bh_held() ||
1142 rcu_read_lock_sched_held() ||
1143 srcu_read_lock_held(srcu_ctlp
) ||
1146 /* Leave because rcu_torture_writer is not yet underway */
1147 cur_ops
->readunlock(idx
);
1150 if (p
->rtort_mbtest
== 0)
1151 atomic_inc(&n_rcu_torture_mberror
);
1152 spin_lock(&rand_lock
);
1153 cur_ops
->read_delay(&rand
);
1154 n_rcu_torture_timers
++;
1155 spin_unlock(&rand_lock
);
1157 pipe_count
= p
->rtort_pipe_count
;
1158 if (pipe_count
> RCU_TORTURE_PIPE_LEN
) {
1159 /* Should not happen, but... */
1160 pipe_count
= RCU_TORTURE_PIPE_LEN
;
1162 completed
= cur_ops
->completed();
1163 if (pipe_count
> 1) {
1164 do_trace_rcu_torture_read(cur_ops
->name
, &p
->rtort_rcu
, ts
,
1165 started
, completed
);
1166 rcu_ftrace_dump(DUMP_ALL
);
1168 __this_cpu_inc(rcu_torture_count
[pipe_count
]);
1169 completed
= completed
- started
;
1170 if (cur_ops
->started
)
1172 if (completed
> RCU_TORTURE_PIPE_LEN
) {
1173 /* Should not happen, but... */
1174 completed
= RCU_TORTURE_PIPE_LEN
;
1176 __this_cpu_inc(rcu_torture_batch
[completed
]);
1178 cur_ops
->readunlock(idx
);
1182 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current,
1183 * incrementing the corresponding element of the pipeline array. The
1184 * counter in the element should never be greater than 1, otherwise, the
1185 * RCU implementation is broken.
1188 rcu_torture_reader(void *arg
)
1190 unsigned long started
;
1191 unsigned long completed
;
1193 DEFINE_TORTURE_RANDOM(rand
);
1194 struct rcu_torture
*p
;
1196 struct timer_list t
;
1197 unsigned long long ts
;
1199 VERBOSE_TOROUT_STRING("rcu_torture_reader task started");
1200 set_user_nice(current
, MAX_NICE
);
1201 if (irqreader
&& cur_ops
->irq_capable
)
1202 setup_timer_on_stack(&t
, rcu_torture_timer
, 0);
1205 if (irqreader
&& cur_ops
->irq_capable
) {
1206 if (!timer_pending(&t
))
1207 mod_timer(&t
, jiffies
+ 1);
1209 idx
= cur_ops
->readlock();
1210 if (cur_ops
->started
)
1211 started
= cur_ops
->started();
1213 started
= cur_ops
->completed();
1214 ts
= rcu_trace_clock_local();
1215 p
= rcu_dereference_check(rcu_torture_current
,
1216 rcu_read_lock_bh_held() ||
1217 rcu_read_lock_sched_held() ||
1218 srcu_read_lock_held(srcu_ctlp
) ||
1221 /* Wait for rcu_torture_writer to get underway */
1222 cur_ops
->readunlock(idx
);
1223 schedule_timeout_interruptible(HZ
);
1226 if (p
->rtort_mbtest
== 0)
1227 atomic_inc(&n_rcu_torture_mberror
);
1228 cur_ops
->read_delay(&rand
);
1230 pipe_count
= p
->rtort_pipe_count
;
1231 if (pipe_count
> RCU_TORTURE_PIPE_LEN
) {
1232 /* Should not happen, but... */
1233 pipe_count
= RCU_TORTURE_PIPE_LEN
;
1235 completed
= cur_ops
->completed();
1236 if (pipe_count
> 1) {
1237 do_trace_rcu_torture_read(cur_ops
->name
, &p
->rtort_rcu
,
1238 ts
, started
, completed
);
1239 rcu_ftrace_dump(DUMP_ALL
);
1241 __this_cpu_inc(rcu_torture_count
[pipe_count
]);
1242 completed
= completed
- started
;
1243 if (cur_ops
->started
)
1245 if (completed
> RCU_TORTURE_PIPE_LEN
) {
1246 /* Should not happen, but... */
1247 completed
= RCU_TORTURE_PIPE_LEN
;
1249 __this_cpu_inc(rcu_torture_batch
[completed
]);
1251 cur_ops
->readunlock(idx
);
1252 stutter_wait("rcu_torture_reader");
1253 } while (!torture_must_stop());
1254 if (irqreader
&& cur_ops
->irq_capable
) {
1256 destroy_timer_on_stack(&t
);
1258 torture_kthread_stopping("rcu_torture_reader");
1263 * Print torture statistics. Caller must ensure that there is only
1264 * one call to this function at a given time!!! This is normally
1265 * accomplished by relying on the module system to only have one copy
1266 * of the module loaded, and then by giving the rcu_torture_stats
1267 * kthread full control (or the init/cleanup functions when rcu_torture_stats
1268 * thread is not running).
1271 rcu_torture_stats_print(void)
1275 long pipesummary
[RCU_TORTURE_PIPE_LEN
+ 1] = { 0 };
1276 long batchsummary
[RCU_TORTURE_PIPE_LEN
+ 1] = { 0 };
1277 static unsigned long rtcv_snap
= ULONG_MAX
;
1278 struct task_struct
*wtp
;
1280 for_each_possible_cpu(cpu
) {
1281 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++) {
1282 pipesummary
[i
] += per_cpu(rcu_torture_count
, cpu
)[i
];
1283 batchsummary
[i
] += per_cpu(rcu_torture_batch
, cpu
)[i
];
1286 for (i
= RCU_TORTURE_PIPE_LEN
- 1; i
>= 0; i
--) {
1287 if (pipesummary
[i
] != 0)
1291 pr_alert("%s%s ", torture_type
, TORTURE_FLAG
);
1292 pr_cont("rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
1293 rcu_torture_current
,
1294 rcu_torture_current_version
,
1295 list_empty(&rcu_torture_freelist
),
1296 atomic_read(&n_rcu_torture_alloc
),
1297 atomic_read(&n_rcu_torture_alloc_fail
),
1298 atomic_read(&n_rcu_torture_free
));
1299 pr_cont("rtmbe: %d rtbe: %ld rtbke: %ld rtbre: %ld ",
1300 atomic_read(&n_rcu_torture_mberror
),
1301 n_rcu_torture_barrier_error
,
1302 n_rcu_torture_boost_ktrerror
,
1303 n_rcu_torture_boost_rterror
);
1304 pr_cont("rtbf: %ld rtb: %ld nt: %ld ",
1305 n_rcu_torture_boost_failure
,
1306 n_rcu_torture_boosts
,
1307 n_rcu_torture_timers
);
1308 torture_onoff_stats();
1309 pr_cont("barrier: %ld/%ld:%ld ",
1310 n_barrier_successes
,
1312 n_rcu_torture_barrier_error
);
1313 pr_cont("cbflood: %ld\n", atomic_long_read(&n_cbfloods
));
1315 pr_alert("%s%s ", torture_type
, TORTURE_FLAG
);
1316 if (atomic_read(&n_rcu_torture_mberror
) != 0 ||
1317 n_rcu_torture_barrier_error
!= 0 ||
1318 n_rcu_torture_boost_ktrerror
!= 0 ||
1319 n_rcu_torture_boost_rterror
!= 0 ||
1320 n_rcu_torture_boost_failure
!= 0 ||
1322 pr_cont("%s", "!!! ");
1323 atomic_inc(&n_rcu_torture_error
);
1326 pr_cont("Reader Pipe: ");
1327 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++)
1328 pr_cont(" %ld", pipesummary
[i
]);
1331 pr_alert("%s%s ", torture_type
, TORTURE_FLAG
);
1332 pr_cont("Reader Batch: ");
1333 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++)
1334 pr_cont(" %ld", batchsummary
[i
]);
1337 pr_alert("%s%s ", torture_type
, TORTURE_FLAG
);
1338 pr_cont("Free-Block Circulation: ");
1339 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++) {
1340 pr_cont(" %d", atomic_read(&rcu_torture_wcount
[i
]));
1346 if (rtcv_snap
== rcu_torture_current_version
&&
1347 rcu_torture_current
!= NULL
) {
1348 int __maybe_unused flags
= 0;
1349 unsigned long __maybe_unused gpnum
= 0;
1350 unsigned long __maybe_unused completed
= 0;
1352 rcutorture_get_gp_data(cur_ops
->ttype
,
1353 &flags
, &gpnum
, &completed
);
1354 srcutorture_get_gp_data(cur_ops
->ttype
, srcu_ctlp
,
1355 &flags
, &gpnum
, &completed
);
1356 wtp
= READ_ONCE(writer_task
);
1357 pr_alert("??? Writer stall state %s(%d) g%lu c%lu f%#x ->state %#lx\n",
1358 rcu_torture_writer_state_getname(),
1359 rcu_torture_writer_state
,
1360 gpnum
, completed
, flags
,
1361 wtp
== NULL
? ~0UL : wtp
->state
);
1362 show_rcu_gp_kthreads();
1363 rcu_ftrace_dump(DUMP_ALL
);
1365 rtcv_snap
= rcu_torture_current_version
;
1369 * Periodically prints torture statistics, if periodic statistics printing
1370 * was specified via the stat_interval module parameter.
1373 rcu_torture_stats(void *arg
)
1375 VERBOSE_TOROUT_STRING("rcu_torture_stats task started");
1377 schedule_timeout_interruptible(stat_interval
* HZ
);
1378 rcu_torture_stats_print();
1379 torture_shutdown_absorb("rcu_torture_stats");
1380 } while (!torture_must_stop());
1381 torture_kthread_stopping("rcu_torture_stats");
1386 rcu_torture_print_module_parms(struct rcu_torture_ops
*cur_ops
, const char *tag
)
1388 pr_alert("%s" TORTURE_FLAG
1389 "--- %s: nreaders=%d nfakewriters=%d "
1390 "stat_interval=%d verbose=%d test_no_idle_hz=%d "
1391 "shuffle_interval=%d stutter=%d irqreader=%d "
1392 "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
1393 "test_boost=%d/%d test_boost_interval=%d "
1394 "test_boost_duration=%d shutdown_secs=%d "
1395 "stall_cpu=%d stall_cpu_holdoff=%d "
1397 "onoff_interval=%d onoff_holdoff=%d\n",
1398 torture_type
, tag
, nrealreaders
, nfakewriters
,
1399 stat_interval
, verbose
, test_no_idle_hz
, shuffle_interval
,
1400 stutter
, irqreader
, fqs_duration
, fqs_holdoff
, fqs_stutter
,
1401 test_boost
, cur_ops
->can_boost
,
1402 test_boost_interval
, test_boost_duration
, shutdown_secs
,
1403 stall_cpu
, stall_cpu_holdoff
,
1405 onoff_interval
, onoff_holdoff
);
1408 static int rcutorture_booster_cleanup(unsigned int cpu
)
1410 struct task_struct
*t
;
1412 if (boost_tasks
[cpu
] == NULL
)
1414 mutex_lock(&boost_mutex
);
1415 t
= boost_tasks
[cpu
];
1416 boost_tasks
[cpu
] = NULL
;
1417 mutex_unlock(&boost_mutex
);
1419 /* This must be outside of the mutex, otherwise deadlock! */
1420 torture_stop_kthread(rcu_torture_boost
, t
);
1424 static int rcutorture_booster_init(unsigned int cpu
)
1428 if (boost_tasks
[cpu
] != NULL
)
1429 return 0; /* Already created, nothing more to do. */
1431 /* Don't allow time recalculation while creating a new task. */
1432 mutex_lock(&boost_mutex
);
1433 VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task");
1434 boost_tasks
[cpu
] = kthread_create_on_node(rcu_torture_boost
, NULL
,
1436 "rcu_torture_boost");
1437 if (IS_ERR(boost_tasks
[cpu
])) {
1438 retval
= PTR_ERR(boost_tasks
[cpu
]);
1439 VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed");
1440 n_rcu_torture_boost_ktrerror
++;
1441 boost_tasks
[cpu
] = NULL
;
1442 mutex_unlock(&boost_mutex
);
1445 kthread_bind(boost_tasks
[cpu
], cpu
);
1446 wake_up_process(boost_tasks
[cpu
]);
1447 mutex_unlock(&boost_mutex
);
1452 * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then
1453 * induces a CPU stall for the time specified by stall_cpu.
1455 static int rcu_torture_stall(void *args
)
1457 unsigned long stop_at
;
1459 VERBOSE_TOROUT_STRING("rcu_torture_stall task started");
1460 if (stall_cpu_holdoff
> 0) {
1461 VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff");
1462 schedule_timeout_interruptible(stall_cpu_holdoff
* HZ
);
1463 VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff");
1465 if (!kthread_should_stop()) {
1466 stop_at
= get_seconds() + stall_cpu
;
1467 /* RCU CPU stall is expected behavior in following code. */
1468 pr_alert("rcu_torture_stall start.\n");
1471 while (ULONG_CMP_LT(get_seconds(), stop_at
))
1472 continue; /* Induce RCU CPU stall warning. */
1475 pr_alert("rcu_torture_stall end.\n");
1477 torture_shutdown_absorb("rcu_torture_stall");
1478 while (!kthread_should_stop())
1479 schedule_timeout_interruptible(10 * HZ
);
1483 /* Spawn CPU-stall kthread, if stall_cpu specified. */
1484 static int __init
rcu_torture_stall_init(void)
1488 return torture_create_kthread(rcu_torture_stall
, NULL
, stall_task
);
1491 /* Callback function for RCU barrier testing. */
1492 static void rcu_torture_barrier_cbf(struct rcu_head
*rcu
)
1494 atomic_inc(&barrier_cbs_invoked
);
1497 /* kthread function to register callbacks used to test RCU barriers. */
1498 static int rcu_torture_barrier_cbs(void *arg
)
1500 long myid
= (long)arg
;
1503 struct rcu_head rcu
;
1505 init_rcu_head_on_stack(&rcu
);
1506 VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started");
1507 set_user_nice(current
, MAX_NICE
);
1509 wait_event(barrier_cbs_wq
[myid
],
1511 smp_load_acquire(&barrier_phase
)) != lastphase
||
1512 torture_must_stop());
1513 lastphase
= newphase
;
1514 if (torture_must_stop())
1517 * The above smp_load_acquire() ensures barrier_phase load
1518 * is ordered before the following ->call().
1520 local_irq_disable(); /* Just to test no-irq call_rcu(). */
1521 cur_ops
->call(&rcu
, rcu_torture_barrier_cbf
);
1523 if (atomic_dec_and_test(&barrier_cbs_count
))
1524 wake_up(&barrier_wq
);
1525 } while (!torture_must_stop());
1526 if (cur_ops
->cb_barrier
!= NULL
)
1527 cur_ops
->cb_barrier();
1528 destroy_rcu_head_on_stack(&rcu
);
1529 torture_kthread_stopping("rcu_torture_barrier_cbs");
1533 /* kthread function to drive and coordinate RCU barrier testing. */
1534 static int rcu_torture_barrier(void *arg
)
1538 VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting");
1540 atomic_set(&barrier_cbs_invoked
, 0);
1541 atomic_set(&barrier_cbs_count
, n_barrier_cbs
);
1542 /* Ensure barrier_phase ordered after prior assignments. */
1543 smp_store_release(&barrier_phase
, !barrier_phase
);
1544 for (i
= 0; i
< n_barrier_cbs
; i
++)
1545 wake_up(&barrier_cbs_wq
[i
]);
1546 wait_event(barrier_wq
,
1547 atomic_read(&barrier_cbs_count
) == 0 ||
1548 torture_must_stop());
1549 if (torture_must_stop())
1551 n_barrier_attempts
++;
1552 cur_ops
->cb_barrier(); /* Implies smp_mb() for wait_event(). */
1553 if (atomic_read(&barrier_cbs_invoked
) != n_barrier_cbs
) {
1554 n_rcu_torture_barrier_error
++;
1555 pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n",
1556 atomic_read(&barrier_cbs_invoked
),
1560 n_barrier_successes
++;
1561 schedule_timeout_interruptible(HZ
/ 10);
1562 } while (!torture_must_stop());
1563 torture_kthread_stopping("rcu_torture_barrier");
1567 /* Initialize RCU barrier testing. */
1568 static int rcu_torture_barrier_init(void)
1573 if (n_barrier_cbs
<= 0)
1575 if (cur_ops
->call
== NULL
|| cur_ops
->cb_barrier
== NULL
) {
1576 pr_alert("%s" TORTURE_FLAG
1577 " Call or barrier ops missing for %s,\n",
1578 torture_type
, cur_ops
->name
);
1579 pr_alert("%s" TORTURE_FLAG
1580 " RCU barrier testing omitted from run.\n",
1584 atomic_set(&barrier_cbs_count
, 0);
1585 atomic_set(&barrier_cbs_invoked
, 0);
1587 kzalloc(n_barrier_cbs
* sizeof(barrier_cbs_tasks
[0]),
1590 kzalloc(n_barrier_cbs
* sizeof(barrier_cbs_wq
[0]),
1592 if (barrier_cbs_tasks
== NULL
|| !barrier_cbs_wq
)
1594 for (i
= 0; i
< n_barrier_cbs
; i
++) {
1595 init_waitqueue_head(&barrier_cbs_wq
[i
]);
1596 ret
= torture_create_kthread(rcu_torture_barrier_cbs
,
1598 barrier_cbs_tasks
[i
]);
1602 return torture_create_kthread(rcu_torture_barrier
, NULL
, barrier_task
);
1605 /* Clean up after RCU barrier testing. */
1606 static void rcu_torture_barrier_cleanup(void)
1610 torture_stop_kthread(rcu_torture_barrier
, barrier_task
);
1611 if (barrier_cbs_tasks
!= NULL
) {
1612 for (i
= 0; i
< n_barrier_cbs
; i
++)
1613 torture_stop_kthread(rcu_torture_barrier_cbs
,
1614 barrier_cbs_tasks
[i
]);
1615 kfree(barrier_cbs_tasks
);
1616 barrier_cbs_tasks
= NULL
;
1618 if (barrier_cbs_wq
!= NULL
) {
1619 kfree(barrier_cbs_wq
);
1620 barrier_cbs_wq
= NULL
;
1624 static enum cpuhp_state rcutor_hp
;
1627 rcu_torture_cleanup(void)
1631 rcutorture_record_test_transition();
1632 if (torture_cleanup_begin()) {
1633 if (cur_ops
->cb_barrier
!= NULL
)
1634 cur_ops
->cb_barrier();
1638 rcu_torture_barrier_cleanup();
1639 torture_stop_kthread(rcu_torture_stall
, stall_task
);
1640 torture_stop_kthread(rcu_torture_writer
, writer_task
);
1643 for (i
= 0; i
< nrealreaders
; i
++)
1644 torture_stop_kthread(rcu_torture_reader
,
1646 kfree(reader_tasks
);
1648 rcu_torture_current
= NULL
;
1650 if (fakewriter_tasks
) {
1651 for (i
= 0; i
< nfakewriters
; i
++) {
1652 torture_stop_kthread(rcu_torture_fakewriter
,
1653 fakewriter_tasks
[i
]);
1655 kfree(fakewriter_tasks
);
1656 fakewriter_tasks
= NULL
;
1659 torture_stop_kthread(rcu_torture_stats
, stats_task
);
1660 torture_stop_kthread(rcu_torture_fqs
, fqs_task
);
1661 for (i
= 0; i
< ncbflooders
; i
++)
1662 torture_stop_kthread(rcu_torture_cbflood
, cbflood_task
[i
]);
1663 if ((test_boost
== 1 && cur_ops
->can_boost
) ||
1665 cpuhp_remove_state(rcutor_hp
);
1668 * Wait for all RCU callbacks to fire, then do flavor-specific
1669 * cleanup operations.
1671 if (cur_ops
->cb_barrier
!= NULL
)
1672 cur_ops
->cb_barrier();
1673 if (cur_ops
->cleanup
!= NULL
)
1676 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
1678 if (atomic_read(&n_rcu_torture_error
) || n_rcu_torture_barrier_error
)
1679 rcu_torture_print_module_parms(cur_ops
, "End of test: FAILURE");
1680 else if (torture_onoff_failures())
1681 rcu_torture_print_module_parms(cur_ops
,
1682 "End of test: RCU_HOTPLUG");
1684 rcu_torture_print_module_parms(cur_ops
, "End of test: SUCCESS");
1685 torture_cleanup_end();
1688 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
1689 static void rcu_torture_leak_cb(struct rcu_head
*rhp
)
1693 static void rcu_torture_err_cb(struct rcu_head
*rhp
)
1696 * This -might- happen due to race conditions, but is unlikely.
1697 * The scenario that leads to this happening is that the
1698 * first of the pair of duplicate callbacks is queued,
1699 * someone else starts a grace period that includes that
1700 * callback, then the second of the pair must wait for the
1701 * next grace period. Unlikely, but can happen. If it
1702 * does happen, the debug-objects subsystem won't have splatted.
1704 pr_alert("rcutorture: duplicated callback was invoked.\n");
1706 #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1709 * Verify that double-free causes debug-objects to complain, but only
1710 * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test
1711 * cannot be carried out.
1713 static void rcu_test_debug_objects(void)
1715 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
1716 struct rcu_head rh1
;
1717 struct rcu_head rh2
;
1719 init_rcu_head_on_stack(&rh1
);
1720 init_rcu_head_on_stack(&rh2
);
1721 pr_alert("rcutorture: WARN: Duplicate call_rcu() test starting.\n");
1723 /* Try to queue the rh2 pair of callbacks for the same grace period. */
1724 preempt_disable(); /* Prevent preemption from interrupting test. */
1725 rcu_read_lock(); /* Make it impossible to finish a grace period. */
1726 call_rcu(&rh1
, rcu_torture_leak_cb
); /* Start grace period. */
1727 local_irq_disable(); /* Make it harder to start a new grace period. */
1728 call_rcu(&rh2
, rcu_torture_leak_cb
);
1729 call_rcu(&rh2
, rcu_torture_err_cb
); /* Duplicate callback. */
1734 /* Wait for them all to get done so we can safely return. */
1736 pr_alert("rcutorture: WARN: Duplicate call_rcu() test complete.\n");
1737 destroy_rcu_head_on_stack(&rh1
);
1738 destroy_rcu_head_on_stack(&rh2
);
1739 #else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1740 pr_alert("rcutorture: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n");
1741 #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1745 rcu_torture_init(void)
1750 static struct rcu_torture_ops
*torture_ops
[] = {
1751 &rcu_ops
, &rcu_bh_ops
, &rcu_busted_ops
, &srcu_ops
, &srcud_ops
,
1752 &sched_ops
, RCUTORTURE_TASKS_OPS
1755 if (!torture_init_begin(torture_type
, verbose
, &torture_runnable
))
1758 /* Process args and tell the world that the torturer is on the job. */
1759 for (i
= 0; i
< ARRAY_SIZE(torture_ops
); i
++) {
1760 cur_ops
= torture_ops
[i
];
1761 if (strcmp(torture_type
, cur_ops
->name
) == 0)
1764 if (i
== ARRAY_SIZE(torture_ops
)) {
1765 pr_alert("rcu-torture: invalid torture type: \"%s\"\n",
1767 pr_alert("rcu-torture types:");
1768 for (i
= 0; i
< ARRAY_SIZE(torture_ops
); i
++)
1769 pr_alert(" %s", torture_ops
[i
]->name
);
1774 if (cur_ops
->fqs
== NULL
&& fqs_duration
!= 0) {
1775 pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n");
1781 if (nreaders
>= 0) {
1782 nrealreaders
= nreaders
;
1784 nrealreaders
= num_online_cpus() - 2 - nreaders
;
1785 if (nrealreaders
<= 0)
1788 rcu_torture_print_module_parms(cur_ops
, "Start of test");
1790 /* Set up the freelist. */
1792 INIT_LIST_HEAD(&rcu_torture_freelist
);
1793 for (i
= 0; i
< ARRAY_SIZE(rcu_tortures
); i
++) {
1794 rcu_tortures
[i
].rtort_mbtest
= 0;
1795 list_add_tail(&rcu_tortures
[i
].rtort_free
,
1796 &rcu_torture_freelist
);
1799 /* Initialize the statistics so that each run gets its own numbers. */
1801 rcu_torture_current
= NULL
;
1802 rcu_torture_current_version
= 0;
1803 atomic_set(&n_rcu_torture_alloc
, 0);
1804 atomic_set(&n_rcu_torture_alloc_fail
, 0);
1805 atomic_set(&n_rcu_torture_free
, 0);
1806 atomic_set(&n_rcu_torture_mberror
, 0);
1807 atomic_set(&n_rcu_torture_error
, 0);
1808 n_rcu_torture_barrier_error
= 0;
1809 n_rcu_torture_boost_ktrerror
= 0;
1810 n_rcu_torture_boost_rterror
= 0;
1811 n_rcu_torture_boost_failure
= 0;
1812 n_rcu_torture_boosts
= 0;
1813 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++)
1814 atomic_set(&rcu_torture_wcount
[i
], 0);
1815 for_each_possible_cpu(cpu
) {
1816 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++) {
1817 per_cpu(rcu_torture_count
, cpu
)[i
] = 0;
1818 per_cpu(rcu_torture_batch
, cpu
)[i
] = 0;
1822 /* Start up the kthreads. */
1824 firsterr
= torture_create_kthread(rcu_torture_writer
, NULL
,
1828 if (nfakewriters
> 0) {
1829 fakewriter_tasks
= kzalloc(nfakewriters
*
1830 sizeof(fakewriter_tasks
[0]),
1832 if (fakewriter_tasks
== NULL
) {
1833 VERBOSE_TOROUT_ERRSTRING("out of memory");
1838 for (i
= 0; i
< nfakewriters
; i
++) {
1839 firsterr
= torture_create_kthread(rcu_torture_fakewriter
,
1840 NULL
, fakewriter_tasks
[i
]);
1844 reader_tasks
= kzalloc(nrealreaders
* sizeof(reader_tasks
[0]),
1846 if (reader_tasks
== NULL
) {
1847 VERBOSE_TOROUT_ERRSTRING("out of memory");
1851 for (i
= 0; i
< nrealreaders
; i
++) {
1852 firsterr
= torture_create_kthread(rcu_torture_reader
, NULL
,
1857 if (stat_interval
> 0) {
1858 firsterr
= torture_create_kthread(rcu_torture_stats
, NULL
,
1863 if (test_no_idle_hz
&& shuffle_interval
> 0) {
1864 firsterr
= torture_shuffle_init(shuffle_interval
* HZ
);
1871 firsterr
= torture_stutter_init(stutter
* HZ
);
1875 if (fqs_duration
< 0)
1878 /* Create the fqs thread */
1879 firsterr
= torture_create_kthread(rcu_torture_fqs
, NULL
,
1884 if (test_boost_interval
< 1)
1885 test_boost_interval
= 1;
1886 if (test_boost_duration
< 2)
1887 test_boost_duration
= 2;
1888 if ((test_boost
== 1 && cur_ops
->can_boost
) ||
1891 boost_starttime
= jiffies
+ test_boost_interval
* HZ
;
1893 firsterr
= cpuhp_setup_state(CPUHP_AP_ONLINE_DYN
, "RCU_TORTURE",
1894 rcutorture_booster_init
,
1895 rcutorture_booster_cleanup
);
1898 rcutor_hp
= firsterr
;
1900 firsterr
= torture_shutdown_init(shutdown_secs
, rcu_torture_cleanup
);
1903 firsterr
= torture_onoff_init(onoff_holdoff
* HZ
, onoff_interval
* HZ
);
1906 firsterr
= rcu_torture_stall_init();
1909 firsterr
= rcu_torture_barrier_init();
1913 rcu_test_debug_objects();
1914 if (cbflood_n_burst
> 0) {
1915 /* Create the cbflood threads */
1916 ncbflooders
= (num_online_cpus() + 3) / 4;
1917 cbflood_task
= kcalloc(ncbflooders
, sizeof(*cbflood_task
),
1919 if (!cbflood_task
) {
1920 VERBOSE_TOROUT_ERRSTRING("out of memory");
1924 for (i
= 0; i
< ncbflooders
; i
++) {
1925 firsterr
= torture_create_kthread(rcu_torture_cbflood
,
1932 rcutorture_record_test_transition();
1938 rcu_torture_cleanup();
1942 module_init(rcu_torture_init
);
1943 module_exit(rcu_torture_cleanup
);