1 // SPDX-License-Identifier: GPL-2.0+
3 * Read-Copy Update module-based torture test facility
5 * Copyright (C) IBM Corporation, 2005, 2006
7 * Authors: Paul E. McKenney <paulmck@linux.ibm.com>
8 * Josh Triplett <josh@joshtriplett.org>
10 * See also: Documentation/RCU/torture.txt
13 #define pr_fmt(fmt) fmt
15 #include <linux/types.h>
16 #include <linux/kernel.h>
17 #include <linux/init.h>
18 #include <linux/module.h>
19 #include <linux/kthread.h>
20 #include <linux/err.h>
21 #include <linux/spinlock.h>
22 #include <linux/smp.h>
23 #include <linux/rcupdate.h>
24 #include <linux/interrupt.h>
25 #include <linux/sched/signal.h>
26 #include <uapi/linux/sched/types.h>
27 #include <linux/atomic.h>
28 #include <linux/bitops.h>
29 #include <linux/completion.h>
30 #include <linux/moduleparam.h>
31 #include <linux/percpu.h>
32 #include <linux/notifier.h>
33 #include <linux/reboot.h>
34 #include <linux/freezer.h>
35 #include <linux/cpu.h>
36 #include <linux/delay.h>
37 #include <linux/stat.h>
38 #include <linux/srcu.h>
39 #include <linux/slab.h>
40 #include <linux/trace_clock.h>
41 #include <asm/byteorder.h>
42 #include <linux/torture.h>
43 #include <linux/vmalloc.h>
44 #include <linux/sched/debug.h>
45 #include <linux/sched/sysctl.h>
46 #include <linux/oom.h>
47 #include <linux/tick.h>
51 MODULE_LICENSE("GPL");
52 MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com> and Josh Triplett <josh@joshtriplett.org>");
55 /* Bits for ->extendables field, extendables param, and related definitions. */
56 #define RCUTORTURE_RDR_SHIFT 8 /* Put SRCU index in upper bits. */
57 #define RCUTORTURE_RDR_MASK ((1 << RCUTORTURE_RDR_SHIFT) - 1)
58 #define RCUTORTURE_RDR_BH 0x01 /* Extend readers by disabling bh. */
59 #define RCUTORTURE_RDR_IRQ 0x02 /* ... disabling interrupts. */
60 #define RCUTORTURE_RDR_PREEMPT 0x04 /* ... disabling preemption. */
61 #define RCUTORTURE_RDR_RBH 0x08 /* ... rcu_read_lock_bh(). */
62 #define RCUTORTURE_RDR_SCHED 0x10 /* ... rcu_read_lock_sched(). */
63 #define RCUTORTURE_RDR_RCU 0x20 /* ... entering another RCU reader. */
64 #define RCUTORTURE_RDR_NBITS 6 /* Number of bits defined above. */
65 #define RCUTORTURE_MAX_EXTEND \
66 (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_IRQ | RCUTORTURE_RDR_PREEMPT | \
67 RCUTORTURE_RDR_RBH | RCUTORTURE_RDR_SCHED)
68 #define RCUTORTURE_RDR_MAX_LOOPS 0x7 /* Maximum reader extensions. */
69 /* Must be power of two minus one. */
70 #define RCUTORTURE_RDR_MAX_SEGS (RCUTORTURE_RDR_MAX_LOOPS + 3)
72 torture_param(int, extendables
, RCUTORTURE_MAX_EXTEND
,
73 "Extend readers by disabling bh (1), irqs (2), or preempt (4)");
74 torture_param(int, fqs_duration
, 0,
75 "Duration of fqs bursts (us), 0 to disable");
76 torture_param(int, fqs_holdoff
, 0, "Holdoff time within fqs bursts (us)");
77 torture_param(int, fqs_stutter
, 3, "Wait time between fqs bursts (s)");
78 torture_param(bool, fwd_progress
, 1, "Test grace-period forward progress");
79 torture_param(int, fwd_progress_div
, 4, "Fraction of CPU stall to wait");
80 torture_param(int, fwd_progress_holdoff
, 60,
81 "Time between forward-progress tests (s)");
82 torture_param(bool, fwd_progress_need_resched
, 1,
83 "Hide cond_resched() behind need_resched()");
84 torture_param(bool, gp_cond
, false, "Use conditional/async GP wait primitives");
85 torture_param(bool, gp_exp
, false, "Use expedited GP wait primitives");
86 torture_param(bool, gp_normal
, false,
87 "Use normal (non-expedited) GP wait primitives");
88 torture_param(bool, gp_sync
, false, "Use synchronous GP wait primitives");
89 torture_param(int, irqreader
, 1, "Allow RCU readers from irq handlers");
90 torture_param(int, n_barrier_cbs
, 0,
91 "# of callbacks/kthreads for barrier testing");
92 torture_param(int, nfakewriters
, 4, "Number of RCU fake writer threads");
93 torture_param(int, nreaders
, -1, "Number of RCU reader threads");
94 torture_param(int, object_debug
, 0,
95 "Enable debug-object double call_rcu() testing");
96 torture_param(int, onoff_holdoff
, 0, "Time after boot before CPU hotplugs (s)");
97 torture_param(int, onoff_interval
, 0,
98 "Time between CPU hotplugs (jiffies), 0=disable");
99 torture_param(int, shuffle_interval
, 3, "Number of seconds between shuffles");
100 torture_param(int, shutdown_secs
, 0, "Shutdown time (s), <= zero to disable.");
101 torture_param(int, stall_cpu
, 0, "Stall duration (s), zero to disable.");
102 torture_param(int, stall_cpu_holdoff
, 10,
103 "Time to wait before starting stall (s).");
104 torture_param(int, stall_cpu_irqsoff
, 0, "Disable interrupts while stalling.");
105 torture_param(int, stat_interval
, 60,
106 "Number of seconds between stats printk()s");
107 torture_param(int, stutter
, 5, "Number of seconds to run/halt test");
108 torture_param(int, test_boost
, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
109 torture_param(int, test_boost_duration
, 4,
110 "Duration of each boost test, seconds.");
111 torture_param(int, test_boost_interval
, 7,
112 "Interval between boost tests, seconds.");
113 torture_param(bool, test_no_idle_hz
, true,
114 "Test support for tickless idle CPUs");
115 torture_param(int, verbose
, 1,
116 "Enable verbose debugging printk()s");
118 static char *torture_type
= "rcu";
119 module_param(torture_type
, charp
, 0444);
120 MODULE_PARM_DESC(torture_type
, "Type of RCU to torture (rcu, srcu, ...)");
122 static int nrealreaders
;
123 static struct task_struct
*writer_task
;
124 static struct task_struct
**fakewriter_tasks
;
125 static struct task_struct
**reader_tasks
;
126 static struct task_struct
*stats_task
;
127 static struct task_struct
*fqs_task
;
128 static struct task_struct
*boost_tasks
[NR_CPUS
];
129 static struct task_struct
*stall_task
;
130 static struct task_struct
*fwd_prog_task
;
131 static struct task_struct
**barrier_cbs_tasks
;
132 static struct task_struct
*barrier_task
;
134 #define RCU_TORTURE_PIPE_LEN 10
137 struct rcu_head rtort_rcu
;
138 int rtort_pipe_count
;
139 struct list_head rtort_free
;
143 static LIST_HEAD(rcu_torture_freelist
);
144 static struct rcu_torture __rcu
*rcu_torture_current
;
145 static unsigned long rcu_torture_current_version
;
146 static struct rcu_torture rcu_tortures
[10 * RCU_TORTURE_PIPE_LEN
];
147 static DEFINE_SPINLOCK(rcu_torture_lock
);
148 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN
+ 1], rcu_torture_count
);
149 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN
+ 1], rcu_torture_batch
);
150 static atomic_t rcu_torture_wcount
[RCU_TORTURE_PIPE_LEN
+ 1];
151 static atomic_t n_rcu_torture_alloc
;
152 static atomic_t n_rcu_torture_alloc_fail
;
153 static atomic_t n_rcu_torture_free
;
154 static atomic_t n_rcu_torture_mberror
;
155 static atomic_t n_rcu_torture_error
;
156 static long n_rcu_torture_barrier_error
;
157 static long n_rcu_torture_boost_ktrerror
;
158 static long n_rcu_torture_boost_rterror
;
159 static long n_rcu_torture_boost_failure
;
160 static long n_rcu_torture_boosts
;
161 static atomic_long_t n_rcu_torture_timers
;
162 static long n_barrier_attempts
;
163 static long n_barrier_successes
; /* did rcu_barrier test succeed? */
164 static struct list_head rcu_torture_removed
;
165 static unsigned long shutdown_jiffies
;
167 static int rcu_torture_writer_state
;
168 #define RTWS_FIXED_DELAY 0
170 #define RTWS_REPLACE 2
171 #define RTWS_DEF_FREE 3
172 #define RTWS_EXP_SYNC 4
173 #define RTWS_COND_GET 5
174 #define RTWS_COND_SYNC 6
176 #define RTWS_STUTTER 8
177 #define RTWS_STOPPING 9
178 static const char * const rcu_torture_writer_state_names
[] = {
191 /* Record reader segment types and duration for first failing read. */
194 unsigned long rt_delay_jiffies
;
195 unsigned long rt_delay_ms
;
196 unsigned long rt_delay_us
;
199 static int err_segs_recorded
;
200 static struct rt_read_seg err_segs
[RCUTORTURE_RDR_MAX_SEGS
];
201 static int rt_read_nsegs
;
203 static const char *rcu_torture_writer_state_getname(void)
205 unsigned int i
= READ_ONCE(rcu_torture_writer_state
);
207 if (i
>= ARRAY_SIZE(rcu_torture_writer_state_names
))
209 return rcu_torture_writer_state_names
[i
];
212 #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU)
213 #define rcu_can_boost() 1
214 #else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
215 #define rcu_can_boost() 0
216 #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
218 #ifdef CONFIG_RCU_TRACE
219 static u64 notrace
rcu_trace_clock_local(void)
221 u64 ts
= trace_clock_local();
223 (void)do_div(ts
, NSEC_PER_USEC
);
226 #else /* #ifdef CONFIG_RCU_TRACE */
227 static u64 notrace
rcu_trace_clock_local(void)
231 #endif /* #else #ifdef CONFIG_RCU_TRACE */
234 * Stop aggressive CPU-hog tests a bit before the end of the test in order
235 * to avoid interfering with test shutdown.
237 static bool shutdown_time_arrived(void)
239 return shutdown_secs
&& time_after(jiffies
, shutdown_jiffies
- 30 * HZ
);
242 static unsigned long boost_starttime
; /* jiffies of next boost test start. */
243 static DEFINE_MUTEX(boost_mutex
); /* protect setting boost_starttime */
244 /* and boost task create/destroy. */
245 static atomic_t barrier_cbs_count
; /* Barrier callbacks registered. */
246 static bool barrier_phase
; /* Test phase. */
247 static atomic_t barrier_cbs_invoked
; /* Barrier callbacks invoked. */
248 static wait_queue_head_t
*barrier_cbs_wq
; /* Coordinate barrier testing. */
249 static DECLARE_WAIT_QUEUE_HEAD(barrier_wq
);
251 static bool rcu_fwd_cb_nodelay
; /* Short rcu_torture_delay() delays. */
254 * Allocate an element from the rcu_tortures pool.
256 static struct rcu_torture
*
257 rcu_torture_alloc(void)
261 spin_lock_bh(&rcu_torture_lock
);
262 if (list_empty(&rcu_torture_freelist
)) {
263 atomic_inc(&n_rcu_torture_alloc_fail
);
264 spin_unlock_bh(&rcu_torture_lock
);
267 atomic_inc(&n_rcu_torture_alloc
);
268 p
= rcu_torture_freelist
.next
;
270 spin_unlock_bh(&rcu_torture_lock
);
271 return container_of(p
, struct rcu_torture
, rtort_free
);
275 * Free an element to the rcu_tortures pool.
278 rcu_torture_free(struct rcu_torture
*p
)
280 atomic_inc(&n_rcu_torture_free
);
281 spin_lock_bh(&rcu_torture_lock
);
282 list_add_tail(&p
->rtort_free
, &rcu_torture_freelist
);
283 spin_unlock_bh(&rcu_torture_lock
);
287 * Operations vector for selecting different types of tests.
290 struct rcu_torture_ops
{
293 void (*cleanup
)(void);
294 int (*readlock
)(void);
295 void (*read_delay
)(struct torture_random_state
*rrsp
,
296 struct rt_read_seg
*rtrsp
);
297 void (*readunlock
)(int idx
);
298 unsigned long (*get_gp_seq
)(void);
299 unsigned long (*gp_diff
)(unsigned long new, unsigned long old
);
300 void (*deferred_free
)(struct rcu_torture
*p
);
302 void (*exp_sync
)(void);
303 unsigned long (*get_state
)(void);
304 void (*cond_sync
)(unsigned long oldstate
);
305 call_rcu_func_t call
;
306 void (*cb_barrier
)(void);
309 int (*stall_dur
)(void);
317 static struct rcu_torture_ops
*cur_ops
;
320 * Definitions for rcu torture testing.
323 static int rcu_torture_read_lock(void) __acquires(RCU
)
330 rcu_read_delay(struct torture_random_state
*rrsp
, struct rt_read_seg
*rtrsp
)
332 unsigned long started
;
333 unsigned long completed
;
334 const unsigned long shortdelay_us
= 200;
335 unsigned long longdelay_ms
= 300;
336 unsigned long long ts
;
338 /* We want a short delay sometimes to make a reader delay the grace
339 * period, and we want a long delay occasionally to trigger
340 * force_quiescent_state. */
342 if (!READ_ONCE(rcu_fwd_cb_nodelay
) &&
343 !(torture_random(rrsp
) % (nrealreaders
* 2000 * longdelay_ms
))) {
344 started
= cur_ops
->get_gp_seq();
345 ts
= rcu_trace_clock_local();
346 if (preempt_count() & (SOFTIRQ_MASK
| HARDIRQ_MASK
))
347 longdelay_ms
= 5; /* Avoid triggering BH limits. */
348 mdelay(longdelay_ms
);
349 rtrsp
->rt_delay_ms
= longdelay_ms
;
350 completed
= cur_ops
->get_gp_seq();
351 do_trace_rcu_torture_read(cur_ops
->name
, NULL
, ts
,
354 if (!(torture_random(rrsp
) % (nrealreaders
* 2 * shortdelay_us
))) {
355 udelay(shortdelay_us
);
356 rtrsp
->rt_delay_us
= shortdelay_us
;
358 if (!preempt_count() &&
359 !(torture_random(rrsp
) % (nrealreaders
* 500))) {
360 torture_preempt_schedule(); /* QS only if preemptible. */
361 rtrsp
->rt_preempted
= true;
365 static void rcu_torture_read_unlock(int idx
) __releases(RCU
)
371 * Update callback in the pipe. This should be invoked after a grace period.
374 rcu_torture_pipe_update_one(struct rcu_torture
*rp
)
378 i
= READ_ONCE(rp
->rtort_pipe_count
);
379 if (i
> RCU_TORTURE_PIPE_LEN
)
380 i
= RCU_TORTURE_PIPE_LEN
;
381 atomic_inc(&rcu_torture_wcount
[i
]);
382 WRITE_ONCE(rp
->rtort_pipe_count
, i
+ 1);
383 if (rp
->rtort_pipe_count
>= RCU_TORTURE_PIPE_LEN
) {
384 rp
->rtort_mbtest
= 0;
391 * Update all callbacks in the pipe. Suitable for synchronous grace-period
395 rcu_torture_pipe_update(struct rcu_torture
*old_rp
)
397 struct rcu_torture
*rp
;
398 struct rcu_torture
*rp1
;
401 list_add(&old_rp
->rtort_free
, &rcu_torture_removed
);
402 list_for_each_entry_safe(rp
, rp1
, &rcu_torture_removed
, rtort_free
) {
403 if (rcu_torture_pipe_update_one(rp
)) {
404 list_del(&rp
->rtort_free
);
405 rcu_torture_free(rp
);
411 rcu_torture_cb(struct rcu_head
*p
)
413 struct rcu_torture
*rp
= container_of(p
, struct rcu_torture
, rtort_rcu
);
415 if (torture_must_stop_irq()) {
416 /* Test is ending, just drop callbacks on the floor. */
417 /* The next initialization will pick up the pieces. */
420 if (rcu_torture_pipe_update_one(rp
))
421 rcu_torture_free(rp
);
423 cur_ops
->deferred_free(rp
);
426 static unsigned long rcu_no_completed(void)
431 static void rcu_torture_deferred_free(struct rcu_torture
*p
)
433 call_rcu(&p
->rtort_rcu
, rcu_torture_cb
);
436 static void rcu_sync_torture_init(void)
438 INIT_LIST_HEAD(&rcu_torture_removed
);
441 static struct rcu_torture_ops rcu_ops
= {
443 .init
= rcu_sync_torture_init
,
444 .readlock
= rcu_torture_read_lock
,
445 .read_delay
= rcu_read_delay
,
446 .readunlock
= rcu_torture_read_unlock
,
447 .get_gp_seq
= rcu_get_gp_seq
,
448 .gp_diff
= rcu_seq_diff
,
449 .deferred_free
= rcu_torture_deferred_free
,
450 .sync
= synchronize_rcu
,
451 .exp_sync
= synchronize_rcu_expedited
,
452 .get_state
= get_state_synchronize_rcu
,
453 .cond_sync
= cond_synchronize_rcu
,
455 .cb_barrier
= rcu_barrier
,
456 .fqs
= rcu_force_quiescent_state
,
458 .stall_dur
= rcu_jiffies_till_stall_check
,
460 .can_boost
= rcu_can_boost(),
461 .extendables
= RCUTORTURE_MAX_EXTEND
,
466 * Don't even think about trying any of these in real life!!!
467 * The names includes "busted", and they really means it!
468 * The only purpose of these functions is to provide a buggy RCU
469 * implementation to make sure that rcutorture correctly emits
470 * buggy-RCU error messages.
472 static void rcu_busted_torture_deferred_free(struct rcu_torture
*p
)
474 /* This is a deliberate bug for testing purposes only! */
475 rcu_torture_cb(&p
->rtort_rcu
);
478 static void synchronize_rcu_busted(void)
480 /* This is a deliberate bug for testing purposes only! */
484 call_rcu_busted(struct rcu_head
*head
, rcu_callback_t func
)
486 /* This is a deliberate bug for testing purposes only! */
490 static struct rcu_torture_ops rcu_busted_ops
= {
491 .ttype
= INVALID_RCU_FLAVOR
,
492 .init
= rcu_sync_torture_init
,
493 .readlock
= rcu_torture_read_lock
,
494 .read_delay
= rcu_read_delay
, /* just reuse rcu's version. */
495 .readunlock
= rcu_torture_read_unlock
,
496 .get_gp_seq
= rcu_no_completed
,
497 .deferred_free
= rcu_busted_torture_deferred_free
,
498 .sync
= synchronize_rcu_busted
,
499 .exp_sync
= synchronize_rcu_busted
,
500 .call
= call_rcu_busted
,
509 * Definitions for srcu torture testing.
512 DEFINE_STATIC_SRCU(srcu_ctl
);
513 static struct srcu_struct srcu_ctld
;
514 static struct srcu_struct
*srcu_ctlp
= &srcu_ctl
;
516 static int srcu_torture_read_lock(void) __acquires(srcu_ctlp
)
518 return srcu_read_lock(srcu_ctlp
);
522 srcu_read_delay(struct torture_random_state
*rrsp
, struct rt_read_seg
*rtrsp
)
525 const long uspertick
= 1000000 / HZ
;
526 const long longdelay
= 10;
528 /* We want there to be long-running readers, but not all the time. */
530 delay
= torture_random(rrsp
) %
531 (nrealreaders
* 2 * longdelay
* uspertick
);
532 if (!delay
&& in_task()) {
533 schedule_timeout_interruptible(longdelay
);
534 rtrsp
->rt_delay_jiffies
= longdelay
;
536 rcu_read_delay(rrsp
, rtrsp
);
540 static void srcu_torture_read_unlock(int idx
) __releases(srcu_ctlp
)
542 srcu_read_unlock(srcu_ctlp
, idx
);
545 static unsigned long srcu_torture_completed(void)
547 return srcu_batches_completed(srcu_ctlp
);
550 static void srcu_torture_deferred_free(struct rcu_torture
*rp
)
552 call_srcu(srcu_ctlp
, &rp
->rtort_rcu
, rcu_torture_cb
);
555 static void srcu_torture_synchronize(void)
557 synchronize_srcu(srcu_ctlp
);
560 static void srcu_torture_call(struct rcu_head
*head
,
563 call_srcu(srcu_ctlp
, head
, func
);
566 static void srcu_torture_barrier(void)
568 srcu_barrier(srcu_ctlp
);
571 static void srcu_torture_stats(void)
573 srcu_torture_stats_print(srcu_ctlp
, torture_type
, TORTURE_FLAG
);
576 static void srcu_torture_synchronize_expedited(void)
578 synchronize_srcu_expedited(srcu_ctlp
);
581 static struct rcu_torture_ops srcu_ops
= {
582 .ttype
= SRCU_FLAVOR
,
583 .init
= rcu_sync_torture_init
,
584 .readlock
= srcu_torture_read_lock
,
585 .read_delay
= srcu_read_delay
,
586 .readunlock
= srcu_torture_read_unlock
,
587 .get_gp_seq
= srcu_torture_completed
,
588 .deferred_free
= srcu_torture_deferred_free
,
589 .sync
= srcu_torture_synchronize
,
590 .exp_sync
= srcu_torture_synchronize_expedited
,
591 .call
= srcu_torture_call
,
592 .cb_barrier
= srcu_torture_barrier
,
593 .stats
= srcu_torture_stats
,
598 static void srcu_torture_init(void)
600 rcu_sync_torture_init();
601 WARN_ON(init_srcu_struct(&srcu_ctld
));
602 srcu_ctlp
= &srcu_ctld
;
605 static void srcu_torture_cleanup(void)
607 cleanup_srcu_struct(&srcu_ctld
);
608 srcu_ctlp
= &srcu_ctl
; /* In case of a later rcutorture run. */
611 /* As above, but dynamically allocated. */
612 static struct rcu_torture_ops srcud_ops
= {
613 .ttype
= SRCU_FLAVOR
,
614 .init
= srcu_torture_init
,
615 .cleanup
= srcu_torture_cleanup
,
616 .readlock
= srcu_torture_read_lock
,
617 .read_delay
= srcu_read_delay
,
618 .readunlock
= srcu_torture_read_unlock
,
619 .get_gp_seq
= srcu_torture_completed
,
620 .deferred_free
= srcu_torture_deferred_free
,
621 .sync
= srcu_torture_synchronize
,
622 .exp_sync
= srcu_torture_synchronize_expedited
,
623 .call
= srcu_torture_call
,
624 .cb_barrier
= srcu_torture_barrier
,
625 .stats
= srcu_torture_stats
,
630 /* As above, but broken due to inappropriate reader extension. */
631 static struct rcu_torture_ops busted_srcud_ops
= {
632 .ttype
= SRCU_FLAVOR
,
633 .init
= srcu_torture_init
,
634 .cleanup
= srcu_torture_cleanup
,
635 .readlock
= srcu_torture_read_lock
,
636 .read_delay
= rcu_read_delay
,
637 .readunlock
= srcu_torture_read_unlock
,
638 .get_gp_seq
= srcu_torture_completed
,
639 .deferred_free
= srcu_torture_deferred_free
,
640 .sync
= srcu_torture_synchronize
,
641 .exp_sync
= srcu_torture_synchronize_expedited
,
642 .call
= srcu_torture_call
,
643 .cb_barrier
= srcu_torture_barrier
,
644 .stats
= srcu_torture_stats
,
646 .extendables
= RCUTORTURE_MAX_EXTEND
,
647 .name
= "busted_srcud"
651 * Definitions for RCU-tasks torture testing.
654 static int tasks_torture_read_lock(void)
659 static void tasks_torture_read_unlock(int idx
)
663 static void rcu_tasks_torture_deferred_free(struct rcu_torture
*p
)
665 call_rcu_tasks(&p
->rtort_rcu
, rcu_torture_cb
);
668 static struct rcu_torture_ops tasks_ops
= {
669 .ttype
= RCU_TASKS_FLAVOR
,
670 .init
= rcu_sync_torture_init
,
671 .readlock
= tasks_torture_read_lock
,
672 .read_delay
= rcu_read_delay
, /* just reuse rcu's version. */
673 .readunlock
= tasks_torture_read_unlock
,
674 .get_gp_seq
= rcu_no_completed
,
675 .deferred_free
= rcu_tasks_torture_deferred_free
,
676 .sync
= synchronize_rcu_tasks
,
677 .exp_sync
= synchronize_rcu_tasks
,
678 .call
= call_rcu_tasks
,
679 .cb_barrier
= rcu_barrier_tasks
,
688 * Definitions for trivial CONFIG_PREEMPT=n-only torture testing.
689 * This implementation does not necessarily work well with CPU hotplug.
692 static void synchronize_rcu_trivial(void)
696 for_each_online_cpu(cpu
) {
697 rcutorture_sched_setaffinity(current
->pid
, cpumask_of(cpu
));
698 WARN_ON_ONCE(raw_smp_processor_id() != cpu
);
702 static int rcu_torture_read_lock_trivial(void) __acquires(RCU
)
708 static void rcu_torture_read_unlock_trivial(int idx
) __releases(RCU
)
713 static struct rcu_torture_ops trivial_ops
= {
714 .ttype
= RCU_TRIVIAL_FLAVOR
,
715 .init
= rcu_sync_torture_init
,
716 .readlock
= rcu_torture_read_lock_trivial
,
717 .read_delay
= rcu_read_delay
, /* just reuse rcu's version. */
718 .readunlock
= rcu_torture_read_unlock_trivial
,
719 .get_gp_seq
= rcu_no_completed
,
720 .sync
= synchronize_rcu_trivial
,
721 .exp_sync
= synchronize_rcu_trivial
,
728 static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old
)
730 if (!cur_ops
->gp_diff
)
732 return cur_ops
->gp_diff(new, old
);
735 static bool __maybe_unused
torturing_tasks(void)
737 return cur_ops
== &tasks_ops
;
741 * RCU torture priority-boost testing. Runs one real-time thread per
742 * CPU for moderate bursts, repeatedly registering RCU callbacks and
743 * spinning waiting for them to be invoked. If a given callback takes
744 * too long to be invoked, we assume that priority inversion has occurred.
747 struct rcu_boost_inflight
{
752 static void rcu_torture_boost_cb(struct rcu_head
*head
)
754 struct rcu_boost_inflight
*rbip
=
755 container_of(head
, struct rcu_boost_inflight
, rcu
);
757 /* Ensure RCU-core accesses precede clearing ->inflight */
758 smp_store_release(&rbip
->inflight
, 0);
761 static int old_rt_runtime
= -1;
763 static void rcu_torture_disable_rt_throttle(void)
766 * Disable RT throttling so that rcutorture's boost threads don't get
767 * throttled. Only possible if rcutorture is built-in otherwise the
768 * user should manually do this by setting the sched_rt_period_us and
769 * sched_rt_runtime sysctls.
771 if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST
) || old_rt_runtime
!= -1)
774 old_rt_runtime
= sysctl_sched_rt_runtime
;
775 sysctl_sched_rt_runtime
= -1;
778 static void rcu_torture_enable_rt_throttle(void)
780 if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST
) || old_rt_runtime
== -1)
783 sysctl_sched_rt_runtime
= old_rt_runtime
;
787 static bool rcu_torture_boost_failed(unsigned long start
, unsigned long end
)
789 if (end
- start
> test_boost_duration
* HZ
- HZ
/ 2) {
790 VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed");
791 n_rcu_torture_boost_failure
++;
793 return true; /* failed */
796 return false; /* passed */
799 static int rcu_torture_boost(void *arg
)
801 unsigned long call_rcu_time
;
802 unsigned long endtime
;
803 unsigned long oldstarttime
;
804 struct rcu_boost_inflight rbi
= { .inflight
= 0 };
805 struct sched_param sp
;
807 VERBOSE_TOROUT_STRING("rcu_torture_boost started");
809 /* Set real-time priority. */
810 sp
.sched_priority
= 1;
811 if (sched_setscheduler(current
, SCHED_FIFO
, &sp
) < 0) {
812 VERBOSE_TOROUT_STRING("rcu_torture_boost RT prio failed!");
813 n_rcu_torture_boost_rterror
++;
816 init_rcu_head_on_stack(&rbi
.rcu
);
817 /* Each pass through the following loop does one boost-test cycle. */
819 /* Track if the test failed already in this test interval? */
822 /* Increment n_rcu_torture_boosts once per boost-test */
823 while (!kthread_should_stop()) {
824 if (mutex_trylock(&boost_mutex
)) {
825 n_rcu_torture_boosts
++;
826 mutex_unlock(&boost_mutex
);
829 schedule_timeout_uninterruptible(1);
831 if (kthread_should_stop())
834 /* Wait for the next test interval. */
835 oldstarttime
= boost_starttime
;
836 while (ULONG_CMP_LT(jiffies
, oldstarttime
)) {
837 schedule_timeout_interruptible(oldstarttime
- jiffies
);
838 stutter_wait("rcu_torture_boost");
839 if (torture_must_stop())
843 /* Do one boost-test interval. */
844 endtime
= oldstarttime
+ test_boost_duration
* HZ
;
845 call_rcu_time
= jiffies
;
846 while (ULONG_CMP_LT(jiffies
, endtime
)) {
847 /* If we don't have a callback in flight, post one. */
848 if (!smp_load_acquire(&rbi
.inflight
)) {
849 /* RCU core before ->inflight = 1. */
850 smp_store_release(&rbi
.inflight
, 1);
851 call_rcu(&rbi
.rcu
, rcu_torture_boost_cb
);
852 /* Check if the boost test failed */
854 rcu_torture_boost_failed(call_rcu_time
,
856 call_rcu_time
= jiffies
;
858 stutter_wait("rcu_torture_boost");
859 if (torture_must_stop())
864 * If boost never happened, then inflight will always be 1, in
865 * this case the boost check would never happen in the above
866 * loop so do another one here.
868 if (!failed
&& smp_load_acquire(&rbi
.inflight
))
869 rcu_torture_boost_failed(call_rcu_time
, jiffies
);
872 * Set the start time of the next test interval.
873 * Yes, this is vulnerable to long delays, but such
874 * delays simply cause a false negative for the next
875 * interval. Besides, we are running at RT priority,
876 * so delays should be relatively rare.
878 while (oldstarttime
== boost_starttime
&&
879 !kthread_should_stop()) {
880 if (mutex_trylock(&boost_mutex
)) {
881 boost_starttime
= jiffies
+
882 test_boost_interval
* HZ
;
883 mutex_unlock(&boost_mutex
);
886 schedule_timeout_uninterruptible(1);
889 /* Go do the stutter. */
890 checkwait
: stutter_wait("rcu_torture_boost");
891 } while (!torture_must_stop());
893 /* Clean up and exit. */
894 while (!kthread_should_stop() || smp_load_acquire(&rbi
.inflight
)) {
895 torture_shutdown_absorb("rcu_torture_boost");
896 schedule_timeout_uninterruptible(1);
898 destroy_rcu_head_on_stack(&rbi
.rcu
);
899 torture_kthread_stopping("rcu_torture_boost");
904 * RCU torture force-quiescent-state kthread. Repeatedly induces
905 * bursts of calls to force_quiescent_state(), increasing the probability
906 * of occurrence of some important types of race conditions.
909 rcu_torture_fqs(void *arg
)
911 unsigned long fqs_resume_time
;
912 int fqs_burst_remaining
;
914 VERBOSE_TOROUT_STRING("rcu_torture_fqs task started");
916 fqs_resume_time
= jiffies
+ fqs_stutter
* HZ
;
917 while (ULONG_CMP_LT(jiffies
, fqs_resume_time
) &&
918 !kthread_should_stop()) {
919 schedule_timeout_interruptible(1);
921 fqs_burst_remaining
= fqs_duration
;
922 while (fqs_burst_remaining
> 0 &&
923 !kthread_should_stop()) {
926 fqs_burst_remaining
-= fqs_holdoff
;
928 stutter_wait("rcu_torture_fqs");
929 } while (!torture_must_stop());
930 torture_kthread_stopping("rcu_torture_fqs");
935 * RCU torture writer kthread. Repeatedly substitutes a new structure
936 * for that pointed to by rcu_torture_current, freeing the old structure
937 * after a series of grace periods (the "pipeline").
940 rcu_torture_writer(void *arg
)
942 bool can_expedite
= !rcu_gp_is_expedited() && !rcu_gp_is_normal();
944 unsigned long gp_snap
;
945 bool gp_cond1
= gp_cond
, gp_exp1
= gp_exp
, gp_normal1
= gp_normal
;
946 bool gp_sync1
= gp_sync
;
948 struct rcu_torture
*rp
;
949 struct rcu_torture
*old_rp
;
950 static DEFINE_TORTURE_RANDOM(rand
);
951 int synctype
[] = { RTWS_DEF_FREE
, RTWS_EXP_SYNC
,
952 RTWS_COND_GET
, RTWS_SYNC
};
955 VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
957 pr_alert("%s" TORTURE_FLAG
958 " GP expediting controlled from boot/sysfs for %s.\n",
959 torture_type
, cur_ops
->name
);
961 /* Initialize synctype[] array. If none set, take default. */
962 if (!gp_cond1
&& !gp_exp1
&& !gp_normal1
&& !gp_sync1
)
963 gp_cond1
= gp_exp1
= gp_normal1
= gp_sync1
= true;
964 if (gp_cond1
&& cur_ops
->get_state
&& cur_ops
->cond_sync
) {
965 synctype
[nsynctypes
++] = RTWS_COND_GET
;
966 pr_info("%s: Testing conditional GPs.\n", __func__
);
967 } else if (gp_cond
&& (!cur_ops
->get_state
|| !cur_ops
->cond_sync
)) {
968 pr_alert("%s: gp_cond without primitives.\n", __func__
);
970 if (gp_exp1
&& cur_ops
->exp_sync
) {
971 synctype
[nsynctypes
++] = RTWS_EXP_SYNC
;
972 pr_info("%s: Testing expedited GPs.\n", __func__
);
973 } else if (gp_exp
&& !cur_ops
->exp_sync
) {
974 pr_alert("%s: gp_exp without primitives.\n", __func__
);
976 if (gp_normal1
&& cur_ops
->deferred_free
) {
977 synctype
[nsynctypes
++] = RTWS_DEF_FREE
;
978 pr_info("%s: Testing asynchronous GPs.\n", __func__
);
979 } else if (gp_normal
&& !cur_ops
->deferred_free
) {
980 pr_alert("%s: gp_normal without primitives.\n", __func__
);
982 if (gp_sync1
&& cur_ops
->sync
) {
983 synctype
[nsynctypes
++] = RTWS_SYNC
;
984 pr_info("%s: Testing normal GPs.\n", __func__
);
985 } else if (gp_sync
&& !cur_ops
->sync
) {
986 pr_alert("%s: gp_sync without primitives.\n", __func__
);
988 if (WARN_ONCE(nsynctypes
== 0,
989 "rcu_torture_writer: No update-side primitives.\n")) {
991 * No updates primitives, so don't try updating.
992 * The resulting test won't be testing much, hence the
995 rcu_torture_writer_state
= RTWS_STOPPING
;
996 torture_kthread_stopping("rcu_torture_writer");
1000 rcu_torture_writer_state
= RTWS_FIXED_DELAY
;
1001 schedule_timeout_uninterruptible(1);
1002 rp
= rcu_torture_alloc();
1005 rp
->rtort_pipe_count
= 0;
1006 rcu_torture_writer_state
= RTWS_DELAY
;
1007 udelay(torture_random(&rand
) & 0x3ff);
1008 rcu_torture_writer_state
= RTWS_REPLACE
;
1009 old_rp
= rcu_dereference_check(rcu_torture_current
,
1010 current
== writer_task
);
1011 rp
->rtort_mbtest
= 1;
1012 rcu_assign_pointer(rcu_torture_current
, rp
);
1013 smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */
1015 i
= old_rp
->rtort_pipe_count
;
1016 if (i
> RCU_TORTURE_PIPE_LEN
)
1017 i
= RCU_TORTURE_PIPE_LEN
;
1018 atomic_inc(&rcu_torture_wcount
[i
]);
1019 WRITE_ONCE(old_rp
->rtort_pipe_count
,
1020 old_rp
->rtort_pipe_count
+ 1);
1021 switch (synctype
[torture_random(&rand
) % nsynctypes
]) {
1023 rcu_torture_writer_state
= RTWS_DEF_FREE
;
1024 cur_ops
->deferred_free(old_rp
);
1027 rcu_torture_writer_state
= RTWS_EXP_SYNC
;
1028 cur_ops
->exp_sync();
1029 rcu_torture_pipe_update(old_rp
);
1032 rcu_torture_writer_state
= RTWS_COND_GET
;
1033 gp_snap
= cur_ops
->get_state();
1034 i
= torture_random(&rand
) % 16;
1036 schedule_timeout_interruptible(i
);
1037 udelay(torture_random(&rand
) % 1000);
1038 rcu_torture_writer_state
= RTWS_COND_SYNC
;
1039 cur_ops
->cond_sync(gp_snap
);
1040 rcu_torture_pipe_update(old_rp
);
1043 rcu_torture_writer_state
= RTWS_SYNC
;
1045 rcu_torture_pipe_update(old_rp
);
1052 WRITE_ONCE(rcu_torture_current_version
,
1053 rcu_torture_current_version
+ 1);
1054 /* Cycle through nesting levels of rcu_expedite_gp() calls. */
1056 !(torture_random(&rand
) & 0xff & (!!expediting
- 1))) {
1057 WARN_ON_ONCE(expediting
== 0 && rcu_gp_is_expedited());
1058 if (expediting
>= 0)
1061 rcu_unexpedite_gp();
1062 if (++expediting
> 3)
1063 expediting
= -expediting
;
1064 } else if (!can_expedite
) { /* Disabled during boot, recheck. */
1065 can_expedite
= !rcu_gp_is_expedited() &&
1066 !rcu_gp_is_normal();
1068 rcu_torture_writer_state
= RTWS_STUTTER
;
1069 if (stutter_wait("rcu_torture_writer") &&
1070 !READ_ONCE(rcu_fwd_cb_nodelay
) &&
1071 !cur_ops
->slow_gps
&&
1072 !torture_must_stop() &&
1073 rcu_inkernel_boot_has_ended())
1074 for (i
= 0; i
< ARRAY_SIZE(rcu_tortures
); i
++)
1075 if (list_empty(&rcu_tortures
[i
].rtort_free
) &&
1076 rcu_access_pointer(rcu_torture_current
) !=
1078 rcu_ftrace_dump(DUMP_ALL
);
1079 WARN(1, "%s: rtort_pipe_count: %d\n", __func__
, rcu_tortures
[i
].rtort_pipe_count
);
1081 } while (!torture_must_stop());
1082 /* Reset expediting back to unexpedited. */
1084 expediting
= -expediting
;
1085 while (can_expedite
&& expediting
++ < 0)
1086 rcu_unexpedite_gp();
1087 WARN_ON_ONCE(can_expedite
&& rcu_gp_is_expedited());
1089 pr_alert("%s" TORTURE_FLAG
1090 " Dynamic grace-period expediting was disabled.\n",
1092 rcu_torture_writer_state
= RTWS_STOPPING
;
1093 torture_kthread_stopping("rcu_torture_writer");
1098 * RCU torture fake writer kthread. Repeatedly calls sync, with a random
1099 * delay between calls.
1102 rcu_torture_fakewriter(void *arg
)
1104 DEFINE_TORTURE_RANDOM(rand
);
1106 VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started");
1107 set_user_nice(current
, MAX_NICE
);
1110 schedule_timeout_uninterruptible(1 + torture_random(&rand
)%10);
1111 udelay(torture_random(&rand
) & 0x3ff);
1112 if (cur_ops
->cb_barrier
!= NULL
&&
1113 torture_random(&rand
) % (nfakewriters
* 8) == 0) {
1114 cur_ops
->cb_barrier();
1115 } else if (gp_normal
== gp_exp
) {
1116 if (cur_ops
->sync
&& torture_random(&rand
) & 0x80)
1118 else if (cur_ops
->exp_sync
)
1119 cur_ops
->exp_sync();
1120 } else if (gp_normal
&& cur_ops
->sync
) {
1122 } else if (cur_ops
->exp_sync
) {
1123 cur_ops
->exp_sync();
1125 stutter_wait("rcu_torture_fakewriter");
1126 } while (!torture_must_stop());
1128 torture_kthread_stopping("rcu_torture_fakewriter");
1132 static void rcu_torture_timer_cb(struct rcu_head
*rhp
)
1138 * Do one extension of an RCU read-side critical section using the
1139 * current reader state in readstate (set to zero for initial entry
1140 * to extended critical section), set the new state as specified by
1141 * newstate (set to zero for final exit from extended critical section),
1142 * and random-number-generator state in trsp. If this is neither the
1143 * beginning or end of the critical section and if there was actually a
1144 * change, do a ->read_delay().
1146 static void rcutorture_one_extend(int *readstate
, int newstate
,
1147 struct torture_random_state
*trsp
,
1148 struct rt_read_seg
*rtrsp
)
1151 int idxold
= *readstate
;
1152 int statesnew
= ~*readstate
& newstate
;
1153 int statesold
= *readstate
& ~newstate
;
1155 WARN_ON_ONCE(idxold
< 0);
1156 WARN_ON_ONCE((idxold
>> RCUTORTURE_RDR_SHIFT
) > 1);
1157 rtrsp
->rt_readstate
= newstate
;
1159 /* First, put new protection in place to avoid critical-section gap. */
1160 if (statesnew
& RCUTORTURE_RDR_BH
)
1162 if (statesnew
& RCUTORTURE_RDR_IRQ
)
1163 local_irq_disable();
1164 if (statesnew
& RCUTORTURE_RDR_PREEMPT
)
1166 if (statesnew
& RCUTORTURE_RDR_RBH
)
1168 if (statesnew
& RCUTORTURE_RDR_SCHED
)
1169 rcu_read_lock_sched();
1170 if (statesnew
& RCUTORTURE_RDR_RCU
)
1171 idxnew
= cur_ops
->readlock() << RCUTORTURE_RDR_SHIFT
;
1173 /* Next, remove old protection, irq first due to bh conflict. */
1174 if (statesold
& RCUTORTURE_RDR_IRQ
)
1176 if (statesold
& RCUTORTURE_RDR_BH
)
1178 if (statesold
& RCUTORTURE_RDR_PREEMPT
)
1180 if (statesold
& RCUTORTURE_RDR_RBH
)
1181 rcu_read_unlock_bh();
1182 if (statesold
& RCUTORTURE_RDR_SCHED
)
1183 rcu_read_unlock_sched();
1184 if (statesold
& RCUTORTURE_RDR_RCU
)
1185 cur_ops
->readunlock(idxold
>> RCUTORTURE_RDR_SHIFT
);
1187 /* Delay if neither beginning nor end and there was a change. */
1188 if ((statesnew
|| statesold
) && *readstate
&& newstate
)
1189 cur_ops
->read_delay(trsp
, rtrsp
);
1191 /* Update the reader state. */
1193 idxnew
= idxold
& ~RCUTORTURE_RDR_MASK
;
1194 WARN_ON_ONCE(idxnew
< 0);
1195 WARN_ON_ONCE((idxnew
>> RCUTORTURE_RDR_SHIFT
) > 1);
1196 *readstate
= idxnew
| newstate
;
1197 WARN_ON_ONCE((*readstate
>> RCUTORTURE_RDR_SHIFT
) < 0);
1198 WARN_ON_ONCE((*readstate
>> RCUTORTURE_RDR_SHIFT
) > 1);
1201 /* Return the biggest extendables mask given current RCU and boot parameters. */
1202 static int rcutorture_extend_mask_max(void)
1206 WARN_ON_ONCE(extendables
& ~RCUTORTURE_MAX_EXTEND
);
1207 mask
= extendables
& RCUTORTURE_MAX_EXTEND
& cur_ops
->extendables
;
1208 mask
= mask
| RCUTORTURE_RDR_RCU
;
1212 /* Return a random protection state mask, but with at least one bit set. */
1214 rcutorture_extend_mask(int oldmask
, struct torture_random_state
*trsp
)
1216 int mask
= rcutorture_extend_mask_max();
1217 unsigned long randmask1
= torture_random(trsp
) >> 8;
1218 unsigned long randmask2
= randmask1
>> 3;
1220 WARN_ON_ONCE(mask
>> RCUTORTURE_RDR_SHIFT
);
1221 /* Mostly only one bit (need preemption!), sometimes lots of bits. */
1222 if (!(randmask1
& 0x7))
1223 mask
= mask
& randmask2
;
1225 mask
= mask
& (1 << (randmask2
% RCUTORTURE_RDR_NBITS
));
1226 /* Can't enable bh w/irq disabled. */
1227 if ((mask
& RCUTORTURE_RDR_IRQ
) &&
1228 ((!(mask
& RCUTORTURE_RDR_BH
) && (oldmask
& RCUTORTURE_RDR_BH
)) ||
1229 (!(mask
& RCUTORTURE_RDR_RBH
) && (oldmask
& RCUTORTURE_RDR_RBH
))))
1230 mask
|= RCUTORTURE_RDR_BH
| RCUTORTURE_RDR_RBH
;
1231 return mask
?: RCUTORTURE_RDR_RCU
;
1235 * Do a randomly selected number of extensions of an existing RCU read-side
1238 static struct rt_read_seg
*
1239 rcutorture_loop_extend(int *readstate
, struct torture_random_state
*trsp
,
1240 struct rt_read_seg
*rtrsp
)
1244 int mask
= rcutorture_extend_mask_max();
1246 WARN_ON_ONCE(!*readstate
); /* -Existing- RCU read-side critsect! */
1247 if (!((mask
- 1) & mask
))
1248 return rtrsp
; /* Current RCU reader not extendable. */
1249 /* Bias towards larger numbers of loops. */
1250 i
= (torture_random(trsp
) >> 3);
1251 i
= ((i
| (i
>> 3)) & RCUTORTURE_RDR_MAX_LOOPS
) + 1;
1252 for (j
= 0; j
< i
; j
++) {
1253 mask
= rcutorture_extend_mask(*readstate
, trsp
);
1254 rcutorture_one_extend(readstate
, mask
, trsp
, &rtrsp
[j
]);
1260 * Do one read-side critical section, returning false if there was
1261 * no data to read. Can be invoked both from process context and
1262 * from a timer handler.
1264 static bool rcu_torture_one_read(struct torture_random_state
*trsp
)
1267 unsigned long started
;
1268 unsigned long completed
;
1270 struct rcu_torture
*p
;
1273 struct rt_read_seg rtseg
[RCUTORTURE_RDR_MAX_SEGS
] = { { 0 } };
1274 struct rt_read_seg
*rtrsp
= &rtseg
[0];
1275 struct rt_read_seg
*rtrsp1
;
1276 unsigned long long ts
;
1278 newstate
= rcutorture_extend_mask(readstate
, trsp
);
1279 rcutorture_one_extend(&readstate
, newstate
, trsp
, rtrsp
++);
1280 started
= cur_ops
->get_gp_seq();
1281 ts
= rcu_trace_clock_local();
1282 p
= rcu_dereference_check(rcu_torture_current
,
1283 rcu_read_lock_bh_held() ||
1284 rcu_read_lock_sched_held() ||
1285 srcu_read_lock_held(srcu_ctlp
) ||
1288 /* Wait for rcu_torture_writer to get underway */
1289 rcutorture_one_extend(&readstate
, 0, trsp
, rtrsp
);
1292 if (p
->rtort_mbtest
== 0)
1293 atomic_inc(&n_rcu_torture_mberror
);
1294 rtrsp
= rcutorture_loop_extend(&readstate
, trsp
, rtrsp
);
1296 pipe_count
= READ_ONCE(p
->rtort_pipe_count
);
1297 if (pipe_count
> RCU_TORTURE_PIPE_LEN
) {
1298 /* Should not happen, but... */
1299 pipe_count
= RCU_TORTURE_PIPE_LEN
;
1301 completed
= cur_ops
->get_gp_seq();
1302 if (pipe_count
> 1) {
1303 do_trace_rcu_torture_read(cur_ops
->name
, &p
->rtort_rcu
,
1304 ts
, started
, completed
);
1305 rcu_ftrace_dump(DUMP_ALL
);
1307 __this_cpu_inc(rcu_torture_count
[pipe_count
]);
1308 completed
= rcutorture_seq_diff(completed
, started
);
1309 if (completed
> RCU_TORTURE_PIPE_LEN
) {
1310 /* Should not happen, but... */
1311 completed
= RCU_TORTURE_PIPE_LEN
;
1313 __this_cpu_inc(rcu_torture_batch
[completed
]);
1315 rcutorture_one_extend(&readstate
, 0, trsp
, rtrsp
);
1316 WARN_ON_ONCE(readstate
& RCUTORTURE_RDR_MASK
);
1318 /* If error or close call, record the sequence of reader protections. */
1319 if ((pipe_count
> 1 || completed
> 1) && !xchg(&err_segs_recorded
, 1)) {
1321 for (rtrsp1
= &rtseg
[0]; rtrsp1
< rtrsp
; rtrsp1
++)
1322 err_segs
[i
++] = *rtrsp1
;
1329 static DEFINE_TORTURE_RANDOM_PERCPU(rcu_torture_timer_rand
);
1332 * RCU torture reader from timer handler. Dereferences rcu_torture_current,
1333 * incrementing the corresponding element of the pipeline array. The
1334 * counter in the element should never be greater than 1, otherwise, the
1335 * RCU implementation is broken.
1337 static void rcu_torture_timer(struct timer_list
*unused
)
1339 atomic_long_inc(&n_rcu_torture_timers
);
1340 (void)rcu_torture_one_read(this_cpu_ptr(&rcu_torture_timer_rand
));
1342 /* Test call_rcu() invocation from interrupt handler. */
1343 if (cur_ops
->call
) {
1344 struct rcu_head
*rhp
= kmalloc(sizeof(*rhp
), GFP_NOWAIT
);
1347 cur_ops
->call(rhp
, rcu_torture_timer_cb
);
1352 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current,
1353 * incrementing the corresponding element of the pipeline array. The
1354 * counter in the element should never be greater than 1, otherwise, the
1355 * RCU implementation is broken.
1358 rcu_torture_reader(void *arg
)
1360 unsigned long lastsleep
= jiffies
;
1361 long myid
= (long)arg
;
1362 int mynumonline
= myid
;
1363 DEFINE_TORTURE_RANDOM(rand
);
1364 struct timer_list t
;
1366 VERBOSE_TOROUT_STRING("rcu_torture_reader task started");
1367 set_user_nice(current
, MAX_NICE
);
1368 if (irqreader
&& cur_ops
->irq_capable
)
1369 timer_setup_on_stack(&t
, rcu_torture_timer
, 0);
1370 tick_dep_set_task(current
, TICK_DEP_BIT_RCU
);
1372 if (irqreader
&& cur_ops
->irq_capable
) {
1373 if (!timer_pending(&t
))
1374 mod_timer(&t
, jiffies
+ 1);
1376 if (!rcu_torture_one_read(&rand
) && !torture_must_stop())
1377 schedule_timeout_interruptible(HZ
);
1378 if (time_after(jiffies
, lastsleep
) && !torture_must_stop()) {
1379 schedule_timeout_interruptible(1);
1380 lastsleep
= jiffies
+ 10;
1382 while (num_online_cpus() < mynumonline
&& !torture_must_stop())
1383 schedule_timeout_interruptible(HZ
/ 5);
1384 stutter_wait("rcu_torture_reader");
1385 } while (!torture_must_stop());
1386 if (irqreader
&& cur_ops
->irq_capable
) {
1388 destroy_timer_on_stack(&t
);
1390 tick_dep_clear_task(current
, TICK_DEP_BIT_RCU
);
1391 torture_kthread_stopping("rcu_torture_reader");
1396 * Print torture statistics. Caller must ensure that there is only
1397 * one call to this function at a given time!!! This is normally
1398 * accomplished by relying on the module system to only have one copy
1399 * of the module loaded, and then by giving the rcu_torture_stats
1400 * kthread full control (or the init/cleanup functions when rcu_torture_stats
1401 * thread is not running).
1404 rcu_torture_stats_print(void)
1408 long pipesummary
[RCU_TORTURE_PIPE_LEN
+ 1] = { 0 };
1409 long batchsummary
[RCU_TORTURE_PIPE_LEN
+ 1] = { 0 };
1410 struct rcu_torture
*rtcp
;
1411 static unsigned long rtcv_snap
= ULONG_MAX
;
1412 static bool splatted
;
1413 struct task_struct
*wtp
;
1415 for_each_possible_cpu(cpu
) {
1416 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++) {
1417 pipesummary
[i
] += READ_ONCE(per_cpu(rcu_torture_count
, cpu
)[i
]);
1418 batchsummary
[i
] += READ_ONCE(per_cpu(rcu_torture_batch
, cpu
)[i
]);
1421 for (i
= RCU_TORTURE_PIPE_LEN
- 1; i
>= 0; i
--) {
1422 if (pipesummary
[i
] != 0)
1426 pr_alert("%s%s ", torture_type
, TORTURE_FLAG
);
1427 rtcp
= rcu_access_pointer(rcu_torture_current
);
1428 pr_cont("rtc: %p %s: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
1430 rtcp
&& !rcu_stall_is_suppressed_at_boot() ? "ver" : "VER",
1431 rcu_torture_current_version
,
1432 list_empty(&rcu_torture_freelist
),
1433 atomic_read(&n_rcu_torture_alloc
),
1434 atomic_read(&n_rcu_torture_alloc_fail
),
1435 atomic_read(&n_rcu_torture_free
));
1436 pr_cont("rtmbe: %d rtbe: %ld rtbke: %ld rtbre: %ld ",
1437 atomic_read(&n_rcu_torture_mberror
),
1438 n_rcu_torture_barrier_error
,
1439 n_rcu_torture_boost_ktrerror
,
1440 n_rcu_torture_boost_rterror
);
1441 pr_cont("rtbf: %ld rtb: %ld nt: %ld ",
1442 n_rcu_torture_boost_failure
,
1443 n_rcu_torture_boosts
,
1444 atomic_long_read(&n_rcu_torture_timers
));
1445 torture_onoff_stats();
1446 pr_cont("barrier: %ld/%ld:%ld\n",
1447 n_barrier_successes
,
1449 n_rcu_torture_barrier_error
);
1451 pr_alert("%s%s ", torture_type
, TORTURE_FLAG
);
1452 if (atomic_read(&n_rcu_torture_mberror
) ||
1453 n_rcu_torture_barrier_error
|| n_rcu_torture_boost_ktrerror
||
1454 n_rcu_torture_boost_rterror
|| n_rcu_torture_boost_failure
||
1456 pr_cont("%s", "!!! ");
1457 atomic_inc(&n_rcu_torture_error
);
1458 WARN_ON_ONCE(atomic_read(&n_rcu_torture_mberror
));
1459 WARN_ON_ONCE(n_rcu_torture_barrier_error
); // rcu_barrier()
1460 WARN_ON_ONCE(n_rcu_torture_boost_ktrerror
); // no boost kthread
1461 WARN_ON_ONCE(n_rcu_torture_boost_rterror
); // can't set RT prio
1462 WARN_ON_ONCE(n_rcu_torture_boost_failure
); // RCU boost failed
1463 WARN_ON_ONCE(i
> 1); // Too-short grace period
1465 pr_cont("Reader Pipe: ");
1466 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++)
1467 pr_cont(" %ld", pipesummary
[i
]);
1470 pr_alert("%s%s ", torture_type
, TORTURE_FLAG
);
1471 pr_cont("Reader Batch: ");
1472 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++)
1473 pr_cont(" %ld", batchsummary
[i
]);
1476 pr_alert("%s%s ", torture_type
, TORTURE_FLAG
);
1477 pr_cont("Free-Block Circulation: ");
1478 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++) {
1479 pr_cont(" %d", atomic_read(&rcu_torture_wcount
[i
]));
1485 if (rtcv_snap
== rcu_torture_current_version
&&
1486 rcu_access_pointer(rcu_torture_current
) &&
1487 !rcu_stall_is_suppressed()) {
1488 int __maybe_unused flags
= 0;
1489 unsigned long __maybe_unused gp_seq
= 0;
1491 rcutorture_get_gp_data(cur_ops
->ttype
,
1493 srcutorture_get_gp_data(cur_ops
->ttype
, srcu_ctlp
,
1495 wtp
= READ_ONCE(writer_task
);
1496 pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#lx cpu %d\n",
1497 rcu_torture_writer_state_getname(),
1498 rcu_torture_writer_state
, gp_seq
, flags
,
1499 wtp
== NULL
? ~0UL : wtp
->state
,
1500 wtp
== NULL
? -1 : (int)task_cpu(wtp
));
1501 if (!splatted
&& wtp
) {
1502 sched_show_task(wtp
);
1505 show_rcu_gp_kthreads();
1506 rcu_ftrace_dump(DUMP_ALL
);
1508 rtcv_snap
= rcu_torture_current_version
;
1512 * Periodically prints torture statistics, if periodic statistics printing
1513 * was specified via the stat_interval module parameter.
1516 rcu_torture_stats(void *arg
)
1518 VERBOSE_TOROUT_STRING("rcu_torture_stats task started");
1520 schedule_timeout_interruptible(stat_interval
* HZ
);
1521 rcu_torture_stats_print();
1522 torture_shutdown_absorb("rcu_torture_stats");
1523 } while (!torture_must_stop());
1524 torture_kthread_stopping("rcu_torture_stats");
1529 rcu_torture_print_module_parms(struct rcu_torture_ops
*cur_ops
, const char *tag
)
1531 pr_alert("%s" TORTURE_FLAG
1532 "--- %s: nreaders=%d nfakewriters=%d "
1533 "stat_interval=%d verbose=%d test_no_idle_hz=%d "
1534 "shuffle_interval=%d stutter=%d irqreader=%d "
1535 "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
1536 "test_boost=%d/%d test_boost_interval=%d "
1537 "test_boost_duration=%d shutdown_secs=%d "
1538 "stall_cpu=%d stall_cpu_holdoff=%d stall_cpu_irqsoff=%d "
1540 "onoff_interval=%d onoff_holdoff=%d\n",
1541 torture_type
, tag
, nrealreaders
, nfakewriters
,
1542 stat_interval
, verbose
, test_no_idle_hz
, shuffle_interval
,
1543 stutter
, irqreader
, fqs_duration
, fqs_holdoff
, fqs_stutter
,
1544 test_boost
, cur_ops
->can_boost
,
1545 test_boost_interval
, test_boost_duration
, shutdown_secs
,
1546 stall_cpu
, stall_cpu_holdoff
, stall_cpu_irqsoff
,
1548 onoff_interval
, onoff_holdoff
);
1551 static int rcutorture_booster_cleanup(unsigned int cpu
)
1553 struct task_struct
*t
;
1555 if (boost_tasks
[cpu
] == NULL
)
1557 mutex_lock(&boost_mutex
);
1558 t
= boost_tasks
[cpu
];
1559 boost_tasks
[cpu
] = NULL
;
1560 rcu_torture_enable_rt_throttle();
1561 mutex_unlock(&boost_mutex
);
1563 /* This must be outside of the mutex, otherwise deadlock! */
1564 torture_stop_kthread(rcu_torture_boost
, t
);
1568 static int rcutorture_booster_init(unsigned int cpu
)
1572 if (boost_tasks
[cpu
] != NULL
)
1573 return 0; /* Already created, nothing more to do. */
1575 /* Don't allow time recalculation while creating a new task. */
1576 mutex_lock(&boost_mutex
);
1577 rcu_torture_disable_rt_throttle();
1578 VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task");
1579 boost_tasks
[cpu
] = kthread_create_on_node(rcu_torture_boost
, NULL
,
1581 "rcu_torture_boost");
1582 if (IS_ERR(boost_tasks
[cpu
])) {
1583 retval
= PTR_ERR(boost_tasks
[cpu
]);
1584 VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed");
1585 n_rcu_torture_boost_ktrerror
++;
1586 boost_tasks
[cpu
] = NULL
;
1587 mutex_unlock(&boost_mutex
);
1590 kthread_bind(boost_tasks
[cpu
], cpu
);
1591 wake_up_process(boost_tasks
[cpu
]);
1592 mutex_unlock(&boost_mutex
);
1597 * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then
1598 * induces a CPU stall for the time specified by stall_cpu.
1600 static int rcu_torture_stall(void *args
)
1602 unsigned long stop_at
;
1604 VERBOSE_TOROUT_STRING("rcu_torture_stall task started");
1605 if (stall_cpu_holdoff
> 0) {
1606 VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff");
1607 schedule_timeout_interruptible(stall_cpu_holdoff
* HZ
);
1608 VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff");
1610 if (!kthread_should_stop()) {
1611 stop_at
= ktime_get_seconds() + stall_cpu
;
1612 /* RCU CPU stall is expected behavior in following code. */
1614 if (stall_cpu_irqsoff
)
1615 local_irq_disable();
1618 pr_alert("rcu_torture_stall start on CPU %d.\n",
1619 smp_processor_id());
1620 while (ULONG_CMP_LT((unsigned long)ktime_get_seconds(),
1622 continue; /* Induce RCU CPU stall warning. */
1623 if (stall_cpu_irqsoff
)
1628 pr_alert("rcu_torture_stall end.\n");
1630 torture_shutdown_absorb("rcu_torture_stall");
1631 while (!kthread_should_stop())
1632 schedule_timeout_interruptible(10 * HZ
);
1636 /* Spawn CPU-stall kthread, if stall_cpu specified. */
1637 static int __init
rcu_torture_stall_init(void)
1641 return torture_create_kthread(rcu_torture_stall
, NULL
, stall_task
);
1644 /* State structure for forward-progress self-propagating RCU callback. */
1645 struct fwd_cb_state
{
1651 * Forward-progress self-propagating RCU callback function. Because
1652 * callbacks run from softirq, this function is an implicit RCU read-side
1655 static void rcu_torture_fwd_prog_cb(struct rcu_head
*rhp
)
1657 struct fwd_cb_state
*fcsp
= container_of(rhp
, struct fwd_cb_state
, rh
);
1659 if (READ_ONCE(fcsp
->stop
)) {
1660 WRITE_ONCE(fcsp
->stop
, 2);
1663 cur_ops
->call(&fcsp
->rh
, rcu_torture_fwd_prog_cb
);
1666 /* State for continuous-flood RCU callbacks. */
1669 struct rcu_fwd_cb
*rfc_next
;
1670 struct rcu_fwd
*rfc_rfp
;
1674 #define MAX_FWD_CB_JIFFIES (8 * HZ) /* Maximum CB test duration. */
1675 #define MIN_FWD_CB_LAUNDERS 3 /* This many CB invocations to count. */
1676 #define MIN_FWD_CBS_LAUNDERED 100 /* Number of counted CBs. */
1677 #define FWD_CBS_HIST_DIV 10 /* Histogram buckets/second. */
1678 #define N_LAUNDERS_HIST (2 * MAX_FWD_CB_JIFFIES / (HZ / FWD_CBS_HIST_DIV))
1680 struct rcu_launder_hist
{
1682 unsigned long launder_gp_seq
;
1686 spinlock_t rcu_fwd_lock
;
1687 struct rcu_fwd_cb
*rcu_fwd_cb_head
;
1688 struct rcu_fwd_cb
**rcu_fwd_cb_tail
;
1690 unsigned long rcu_fwd_startat
;
1691 struct rcu_launder_hist n_launders_hist
[N_LAUNDERS_HIST
];
1692 unsigned long rcu_launder_gp_seq_start
;
1695 struct rcu_fwd
*rcu_fwds
;
1696 bool rcu_fwd_emergency_stop
;
1698 static void rcu_torture_fwd_cb_hist(struct rcu_fwd
*rfp
)
1701 unsigned long gps_old
;
1705 for (i
= ARRAY_SIZE(rfp
->n_launders_hist
) - 1; i
> 0; i
--)
1706 if (rfp
->n_launders_hist
[i
].n_launders
> 0)
1708 pr_alert("%s: Callback-invocation histogram (duration %lu jiffies):",
1709 __func__
, jiffies
- rfp
->rcu_fwd_startat
);
1710 gps_old
= rfp
->rcu_launder_gp_seq_start
;
1711 for (j
= 0; j
<= i
; j
++) {
1712 gps
= rfp
->n_launders_hist
[j
].launder_gp_seq
;
1713 pr_cont(" %ds/%d: %ld:%ld",
1714 j
+ 1, FWD_CBS_HIST_DIV
,
1715 rfp
->n_launders_hist
[j
].n_launders
,
1716 rcutorture_seq_diff(gps
, gps_old
));
1722 /* Callback function for continuous-flood RCU callbacks. */
1723 static void rcu_torture_fwd_cb_cr(struct rcu_head
*rhp
)
1725 unsigned long flags
;
1727 struct rcu_fwd_cb
*rfcp
= container_of(rhp
, struct rcu_fwd_cb
, rh
);
1728 struct rcu_fwd_cb
**rfcpp
;
1729 struct rcu_fwd
*rfp
= rfcp
->rfc_rfp
;
1731 rfcp
->rfc_next
= NULL
;
1733 spin_lock_irqsave(&rfp
->rcu_fwd_lock
, flags
);
1734 rfcpp
= rfp
->rcu_fwd_cb_tail
;
1735 rfp
->rcu_fwd_cb_tail
= &rfcp
->rfc_next
;
1736 WRITE_ONCE(*rfcpp
, rfcp
);
1737 WRITE_ONCE(rfp
->n_launders_cb
, rfp
->n_launders_cb
+ 1);
1738 i
= ((jiffies
- rfp
->rcu_fwd_startat
) / (HZ
/ FWD_CBS_HIST_DIV
));
1739 if (i
>= ARRAY_SIZE(rfp
->n_launders_hist
))
1740 i
= ARRAY_SIZE(rfp
->n_launders_hist
) - 1;
1741 rfp
->n_launders_hist
[i
].n_launders
++;
1742 rfp
->n_launders_hist
[i
].launder_gp_seq
= cur_ops
->get_gp_seq();
1743 spin_unlock_irqrestore(&rfp
->rcu_fwd_lock
, flags
);
1746 // Give the scheduler a chance, even on nohz_full CPUs.
1747 static void rcu_torture_fwd_prog_cond_resched(unsigned long iter
)
1749 if (IS_ENABLED(CONFIG_PREEMPTION
) && IS_ENABLED(CONFIG_NO_HZ_FULL
)) {
1750 // Real call_rcu() floods hit userspace, so emulate that.
1751 if (need_resched() || (iter
& 0xfff))
1755 // No userspace emulation: CB invocation throttles call_rcu()
1760 * Free all callbacks on the rcu_fwd_cb_head list, either because the
1761 * test is over or because we hit an OOM event.
1763 static unsigned long rcu_torture_fwd_prog_cbfree(struct rcu_fwd
*rfp
)
1765 unsigned long flags
;
1766 unsigned long freed
= 0;
1767 struct rcu_fwd_cb
*rfcp
;
1770 spin_lock_irqsave(&rfp
->rcu_fwd_lock
, flags
);
1771 rfcp
= rfp
->rcu_fwd_cb_head
;
1773 spin_unlock_irqrestore(&rfp
->rcu_fwd_lock
, flags
);
1776 rfp
->rcu_fwd_cb_head
= rfcp
->rfc_next
;
1777 if (!rfp
->rcu_fwd_cb_head
)
1778 rfp
->rcu_fwd_cb_tail
= &rfp
->rcu_fwd_cb_head
;
1779 spin_unlock_irqrestore(&rfp
->rcu_fwd_lock
, flags
);
1782 rcu_torture_fwd_prog_cond_resched(freed
);
1783 if (tick_nohz_full_enabled()) {
1784 local_irq_save(flags
);
1785 rcu_momentary_dyntick_idle();
1786 local_irq_restore(flags
);
1792 /* Carry out need_resched()/cond_resched() forward-progress testing. */
1793 static void rcu_torture_fwd_prog_nr(struct rcu_fwd
*rfp
,
1794 int *tested
, int *tested_tries
)
1798 struct fwd_cb_state fcs
;
1803 bool selfpropcb
= false;
1804 unsigned long stopat
;
1805 static DEFINE_TORTURE_RANDOM(trs
);
1807 if (cur_ops
->call
&& cur_ops
->sync
&& cur_ops
->cb_barrier
) {
1808 init_rcu_head_on_stack(&fcs
.rh
);
1812 /* Tight loop containing cond_resched(). */
1813 WRITE_ONCE(rcu_fwd_cb_nodelay
, true);
1814 cur_ops
->sync(); /* Later readers see above write. */
1816 WRITE_ONCE(fcs
.stop
, 0);
1817 cur_ops
->call(&fcs
.rh
, rcu_torture_fwd_prog_cb
);
1819 cver
= READ_ONCE(rcu_torture_current_version
);
1820 gps
= cur_ops
->get_gp_seq();
1821 sd
= cur_ops
->stall_dur() + 1;
1822 sd4
= (sd
+ fwd_progress_div
- 1) / fwd_progress_div
;
1823 dur
= sd4
+ torture_random(&trs
) % (sd
- sd4
);
1824 WRITE_ONCE(rfp
->rcu_fwd_startat
, jiffies
);
1825 stopat
= rfp
->rcu_fwd_startat
+ dur
;
1826 while (time_before(jiffies
, stopat
) &&
1827 !shutdown_time_arrived() &&
1828 !READ_ONCE(rcu_fwd_emergency_stop
) && !torture_must_stop()) {
1829 idx
= cur_ops
->readlock();
1831 cur_ops
->readunlock(idx
);
1832 if (!fwd_progress_need_resched
|| need_resched())
1836 if (!time_before(jiffies
, stopat
) &&
1837 !shutdown_time_arrived() &&
1838 !READ_ONCE(rcu_fwd_emergency_stop
) && !torture_must_stop()) {
1840 cver
= READ_ONCE(rcu_torture_current_version
) - cver
;
1841 gps
= rcutorture_seq_diff(cur_ops
->get_gp_seq(), gps
);
1842 WARN_ON(!cver
&& gps
< 2);
1843 pr_alert("%s: Duration %ld cver %ld gps %ld\n", __func__
, dur
, cver
, gps
);
1846 WRITE_ONCE(fcs
.stop
, 1);
1847 cur_ops
->sync(); /* Wait for running CB to complete. */
1848 cur_ops
->cb_barrier(); /* Wait for queued callbacks. */
1852 WARN_ON(READ_ONCE(fcs
.stop
) != 2);
1853 destroy_rcu_head_on_stack(&fcs
.rh
);
1855 schedule_timeout_uninterruptible(HZ
/ 10); /* Let kthreads recover. */
1856 WRITE_ONCE(rcu_fwd_cb_nodelay
, false);
1859 /* Carry out call_rcu() forward-progress testing. */
1860 static void rcu_torture_fwd_prog_cr(struct rcu_fwd
*rfp
)
1863 unsigned long flags
;
1867 long n_launders_cb_snap
;
1871 struct rcu_fwd_cb
*rfcp
;
1872 struct rcu_fwd_cb
*rfcpn
;
1873 unsigned long stopat
;
1874 unsigned long stoppedat
;
1876 if (READ_ONCE(rcu_fwd_emergency_stop
))
1877 return; /* Get out of the way quickly, no GP wait! */
1879 return; /* Can't do call_rcu() fwd prog without ->call. */
1881 /* Loop continuously posting RCU callbacks. */
1882 WRITE_ONCE(rcu_fwd_cb_nodelay
, true);
1883 cur_ops
->sync(); /* Later readers see above write. */
1884 WRITE_ONCE(rfp
->rcu_fwd_startat
, jiffies
);
1885 stopat
= rfp
->rcu_fwd_startat
+ MAX_FWD_CB_JIFFIES
;
1887 rfp
->n_launders_cb
= 0; // Hoist initialization for multi-kthread
1891 for (i
= 0; i
< ARRAY_SIZE(rfp
->n_launders_hist
); i
++)
1892 rfp
->n_launders_hist
[i
].n_launders
= 0;
1893 cver
= READ_ONCE(rcu_torture_current_version
);
1894 gps
= cur_ops
->get_gp_seq();
1895 rfp
->rcu_launder_gp_seq_start
= gps
;
1896 tick_dep_set_task(current
, TICK_DEP_BIT_RCU
);
1897 while (time_before(jiffies
, stopat
) &&
1898 !shutdown_time_arrived() &&
1899 !READ_ONCE(rcu_fwd_emergency_stop
) && !torture_must_stop()) {
1900 rfcp
= READ_ONCE(rfp
->rcu_fwd_cb_head
);
1903 rfcpn
= READ_ONCE(rfcp
->rfc_next
);
1905 if (rfcp
->rfc_gps
>= MIN_FWD_CB_LAUNDERS
&&
1906 ++n_max_gps
>= MIN_FWD_CBS_LAUNDERED
)
1908 rfp
->rcu_fwd_cb_head
= rfcpn
;
1912 rfcp
= kmalloc(sizeof(*rfcp
), GFP_KERNEL
);
1913 if (WARN_ON_ONCE(!rfcp
)) {
1914 schedule_timeout_interruptible(1);
1920 rfcp
->rfc_rfp
= rfp
;
1922 cur_ops
->call(&rfcp
->rh
, rcu_torture_fwd_cb_cr
);
1923 rcu_torture_fwd_prog_cond_resched(n_launders
+ n_max_cbs
);
1924 if (tick_nohz_full_enabled()) {
1925 local_irq_save(flags
);
1926 rcu_momentary_dyntick_idle();
1927 local_irq_restore(flags
);
1930 stoppedat
= jiffies
;
1931 n_launders_cb_snap
= READ_ONCE(rfp
->n_launders_cb
);
1932 cver
= READ_ONCE(rcu_torture_current_version
) - cver
;
1933 gps
= rcutorture_seq_diff(cur_ops
->get_gp_seq(), gps
);
1934 cur_ops
->cb_barrier(); /* Wait for callbacks to be invoked. */
1935 (void)rcu_torture_fwd_prog_cbfree(rfp
);
1937 if (!torture_must_stop() && !READ_ONCE(rcu_fwd_emergency_stop
) &&
1938 !shutdown_time_arrived()) {
1939 WARN_ON(n_max_gps
< MIN_FWD_CBS_LAUNDERED
);
1940 pr_alert("%s Duration %lu barrier: %lu pending %ld n_launders: %ld n_launders_sa: %ld n_max_gps: %ld n_max_cbs: %ld cver %ld gps %ld\n",
1942 stoppedat
- rfp
->rcu_fwd_startat
, jiffies
- stoppedat
,
1943 n_launders
+ n_max_cbs
- n_launders_cb_snap
,
1944 n_launders
, n_launders_sa
,
1945 n_max_gps
, n_max_cbs
, cver
, gps
);
1946 rcu_torture_fwd_cb_hist(rfp
);
1948 schedule_timeout_uninterruptible(HZ
); /* Let CBs drain. */
1949 tick_dep_clear_task(current
, TICK_DEP_BIT_RCU
);
1950 WRITE_ONCE(rcu_fwd_cb_nodelay
, false);
1955 * OOM notifier, but this only prints diagnostic information for the
1956 * current forward-progress test.
1958 static int rcutorture_oom_notify(struct notifier_block
*self
,
1959 unsigned long notused
, void *nfreed
)
1961 struct rcu_fwd
*rfp
= rcu_fwds
;
1963 WARN(1, "%s invoked upon OOM during forward-progress testing.\n",
1965 rcu_torture_fwd_cb_hist(rfp
);
1966 rcu_fwd_progress_check(1 + (jiffies
- READ_ONCE(rfp
->rcu_fwd_startat
)) / 2);
1967 WRITE_ONCE(rcu_fwd_emergency_stop
, true);
1968 smp_mb(); /* Emergency stop before free and wait to avoid hangs. */
1969 pr_info("%s: Freed %lu RCU callbacks.\n",
1970 __func__
, rcu_torture_fwd_prog_cbfree(rfp
));
1972 pr_info("%s: Freed %lu RCU callbacks.\n",
1973 __func__
, rcu_torture_fwd_prog_cbfree(rfp
));
1975 pr_info("%s: Freed %lu RCU callbacks.\n",
1976 __func__
, rcu_torture_fwd_prog_cbfree(rfp
));
1977 smp_mb(); /* Frees before return to avoid redoing OOM. */
1978 (*(unsigned long *)nfreed
)++; /* Forward progress CBs freed! */
1979 pr_info("%s returning after OOM processing.\n", __func__
);
1983 static struct notifier_block rcutorture_oom_nb
= {
1984 .notifier_call
= rcutorture_oom_notify
1987 /* Carry out grace-period forward-progress testing. */
1988 static int rcu_torture_fwd_prog(void *args
)
1990 struct rcu_fwd
*rfp
= args
;
1992 int tested_tries
= 0;
1994 VERBOSE_TOROUT_STRING("rcu_torture_fwd_progress task started");
1995 rcu_bind_current_to_nocb();
1996 if (!IS_ENABLED(CONFIG_SMP
) || !IS_ENABLED(CONFIG_RCU_BOOST
))
1997 set_user_nice(current
, MAX_NICE
);
1999 schedule_timeout_interruptible(fwd_progress_holdoff
* HZ
);
2000 WRITE_ONCE(rcu_fwd_emergency_stop
, false);
2001 register_oom_notifier(&rcutorture_oom_nb
);
2002 if (!IS_ENABLED(CONFIG_TINY_RCU
) ||
2003 rcu_inkernel_boot_has_ended())
2004 rcu_torture_fwd_prog_nr(rfp
, &tested
, &tested_tries
);
2005 if (rcu_inkernel_boot_has_ended())
2006 rcu_torture_fwd_prog_cr(rfp
);
2007 unregister_oom_notifier(&rcutorture_oom_nb
);
2009 /* Avoid slow periods, better to test when busy. */
2010 stutter_wait("rcu_torture_fwd_prog");
2011 } while (!torture_must_stop());
2012 /* Short runs might not contain a valid forward-progress attempt. */
2013 WARN_ON(!tested
&& tested_tries
>= 5);
2014 pr_alert("%s: tested %d tested_tries %d\n", __func__
, tested
, tested_tries
);
2015 torture_kthread_stopping("rcu_torture_fwd_prog");
2019 /* If forward-progress checking is requested and feasible, spawn the thread. */
2020 static int __init
rcu_torture_fwd_prog_init(void)
2022 struct rcu_fwd
*rfp
;
2025 return 0; /* Not requested, so don't do it. */
2026 if (!cur_ops
->stall_dur
|| cur_ops
->stall_dur() <= 0 ||
2027 cur_ops
== &rcu_busted_ops
) {
2028 VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, unsupported by RCU flavor under test");
2031 if (stall_cpu
> 0) {
2032 VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, conflicts with CPU-stall testing");
2033 if (IS_MODULE(CONFIG_RCU_TORTURE_TESTS
))
2034 return -EINVAL
; /* In module, can fail back to user. */
2035 WARN_ON(1); /* Make sure rcutorture notices conflict. */
2038 if (fwd_progress_holdoff
<= 0)
2039 fwd_progress_holdoff
= 1;
2040 if (fwd_progress_div
<= 0)
2041 fwd_progress_div
= 4;
2042 rfp
= kzalloc(sizeof(*rfp
), GFP_KERNEL
);
2045 spin_lock_init(&rfp
->rcu_fwd_lock
);
2046 rfp
->rcu_fwd_cb_tail
= &rfp
->rcu_fwd_cb_head
;
2047 return torture_create_kthread(rcu_torture_fwd_prog
, rfp
, fwd_prog_task
);
2050 /* Callback function for RCU barrier testing. */
2051 static void rcu_torture_barrier_cbf(struct rcu_head
*rcu
)
2053 atomic_inc(&barrier_cbs_invoked
);
2056 /* IPI handler to get callback posted on desired CPU, if online. */
2057 static void rcu_torture_barrier1cb(void *rcu_void
)
2059 struct rcu_head
*rhp
= rcu_void
;
2061 cur_ops
->call(rhp
, rcu_torture_barrier_cbf
);
2064 /* kthread function to register callbacks used to test RCU barriers. */
2065 static int rcu_torture_barrier_cbs(void *arg
)
2067 long myid
= (long)arg
;
2070 struct rcu_head rcu
;
2072 init_rcu_head_on_stack(&rcu
);
2073 VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started");
2074 set_user_nice(current
, MAX_NICE
);
2076 wait_event(barrier_cbs_wq
[myid
],
2078 smp_load_acquire(&barrier_phase
)) != lastphase
||
2079 torture_must_stop());
2080 lastphase
= newphase
;
2081 if (torture_must_stop())
2084 * The above smp_load_acquire() ensures barrier_phase load
2085 * is ordered before the following ->call().
2087 if (smp_call_function_single(myid
, rcu_torture_barrier1cb
,
2089 // IPI failed, so use direct call from current CPU.
2090 cur_ops
->call(&rcu
, rcu_torture_barrier_cbf
);
2092 if (atomic_dec_and_test(&barrier_cbs_count
))
2093 wake_up(&barrier_wq
);
2094 } while (!torture_must_stop());
2095 if (cur_ops
->cb_barrier
!= NULL
)
2096 cur_ops
->cb_barrier();
2097 destroy_rcu_head_on_stack(&rcu
);
2098 torture_kthread_stopping("rcu_torture_barrier_cbs");
2102 /* kthread function to drive and coordinate RCU barrier testing. */
2103 static int rcu_torture_barrier(void *arg
)
2107 VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting");
2109 atomic_set(&barrier_cbs_invoked
, 0);
2110 atomic_set(&barrier_cbs_count
, n_barrier_cbs
);
2111 /* Ensure barrier_phase ordered after prior assignments. */
2112 smp_store_release(&barrier_phase
, !barrier_phase
);
2113 for (i
= 0; i
< n_barrier_cbs
; i
++)
2114 wake_up(&barrier_cbs_wq
[i
]);
2115 wait_event(barrier_wq
,
2116 atomic_read(&barrier_cbs_count
) == 0 ||
2117 torture_must_stop());
2118 if (torture_must_stop())
2120 n_barrier_attempts
++;
2121 cur_ops
->cb_barrier(); /* Implies smp_mb() for wait_event(). */
2122 if (atomic_read(&barrier_cbs_invoked
) != n_barrier_cbs
) {
2123 n_rcu_torture_barrier_error
++;
2124 pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n",
2125 atomic_read(&barrier_cbs_invoked
),
2128 // Wait manually for the remaining callbacks
2131 if (WARN_ON(i
++ > HZ
))
2133 schedule_timeout_interruptible(1);
2134 cur_ops
->cb_barrier();
2135 } while (atomic_read(&barrier_cbs_invoked
) !=
2137 !torture_must_stop());
2138 smp_mb(); // Can't trust ordering if broken.
2139 if (!torture_must_stop())
2140 pr_err("Recovered: barrier_cbs_invoked = %d\n",
2141 atomic_read(&barrier_cbs_invoked
));
2143 n_barrier_successes
++;
2145 schedule_timeout_interruptible(HZ
/ 10);
2146 } while (!torture_must_stop());
2147 torture_kthread_stopping("rcu_torture_barrier");
2151 /* Initialize RCU barrier testing. */
2152 static int rcu_torture_barrier_init(void)
2157 if (n_barrier_cbs
<= 0)
2159 if (cur_ops
->call
== NULL
|| cur_ops
->cb_barrier
== NULL
) {
2160 pr_alert("%s" TORTURE_FLAG
2161 " Call or barrier ops missing for %s,\n",
2162 torture_type
, cur_ops
->name
);
2163 pr_alert("%s" TORTURE_FLAG
2164 " RCU barrier testing omitted from run.\n",
2168 atomic_set(&barrier_cbs_count
, 0);
2169 atomic_set(&barrier_cbs_invoked
, 0);
2171 kcalloc(n_barrier_cbs
, sizeof(barrier_cbs_tasks
[0]),
2174 kcalloc(n_barrier_cbs
, sizeof(barrier_cbs_wq
[0]), GFP_KERNEL
);
2175 if (barrier_cbs_tasks
== NULL
|| !barrier_cbs_wq
)
2177 for (i
= 0; i
< n_barrier_cbs
; i
++) {
2178 init_waitqueue_head(&barrier_cbs_wq
[i
]);
2179 ret
= torture_create_kthread(rcu_torture_barrier_cbs
,
2181 barrier_cbs_tasks
[i
]);
2185 return torture_create_kthread(rcu_torture_barrier
, NULL
, barrier_task
);
2188 /* Clean up after RCU barrier testing. */
2189 static void rcu_torture_barrier_cleanup(void)
2193 torture_stop_kthread(rcu_torture_barrier
, barrier_task
);
2194 if (barrier_cbs_tasks
!= NULL
) {
2195 for (i
= 0; i
< n_barrier_cbs
; i
++)
2196 torture_stop_kthread(rcu_torture_barrier_cbs
,
2197 barrier_cbs_tasks
[i
]);
2198 kfree(barrier_cbs_tasks
);
2199 barrier_cbs_tasks
= NULL
;
2201 if (barrier_cbs_wq
!= NULL
) {
2202 kfree(barrier_cbs_wq
);
2203 barrier_cbs_wq
= NULL
;
2207 static bool rcu_torture_can_boost(void)
2209 static int boost_warn_once
;
2212 if (!(test_boost
== 1 && cur_ops
->can_boost
) && test_boost
!= 2)
2215 prio
= rcu_get_gp_kthreads_prio();
2220 if (boost_warn_once
== 1)
2223 pr_alert("%s: WARN: RCU kthread priority too low to test boosting. Skipping RCU boost test. Try passing rcutree.kthread_prio > 1 on the kernel command line.\n", KBUILD_MODNAME
);
2224 boost_warn_once
= 1;
2231 static enum cpuhp_state rcutor_hp
;
2234 rcu_torture_cleanup(void)
2238 unsigned long gp_seq
= 0;
2241 if (torture_cleanup_begin()) {
2242 if (cur_ops
->cb_barrier
!= NULL
)
2243 cur_ops
->cb_barrier();
2247 torture_cleanup_end();
2251 show_rcu_gp_kthreads();
2252 rcu_torture_barrier_cleanup();
2253 torture_stop_kthread(rcu_torture_fwd_prog
, fwd_prog_task
);
2254 torture_stop_kthread(rcu_torture_stall
, stall_task
);
2255 torture_stop_kthread(rcu_torture_writer
, writer_task
);
2258 for (i
= 0; i
< nrealreaders
; i
++)
2259 torture_stop_kthread(rcu_torture_reader
,
2261 kfree(reader_tasks
);
2263 rcu_torture_current
= NULL
;
2265 if (fakewriter_tasks
) {
2266 for (i
= 0; i
< nfakewriters
; i
++) {
2267 torture_stop_kthread(rcu_torture_fakewriter
,
2268 fakewriter_tasks
[i
]);
2270 kfree(fakewriter_tasks
);
2271 fakewriter_tasks
= NULL
;
2274 rcutorture_get_gp_data(cur_ops
->ttype
, &flags
, &gp_seq
);
2275 srcutorture_get_gp_data(cur_ops
->ttype
, srcu_ctlp
, &flags
, &gp_seq
);
2276 pr_alert("%s: End-test grace-period state: g%lu f%#x\n",
2277 cur_ops
->name
, gp_seq
, flags
);
2278 torture_stop_kthread(rcu_torture_stats
, stats_task
);
2279 torture_stop_kthread(rcu_torture_fqs
, fqs_task
);
2280 if (rcu_torture_can_boost())
2281 cpuhp_remove_state(rcutor_hp
);
2284 * Wait for all RCU callbacks to fire, then do torture-type-specific
2285 * cleanup operations.
2287 if (cur_ops
->cb_barrier
!= NULL
)
2288 cur_ops
->cb_barrier();
2289 if (cur_ops
->cleanup
!= NULL
)
2292 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
2294 if (err_segs_recorded
) {
2295 pr_alert("Failure/close-call rcutorture reader segments:\n");
2296 if (rt_read_nsegs
== 0)
2297 pr_alert("\t: No segments recorded!!!\n");
2299 for (i
= 0; i
< rt_read_nsegs
; i
++) {
2300 pr_alert("\t%d: %#x ", i
, err_segs
[i
].rt_readstate
);
2301 if (err_segs
[i
].rt_delay_jiffies
!= 0) {
2302 pr_cont("%s%ldjiffies", firsttime
? "" : "+",
2303 err_segs
[i
].rt_delay_jiffies
);
2306 if (err_segs
[i
].rt_delay_ms
!= 0) {
2307 pr_cont("%s%ldms", firsttime
? "" : "+",
2308 err_segs
[i
].rt_delay_ms
);
2311 if (err_segs
[i
].rt_delay_us
!= 0) {
2312 pr_cont("%s%ldus", firsttime
? "" : "+",
2313 err_segs
[i
].rt_delay_us
);
2317 err_segs
[i
].rt_preempted
? "preempted" : "");
2321 if (atomic_read(&n_rcu_torture_error
) || n_rcu_torture_barrier_error
)
2322 rcu_torture_print_module_parms(cur_ops
, "End of test: FAILURE");
2323 else if (torture_onoff_failures())
2324 rcu_torture_print_module_parms(cur_ops
,
2325 "End of test: RCU_HOTPLUG");
2327 rcu_torture_print_module_parms(cur_ops
, "End of test: SUCCESS");
2328 torture_cleanup_end();
2331 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
2332 static void rcu_torture_leak_cb(struct rcu_head
*rhp
)
2336 static void rcu_torture_err_cb(struct rcu_head
*rhp
)
2339 * This -might- happen due to race conditions, but is unlikely.
2340 * The scenario that leads to this happening is that the
2341 * first of the pair of duplicate callbacks is queued,
2342 * someone else starts a grace period that includes that
2343 * callback, then the second of the pair must wait for the
2344 * next grace period. Unlikely, but can happen. If it
2345 * does happen, the debug-objects subsystem won't have splatted.
2347 pr_alert("%s: duplicated callback was invoked.\n", KBUILD_MODNAME
);
2349 #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
2352 * Verify that double-free causes debug-objects to complain, but only
2353 * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test
2354 * cannot be carried out.
2356 static void rcu_test_debug_objects(void)
2358 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
2359 struct rcu_head rh1
;
2360 struct rcu_head rh2
;
2362 init_rcu_head_on_stack(&rh1
);
2363 init_rcu_head_on_stack(&rh2
);
2364 pr_alert("%s: WARN: Duplicate call_rcu() test starting.\n", KBUILD_MODNAME
);
2366 /* Try to queue the rh2 pair of callbacks for the same grace period. */
2367 preempt_disable(); /* Prevent preemption from interrupting test. */
2368 rcu_read_lock(); /* Make it impossible to finish a grace period. */
2369 call_rcu(&rh1
, rcu_torture_leak_cb
); /* Start grace period. */
2370 local_irq_disable(); /* Make it harder to start a new grace period. */
2371 call_rcu(&rh2
, rcu_torture_leak_cb
);
2372 call_rcu(&rh2
, rcu_torture_err_cb
); /* Duplicate callback. */
2377 /* Wait for them all to get done so we can safely return. */
2379 pr_alert("%s: WARN: Duplicate call_rcu() test complete.\n", KBUILD_MODNAME
);
2380 destroy_rcu_head_on_stack(&rh1
);
2381 destroy_rcu_head_on_stack(&rh2
);
2382 #else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
2383 pr_alert("%s: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n", KBUILD_MODNAME
);
2384 #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
2387 static void rcutorture_sync(void)
2389 static unsigned long n
;
2391 if (cur_ops
->sync
&& !(++n
& 0xfff))
2396 rcu_torture_init(void)
2401 static struct rcu_torture_ops
*torture_ops
[] = {
2402 &rcu_ops
, &rcu_busted_ops
, &srcu_ops
, &srcud_ops
,
2403 &busted_srcud_ops
, &tasks_ops
, &trivial_ops
,
2406 if (!torture_init_begin(torture_type
, verbose
))
2409 /* Process args and tell the world that the torturer is on the job. */
2410 for (i
= 0; i
< ARRAY_SIZE(torture_ops
); i
++) {
2411 cur_ops
= torture_ops
[i
];
2412 if (strcmp(torture_type
, cur_ops
->name
) == 0)
2415 if (i
== ARRAY_SIZE(torture_ops
)) {
2416 pr_alert("rcu-torture: invalid torture type: \"%s\"\n",
2418 pr_alert("rcu-torture types:");
2419 for (i
= 0; i
< ARRAY_SIZE(torture_ops
); i
++)
2420 pr_cont(" %s", torture_ops
[i
]->name
);
2422 WARN_ON(!IS_MODULE(CONFIG_RCU_TORTURE_TEST
));
2427 if (cur_ops
->fqs
== NULL
&& fqs_duration
!= 0) {
2428 pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n");
2434 if (nreaders
>= 0) {
2435 nrealreaders
= nreaders
;
2437 nrealreaders
= num_online_cpus() - 2 - nreaders
;
2438 if (nrealreaders
<= 0)
2441 rcu_torture_print_module_parms(cur_ops
, "Start of test");
2443 /* Set up the freelist. */
2445 INIT_LIST_HEAD(&rcu_torture_freelist
);
2446 for (i
= 0; i
< ARRAY_SIZE(rcu_tortures
); i
++) {
2447 rcu_tortures
[i
].rtort_mbtest
= 0;
2448 list_add_tail(&rcu_tortures
[i
].rtort_free
,
2449 &rcu_torture_freelist
);
2452 /* Initialize the statistics so that each run gets its own numbers. */
2454 rcu_torture_current
= NULL
;
2455 rcu_torture_current_version
= 0;
2456 atomic_set(&n_rcu_torture_alloc
, 0);
2457 atomic_set(&n_rcu_torture_alloc_fail
, 0);
2458 atomic_set(&n_rcu_torture_free
, 0);
2459 atomic_set(&n_rcu_torture_mberror
, 0);
2460 atomic_set(&n_rcu_torture_error
, 0);
2461 n_rcu_torture_barrier_error
= 0;
2462 n_rcu_torture_boost_ktrerror
= 0;
2463 n_rcu_torture_boost_rterror
= 0;
2464 n_rcu_torture_boost_failure
= 0;
2465 n_rcu_torture_boosts
= 0;
2466 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++)
2467 atomic_set(&rcu_torture_wcount
[i
], 0);
2468 for_each_possible_cpu(cpu
) {
2469 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++) {
2470 per_cpu(rcu_torture_count
, cpu
)[i
] = 0;
2471 per_cpu(rcu_torture_batch
, cpu
)[i
] = 0;
2474 err_segs_recorded
= 0;
2477 /* Start up the kthreads. */
2479 firsterr
= torture_create_kthread(rcu_torture_writer
, NULL
,
2483 if (nfakewriters
> 0) {
2484 fakewriter_tasks
= kcalloc(nfakewriters
,
2485 sizeof(fakewriter_tasks
[0]),
2487 if (fakewriter_tasks
== NULL
) {
2488 VERBOSE_TOROUT_ERRSTRING("out of memory");
2493 for (i
= 0; i
< nfakewriters
; i
++) {
2494 firsterr
= torture_create_kthread(rcu_torture_fakewriter
,
2495 NULL
, fakewriter_tasks
[i
]);
2499 reader_tasks
= kcalloc(nrealreaders
, sizeof(reader_tasks
[0]),
2501 if (reader_tasks
== NULL
) {
2502 VERBOSE_TOROUT_ERRSTRING("out of memory");
2506 for (i
= 0; i
< nrealreaders
; i
++) {
2507 firsterr
= torture_create_kthread(rcu_torture_reader
, (void *)i
,
2512 if (stat_interval
> 0) {
2513 firsterr
= torture_create_kthread(rcu_torture_stats
, NULL
,
2518 if (test_no_idle_hz
&& shuffle_interval
> 0) {
2519 firsterr
= torture_shuffle_init(shuffle_interval
* HZ
);
2528 t
= cur_ops
->stall_dur
? cur_ops
->stall_dur() : stutter
* HZ
;
2529 firsterr
= torture_stutter_init(stutter
* HZ
, t
);
2533 if (fqs_duration
< 0)
2536 /* Create the fqs thread */
2537 firsterr
= torture_create_kthread(rcu_torture_fqs
, NULL
,
2542 if (test_boost_interval
< 1)
2543 test_boost_interval
= 1;
2544 if (test_boost_duration
< 2)
2545 test_boost_duration
= 2;
2546 if (rcu_torture_can_boost()) {
2548 boost_starttime
= jiffies
+ test_boost_interval
* HZ
;
2550 firsterr
= cpuhp_setup_state(CPUHP_AP_ONLINE_DYN
, "RCU_TORTURE",
2551 rcutorture_booster_init
,
2552 rcutorture_booster_cleanup
);
2555 rcutor_hp
= firsterr
;
2557 shutdown_jiffies
= jiffies
+ shutdown_secs
* HZ
;
2558 firsterr
= torture_shutdown_init(shutdown_secs
, rcu_torture_cleanup
);
2561 firsterr
= torture_onoff_init(onoff_holdoff
* HZ
, onoff_interval
,
2565 firsterr
= rcu_torture_stall_init();
2568 firsterr
= rcu_torture_fwd_prog_init();
2571 firsterr
= rcu_torture_barrier_init();
2575 rcu_test_debug_objects();
2581 rcu_torture_cleanup();
2585 module_init(rcu_torture_init
);
2586 module_exit(rcu_torture_cleanup
);