2 * Read-Copy Update module-based torture test facility
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 * Copyright (C) IBM Corporation, 2005, 2006
20 * Authors: Paul E. McKenney <paulmck@us.ibm.com>
21 * Josh Triplett <josh@freedesktop.org>
23 * See also: Documentation/RCU/torture.txt
25 #include <linux/types.h>
26 #include <linux/kernel.h>
27 #include <linux/init.h>
28 #include <linux/module.h>
29 #include <linux/kthread.h>
30 #include <linux/err.h>
31 #include <linux/spinlock.h>
32 #include <linux/smp.h>
33 #include <linux/rcupdate.h>
34 #include <linux/interrupt.h>
35 #include <linux/sched.h>
36 #include <linux/atomic.h>
37 #include <linux/bitops.h>
38 #include <linux/completion.h>
39 #include <linux/moduleparam.h>
40 #include <linux/percpu.h>
41 #include <linux/notifier.h>
42 #include <linux/reboot.h>
43 #include <linux/freezer.h>
44 #include <linux/cpu.h>
45 #include <linux/delay.h>
46 #include <linux/stat.h>
47 #include <linux/srcu.h>
48 #include <linux/slab.h>
49 #include <asm/byteorder.h>
51 MODULE_LICENSE("GPL");
52 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and "
53 "Josh Triplett <josh@freedesktop.org>");
55 static int nreaders
= -1; /* # reader threads, defaults to 2*ncpus */
56 static int nfakewriters
= 4; /* # fake writer threads */
57 static int stat_interval
; /* Interval between stats, in seconds. */
58 /* Defaults to "only at end of test". */
59 static bool verbose
; /* Print more debug info. */
60 static bool test_no_idle_hz
; /* Test RCU's support for tickless idle CPUs. */
61 static int shuffle_interval
= 3; /* Interval between shuffles (in sec)*/
62 static int stutter
= 5; /* Start/stop testing interval (in sec) */
63 static int irqreader
= 1; /* RCU readers from irq (timers). */
64 static int fqs_duration
; /* Duration of bursts (us), 0 to disable. */
65 static int fqs_holdoff
; /* Hold time within burst (us). */
66 static int fqs_stutter
= 3; /* Wait time between bursts (s). */
67 static int n_barrier_cbs
; /* Number of callbacks to test RCU barriers. */
68 static int onoff_interval
; /* Wait time between CPU hotplugs, 0=disable. */
69 static int onoff_holdoff
; /* Seconds after boot before CPU hotplugs. */
70 static int shutdown_secs
; /* Shutdown time (s). <=0 for no shutdown. */
71 static int stall_cpu
; /* CPU-stall duration (s). 0 for no stall. */
72 static int stall_cpu_holdoff
= 10; /* Time to wait until stall (s). */
73 static int test_boost
= 1; /* Test RCU prio boost: 0=no, 1=maybe, 2=yes. */
74 static int test_boost_interval
= 7; /* Interval between boost tests, seconds. */
75 static int test_boost_duration
= 4; /* Duration of each boost test, seconds. */
76 static char *torture_type
= "rcu"; /* What RCU implementation to torture. */
78 module_param(nreaders
, int, 0444);
79 MODULE_PARM_DESC(nreaders
, "Number of RCU reader threads");
80 module_param(nfakewriters
, int, 0444);
81 MODULE_PARM_DESC(nfakewriters
, "Number of RCU fake writer threads");
82 module_param(stat_interval
, int, 0644);
83 MODULE_PARM_DESC(stat_interval
, "Number of seconds between stats printk()s");
84 module_param(verbose
, bool, 0444);
85 MODULE_PARM_DESC(verbose
, "Enable verbose debugging printk()s");
86 module_param(test_no_idle_hz
, bool, 0444);
87 MODULE_PARM_DESC(test_no_idle_hz
, "Test support for tickless idle CPUs");
88 module_param(shuffle_interval
, int, 0444);
89 MODULE_PARM_DESC(shuffle_interval
, "Number of seconds between shuffles");
90 module_param(stutter
, int, 0444);
91 MODULE_PARM_DESC(stutter
, "Number of seconds to run/halt test");
92 module_param(irqreader
, int, 0444);
93 MODULE_PARM_DESC(irqreader
, "Allow RCU readers from irq handlers");
94 module_param(fqs_duration
, int, 0444);
95 MODULE_PARM_DESC(fqs_duration
, "Duration of fqs bursts (us)");
96 module_param(fqs_holdoff
, int, 0444);
97 MODULE_PARM_DESC(fqs_holdoff
, "Holdoff time within fqs bursts (us)");
98 module_param(fqs_stutter
, int, 0444);
99 MODULE_PARM_DESC(fqs_stutter
, "Wait time between fqs bursts (s)");
100 module_param(n_barrier_cbs
, int, 0444);
101 MODULE_PARM_DESC(n_barrier_cbs
, "# of callbacks/kthreads for barrier testing");
102 module_param(onoff_interval
, int, 0444);
103 MODULE_PARM_DESC(onoff_interval
, "Time between CPU hotplugs (s), 0=disable");
104 module_param(onoff_holdoff
, int, 0444);
105 MODULE_PARM_DESC(onoff_holdoff
, "Time after boot before CPU hotplugs (s)");
106 module_param(shutdown_secs
, int, 0444);
107 MODULE_PARM_DESC(shutdown_secs
, "Shutdown time (s), zero to disable.");
108 module_param(stall_cpu
, int, 0444);
109 MODULE_PARM_DESC(stall_cpu
, "Stall duration (s), zero to disable.");
110 module_param(stall_cpu_holdoff
, int, 0444);
111 MODULE_PARM_DESC(stall_cpu_holdoff
, "Time to wait before starting stall (s).");
112 module_param(test_boost
, int, 0444);
113 MODULE_PARM_DESC(test_boost
, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
114 module_param(test_boost_interval
, int, 0444);
115 MODULE_PARM_DESC(test_boost_interval
, "Interval between boost tests, seconds.");
116 module_param(test_boost_duration
, int, 0444);
117 MODULE_PARM_DESC(test_boost_duration
, "Duration of each boost test, seconds.");
118 module_param(torture_type
, charp
, 0444);
119 MODULE_PARM_DESC(torture_type
, "Type of RCU to torture (rcu, rcu_bh, srcu)");
121 #define TORTURE_FLAG "-torture:"
122 #define PRINTK_STRING(s) \
123 do { printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0)
124 #define VERBOSE_PRINTK_STRING(s) \
125 do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0)
126 #define VERBOSE_PRINTK_ERRSTRING(s) \
127 do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0)
129 static char printk_buf
[4096];
131 static int nrealreaders
;
132 static struct task_struct
*writer_task
;
133 static struct task_struct
**fakewriter_tasks
;
134 static struct task_struct
**reader_tasks
;
135 static struct task_struct
*stats_task
;
136 static struct task_struct
*shuffler_task
;
137 static struct task_struct
*stutter_task
;
138 static struct task_struct
*fqs_task
;
139 static struct task_struct
*boost_tasks
[NR_CPUS
];
140 static struct task_struct
*shutdown_task
;
141 #ifdef CONFIG_HOTPLUG_CPU
142 static struct task_struct
*onoff_task
;
143 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
144 static struct task_struct
*stall_task
;
145 static struct task_struct
**barrier_cbs_tasks
;
146 static struct task_struct
*barrier_task
;
148 #define RCU_TORTURE_PIPE_LEN 10
151 struct rcu_head rtort_rcu
;
152 int rtort_pipe_count
;
153 struct list_head rtort_free
;
157 static LIST_HEAD(rcu_torture_freelist
);
158 static struct rcu_torture __rcu
*rcu_torture_current
;
159 static unsigned long rcu_torture_current_version
;
160 static struct rcu_torture rcu_tortures
[10 * RCU_TORTURE_PIPE_LEN
];
161 static DEFINE_SPINLOCK(rcu_torture_lock
);
162 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN
+ 1], rcu_torture_count
) =
164 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN
+ 1], rcu_torture_batch
) =
166 static atomic_t rcu_torture_wcount
[RCU_TORTURE_PIPE_LEN
+ 1];
167 static atomic_t n_rcu_torture_alloc
;
168 static atomic_t n_rcu_torture_alloc_fail
;
169 static atomic_t n_rcu_torture_free
;
170 static atomic_t n_rcu_torture_mberror
;
171 static atomic_t n_rcu_torture_error
;
172 static long n_rcu_torture_barrier_error
;
173 static long n_rcu_torture_boost_ktrerror
;
174 static long n_rcu_torture_boost_rterror
;
175 static long n_rcu_torture_boost_failure
;
176 static long n_rcu_torture_boosts
;
177 static long n_rcu_torture_timers
;
178 static long n_offline_attempts
;
179 static long n_offline_successes
;
180 static long n_online_attempts
;
181 static long n_online_successes
;
182 static long n_barrier_attempts
;
183 static long n_barrier_successes
;
184 static struct list_head rcu_torture_removed
;
185 static cpumask_var_t shuffle_tmp_mask
;
187 static int stutter_pause_test
;
189 #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
190 #define RCUTORTURE_RUNNABLE_INIT 1
192 #define RCUTORTURE_RUNNABLE_INIT 0
194 int rcutorture_runnable
= RCUTORTURE_RUNNABLE_INIT
;
195 module_param(rcutorture_runnable
, int, 0444);
196 MODULE_PARM_DESC(rcutorture_runnable
, "Start rcutorture at boot");
198 #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU)
199 #define rcu_can_boost() 1
200 #else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
201 #define rcu_can_boost() 0
202 #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
204 static unsigned long shutdown_time
; /* jiffies to system shutdown. */
205 static unsigned long boost_starttime
; /* jiffies of next boost test start. */
206 DEFINE_MUTEX(boost_mutex
); /* protect setting boost_starttime */
207 /* and boost task create/destroy. */
208 static atomic_t barrier_cbs_count
; /* Barrier callbacks registered. */
209 static bool barrier_phase
; /* Test phase. */
210 static atomic_t barrier_cbs_invoked
; /* Barrier callbacks invoked. */
211 static wait_queue_head_t
*barrier_cbs_wq
; /* Coordinate barrier testing. */
212 static DECLARE_WAIT_QUEUE_HEAD(barrier_wq
);
214 /* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */
216 #define FULLSTOP_DONTSTOP 0 /* Normal operation. */
217 #define FULLSTOP_SHUTDOWN 1 /* System shutdown with rcutorture running. */
218 #define FULLSTOP_RMMOD 2 /* Normal rmmod of rcutorture. */
219 static int fullstop
= FULLSTOP_RMMOD
;
221 * Protect fullstop transitions and spawning of kthreads.
223 static DEFINE_MUTEX(fullstop_mutex
);
225 /* Forward reference. */
226 static void rcu_torture_cleanup(void);
229 * Detect and respond to a system shutdown.
232 rcutorture_shutdown_notify(struct notifier_block
*unused1
,
233 unsigned long unused2
, void *unused3
)
235 mutex_lock(&fullstop_mutex
);
236 if (fullstop
== FULLSTOP_DONTSTOP
)
237 fullstop
= FULLSTOP_SHUTDOWN
;
239 printk(KERN_WARNING
/* but going down anyway, so... */
240 "Concurrent 'rmmod rcutorture' and shutdown illegal!\n");
241 mutex_unlock(&fullstop_mutex
);
246 * Absorb kthreads into a kernel function that won't return, so that
247 * they won't ever access module text or data again.
249 static void rcutorture_shutdown_absorb(char *title
)
251 if (ACCESS_ONCE(fullstop
) == FULLSTOP_SHUTDOWN
) {
253 "rcutorture thread %s parking due to system shutdown\n",
255 schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT
);
260 * Allocate an element from the rcu_tortures pool.
262 static struct rcu_torture
*
263 rcu_torture_alloc(void)
267 spin_lock_bh(&rcu_torture_lock
);
268 if (list_empty(&rcu_torture_freelist
)) {
269 atomic_inc(&n_rcu_torture_alloc_fail
);
270 spin_unlock_bh(&rcu_torture_lock
);
273 atomic_inc(&n_rcu_torture_alloc
);
274 p
= rcu_torture_freelist
.next
;
276 spin_unlock_bh(&rcu_torture_lock
);
277 return container_of(p
, struct rcu_torture
, rtort_free
);
281 * Free an element to the rcu_tortures pool.
284 rcu_torture_free(struct rcu_torture
*p
)
286 atomic_inc(&n_rcu_torture_free
);
287 spin_lock_bh(&rcu_torture_lock
);
288 list_add_tail(&p
->rtort_free
, &rcu_torture_freelist
);
289 spin_unlock_bh(&rcu_torture_lock
);
292 struct rcu_random_state
{
293 unsigned long rrs_state
;
297 #define RCU_RANDOM_MULT 39916801 /* prime */
298 #define RCU_RANDOM_ADD 479001701 /* prime */
299 #define RCU_RANDOM_REFRESH 10000
301 #define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 }
304 * Crude but fast random-number generator. Uses a linear congruential
305 * generator, with occasional help from cpu_clock().
308 rcu_random(struct rcu_random_state
*rrsp
)
310 if (--rrsp
->rrs_count
< 0) {
311 rrsp
->rrs_state
+= (unsigned long)local_clock();
312 rrsp
->rrs_count
= RCU_RANDOM_REFRESH
;
314 rrsp
->rrs_state
= rrsp
->rrs_state
* RCU_RANDOM_MULT
+ RCU_RANDOM_ADD
;
315 return swahw32(rrsp
->rrs_state
);
319 rcu_stutter_wait(char *title
)
321 while (stutter_pause_test
|| !rcutorture_runnable
) {
322 if (rcutorture_runnable
)
323 schedule_timeout_interruptible(1);
325 schedule_timeout_interruptible(round_jiffies_relative(HZ
));
326 rcutorture_shutdown_absorb(title
);
331 * Operations vector for selecting different types of tests.
334 struct rcu_torture_ops
{
336 void (*cleanup
)(void);
337 int (*readlock
)(void);
338 void (*read_delay
)(struct rcu_random_state
*rrsp
);
339 void (*readunlock
)(int idx
);
340 int (*completed
)(void);
341 void (*deferred_free
)(struct rcu_torture
*p
);
343 void (*call
)(struct rcu_head
*head
, void (*func
)(struct rcu_head
*rcu
));
344 void (*cb_barrier
)(void);
346 int (*stats
)(char *page
);
352 static struct rcu_torture_ops
*cur_ops
;
355 * Definitions for rcu torture testing.
358 static int rcu_torture_read_lock(void) __acquires(RCU
)
364 static void rcu_read_delay(struct rcu_random_state
*rrsp
)
366 const unsigned long shortdelay_us
= 200;
367 const unsigned long longdelay_ms
= 50;
369 /* We want a short delay sometimes to make a reader delay the grace
370 * period, and we want a long delay occasionally to trigger
371 * force_quiescent_state. */
373 if (!(rcu_random(rrsp
) % (nrealreaders
* 2000 * longdelay_ms
)))
374 mdelay(longdelay_ms
);
375 if (!(rcu_random(rrsp
) % (nrealreaders
* 2 * shortdelay_us
)))
376 udelay(shortdelay_us
);
377 #ifdef CONFIG_PREEMPT
378 if (!preempt_count() && !(rcu_random(rrsp
) % (nrealreaders
* 20000)))
379 preempt_schedule(); /* No QS if preempt_disable() in effect */
383 static void rcu_torture_read_unlock(int idx
) __releases(RCU
)
388 static int rcu_torture_completed(void)
390 return rcu_batches_completed();
394 rcu_torture_cb(struct rcu_head
*p
)
397 struct rcu_torture
*rp
= container_of(p
, struct rcu_torture
, rtort_rcu
);
399 if (fullstop
!= FULLSTOP_DONTSTOP
) {
400 /* Test is ending, just drop callbacks on the floor. */
401 /* The next initialization will pick up the pieces. */
404 i
= rp
->rtort_pipe_count
;
405 if (i
> RCU_TORTURE_PIPE_LEN
)
406 i
= RCU_TORTURE_PIPE_LEN
;
407 atomic_inc(&rcu_torture_wcount
[i
]);
408 if (++rp
->rtort_pipe_count
>= RCU_TORTURE_PIPE_LEN
) {
409 rp
->rtort_mbtest
= 0;
410 rcu_torture_free(rp
);
412 cur_ops
->deferred_free(rp
);
415 static int rcu_no_completed(void)
420 static void rcu_torture_deferred_free(struct rcu_torture
*p
)
422 call_rcu(&p
->rtort_rcu
, rcu_torture_cb
);
425 static struct rcu_torture_ops rcu_ops
= {
428 .readlock
= rcu_torture_read_lock
,
429 .read_delay
= rcu_read_delay
,
430 .readunlock
= rcu_torture_read_unlock
,
431 .completed
= rcu_torture_completed
,
432 .deferred_free
= rcu_torture_deferred_free
,
433 .sync
= synchronize_rcu
,
435 .cb_barrier
= rcu_barrier
,
436 .fqs
= rcu_force_quiescent_state
,
439 .can_boost
= rcu_can_boost(),
443 static void rcu_sync_torture_deferred_free(struct rcu_torture
*p
)
446 struct rcu_torture
*rp
;
447 struct rcu_torture
*rp1
;
450 list_add(&p
->rtort_free
, &rcu_torture_removed
);
451 list_for_each_entry_safe(rp
, rp1
, &rcu_torture_removed
, rtort_free
) {
452 i
= rp
->rtort_pipe_count
;
453 if (i
> RCU_TORTURE_PIPE_LEN
)
454 i
= RCU_TORTURE_PIPE_LEN
;
455 atomic_inc(&rcu_torture_wcount
[i
]);
456 if (++rp
->rtort_pipe_count
>= RCU_TORTURE_PIPE_LEN
) {
457 rp
->rtort_mbtest
= 0;
458 list_del(&rp
->rtort_free
);
459 rcu_torture_free(rp
);
464 static void rcu_sync_torture_init(void)
466 INIT_LIST_HEAD(&rcu_torture_removed
);
469 static struct rcu_torture_ops rcu_sync_ops
= {
470 .init
= rcu_sync_torture_init
,
472 .readlock
= rcu_torture_read_lock
,
473 .read_delay
= rcu_read_delay
,
474 .readunlock
= rcu_torture_read_unlock
,
475 .completed
= rcu_torture_completed
,
476 .deferred_free
= rcu_sync_torture_deferred_free
,
477 .sync
= synchronize_rcu
,
480 .fqs
= rcu_force_quiescent_state
,
483 .can_boost
= rcu_can_boost(),
487 static struct rcu_torture_ops rcu_expedited_ops
= {
488 .init
= rcu_sync_torture_init
,
490 .readlock
= rcu_torture_read_lock
,
491 .read_delay
= rcu_read_delay
, /* just reuse rcu's version. */
492 .readunlock
= rcu_torture_read_unlock
,
493 .completed
= rcu_no_completed
,
494 .deferred_free
= rcu_sync_torture_deferred_free
,
495 .sync
= synchronize_rcu_expedited
,
498 .fqs
= rcu_force_quiescent_state
,
501 .can_boost
= rcu_can_boost(),
502 .name
= "rcu_expedited"
506 * Definitions for rcu_bh torture testing.
509 static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH
)
515 static void rcu_bh_torture_read_unlock(int idx
) __releases(RCU_BH
)
517 rcu_read_unlock_bh();
520 static int rcu_bh_torture_completed(void)
522 return rcu_batches_completed_bh();
525 static void rcu_bh_torture_deferred_free(struct rcu_torture
*p
)
527 call_rcu_bh(&p
->rtort_rcu
, rcu_torture_cb
);
530 static struct rcu_torture_ops rcu_bh_ops
= {
533 .readlock
= rcu_bh_torture_read_lock
,
534 .read_delay
= rcu_read_delay
, /* just reuse rcu's version. */
535 .readunlock
= rcu_bh_torture_read_unlock
,
536 .completed
= rcu_bh_torture_completed
,
537 .deferred_free
= rcu_bh_torture_deferred_free
,
538 .sync
= synchronize_rcu_bh
,
540 .cb_barrier
= rcu_barrier_bh
,
541 .fqs
= rcu_bh_force_quiescent_state
,
547 static struct rcu_torture_ops rcu_bh_sync_ops
= {
548 .init
= rcu_sync_torture_init
,
550 .readlock
= rcu_bh_torture_read_lock
,
551 .read_delay
= rcu_read_delay
, /* just reuse rcu's version. */
552 .readunlock
= rcu_bh_torture_read_unlock
,
553 .completed
= rcu_bh_torture_completed
,
554 .deferred_free
= rcu_sync_torture_deferred_free
,
555 .sync
= synchronize_rcu_bh
,
558 .fqs
= rcu_bh_force_quiescent_state
,
561 .name
= "rcu_bh_sync"
564 static struct rcu_torture_ops rcu_bh_expedited_ops
= {
565 .init
= rcu_sync_torture_init
,
567 .readlock
= rcu_bh_torture_read_lock
,
568 .read_delay
= rcu_read_delay
, /* just reuse rcu's version. */
569 .readunlock
= rcu_bh_torture_read_unlock
,
570 .completed
= rcu_bh_torture_completed
,
571 .deferred_free
= rcu_sync_torture_deferred_free
,
572 .sync
= synchronize_rcu_bh_expedited
,
575 .fqs
= rcu_bh_force_quiescent_state
,
578 .name
= "rcu_bh_expedited"
582 * Definitions for srcu torture testing.
585 static struct srcu_struct srcu_ctl
;
587 static void srcu_torture_init(void)
589 init_srcu_struct(&srcu_ctl
);
590 rcu_sync_torture_init();
593 static void srcu_torture_cleanup(void)
595 synchronize_srcu(&srcu_ctl
);
596 cleanup_srcu_struct(&srcu_ctl
);
599 static int srcu_torture_read_lock(void) __acquires(&srcu_ctl
)
601 return srcu_read_lock(&srcu_ctl
);
604 static void srcu_read_delay(struct rcu_random_state
*rrsp
)
607 const long uspertick
= 1000000 / HZ
;
608 const long longdelay
= 10;
610 /* We want there to be long-running readers, but not all the time. */
612 delay
= rcu_random(rrsp
) % (nrealreaders
* 2 * longdelay
* uspertick
);
614 schedule_timeout_interruptible(longdelay
);
616 rcu_read_delay(rrsp
);
619 static void srcu_torture_read_unlock(int idx
) __releases(&srcu_ctl
)
621 srcu_read_unlock(&srcu_ctl
, idx
);
624 static int srcu_torture_completed(void)
626 return srcu_batches_completed(&srcu_ctl
);
629 static void srcu_torture_deferred_free(struct rcu_torture
*rp
)
631 call_srcu(&srcu_ctl
, &rp
->rtort_rcu
, rcu_torture_cb
);
634 static void srcu_torture_synchronize(void)
636 synchronize_srcu(&srcu_ctl
);
639 static void srcu_torture_call(struct rcu_head
*head
,
640 void (*func
)(struct rcu_head
*head
))
642 call_srcu(&srcu_ctl
, head
, func
);
645 static void srcu_torture_barrier(void)
647 srcu_barrier(&srcu_ctl
);
650 static int srcu_torture_stats(char *page
)
654 int idx
= srcu_ctl
.completed
& 0x1;
656 cnt
+= sprintf(&page
[cnt
], "%s%s per-CPU(idx=%d):",
657 torture_type
, TORTURE_FLAG
, idx
);
658 for_each_possible_cpu(cpu
) {
659 cnt
+= sprintf(&page
[cnt
], " %d(%lu,%lu)", cpu
,
660 per_cpu_ptr(srcu_ctl
.per_cpu_ref
, cpu
)->c
[!idx
],
661 per_cpu_ptr(srcu_ctl
.per_cpu_ref
, cpu
)->c
[idx
]);
663 cnt
+= sprintf(&page
[cnt
], "\n");
667 static struct rcu_torture_ops srcu_ops
= {
668 .init
= srcu_torture_init
,
669 .cleanup
= srcu_torture_cleanup
,
670 .readlock
= srcu_torture_read_lock
,
671 .read_delay
= srcu_read_delay
,
672 .readunlock
= srcu_torture_read_unlock
,
673 .completed
= srcu_torture_completed
,
674 .deferred_free
= srcu_torture_deferred_free
,
675 .sync
= srcu_torture_synchronize
,
676 .call
= srcu_torture_call
,
677 .cb_barrier
= srcu_torture_barrier
,
678 .stats
= srcu_torture_stats
,
682 static struct rcu_torture_ops srcu_sync_ops
= {
683 .init
= srcu_torture_init
,
684 .cleanup
= srcu_torture_cleanup
,
685 .readlock
= srcu_torture_read_lock
,
686 .read_delay
= srcu_read_delay
,
687 .readunlock
= srcu_torture_read_unlock
,
688 .completed
= srcu_torture_completed
,
689 .deferred_free
= rcu_sync_torture_deferred_free
,
690 .sync
= srcu_torture_synchronize
,
693 .stats
= srcu_torture_stats
,
697 static int srcu_torture_read_lock_raw(void) __acquires(&srcu_ctl
)
699 return srcu_read_lock_raw(&srcu_ctl
);
702 static void srcu_torture_read_unlock_raw(int idx
) __releases(&srcu_ctl
)
704 srcu_read_unlock_raw(&srcu_ctl
, idx
);
707 static struct rcu_torture_ops srcu_raw_ops
= {
708 .init
= srcu_torture_init
,
709 .cleanup
= srcu_torture_cleanup
,
710 .readlock
= srcu_torture_read_lock_raw
,
711 .read_delay
= srcu_read_delay
,
712 .readunlock
= srcu_torture_read_unlock_raw
,
713 .completed
= srcu_torture_completed
,
714 .deferred_free
= srcu_torture_deferred_free
,
715 .sync
= srcu_torture_synchronize
,
718 .stats
= srcu_torture_stats
,
722 static struct rcu_torture_ops srcu_raw_sync_ops
= {
723 .init
= srcu_torture_init
,
724 .cleanup
= srcu_torture_cleanup
,
725 .readlock
= srcu_torture_read_lock_raw
,
726 .read_delay
= srcu_read_delay
,
727 .readunlock
= srcu_torture_read_unlock_raw
,
728 .completed
= srcu_torture_completed
,
729 .deferred_free
= rcu_sync_torture_deferred_free
,
730 .sync
= srcu_torture_synchronize
,
733 .stats
= srcu_torture_stats
,
734 .name
= "srcu_raw_sync"
737 static void srcu_torture_synchronize_expedited(void)
739 synchronize_srcu_expedited(&srcu_ctl
);
742 static struct rcu_torture_ops srcu_expedited_ops
= {
743 .init
= srcu_torture_init
,
744 .cleanup
= srcu_torture_cleanup
,
745 .readlock
= srcu_torture_read_lock
,
746 .read_delay
= srcu_read_delay
,
747 .readunlock
= srcu_torture_read_unlock
,
748 .completed
= srcu_torture_completed
,
749 .deferred_free
= rcu_sync_torture_deferred_free
,
750 .sync
= srcu_torture_synchronize_expedited
,
753 .stats
= srcu_torture_stats
,
754 .name
= "srcu_expedited"
758 * Definitions for sched torture testing.
761 static int sched_torture_read_lock(void)
767 static void sched_torture_read_unlock(int idx
)
772 static void rcu_sched_torture_deferred_free(struct rcu_torture
*p
)
774 call_rcu_sched(&p
->rtort_rcu
, rcu_torture_cb
);
777 static struct rcu_torture_ops sched_ops
= {
778 .init
= rcu_sync_torture_init
,
780 .readlock
= sched_torture_read_lock
,
781 .read_delay
= rcu_read_delay
, /* just reuse rcu's version. */
782 .readunlock
= sched_torture_read_unlock
,
783 .completed
= rcu_no_completed
,
784 .deferred_free
= rcu_sched_torture_deferred_free
,
785 .sync
= synchronize_sched
,
786 .cb_barrier
= rcu_barrier_sched
,
787 .fqs
= rcu_sched_force_quiescent_state
,
793 static struct rcu_torture_ops sched_sync_ops
= {
794 .init
= rcu_sync_torture_init
,
796 .readlock
= sched_torture_read_lock
,
797 .read_delay
= rcu_read_delay
, /* just reuse rcu's version. */
798 .readunlock
= sched_torture_read_unlock
,
799 .completed
= rcu_no_completed
,
800 .deferred_free
= rcu_sync_torture_deferred_free
,
801 .sync
= synchronize_sched
,
803 .fqs
= rcu_sched_force_quiescent_state
,
808 static struct rcu_torture_ops sched_expedited_ops
= {
809 .init
= rcu_sync_torture_init
,
811 .readlock
= sched_torture_read_lock
,
812 .read_delay
= rcu_read_delay
, /* just reuse rcu's version. */
813 .readunlock
= sched_torture_read_unlock
,
814 .completed
= rcu_no_completed
,
815 .deferred_free
= rcu_sync_torture_deferred_free
,
816 .sync
= synchronize_sched_expedited
,
818 .fqs
= rcu_sched_force_quiescent_state
,
821 .name
= "sched_expedited"
825 * RCU torture priority-boost testing. Runs one real-time thread per
826 * CPU for moderate bursts, repeatedly registering RCU callbacks and
827 * spinning waiting for them to be invoked. If a given callback takes
828 * too long to be invoked, we assume that priority inversion has occurred.
831 struct rcu_boost_inflight
{
836 static void rcu_torture_boost_cb(struct rcu_head
*head
)
838 struct rcu_boost_inflight
*rbip
=
839 container_of(head
, struct rcu_boost_inflight
, rcu
);
841 smp_mb(); /* Ensure RCU-core accesses precede clearing ->inflight */
845 static int rcu_torture_boost(void *arg
)
847 unsigned long call_rcu_time
;
848 unsigned long endtime
;
849 unsigned long oldstarttime
;
850 struct rcu_boost_inflight rbi
= { .inflight
= 0 };
851 struct sched_param sp
;
853 VERBOSE_PRINTK_STRING("rcu_torture_boost started");
855 /* Set real-time priority. */
856 sp
.sched_priority
= 1;
857 if (sched_setscheduler(current
, SCHED_FIFO
, &sp
) < 0) {
858 VERBOSE_PRINTK_STRING("rcu_torture_boost RT prio failed!");
859 n_rcu_torture_boost_rterror
++;
862 init_rcu_head_on_stack(&rbi
.rcu
);
863 /* Each pass through the following loop does one boost-test cycle. */
865 /* Wait for the next test interval. */
866 oldstarttime
= boost_starttime
;
867 while (ULONG_CMP_LT(jiffies
, oldstarttime
)) {
868 schedule_timeout_uninterruptible(1);
869 rcu_stutter_wait("rcu_torture_boost");
870 if (kthread_should_stop() ||
871 fullstop
!= FULLSTOP_DONTSTOP
)
875 /* Do one boost-test interval. */
876 endtime
= oldstarttime
+ test_boost_duration
* HZ
;
877 call_rcu_time
= jiffies
;
878 while (ULONG_CMP_LT(jiffies
, endtime
)) {
879 /* If we don't have a callback in flight, post one. */
881 smp_mb(); /* RCU core before ->inflight = 1. */
883 call_rcu(&rbi
.rcu
, rcu_torture_boost_cb
);
884 if (jiffies
- call_rcu_time
>
885 test_boost_duration
* HZ
- HZ
/ 2) {
886 VERBOSE_PRINTK_STRING("rcu_torture_boost boosting failed");
887 n_rcu_torture_boost_failure
++;
889 call_rcu_time
= jiffies
;
892 rcu_stutter_wait("rcu_torture_boost");
893 if (kthread_should_stop() ||
894 fullstop
!= FULLSTOP_DONTSTOP
)
899 * Set the start time of the next test interval.
900 * Yes, this is vulnerable to long delays, but such
901 * delays simply cause a false negative for the next
902 * interval. Besides, we are running at RT priority,
903 * so delays should be relatively rare.
905 while (oldstarttime
== boost_starttime
&&
906 !kthread_should_stop()) {
907 if (mutex_trylock(&boost_mutex
)) {
908 boost_starttime
= jiffies
+
909 test_boost_interval
* HZ
;
910 n_rcu_torture_boosts
++;
911 mutex_unlock(&boost_mutex
);
914 schedule_timeout_uninterruptible(1);
917 /* Go do the stutter. */
918 checkwait
: rcu_stutter_wait("rcu_torture_boost");
919 } while (!kthread_should_stop() && fullstop
== FULLSTOP_DONTSTOP
);
921 /* Clean up and exit. */
922 VERBOSE_PRINTK_STRING("rcu_torture_boost task stopping");
923 rcutorture_shutdown_absorb("rcu_torture_boost");
924 while (!kthread_should_stop() || rbi
.inflight
)
925 schedule_timeout_uninterruptible(1);
926 smp_mb(); /* order accesses to ->inflight before stack-frame death. */
927 destroy_rcu_head_on_stack(&rbi
.rcu
);
932 * RCU torture force-quiescent-state kthread. Repeatedly induces
933 * bursts of calls to force_quiescent_state(), increasing the probability
934 * of occurrence of some important types of race conditions.
937 rcu_torture_fqs(void *arg
)
939 unsigned long fqs_resume_time
;
940 int fqs_burst_remaining
;
942 VERBOSE_PRINTK_STRING("rcu_torture_fqs task started");
944 fqs_resume_time
= jiffies
+ fqs_stutter
* HZ
;
945 while (ULONG_CMP_LT(jiffies
, fqs_resume_time
) &&
946 !kthread_should_stop()) {
947 schedule_timeout_interruptible(1);
949 fqs_burst_remaining
= fqs_duration
;
950 while (fqs_burst_remaining
> 0 &&
951 !kthread_should_stop()) {
954 fqs_burst_remaining
-= fqs_holdoff
;
956 rcu_stutter_wait("rcu_torture_fqs");
957 } while (!kthread_should_stop() && fullstop
== FULLSTOP_DONTSTOP
);
958 VERBOSE_PRINTK_STRING("rcu_torture_fqs task stopping");
959 rcutorture_shutdown_absorb("rcu_torture_fqs");
960 while (!kthread_should_stop())
961 schedule_timeout_uninterruptible(1);
966 * RCU torture writer kthread. Repeatedly substitutes a new structure
967 * for that pointed to by rcu_torture_current, freeing the old structure
968 * after a series of grace periods (the "pipeline").
971 rcu_torture_writer(void *arg
)
974 long oldbatch
= rcu_batches_completed();
975 struct rcu_torture
*rp
;
976 struct rcu_torture
*old_rp
;
977 static DEFINE_RCU_RANDOM(rand
);
979 VERBOSE_PRINTK_STRING("rcu_torture_writer task started");
980 set_user_nice(current
, 19);
983 schedule_timeout_uninterruptible(1);
984 rp
= rcu_torture_alloc();
987 rp
->rtort_pipe_count
= 0;
988 udelay(rcu_random(&rand
) & 0x3ff);
989 old_rp
= rcu_dereference_check(rcu_torture_current
,
990 current
== writer_task
);
991 rp
->rtort_mbtest
= 1;
992 rcu_assign_pointer(rcu_torture_current
, rp
);
993 smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */
995 i
= old_rp
->rtort_pipe_count
;
996 if (i
> RCU_TORTURE_PIPE_LEN
)
997 i
= RCU_TORTURE_PIPE_LEN
;
998 atomic_inc(&rcu_torture_wcount
[i
]);
999 old_rp
->rtort_pipe_count
++;
1000 cur_ops
->deferred_free(old_rp
);
1002 rcutorture_record_progress(++rcu_torture_current_version
);
1003 oldbatch
= cur_ops
->completed();
1004 rcu_stutter_wait("rcu_torture_writer");
1005 } while (!kthread_should_stop() && fullstop
== FULLSTOP_DONTSTOP
);
1006 VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping");
1007 rcutorture_shutdown_absorb("rcu_torture_writer");
1008 while (!kthread_should_stop())
1009 schedule_timeout_uninterruptible(1);
1014 * RCU torture fake writer kthread. Repeatedly calls sync, with a random
1015 * delay between calls.
1018 rcu_torture_fakewriter(void *arg
)
1020 DEFINE_RCU_RANDOM(rand
);
1022 VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task started");
1023 set_user_nice(current
, 19);
1026 schedule_timeout_uninterruptible(1 + rcu_random(&rand
)%10);
1027 udelay(rcu_random(&rand
) & 0x3ff);
1029 rcu_stutter_wait("rcu_torture_fakewriter");
1030 } while (!kthread_should_stop() && fullstop
== FULLSTOP_DONTSTOP
);
1032 VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping");
1033 rcutorture_shutdown_absorb("rcu_torture_fakewriter");
1034 while (!kthread_should_stop())
1035 schedule_timeout_uninterruptible(1);
1039 void rcutorture_trace_dump(void)
1041 static atomic_t beenhere
= ATOMIC_INIT(0);
1043 if (atomic_read(&beenhere
))
1045 if (atomic_xchg(&beenhere
, 1) != 0)
1047 do_trace_rcu_torture_read(cur_ops
->name
, (struct rcu_head
*)~0UL);
1048 ftrace_dump(DUMP_ALL
);
1052 * RCU torture reader from timer handler. Dereferences rcu_torture_current,
1053 * incrementing the corresponding element of the pipeline array. The
1054 * counter in the element should never be greater than 1, otherwise, the
1055 * RCU implementation is broken.
1057 static void rcu_torture_timer(unsigned long unused
)
1061 static DEFINE_RCU_RANDOM(rand
);
1062 static DEFINE_SPINLOCK(rand_lock
);
1063 struct rcu_torture
*p
;
1066 idx
= cur_ops
->readlock();
1067 completed
= cur_ops
->completed();
1068 p
= rcu_dereference_check(rcu_torture_current
,
1069 rcu_read_lock_bh_held() ||
1070 rcu_read_lock_sched_held() ||
1071 srcu_read_lock_held(&srcu_ctl
));
1073 /* Leave because rcu_torture_writer is not yet underway */
1074 cur_ops
->readunlock(idx
);
1077 do_trace_rcu_torture_read(cur_ops
->name
, &p
->rtort_rcu
);
1078 if (p
->rtort_mbtest
== 0)
1079 atomic_inc(&n_rcu_torture_mberror
);
1080 spin_lock(&rand_lock
);
1081 cur_ops
->read_delay(&rand
);
1082 n_rcu_torture_timers
++;
1083 spin_unlock(&rand_lock
);
1085 pipe_count
= p
->rtort_pipe_count
;
1086 if (pipe_count
> RCU_TORTURE_PIPE_LEN
) {
1087 /* Should not happen, but... */
1088 pipe_count
= RCU_TORTURE_PIPE_LEN
;
1091 rcutorture_trace_dump();
1092 __this_cpu_inc(rcu_torture_count
[pipe_count
]);
1093 completed
= cur_ops
->completed() - completed
;
1094 if (completed
> RCU_TORTURE_PIPE_LEN
) {
1095 /* Should not happen, but... */
1096 completed
= RCU_TORTURE_PIPE_LEN
;
1098 __this_cpu_inc(rcu_torture_batch
[completed
]);
1100 cur_ops
->readunlock(idx
);
1104 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current,
1105 * incrementing the corresponding element of the pipeline array. The
1106 * counter in the element should never be greater than 1, otherwise, the
1107 * RCU implementation is broken.
1110 rcu_torture_reader(void *arg
)
1114 DEFINE_RCU_RANDOM(rand
);
1115 struct rcu_torture
*p
;
1117 struct timer_list t
;
1119 VERBOSE_PRINTK_STRING("rcu_torture_reader task started");
1120 set_user_nice(current
, 19);
1121 if (irqreader
&& cur_ops
->irq_capable
)
1122 setup_timer_on_stack(&t
, rcu_torture_timer
, 0);
1125 if (irqreader
&& cur_ops
->irq_capable
) {
1126 if (!timer_pending(&t
))
1127 mod_timer(&t
, jiffies
+ 1);
1129 idx
= cur_ops
->readlock();
1130 completed
= cur_ops
->completed();
1131 p
= rcu_dereference_check(rcu_torture_current
,
1132 rcu_read_lock_bh_held() ||
1133 rcu_read_lock_sched_held() ||
1134 srcu_read_lock_held(&srcu_ctl
));
1136 /* Wait for rcu_torture_writer to get underway */
1137 cur_ops
->readunlock(idx
);
1138 schedule_timeout_interruptible(HZ
);
1141 do_trace_rcu_torture_read(cur_ops
->name
, &p
->rtort_rcu
);
1142 if (p
->rtort_mbtest
== 0)
1143 atomic_inc(&n_rcu_torture_mberror
);
1144 cur_ops
->read_delay(&rand
);
1146 pipe_count
= p
->rtort_pipe_count
;
1147 if (pipe_count
> RCU_TORTURE_PIPE_LEN
) {
1148 /* Should not happen, but... */
1149 pipe_count
= RCU_TORTURE_PIPE_LEN
;
1152 rcutorture_trace_dump();
1153 __this_cpu_inc(rcu_torture_count
[pipe_count
]);
1154 completed
= cur_ops
->completed() - completed
;
1155 if (completed
> RCU_TORTURE_PIPE_LEN
) {
1156 /* Should not happen, but... */
1157 completed
= RCU_TORTURE_PIPE_LEN
;
1159 __this_cpu_inc(rcu_torture_batch
[completed
]);
1161 cur_ops
->readunlock(idx
);
1163 rcu_stutter_wait("rcu_torture_reader");
1164 } while (!kthread_should_stop() && fullstop
== FULLSTOP_DONTSTOP
);
1165 VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping");
1166 rcutorture_shutdown_absorb("rcu_torture_reader");
1167 if (irqreader
&& cur_ops
->irq_capable
)
1169 while (!kthread_should_stop())
1170 schedule_timeout_uninterruptible(1);
1175 * Create an RCU-torture statistics message in the specified buffer.
1178 rcu_torture_printk(char *page
)
1183 long pipesummary
[RCU_TORTURE_PIPE_LEN
+ 1] = { 0 };
1184 long batchsummary
[RCU_TORTURE_PIPE_LEN
+ 1] = { 0 };
1186 for_each_possible_cpu(cpu
) {
1187 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++) {
1188 pipesummary
[i
] += per_cpu(rcu_torture_count
, cpu
)[i
];
1189 batchsummary
[i
] += per_cpu(rcu_torture_batch
, cpu
)[i
];
1192 for (i
= RCU_TORTURE_PIPE_LEN
- 1; i
>= 0; i
--) {
1193 if (pipesummary
[i
] != 0)
1196 cnt
+= sprintf(&page
[cnt
], "%s%s ", torture_type
, TORTURE_FLAG
);
1197 cnt
+= sprintf(&page
[cnt
],
1198 "rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d "
1199 "rtmbe: %d rtbke: %ld rtbre: %ld "
1200 "rtbf: %ld rtb: %ld nt: %ld "
1201 "onoff: %ld/%ld:%ld/%ld "
1202 "barrier: %ld/%ld:%ld",
1203 rcu_torture_current
,
1204 rcu_torture_current_version
,
1205 list_empty(&rcu_torture_freelist
),
1206 atomic_read(&n_rcu_torture_alloc
),
1207 atomic_read(&n_rcu_torture_alloc_fail
),
1208 atomic_read(&n_rcu_torture_free
),
1209 atomic_read(&n_rcu_torture_mberror
),
1210 n_rcu_torture_boost_ktrerror
,
1211 n_rcu_torture_boost_rterror
,
1212 n_rcu_torture_boost_failure
,
1213 n_rcu_torture_boosts
,
1214 n_rcu_torture_timers
,
1217 n_offline_successes
,
1219 n_barrier_successes
,
1221 n_rcu_torture_barrier_error
);
1222 cnt
+= sprintf(&page
[cnt
], "\n%s%s ", torture_type
, TORTURE_FLAG
);
1223 if (atomic_read(&n_rcu_torture_mberror
) != 0 ||
1224 n_rcu_torture_barrier_error
!= 0 ||
1225 n_rcu_torture_boost_ktrerror
!= 0 ||
1226 n_rcu_torture_boost_rterror
!= 0 ||
1227 n_rcu_torture_boost_failure
!= 0 ||
1229 cnt
+= sprintf(&page
[cnt
], "!!! ");
1230 atomic_inc(&n_rcu_torture_error
);
1233 cnt
+= sprintf(&page
[cnt
], "Reader Pipe: ");
1234 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++)
1235 cnt
+= sprintf(&page
[cnt
], " %ld", pipesummary
[i
]);
1236 cnt
+= sprintf(&page
[cnt
], "\n%s%s ", torture_type
, TORTURE_FLAG
);
1237 cnt
+= sprintf(&page
[cnt
], "Reader Batch: ");
1238 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++)
1239 cnt
+= sprintf(&page
[cnt
], " %ld", batchsummary
[i
]);
1240 cnt
+= sprintf(&page
[cnt
], "\n%s%s ", torture_type
, TORTURE_FLAG
);
1241 cnt
+= sprintf(&page
[cnt
], "Free-Block Circulation: ");
1242 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++) {
1243 cnt
+= sprintf(&page
[cnt
], " %d",
1244 atomic_read(&rcu_torture_wcount
[i
]));
1246 cnt
+= sprintf(&page
[cnt
], "\n");
1248 cnt
+= cur_ops
->stats(&page
[cnt
]);
1253 * Print torture statistics. Caller must ensure that there is only
1254 * one call to this function at a given time!!! This is normally
1255 * accomplished by relying on the module system to only have one copy
1256 * of the module loaded, and then by giving the rcu_torture_stats
1257 * kthread full control (or the init/cleanup functions when rcu_torture_stats
1258 * thread is not running).
1261 rcu_torture_stats_print(void)
1265 cnt
= rcu_torture_printk(printk_buf
);
1266 printk(KERN_ALERT
"%s", printk_buf
);
1270 * Periodically prints torture statistics, if periodic statistics printing
1271 * was specified via the stat_interval module parameter.
1273 * No need to worry about fullstop here, since this one doesn't reference
1274 * volatile state or register callbacks.
1277 rcu_torture_stats(void *arg
)
1279 VERBOSE_PRINTK_STRING("rcu_torture_stats task started");
1281 schedule_timeout_interruptible(stat_interval
* HZ
);
1282 rcu_torture_stats_print();
1283 rcutorture_shutdown_absorb("rcu_torture_stats");
1284 } while (!kthread_should_stop());
1285 VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping");
1289 static int rcu_idle_cpu
; /* Force all torture tasks off this CPU */
1291 /* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case
1292 * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs.
1294 static void rcu_torture_shuffle_tasks(void)
1298 cpumask_setall(shuffle_tmp_mask
);
1301 /* No point in shuffling if there is only one online CPU (ex: UP) */
1302 if (num_online_cpus() == 1) {
1307 if (rcu_idle_cpu
!= -1)
1308 cpumask_clear_cpu(rcu_idle_cpu
, shuffle_tmp_mask
);
1310 set_cpus_allowed_ptr(current
, shuffle_tmp_mask
);
1313 for (i
= 0; i
< nrealreaders
; i
++)
1314 if (reader_tasks
[i
])
1315 set_cpus_allowed_ptr(reader_tasks
[i
],
1319 if (fakewriter_tasks
) {
1320 for (i
= 0; i
< nfakewriters
; i
++)
1321 if (fakewriter_tasks
[i
])
1322 set_cpus_allowed_ptr(fakewriter_tasks
[i
],
1327 set_cpus_allowed_ptr(writer_task
, shuffle_tmp_mask
);
1330 set_cpus_allowed_ptr(stats_task
, shuffle_tmp_mask
);
1332 if (rcu_idle_cpu
== -1)
1333 rcu_idle_cpu
= num_online_cpus() - 1;
1340 /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the
1341 * system to become idle at a time and cut off its timer ticks. This is meant
1342 * to test the support for such tickless idle CPU in RCU.
1345 rcu_torture_shuffle(void *arg
)
1347 VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started");
1349 schedule_timeout_interruptible(shuffle_interval
* HZ
);
1350 rcu_torture_shuffle_tasks();
1351 rcutorture_shutdown_absorb("rcu_torture_shuffle");
1352 } while (!kthread_should_stop());
1353 VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping");
1357 /* Cause the rcutorture test to "stutter", starting and stopping all
1358 * threads periodically.
1361 rcu_torture_stutter(void *arg
)
1363 VERBOSE_PRINTK_STRING("rcu_torture_stutter task started");
1365 schedule_timeout_interruptible(stutter
* HZ
);
1366 stutter_pause_test
= 1;
1367 if (!kthread_should_stop())
1368 schedule_timeout_interruptible(stutter
* HZ
);
1369 stutter_pause_test
= 0;
1370 rcutorture_shutdown_absorb("rcu_torture_stutter");
1371 } while (!kthread_should_stop());
1372 VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping");
1377 rcu_torture_print_module_parms(struct rcu_torture_ops
*cur_ops
, char *tag
)
1379 printk(KERN_ALERT
"%s" TORTURE_FLAG
1380 "--- %s: nreaders=%d nfakewriters=%d "
1381 "stat_interval=%d verbose=%d test_no_idle_hz=%d "
1382 "shuffle_interval=%d stutter=%d irqreader=%d "
1383 "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
1384 "test_boost=%d/%d test_boost_interval=%d "
1385 "test_boost_duration=%d shutdown_secs=%d "
1386 "onoff_interval=%d onoff_holdoff=%d\n",
1387 torture_type
, tag
, nrealreaders
, nfakewriters
,
1388 stat_interval
, verbose
, test_no_idle_hz
, shuffle_interval
,
1389 stutter
, irqreader
, fqs_duration
, fqs_holdoff
, fqs_stutter
,
1390 test_boost
, cur_ops
->can_boost
,
1391 test_boost_interval
, test_boost_duration
, shutdown_secs
,
1392 onoff_interval
, onoff_holdoff
);
1395 static struct notifier_block rcutorture_shutdown_nb
= {
1396 .notifier_call
= rcutorture_shutdown_notify
,
1399 static void rcutorture_booster_cleanup(int cpu
)
1401 struct task_struct
*t
;
1403 if (boost_tasks
[cpu
] == NULL
)
1405 mutex_lock(&boost_mutex
);
1406 VERBOSE_PRINTK_STRING("Stopping rcu_torture_boost task");
1407 t
= boost_tasks
[cpu
];
1408 boost_tasks
[cpu
] = NULL
;
1409 mutex_unlock(&boost_mutex
);
1411 /* This must be outside of the mutex, otherwise deadlock! */
1413 boost_tasks
[cpu
] = NULL
;
1416 static int rcutorture_booster_init(int cpu
)
1420 if (boost_tasks
[cpu
] != NULL
)
1421 return 0; /* Already created, nothing more to do. */
1423 /* Don't allow time recalculation while creating a new task. */
1424 mutex_lock(&boost_mutex
);
1425 VERBOSE_PRINTK_STRING("Creating rcu_torture_boost task");
1426 boost_tasks
[cpu
] = kthread_create_on_node(rcu_torture_boost
, NULL
,
1428 "rcu_torture_boost");
1429 if (IS_ERR(boost_tasks
[cpu
])) {
1430 retval
= PTR_ERR(boost_tasks
[cpu
]);
1431 VERBOSE_PRINTK_STRING("rcu_torture_boost task create failed");
1432 n_rcu_torture_boost_ktrerror
++;
1433 boost_tasks
[cpu
] = NULL
;
1434 mutex_unlock(&boost_mutex
);
1437 kthread_bind(boost_tasks
[cpu
], cpu
);
1438 wake_up_process(boost_tasks
[cpu
]);
1439 mutex_unlock(&boost_mutex
);
1444 * Cause the rcutorture test to shutdown the system after the test has
1445 * run for the time specified by the shutdown_secs module parameter.
1448 rcu_torture_shutdown(void *arg
)
1451 unsigned long jiffies_snap
;
1453 VERBOSE_PRINTK_STRING("rcu_torture_shutdown task started");
1454 jiffies_snap
= ACCESS_ONCE(jiffies
);
1455 while (ULONG_CMP_LT(jiffies_snap
, shutdown_time
) &&
1456 !kthread_should_stop()) {
1457 delta
= shutdown_time
- jiffies_snap
;
1459 printk(KERN_ALERT
"%s" TORTURE_FLAG
1460 "rcu_torture_shutdown task: %lu "
1461 "jiffies remaining\n",
1462 torture_type
, delta
);
1463 schedule_timeout_interruptible(delta
);
1464 jiffies_snap
= ACCESS_ONCE(jiffies
);
1466 if (kthread_should_stop()) {
1467 VERBOSE_PRINTK_STRING("rcu_torture_shutdown task stopping");
1471 /* OK, shut down the system. */
1473 VERBOSE_PRINTK_STRING("rcu_torture_shutdown task shutting down system");
1474 shutdown_task
= NULL
; /* Avoid self-kill deadlock. */
1475 rcu_torture_cleanup(); /* Get the success/failure message. */
1476 kernel_power_off(); /* Shut down the system. */
1480 #ifdef CONFIG_HOTPLUG_CPU
1483 * Execute random CPU-hotplug operations at the interval specified
1484 * by the onoff_interval.
1486 static int __cpuinit
1487 rcu_torture_onoff(void *arg
)
1491 DEFINE_RCU_RANDOM(rand
);
1493 VERBOSE_PRINTK_STRING("rcu_torture_onoff task started");
1494 for_each_online_cpu(cpu
)
1496 WARN_ON(maxcpu
< 0);
1497 if (onoff_holdoff
> 0) {
1498 VERBOSE_PRINTK_STRING("rcu_torture_onoff begin holdoff");
1499 schedule_timeout_interruptible(onoff_holdoff
* HZ
);
1500 VERBOSE_PRINTK_STRING("rcu_torture_onoff end holdoff");
1502 while (!kthread_should_stop()) {
1503 cpu
= (rcu_random(&rand
) >> 4) % (maxcpu
+ 1);
1504 if (cpu_online(cpu
) && cpu_is_hotpluggable(cpu
)) {
1506 printk(KERN_ALERT
"%s" TORTURE_FLAG
1507 "rcu_torture_onoff task: offlining %d\n",
1509 n_offline_attempts
++;
1510 if (cpu_down(cpu
) == 0) {
1512 printk(KERN_ALERT
"%s" TORTURE_FLAG
1513 "rcu_torture_onoff task: "
1516 n_offline_successes
++;
1518 } else if (cpu_is_hotpluggable(cpu
)) {
1520 printk(KERN_ALERT
"%s" TORTURE_FLAG
1521 "rcu_torture_onoff task: onlining %d\n",
1523 n_online_attempts
++;
1524 if (cpu_up(cpu
) == 0) {
1526 printk(KERN_ALERT
"%s" TORTURE_FLAG
1527 "rcu_torture_onoff task: "
1530 n_online_successes
++;
1533 schedule_timeout_interruptible(onoff_interval
* HZ
);
1535 VERBOSE_PRINTK_STRING("rcu_torture_onoff task stopping");
1539 static int __cpuinit
1540 rcu_torture_onoff_init(void)
1544 if (onoff_interval
<= 0)
1546 onoff_task
= kthread_run(rcu_torture_onoff
, NULL
, "rcu_torture_onoff");
1547 if (IS_ERR(onoff_task
)) {
1548 ret
= PTR_ERR(onoff_task
);
1555 static void rcu_torture_onoff_cleanup(void)
1557 if (onoff_task
== NULL
)
1559 VERBOSE_PRINTK_STRING("Stopping rcu_torture_onoff task");
1560 kthread_stop(onoff_task
);
1564 #else /* #ifdef CONFIG_HOTPLUG_CPU */
1567 rcu_torture_onoff_init(void)
1572 static void rcu_torture_onoff_cleanup(void)
1576 #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */
1579 * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then
1580 * induces a CPU stall for the time specified by stall_cpu.
1582 static int __cpuinit
rcu_torture_stall(void *args
)
1584 unsigned long stop_at
;
1586 VERBOSE_PRINTK_STRING("rcu_torture_stall task started");
1587 if (stall_cpu_holdoff
> 0) {
1588 VERBOSE_PRINTK_STRING("rcu_torture_stall begin holdoff");
1589 schedule_timeout_interruptible(stall_cpu_holdoff
* HZ
);
1590 VERBOSE_PRINTK_STRING("rcu_torture_stall end holdoff");
1592 if (!kthread_should_stop()) {
1593 stop_at
= get_seconds() + stall_cpu
;
1594 /* RCU CPU stall is expected behavior in following code. */
1595 printk(KERN_ALERT
"rcu_torture_stall start.\n");
1598 while (ULONG_CMP_LT(get_seconds(), stop_at
))
1599 continue; /* Induce RCU CPU stall warning. */
1602 printk(KERN_ALERT
"rcu_torture_stall end.\n");
1604 rcutorture_shutdown_absorb("rcu_torture_stall");
1605 while (!kthread_should_stop())
1606 schedule_timeout_interruptible(10 * HZ
);
1610 /* Spawn CPU-stall kthread, if stall_cpu specified. */
1611 static int __init
rcu_torture_stall_init(void)
1617 stall_task
= kthread_run(rcu_torture_stall
, NULL
, "rcu_torture_stall");
1618 if (IS_ERR(stall_task
)) {
1619 ret
= PTR_ERR(stall_task
);
1626 /* Clean up after the CPU-stall kthread, if one was spawned. */
1627 static void rcu_torture_stall_cleanup(void)
1629 if (stall_task
== NULL
)
1631 VERBOSE_PRINTK_STRING("Stopping rcu_torture_stall_task.");
1632 kthread_stop(stall_task
);
1636 /* Callback function for RCU barrier testing. */
1637 void rcu_torture_barrier_cbf(struct rcu_head
*rcu
)
1639 atomic_inc(&barrier_cbs_invoked
);
1642 /* kthread function to register callbacks used to test RCU barriers. */
1643 static int rcu_torture_barrier_cbs(void *arg
)
1645 long myid
= (long)arg
;
1647 struct rcu_head rcu
;
1649 init_rcu_head_on_stack(&rcu
);
1650 VERBOSE_PRINTK_STRING("rcu_torture_barrier_cbs task started");
1651 set_user_nice(current
, 19);
1653 wait_event(barrier_cbs_wq
[myid
],
1654 barrier_phase
!= lastphase
||
1655 kthread_should_stop() ||
1656 fullstop
!= FULLSTOP_DONTSTOP
);
1657 lastphase
= barrier_phase
;
1658 smp_mb(); /* ensure barrier_phase load before ->call(). */
1659 if (kthread_should_stop() || fullstop
!= FULLSTOP_DONTSTOP
)
1661 cur_ops
->call(&rcu
, rcu_torture_barrier_cbf
);
1662 if (atomic_dec_and_test(&barrier_cbs_count
))
1663 wake_up(&barrier_wq
);
1664 } while (!kthread_should_stop() && fullstop
== FULLSTOP_DONTSTOP
);
1665 VERBOSE_PRINTK_STRING("rcu_torture_barrier_cbs task stopping");
1666 rcutorture_shutdown_absorb("rcu_torture_barrier_cbs");
1667 while (!kthread_should_stop())
1668 schedule_timeout_interruptible(1);
1669 cur_ops
->cb_barrier();
1670 destroy_rcu_head_on_stack(&rcu
);
1674 /* kthread function to drive and coordinate RCU barrier testing. */
1675 static int rcu_torture_barrier(void *arg
)
1679 VERBOSE_PRINTK_STRING("rcu_torture_barrier task starting");
1681 atomic_set(&barrier_cbs_invoked
, 0);
1682 atomic_set(&barrier_cbs_count
, n_barrier_cbs
);
1683 smp_mb(); /* Ensure barrier_phase after prior assignments. */
1684 barrier_phase
= !barrier_phase
;
1685 for (i
= 0; i
< n_barrier_cbs
; i
++)
1686 wake_up(&barrier_cbs_wq
[i
]);
1687 wait_event(barrier_wq
,
1688 atomic_read(&barrier_cbs_count
) == 0 ||
1689 kthread_should_stop() ||
1690 fullstop
!= FULLSTOP_DONTSTOP
);
1691 if (kthread_should_stop() || fullstop
!= FULLSTOP_DONTSTOP
)
1693 n_barrier_attempts
++;
1694 cur_ops
->cb_barrier();
1695 if (atomic_read(&barrier_cbs_invoked
) != n_barrier_cbs
) {
1696 n_rcu_torture_barrier_error
++;
1699 n_barrier_successes
++;
1700 schedule_timeout_interruptible(HZ
/ 10);
1701 } while (!kthread_should_stop() && fullstop
== FULLSTOP_DONTSTOP
);
1702 VERBOSE_PRINTK_STRING("rcu_torture_barrier task stopping");
1703 rcutorture_shutdown_absorb("rcu_torture_barrier");
1704 while (!kthread_should_stop())
1705 schedule_timeout_interruptible(1);
1709 /* Initialize RCU barrier testing. */
1710 static int rcu_torture_barrier_init(void)
1715 if (n_barrier_cbs
== 0)
1717 if (cur_ops
->call
== NULL
|| cur_ops
->cb_barrier
== NULL
) {
1718 printk(KERN_ALERT
"%s" TORTURE_FLAG
1719 " Call or barrier ops missing for %s,\n",
1720 torture_type
, cur_ops
->name
);
1721 printk(KERN_ALERT
"%s" TORTURE_FLAG
1722 " RCU barrier testing omitted from run.\n",
1726 atomic_set(&barrier_cbs_count
, 0);
1727 atomic_set(&barrier_cbs_invoked
, 0);
1729 kzalloc(n_barrier_cbs
* sizeof(barrier_cbs_tasks
[0]),
1732 kzalloc(n_barrier_cbs
* sizeof(barrier_cbs_wq
[0]),
1734 if (barrier_cbs_tasks
== NULL
|| barrier_cbs_wq
== 0)
1736 for (i
= 0; i
< n_barrier_cbs
; i
++) {
1737 init_waitqueue_head(&barrier_cbs_wq
[i
]);
1738 barrier_cbs_tasks
[i
] = kthread_run(rcu_torture_barrier_cbs
,
1740 "rcu_torture_barrier_cbs");
1741 if (IS_ERR(barrier_cbs_tasks
[i
])) {
1742 ret
= PTR_ERR(barrier_cbs_tasks
[i
]);
1743 VERBOSE_PRINTK_ERRSTRING("Failed to create rcu_torture_barrier_cbs");
1744 barrier_cbs_tasks
[i
] = NULL
;
1748 barrier_task
= kthread_run(rcu_torture_barrier
, NULL
,
1749 "rcu_torture_barrier");
1750 if (IS_ERR(barrier_task
)) {
1751 ret
= PTR_ERR(barrier_task
);
1752 VERBOSE_PRINTK_ERRSTRING("Failed to create rcu_torture_barrier");
1753 barrier_task
= NULL
;
1758 /* Clean up after RCU barrier testing. */
1759 static void rcu_torture_barrier_cleanup(void)
1763 if (barrier_task
!= NULL
) {
1764 VERBOSE_PRINTK_STRING("Stopping rcu_torture_barrier task");
1765 kthread_stop(barrier_task
);
1766 barrier_task
= NULL
;
1768 if (barrier_cbs_tasks
!= NULL
) {
1769 for (i
= 0; i
< n_barrier_cbs
; i
++) {
1770 if (barrier_cbs_tasks
[i
] != NULL
) {
1771 VERBOSE_PRINTK_STRING("Stopping rcu_torture_barrier_cbs task");
1772 kthread_stop(barrier_cbs_tasks
[i
]);
1773 barrier_cbs_tasks
[i
] = NULL
;
1776 kfree(barrier_cbs_tasks
);
1777 barrier_cbs_tasks
= NULL
;
1779 if (barrier_cbs_wq
!= NULL
) {
1780 kfree(barrier_cbs_wq
);
1781 barrier_cbs_wq
= NULL
;
1785 static int rcutorture_cpu_notify(struct notifier_block
*self
,
1786 unsigned long action
, void *hcpu
)
1788 long cpu
= (long)hcpu
;
1792 case CPU_DOWN_FAILED
:
1793 (void)rcutorture_booster_init(cpu
);
1795 case CPU_DOWN_PREPARE
:
1796 rcutorture_booster_cleanup(cpu
);
1804 static struct notifier_block rcutorture_cpu_nb
= {
1805 .notifier_call
= rcutorture_cpu_notify
,
1809 rcu_torture_cleanup(void)
1813 mutex_lock(&fullstop_mutex
);
1814 rcutorture_record_test_transition();
1815 if (fullstop
== FULLSTOP_SHUTDOWN
) {
1816 printk(KERN_WARNING
/* but going down anyway, so... */
1817 "Concurrent 'rmmod rcutorture' and shutdown illegal!\n");
1818 mutex_unlock(&fullstop_mutex
);
1819 schedule_timeout_uninterruptible(10);
1820 if (cur_ops
->cb_barrier
!= NULL
)
1821 cur_ops
->cb_barrier();
1824 fullstop
= FULLSTOP_RMMOD
;
1825 mutex_unlock(&fullstop_mutex
);
1826 unregister_reboot_notifier(&rcutorture_shutdown_nb
);
1827 rcu_torture_barrier_cleanup();
1828 rcu_torture_stall_cleanup();
1830 VERBOSE_PRINTK_STRING("Stopping rcu_torture_stutter task");
1831 kthread_stop(stutter_task
);
1833 stutter_task
= NULL
;
1834 if (shuffler_task
) {
1835 VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task");
1836 kthread_stop(shuffler_task
);
1837 free_cpumask_var(shuffle_tmp_mask
);
1839 shuffler_task
= NULL
;
1842 VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task");
1843 kthread_stop(writer_task
);
1848 for (i
= 0; i
< nrealreaders
; i
++) {
1849 if (reader_tasks
[i
]) {
1850 VERBOSE_PRINTK_STRING(
1851 "Stopping rcu_torture_reader task");
1852 kthread_stop(reader_tasks
[i
]);
1854 reader_tasks
[i
] = NULL
;
1856 kfree(reader_tasks
);
1857 reader_tasks
= NULL
;
1859 rcu_torture_current
= NULL
;
1861 if (fakewriter_tasks
) {
1862 for (i
= 0; i
< nfakewriters
; i
++) {
1863 if (fakewriter_tasks
[i
]) {
1864 VERBOSE_PRINTK_STRING(
1865 "Stopping rcu_torture_fakewriter task");
1866 kthread_stop(fakewriter_tasks
[i
]);
1868 fakewriter_tasks
[i
] = NULL
;
1870 kfree(fakewriter_tasks
);
1871 fakewriter_tasks
= NULL
;
1875 VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task");
1876 kthread_stop(stats_task
);
1881 VERBOSE_PRINTK_STRING("Stopping rcu_torture_fqs task");
1882 kthread_stop(fqs_task
);
1885 if ((test_boost
== 1 && cur_ops
->can_boost
) ||
1887 unregister_cpu_notifier(&rcutorture_cpu_nb
);
1888 for_each_possible_cpu(i
)
1889 rcutorture_booster_cleanup(i
);
1891 if (shutdown_task
!= NULL
) {
1892 VERBOSE_PRINTK_STRING("Stopping rcu_torture_shutdown task");
1893 kthread_stop(shutdown_task
);
1895 shutdown_task
= NULL
;
1896 rcu_torture_onoff_cleanup();
1898 /* Wait for all RCU callbacks to fire. */
1900 if (cur_ops
->cb_barrier
!= NULL
)
1901 cur_ops
->cb_barrier();
1903 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
1905 if (cur_ops
->cleanup
)
1907 if (atomic_read(&n_rcu_torture_error
) || n_rcu_torture_barrier_error
)
1908 rcu_torture_print_module_parms(cur_ops
, "End of test: FAILURE");
1909 else if (n_online_successes
!= n_online_attempts
||
1910 n_offline_successes
!= n_offline_attempts
)
1911 rcu_torture_print_module_parms(cur_ops
,
1912 "End of test: RCU_HOTPLUG");
1914 rcu_torture_print_module_parms(cur_ops
, "End of test: SUCCESS");
1918 rcu_torture_init(void)
1924 static struct rcu_torture_ops
*torture_ops
[] =
1925 { &rcu_ops
, &rcu_sync_ops
, &rcu_expedited_ops
,
1926 &rcu_bh_ops
, &rcu_bh_sync_ops
, &rcu_bh_expedited_ops
,
1927 &srcu_ops
, &srcu_sync_ops
, &srcu_expedited_ops
,
1928 &srcu_raw_ops
, &srcu_raw_sync_ops
,
1929 &sched_ops
, &sched_sync_ops
, &sched_expedited_ops
, };
1931 mutex_lock(&fullstop_mutex
);
1933 /* Process args and tell the world that the torturer is on the job. */
1934 for (i
= 0; i
< ARRAY_SIZE(torture_ops
); i
++) {
1935 cur_ops
= torture_ops
[i
];
1936 if (strcmp(torture_type
, cur_ops
->name
) == 0)
1939 if (i
== ARRAY_SIZE(torture_ops
)) {
1940 printk(KERN_ALERT
"rcu-torture: invalid torture type: \"%s\"\n",
1942 printk(KERN_ALERT
"rcu-torture types:");
1943 for (i
= 0; i
< ARRAY_SIZE(torture_ops
); i
++)
1944 printk(KERN_ALERT
" %s", torture_ops
[i
]->name
);
1945 printk(KERN_ALERT
"\n");
1946 mutex_unlock(&fullstop_mutex
);
1949 if (cur_ops
->fqs
== NULL
&& fqs_duration
!= 0) {
1950 printk(KERN_ALERT
"rcu-torture: ->fqs NULL and non-zero "
1951 "fqs_duration, fqs disabled.\n");
1955 cur_ops
->init(); /* no "goto unwind" prior to this point!!! */
1958 nrealreaders
= nreaders
;
1960 nrealreaders
= 2 * num_online_cpus();
1961 rcu_torture_print_module_parms(cur_ops
, "Start of test");
1962 fullstop
= FULLSTOP_DONTSTOP
;
1964 /* Set up the freelist. */
1966 INIT_LIST_HEAD(&rcu_torture_freelist
);
1967 for (i
= 0; i
< ARRAY_SIZE(rcu_tortures
); i
++) {
1968 rcu_tortures
[i
].rtort_mbtest
= 0;
1969 list_add_tail(&rcu_tortures
[i
].rtort_free
,
1970 &rcu_torture_freelist
);
1973 /* Initialize the statistics so that each run gets its own numbers. */
1975 rcu_torture_current
= NULL
;
1976 rcu_torture_current_version
= 0;
1977 atomic_set(&n_rcu_torture_alloc
, 0);
1978 atomic_set(&n_rcu_torture_alloc_fail
, 0);
1979 atomic_set(&n_rcu_torture_free
, 0);
1980 atomic_set(&n_rcu_torture_mberror
, 0);
1981 atomic_set(&n_rcu_torture_error
, 0);
1982 n_rcu_torture_barrier_error
= 0;
1983 n_rcu_torture_boost_ktrerror
= 0;
1984 n_rcu_torture_boost_rterror
= 0;
1985 n_rcu_torture_boost_failure
= 0;
1986 n_rcu_torture_boosts
= 0;
1987 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++)
1988 atomic_set(&rcu_torture_wcount
[i
], 0);
1989 for_each_possible_cpu(cpu
) {
1990 for (i
= 0; i
< RCU_TORTURE_PIPE_LEN
+ 1; i
++) {
1991 per_cpu(rcu_torture_count
, cpu
)[i
] = 0;
1992 per_cpu(rcu_torture_batch
, cpu
)[i
] = 0;
1996 /* Start up the kthreads. */
1998 VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task");
1999 writer_task
= kthread_run(rcu_torture_writer
, NULL
,
2000 "rcu_torture_writer");
2001 if (IS_ERR(writer_task
)) {
2002 firsterr
= PTR_ERR(writer_task
);
2003 VERBOSE_PRINTK_ERRSTRING("Failed to create writer");
2007 fakewriter_tasks
= kzalloc(nfakewriters
* sizeof(fakewriter_tasks
[0]),
2009 if (fakewriter_tasks
== NULL
) {
2010 VERBOSE_PRINTK_ERRSTRING("out of memory");
2014 for (i
= 0; i
< nfakewriters
; i
++) {
2015 VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task");
2016 fakewriter_tasks
[i
] = kthread_run(rcu_torture_fakewriter
, NULL
,
2017 "rcu_torture_fakewriter");
2018 if (IS_ERR(fakewriter_tasks
[i
])) {
2019 firsterr
= PTR_ERR(fakewriter_tasks
[i
]);
2020 VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter");
2021 fakewriter_tasks
[i
] = NULL
;
2025 reader_tasks
= kzalloc(nrealreaders
* sizeof(reader_tasks
[0]),
2027 if (reader_tasks
== NULL
) {
2028 VERBOSE_PRINTK_ERRSTRING("out of memory");
2032 for (i
= 0; i
< nrealreaders
; i
++) {
2033 VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task");
2034 reader_tasks
[i
] = kthread_run(rcu_torture_reader
, NULL
,
2035 "rcu_torture_reader");
2036 if (IS_ERR(reader_tasks
[i
])) {
2037 firsterr
= PTR_ERR(reader_tasks
[i
]);
2038 VERBOSE_PRINTK_ERRSTRING("Failed to create reader");
2039 reader_tasks
[i
] = NULL
;
2043 if (stat_interval
> 0) {
2044 VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task");
2045 stats_task
= kthread_run(rcu_torture_stats
, NULL
,
2046 "rcu_torture_stats");
2047 if (IS_ERR(stats_task
)) {
2048 firsterr
= PTR_ERR(stats_task
);
2049 VERBOSE_PRINTK_ERRSTRING("Failed to create stats");
2054 if (test_no_idle_hz
) {
2055 rcu_idle_cpu
= num_online_cpus() - 1;
2057 if (!alloc_cpumask_var(&shuffle_tmp_mask
, GFP_KERNEL
)) {
2059 VERBOSE_PRINTK_ERRSTRING("Failed to alloc mask");
2063 /* Create the shuffler thread */
2064 shuffler_task
= kthread_run(rcu_torture_shuffle
, NULL
,
2065 "rcu_torture_shuffle");
2066 if (IS_ERR(shuffler_task
)) {
2067 free_cpumask_var(shuffle_tmp_mask
);
2068 firsterr
= PTR_ERR(shuffler_task
);
2069 VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler");
2070 shuffler_task
= NULL
;
2077 /* Create the stutter thread */
2078 stutter_task
= kthread_run(rcu_torture_stutter
, NULL
,
2079 "rcu_torture_stutter");
2080 if (IS_ERR(stutter_task
)) {
2081 firsterr
= PTR_ERR(stutter_task
);
2082 VERBOSE_PRINTK_ERRSTRING("Failed to create stutter");
2083 stutter_task
= NULL
;
2087 if (fqs_duration
< 0)
2090 /* Create the stutter thread */
2091 fqs_task
= kthread_run(rcu_torture_fqs
, NULL
,
2093 if (IS_ERR(fqs_task
)) {
2094 firsterr
= PTR_ERR(fqs_task
);
2095 VERBOSE_PRINTK_ERRSTRING("Failed to create fqs");
2100 if (test_boost_interval
< 1)
2101 test_boost_interval
= 1;
2102 if (test_boost_duration
< 2)
2103 test_boost_duration
= 2;
2104 if ((test_boost
== 1 && cur_ops
->can_boost
) ||
2107 boost_starttime
= jiffies
+ test_boost_interval
* HZ
;
2108 register_cpu_notifier(&rcutorture_cpu_nb
);
2109 for_each_possible_cpu(i
) {
2110 if (cpu_is_offline(i
))
2111 continue; /* Heuristic: CPU can go offline. */
2112 retval
= rcutorture_booster_init(i
);
2119 if (shutdown_secs
> 0) {
2120 shutdown_time
= jiffies
+ shutdown_secs
* HZ
;
2121 shutdown_task
= kthread_run(rcu_torture_shutdown
, NULL
,
2122 "rcu_torture_shutdown");
2123 if (IS_ERR(shutdown_task
)) {
2124 firsterr
= PTR_ERR(shutdown_task
);
2125 VERBOSE_PRINTK_ERRSTRING("Failed to create shutdown");
2126 shutdown_task
= NULL
;
2130 i
= rcu_torture_onoff_init();
2135 register_reboot_notifier(&rcutorture_shutdown_nb
);
2136 i
= rcu_torture_stall_init();
2141 retval
= rcu_torture_barrier_init();
2146 rcutorture_record_test_transition();
2147 mutex_unlock(&fullstop_mutex
);
2151 mutex_unlock(&fullstop_mutex
);
2152 rcu_torture_cleanup();
2156 module_init(rcu_torture_init
);
2157 module_exit(rcu_torture_cleanup
);