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1 | /* | |
2 | * Read-Copy Update module-based torture test facility | |
3 | * | |
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. | |
8 | * | |
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. | |
13 | * | |
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. | |
17 | * | |
18 | * Copyright (C) IBM Corporation, 2005, 2006 | |
19 | * | |
20 | * Authors: Paul E. McKenney <paulmck@us.ibm.com> | |
21 | * Josh Triplett <josh@freedesktop.org> | |
22 | * | |
23 | * See also: Documentation/RCU/torture.txt | |
24 | */ | |
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> | |
50 | ||
51 | MODULE_LICENSE("GPL"); | |
52 | MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and " | |
53 | "Josh Triplett <josh@freedesktop.org>"); | |
54 | ||
55 | static int nreaders = -1; /* # reader threads, defaults to 2*ncpus */ | |
56 | static int nfakewriters = 4; /* # fake writer threads */ | |
57 | static int stat_interval; /* Interval between stats, in seconds. */ | |
58 | /* Defaults to "only at end of test". */ | |
59 | static int verbose; /* Print more debug info. */ | |
60 | static int test_no_idle_hz; /* Test RCU's support for tickless idle CPUs. */ | |
61 | static int shuffle_interval = 3; /* Interval between shuffles (in sec)*/ | |
62 | static int stutter = 5; /* Start/stop testing interval (in sec) */ | |
63 | static int irqreader = 1; /* RCU readers from irq (timers). */ | |
64 | static 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 onoff_interval; /* Wait time between CPU hotplugs, 0=disable. */ | |
68 | static int shutdown_secs; /* Shutdown time (s). <=0 for no shutdown. */ | |
69 | static int test_boost = 1; /* Test RCU prio boost: 0=no, 1=maybe, 2=yes. */ | |
70 | static int test_boost_interval = 7; /* Interval between boost tests, seconds. */ | |
71 | static int test_boost_duration = 4; /* Duration of each boost test, seconds. */ | |
72 | static char *torture_type = "rcu"; /* What RCU implementation to torture. */ | |
73 | ||
74 | module_param(nreaders, int, 0444); | |
75 | MODULE_PARM_DESC(nreaders, "Number of RCU reader threads"); | |
76 | module_param(nfakewriters, int, 0444); | |
77 | MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads"); | |
78 | module_param(stat_interval, int, 0644); | |
79 | MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s"); | |
80 | module_param(verbose, bool, 0444); | |
81 | MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s"); | |
82 | module_param(test_no_idle_hz, bool, 0444); | |
83 | MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs"); | |
84 | module_param(shuffle_interval, int, 0444); | |
85 | MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles"); | |
86 | module_param(stutter, int, 0444); | |
87 | MODULE_PARM_DESC(stutter, "Number of seconds to run/halt test"); | |
88 | module_param(irqreader, int, 0444); | |
89 | MODULE_PARM_DESC(irqreader, "Allow RCU readers from irq handlers"); | |
90 | module_param(fqs_duration, int, 0444); | |
91 | MODULE_PARM_DESC(fqs_duration, "Duration of fqs bursts (us)"); | |
92 | module_param(fqs_holdoff, int, 0444); | |
93 | MODULE_PARM_DESC(fqs_holdoff, "Holdoff time within fqs bursts (us)"); | |
94 | module_param(fqs_stutter, int, 0444); | |
95 | MODULE_PARM_DESC(fqs_stutter, "Wait time between fqs bursts (s)"); | |
96 | module_param(onoff_interval, int, 0444); | |
97 | MODULE_PARM_DESC(onoff_interval, "Time between CPU hotplugs (s), 0=disable"); | |
98 | module_param(shutdown_secs, int, 0444); | |
99 | MODULE_PARM_DESC(shutdown_secs, "Shutdown time (s), zero to disable."); | |
100 | module_param(test_boost, int, 0444); | |
101 | MODULE_PARM_DESC(test_boost, "Test RCU prio boost: 0=no, 1=maybe, 2=yes."); | |
102 | module_param(test_boost_interval, int, 0444); | |
103 | MODULE_PARM_DESC(test_boost_interval, "Interval between boost tests, seconds."); | |
104 | module_param(test_boost_duration, int, 0444); | |
105 | MODULE_PARM_DESC(test_boost_duration, "Duration of each boost test, seconds."); | |
106 | module_param(torture_type, charp, 0444); | |
107 | MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)"); | |
108 | ||
109 | #define TORTURE_FLAG "-torture:" | |
110 | #define PRINTK_STRING(s) \ | |
111 | do { printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0) | |
112 | #define VERBOSE_PRINTK_STRING(s) \ | |
113 | do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0) | |
114 | #define VERBOSE_PRINTK_ERRSTRING(s) \ | |
115 | do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0) | |
116 | ||
117 | static char printk_buf[4096]; | |
118 | ||
119 | static int nrealreaders; | |
120 | static struct task_struct *writer_task; | |
121 | static struct task_struct **fakewriter_tasks; | |
122 | static struct task_struct **reader_tasks; | |
123 | static struct task_struct *stats_task; | |
124 | static struct task_struct *shuffler_task; | |
125 | static struct task_struct *stutter_task; | |
126 | static struct task_struct *fqs_task; | |
127 | static struct task_struct *boost_tasks[NR_CPUS]; | |
128 | static struct task_struct *shutdown_task; | |
129 | #ifdef CONFIG_HOTPLUG_CPU | |
130 | static struct task_struct *onoff_task; | |
131 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
132 | ||
133 | #define RCU_TORTURE_PIPE_LEN 10 | |
134 | ||
135 | struct rcu_torture { | |
136 | struct rcu_head rtort_rcu; | |
137 | int rtort_pipe_count; | |
138 | struct list_head rtort_free; | |
139 | int rtort_mbtest; | |
140 | }; | |
141 | ||
142 | static LIST_HEAD(rcu_torture_freelist); | |
143 | static struct rcu_torture __rcu *rcu_torture_current; | |
144 | static unsigned long rcu_torture_current_version; | |
145 | static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; | |
146 | static DEFINE_SPINLOCK(rcu_torture_lock); | |
147 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) = | |
148 | { 0 }; | |
149 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) = | |
150 | { 0 }; | |
151 | static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1]; | |
152 | static atomic_t n_rcu_torture_alloc; | |
153 | static atomic_t n_rcu_torture_alloc_fail; | |
154 | static atomic_t n_rcu_torture_free; | |
155 | static atomic_t n_rcu_torture_mberror; | |
156 | static atomic_t n_rcu_torture_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 long n_rcu_torture_timers; | |
162 | static long n_offline_attempts; | |
163 | static long n_offline_successes; | |
164 | static long n_online_attempts; | |
165 | static long n_online_successes; | |
166 | static struct list_head rcu_torture_removed; | |
167 | static cpumask_var_t shuffle_tmp_mask; | |
168 | ||
169 | static int stutter_pause_test; | |
170 | ||
171 | #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE) | |
172 | #define RCUTORTURE_RUNNABLE_INIT 1 | |
173 | #else | |
174 | #define RCUTORTURE_RUNNABLE_INIT 0 | |
175 | #endif | |
176 | int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT; | |
177 | module_param(rcutorture_runnable, int, 0444); | |
178 | MODULE_PARM_DESC(rcutorture_runnable, "Start rcutorture at boot"); | |
179 | ||
180 | #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) | |
181 | #define rcu_can_boost() 1 | |
182 | #else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ | |
183 | #define rcu_can_boost() 0 | |
184 | #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ | |
185 | ||
186 | static unsigned long shutdown_time; /* jiffies to system shutdown. */ | |
187 | static unsigned long boost_starttime; /* jiffies of next boost test start. */ | |
188 | DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */ | |
189 | /* and boost task create/destroy. */ | |
190 | ||
191 | /* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */ | |
192 | ||
193 | #define FULLSTOP_DONTSTOP 0 /* Normal operation. */ | |
194 | #define FULLSTOP_SHUTDOWN 1 /* System shutdown with rcutorture running. */ | |
195 | #define FULLSTOP_RMMOD 2 /* Normal rmmod of rcutorture. */ | |
196 | static int fullstop = FULLSTOP_RMMOD; | |
197 | /* | |
198 | * Protect fullstop transitions and spawning of kthreads. | |
199 | */ | |
200 | static DEFINE_MUTEX(fullstop_mutex); | |
201 | ||
202 | /* Forward reference. */ | |
203 | static void rcu_torture_cleanup(void); | |
204 | ||
205 | /* | |
206 | * Detect and respond to a system shutdown. | |
207 | */ | |
208 | static int | |
209 | rcutorture_shutdown_notify(struct notifier_block *unused1, | |
210 | unsigned long unused2, void *unused3) | |
211 | { | |
212 | mutex_lock(&fullstop_mutex); | |
213 | if (fullstop == FULLSTOP_DONTSTOP) | |
214 | fullstop = FULLSTOP_SHUTDOWN; | |
215 | else | |
216 | printk(KERN_WARNING /* but going down anyway, so... */ | |
217 | "Concurrent 'rmmod rcutorture' and shutdown illegal!\n"); | |
218 | mutex_unlock(&fullstop_mutex); | |
219 | return NOTIFY_DONE; | |
220 | } | |
221 | ||
222 | /* | |
223 | * Absorb kthreads into a kernel function that won't return, so that | |
224 | * they won't ever access module text or data again. | |
225 | */ | |
226 | static void rcutorture_shutdown_absorb(char *title) | |
227 | { | |
228 | if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { | |
229 | printk(KERN_NOTICE | |
230 | "rcutorture thread %s parking due to system shutdown\n", | |
231 | title); | |
232 | schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT); | |
233 | } | |
234 | } | |
235 | ||
236 | /* | |
237 | * Allocate an element from the rcu_tortures pool. | |
238 | */ | |
239 | static struct rcu_torture * | |
240 | rcu_torture_alloc(void) | |
241 | { | |
242 | struct list_head *p; | |
243 | ||
244 | spin_lock_bh(&rcu_torture_lock); | |
245 | if (list_empty(&rcu_torture_freelist)) { | |
246 | atomic_inc(&n_rcu_torture_alloc_fail); | |
247 | spin_unlock_bh(&rcu_torture_lock); | |
248 | return NULL; | |
249 | } | |
250 | atomic_inc(&n_rcu_torture_alloc); | |
251 | p = rcu_torture_freelist.next; | |
252 | list_del_init(p); | |
253 | spin_unlock_bh(&rcu_torture_lock); | |
254 | return container_of(p, struct rcu_torture, rtort_free); | |
255 | } | |
256 | ||
257 | /* | |
258 | * Free an element to the rcu_tortures pool. | |
259 | */ | |
260 | static void | |
261 | rcu_torture_free(struct rcu_torture *p) | |
262 | { | |
263 | atomic_inc(&n_rcu_torture_free); | |
264 | spin_lock_bh(&rcu_torture_lock); | |
265 | list_add_tail(&p->rtort_free, &rcu_torture_freelist); | |
266 | spin_unlock_bh(&rcu_torture_lock); | |
267 | } | |
268 | ||
269 | struct rcu_random_state { | |
270 | unsigned long rrs_state; | |
271 | long rrs_count; | |
272 | }; | |
273 | ||
274 | #define RCU_RANDOM_MULT 39916801 /* prime */ | |
275 | #define RCU_RANDOM_ADD 479001701 /* prime */ | |
276 | #define RCU_RANDOM_REFRESH 10000 | |
277 | ||
278 | #define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 } | |
279 | ||
280 | /* | |
281 | * Crude but fast random-number generator. Uses a linear congruential | |
282 | * generator, with occasional help from cpu_clock(). | |
283 | */ | |
284 | static unsigned long | |
285 | rcu_random(struct rcu_random_state *rrsp) | |
286 | { | |
287 | if (--rrsp->rrs_count < 0) { | |
288 | rrsp->rrs_state += (unsigned long)local_clock(); | |
289 | rrsp->rrs_count = RCU_RANDOM_REFRESH; | |
290 | } | |
291 | rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD; | |
292 | return swahw32(rrsp->rrs_state); | |
293 | } | |
294 | ||
295 | static void | |
296 | rcu_stutter_wait(char *title) | |
297 | { | |
298 | while (stutter_pause_test || !rcutorture_runnable) { | |
299 | if (rcutorture_runnable) | |
300 | schedule_timeout_interruptible(1); | |
301 | else | |
302 | schedule_timeout_interruptible(round_jiffies_relative(HZ)); | |
303 | rcutorture_shutdown_absorb(title); | |
304 | } | |
305 | } | |
306 | ||
307 | /* | |
308 | * Operations vector for selecting different types of tests. | |
309 | */ | |
310 | ||
311 | struct rcu_torture_ops { | |
312 | void (*init)(void); | |
313 | void (*cleanup)(void); | |
314 | int (*readlock)(void); | |
315 | void (*read_delay)(struct rcu_random_state *rrsp); | |
316 | void (*readunlock)(int idx); | |
317 | int (*completed)(void); | |
318 | void (*deferred_free)(struct rcu_torture *p); | |
319 | void (*sync)(void); | |
320 | void (*cb_barrier)(void); | |
321 | void (*fqs)(void); | |
322 | int (*stats)(char *page); | |
323 | int irq_capable; | |
324 | int can_boost; | |
325 | char *name; | |
326 | }; | |
327 | ||
328 | static struct rcu_torture_ops *cur_ops; | |
329 | ||
330 | /* | |
331 | * Definitions for rcu torture testing. | |
332 | */ | |
333 | ||
334 | static int rcu_torture_read_lock(void) __acquires(RCU) | |
335 | { | |
336 | rcu_read_lock(); | |
337 | return 0; | |
338 | } | |
339 | ||
340 | static void rcu_read_delay(struct rcu_random_state *rrsp) | |
341 | { | |
342 | const unsigned long shortdelay_us = 200; | |
343 | const unsigned long longdelay_ms = 50; | |
344 | ||
345 | /* We want a short delay sometimes to make a reader delay the grace | |
346 | * period, and we want a long delay occasionally to trigger | |
347 | * force_quiescent_state. */ | |
348 | ||
349 | if (!(rcu_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) | |
350 | mdelay(longdelay_ms); | |
351 | if (!(rcu_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) | |
352 | udelay(shortdelay_us); | |
353 | #ifdef CONFIG_PREEMPT | |
354 | if (!preempt_count() && !(rcu_random(rrsp) % (nrealreaders * 20000))) | |
355 | preempt_schedule(); /* No QS if preempt_disable() in effect */ | |
356 | #endif | |
357 | } | |
358 | ||
359 | static void rcu_torture_read_unlock(int idx) __releases(RCU) | |
360 | { | |
361 | rcu_read_unlock(); | |
362 | } | |
363 | ||
364 | static int rcu_torture_completed(void) | |
365 | { | |
366 | return rcu_batches_completed(); | |
367 | } | |
368 | ||
369 | static void | |
370 | rcu_torture_cb(struct rcu_head *p) | |
371 | { | |
372 | int i; | |
373 | struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); | |
374 | ||
375 | if (fullstop != FULLSTOP_DONTSTOP) { | |
376 | /* Test is ending, just drop callbacks on the floor. */ | |
377 | /* The next initialization will pick up the pieces. */ | |
378 | return; | |
379 | } | |
380 | i = rp->rtort_pipe_count; | |
381 | if (i > RCU_TORTURE_PIPE_LEN) | |
382 | i = RCU_TORTURE_PIPE_LEN; | |
383 | atomic_inc(&rcu_torture_wcount[i]); | |
384 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
385 | rp->rtort_mbtest = 0; | |
386 | rcu_torture_free(rp); | |
387 | } else | |
388 | cur_ops->deferred_free(rp); | |
389 | } | |
390 | ||
391 | static int rcu_no_completed(void) | |
392 | { | |
393 | return 0; | |
394 | } | |
395 | ||
396 | static void rcu_torture_deferred_free(struct rcu_torture *p) | |
397 | { | |
398 | call_rcu(&p->rtort_rcu, rcu_torture_cb); | |
399 | } | |
400 | ||
401 | static struct rcu_torture_ops rcu_ops = { | |
402 | .init = NULL, | |
403 | .cleanup = NULL, | |
404 | .readlock = rcu_torture_read_lock, | |
405 | .read_delay = rcu_read_delay, | |
406 | .readunlock = rcu_torture_read_unlock, | |
407 | .completed = rcu_torture_completed, | |
408 | .deferred_free = rcu_torture_deferred_free, | |
409 | .sync = synchronize_rcu, | |
410 | .cb_barrier = rcu_barrier, | |
411 | .fqs = rcu_force_quiescent_state, | |
412 | .stats = NULL, | |
413 | .irq_capable = 1, | |
414 | .can_boost = rcu_can_boost(), | |
415 | .name = "rcu" | |
416 | }; | |
417 | ||
418 | static void rcu_sync_torture_deferred_free(struct rcu_torture *p) | |
419 | { | |
420 | int i; | |
421 | struct rcu_torture *rp; | |
422 | struct rcu_torture *rp1; | |
423 | ||
424 | cur_ops->sync(); | |
425 | list_add(&p->rtort_free, &rcu_torture_removed); | |
426 | list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) { | |
427 | i = rp->rtort_pipe_count; | |
428 | if (i > RCU_TORTURE_PIPE_LEN) | |
429 | i = RCU_TORTURE_PIPE_LEN; | |
430 | atomic_inc(&rcu_torture_wcount[i]); | |
431 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
432 | rp->rtort_mbtest = 0; | |
433 | list_del(&rp->rtort_free); | |
434 | rcu_torture_free(rp); | |
435 | } | |
436 | } | |
437 | } | |
438 | ||
439 | static void rcu_sync_torture_init(void) | |
440 | { | |
441 | INIT_LIST_HEAD(&rcu_torture_removed); | |
442 | } | |
443 | ||
444 | static struct rcu_torture_ops rcu_sync_ops = { | |
445 | .init = rcu_sync_torture_init, | |
446 | .cleanup = NULL, | |
447 | .readlock = rcu_torture_read_lock, | |
448 | .read_delay = rcu_read_delay, | |
449 | .readunlock = rcu_torture_read_unlock, | |
450 | .completed = rcu_torture_completed, | |
451 | .deferred_free = rcu_sync_torture_deferred_free, | |
452 | .sync = synchronize_rcu, | |
453 | .cb_barrier = NULL, | |
454 | .fqs = rcu_force_quiescent_state, | |
455 | .stats = NULL, | |
456 | .irq_capable = 1, | |
457 | .can_boost = rcu_can_boost(), | |
458 | .name = "rcu_sync" | |
459 | }; | |
460 | ||
461 | static struct rcu_torture_ops rcu_expedited_ops = { | |
462 | .init = rcu_sync_torture_init, | |
463 | .cleanup = NULL, | |
464 | .readlock = rcu_torture_read_lock, | |
465 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
466 | .readunlock = rcu_torture_read_unlock, | |
467 | .completed = rcu_no_completed, | |
468 | .deferred_free = rcu_sync_torture_deferred_free, | |
469 | .sync = synchronize_rcu_expedited, | |
470 | .cb_barrier = NULL, | |
471 | .fqs = rcu_force_quiescent_state, | |
472 | .stats = NULL, | |
473 | .irq_capable = 1, | |
474 | .can_boost = rcu_can_boost(), | |
475 | .name = "rcu_expedited" | |
476 | }; | |
477 | ||
478 | /* | |
479 | * Definitions for rcu_bh torture testing. | |
480 | */ | |
481 | ||
482 | static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH) | |
483 | { | |
484 | rcu_read_lock_bh(); | |
485 | return 0; | |
486 | } | |
487 | ||
488 | static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH) | |
489 | { | |
490 | rcu_read_unlock_bh(); | |
491 | } | |
492 | ||
493 | static int rcu_bh_torture_completed(void) | |
494 | { | |
495 | return rcu_batches_completed_bh(); | |
496 | } | |
497 | ||
498 | static void rcu_bh_torture_deferred_free(struct rcu_torture *p) | |
499 | { | |
500 | call_rcu_bh(&p->rtort_rcu, rcu_torture_cb); | |
501 | } | |
502 | ||
503 | static struct rcu_torture_ops rcu_bh_ops = { | |
504 | .init = NULL, | |
505 | .cleanup = NULL, | |
506 | .readlock = rcu_bh_torture_read_lock, | |
507 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
508 | .readunlock = rcu_bh_torture_read_unlock, | |
509 | .completed = rcu_bh_torture_completed, | |
510 | .deferred_free = rcu_bh_torture_deferred_free, | |
511 | .sync = synchronize_rcu_bh, | |
512 | .cb_barrier = rcu_barrier_bh, | |
513 | .fqs = rcu_bh_force_quiescent_state, | |
514 | .stats = NULL, | |
515 | .irq_capable = 1, | |
516 | .name = "rcu_bh" | |
517 | }; | |
518 | ||
519 | static struct rcu_torture_ops rcu_bh_sync_ops = { | |
520 | .init = rcu_sync_torture_init, | |
521 | .cleanup = NULL, | |
522 | .readlock = rcu_bh_torture_read_lock, | |
523 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
524 | .readunlock = rcu_bh_torture_read_unlock, | |
525 | .completed = rcu_bh_torture_completed, | |
526 | .deferred_free = rcu_sync_torture_deferred_free, | |
527 | .sync = synchronize_rcu_bh, | |
528 | .cb_barrier = NULL, | |
529 | .fqs = rcu_bh_force_quiescent_state, | |
530 | .stats = NULL, | |
531 | .irq_capable = 1, | |
532 | .name = "rcu_bh_sync" | |
533 | }; | |
534 | ||
535 | static struct rcu_torture_ops rcu_bh_expedited_ops = { | |
536 | .init = rcu_sync_torture_init, | |
537 | .cleanup = NULL, | |
538 | .readlock = rcu_bh_torture_read_lock, | |
539 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
540 | .readunlock = rcu_bh_torture_read_unlock, | |
541 | .completed = rcu_bh_torture_completed, | |
542 | .deferred_free = rcu_sync_torture_deferred_free, | |
543 | .sync = synchronize_rcu_bh_expedited, | |
544 | .cb_barrier = NULL, | |
545 | .fqs = rcu_bh_force_quiescent_state, | |
546 | .stats = NULL, | |
547 | .irq_capable = 1, | |
548 | .name = "rcu_bh_expedited" | |
549 | }; | |
550 | ||
551 | /* | |
552 | * Definitions for srcu torture testing. | |
553 | */ | |
554 | ||
555 | static struct srcu_struct srcu_ctl; | |
556 | ||
557 | static void srcu_torture_init(void) | |
558 | { | |
559 | init_srcu_struct(&srcu_ctl); | |
560 | rcu_sync_torture_init(); | |
561 | } | |
562 | ||
563 | static void srcu_torture_cleanup(void) | |
564 | { | |
565 | synchronize_srcu(&srcu_ctl); | |
566 | cleanup_srcu_struct(&srcu_ctl); | |
567 | } | |
568 | ||
569 | static int srcu_torture_read_lock(void) __acquires(&srcu_ctl) | |
570 | { | |
571 | return srcu_read_lock(&srcu_ctl); | |
572 | } | |
573 | ||
574 | static void srcu_read_delay(struct rcu_random_state *rrsp) | |
575 | { | |
576 | long delay; | |
577 | const long uspertick = 1000000 / HZ; | |
578 | const long longdelay = 10; | |
579 | ||
580 | /* We want there to be long-running readers, but not all the time. */ | |
581 | ||
582 | delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick); | |
583 | if (!delay) | |
584 | schedule_timeout_interruptible(longdelay); | |
585 | else | |
586 | rcu_read_delay(rrsp); | |
587 | } | |
588 | ||
589 | static void srcu_torture_read_unlock(int idx) __releases(&srcu_ctl) | |
590 | { | |
591 | srcu_read_unlock(&srcu_ctl, idx); | |
592 | } | |
593 | ||
594 | static int srcu_torture_completed(void) | |
595 | { | |
596 | return srcu_batches_completed(&srcu_ctl); | |
597 | } | |
598 | ||
599 | static void srcu_torture_synchronize(void) | |
600 | { | |
601 | synchronize_srcu(&srcu_ctl); | |
602 | } | |
603 | ||
604 | static int srcu_torture_stats(char *page) | |
605 | { | |
606 | int cnt = 0; | |
607 | int cpu; | |
608 | int idx = srcu_ctl.completed & 0x1; | |
609 | ||
610 | cnt += sprintf(&page[cnt], "%s%s per-CPU(idx=%d):", | |
611 | torture_type, TORTURE_FLAG, idx); | |
612 | for_each_possible_cpu(cpu) { | |
613 | cnt += sprintf(&page[cnt], " %d(%d,%d)", cpu, | |
614 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[!idx], | |
615 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[idx]); | |
616 | } | |
617 | cnt += sprintf(&page[cnt], "\n"); | |
618 | return cnt; | |
619 | } | |
620 | ||
621 | static struct rcu_torture_ops srcu_ops = { | |
622 | .init = srcu_torture_init, | |
623 | .cleanup = srcu_torture_cleanup, | |
624 | .readlock = srcu_torture_read_lock, | |
625 | .read_delay = srcu_read_delay, | |
626 | .readunlock = srcu_torture_read_unlock, | |
627 | .completed = srcu_torture_completed, | |
628 | .deferred_free = rcu_sync_torture_deferred_free, | |
629 | .sync = srcu_torture_synchronize, | |
630 | .cb_barrier = NULL, | |
631 | .stats = srcu_torture_stats, | |
632 | .name = "srcu" | |
633 | }; | |
634 | ||
635 | static int srcu_torture_read_lock_raw(void) __acquires(&srcu_ctl) | |
636 | { | |
637 | return srcu_read_lock_raw(&srcu_ctl); | |
638 | } | |
639 | ||
640 | static void srcu_torture_read_unlock_raw(int idx) __releases(&srcu_ctl) | |
641 | { | |
642 | srcu_read_unlock_raw(&srcu_ctl, idx); | |
643 | } | |
644 | ||
645 | static struct rcu_torture_ops srcu_raw_ops = { | |
646 | .init = srcu_torture_init, | |
647 | .cleanup = srcu_torture_cleanup, | |
648 | .readlock = srcu_torture_read_lock_raw, | |
649 | .read_delay = srcu_read_delay, | |
650 | .readunlock = srcu_torture_read_unlock_raw, | |
651 | .completed = srcu_torture_completed, | |
652 | .deferred_free = rcu_sync_torture_deferred_free, | |
653 | .sync = srcu_torture_synchronize, | |
654 | .cb_barrier = NULL, | |
655 | .stats = srcu_torture_stats, | |
656 | .name = "srcu_raw" | |
657 | }; | |
658 | ||
659 | static void srcu_torture_synchronize_expedited(void) | |
660 | { | |
661 | synchronize_srcu_expedited(&srcu_ctl); | |
662 | } | |
663 | ||
664 | static struct rcu_torture_ops srcu_expedited_ops = { | |
665 | .init = srcu_torture_init, | |
666 | .cleanup = srcu_torture_cleanup, | |
667 | .readlock = srcu_torture_read_lock, | |
668 | .read_delay = srcu_read_delay, | |
669 | .readunlock = srcu_torture_read_unlock, | |
670 | .completed = srcu_torture_completed, | |
671 | .deferred_free = rcu_sync_torture_deferred_free, | |
672 | .sync = srcu_torture_synchronize_expedited, | |
673 | .cb_barrier = NULL, | |
674 | .stats = srcu_torture_stats, | |
675 | .name = "srcu_expedited" | |
676 | }; | |
677 | ||
678 | /* | |
679 | * Definitions for sched torture testing. | |
680 | */ | |
681 | ||
682 | static int sched_torture_read_lock(void) | |
683 | { | |
684 | preempt_disable(); | |
685 | return 0; | |
686 | } | |
687 | ||
688 | static void sched_torture_read_unlock(int idx) | |
689 | { | |
690 | preempt_enable(); | |
691 | } | |
692 | ||
693 | static void rcu_sched_torture_deferred_free(struct rcu_torture *p) | |
694 | { | |
695 | call_rcu_sched(&p->rtort_rcu, rcu_torture_cb); | |
696 | } | |
697 | ||
698 | static struct rcu_torture_ops sched_ops = { | |
699 | .init = rcu_sync_torture_init, | |
700 | .cleanup = NULL, | |
701 | .readlock = sched_torture_read_lock, | |
702 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
703 | .readunlock = sched_torture_read_unlock, | |
704 | .completed = rcu_no_completed, | |
705 | .deferred_free = rcu_sched_torture_deferred_free, | |
706 | .sync = synchronize_sched, | |
707 | .cb_barrier = rcu_barrier_sched, | |
708 | .fqs = rcu_sched_force_quiescent_state, | |
709 | .stats = NULL, | |
710 | .irq_capable = 1, | |
711 | .name = "sched" | |
712 | }; | |
713 | ||
714 | static struct rcu_torture_ops sched_sync_ops = { | |
715 | .init = rcu_sync_torture_init, | |
716 | .cleanup = NULL, | |
717 | .readlock = sched_torture_read_lock, | |
718 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
719 | .readunlock = sched_torture_read_unlock, | |
720 | .completed = rcu_no_completed, | |
721 | .deferred_free = rcu_sync_torture_deferred_free, | |
722 | .sync = synchronize_sched, | |
723 | .cb_barrier = NULL, | |
724 | .fqs = rcu_sched_force_quiescent_state, | |
725 | .stats = NULL, | |
726 | .name = "sched_sync" | |
727 | }; | |
728 | ||
729 | static struct rcu_torture_ops sched_expedited_ops = { | |
730 | .init = rcu_sync_torture_init, | |
731 | .cleanup = NULL, | |
732 | .readlock = sched_torture_read_lock, | |
733 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
734 | .readunlock = sched_torture_read_unlock, | |
735 | .completed = rcu_no_completed, | |
736 | .deferred_free = rcu_sync_torture_deferred_free, | |
737 | .sync = synchronize_sched_expedited, | |
738 | .cb_barrier = NULL, | |
739 | .fqs = rcu_sched_force_quiescent_state, | |
740 | .stats = NULL, | |
741 | .irq_capable = 1, | |
742 | .name = "sched_expedited" | |
743 | }; | |
744 | ||
745 | /* | |
746 | * RCU torture priority-boost testing. Runs one real-time thread per | |
747 | * CPU for moderate bursts, repeatedly registering RCU callbacks and | |
748 | * spinning waiting for them to be invoked. If a given callback takes | |
749 | * too long to be invoked, we assume that priority inversion has occurred. | |
750 | */ | |
751 | ||
752 | struct rcu_boost_inflight { | |
753 | struct rcu_head rcu; | |
754 | int inflight; | |
755 | }; | |
756 | ||
757 | static void rcu_torture_boost_cb(struct rcu_head *head) | |
758 | { | |
759 | struct rcu_boost_inflight *rbip = | |
760 | container_of(head, struct rcu_boost_inflight, rcu); | |
761 | ||
762 | smp_mb(); /* Ensure RCU-core accesses precede clearing ->inflight */ | |
763 | rbip->inflight = 0; | |
764 | } | |
765 | ||
766 | static int rcu_torture_boost(void *arg) | |
767 | { | |
768 | unsigned long call_rcu_time; | |
769 | unsigned long endtime; | |
770 | unsigned long oldstarttime; | |
771 | struct rcu_boost_inflight rbi = { .inflight = 0 }; | |
772 | struct sched_param sp; | |
773 | ||
774 | VERBOSE_PRINTK_STRING("rcu_torture_boost started"); | |
775 | ||
776 | /* Set real-time priority. */ | |
777 | sp.sched_priority = 1; | |
778 | if (sched_setscheduler(current, SCHED_FIFO, &sp) < 0) { | |
779 | VERBOSE_PRINTK_STRING("rcu_torture_boost RT prio failed!"); | |
780 | n_rcu_torture_boost_rterror++; | |
781 | } | |
782 | ||
783 | init_rcu_head_on_stack(&rbi.rcu); | |
784 | /* Each pass through the following loop does one boost-test cycle. */ | |
785 | do { | |
786 | /* Wait for the next test interval. */ | |
787 | oldstarttime = boost_starttime; | |
788 | while (ULONG_CMP_LT(jiffies, oldstarttime)) { | |
789 | schedule_timeout_uninterruptible(1); | |
790 | rcu_stutter_wait("rcu_torture_boost"); | |
791 | if (kthread_should_stop() || | |
792 | fullstop != FULLSTOP_DONTSTOP) | |
793 | goto checkwait; | |
794 | } | |
795 | ||
796 | /* Do one boost-test interval. */ | |
797 | endtime = oldstarttime + test_boost_duration * HZ; | |
798 | call_rcu_time = jiffies; | |
799 | while (ULONG_CMP_LT(jiffies, endtime)) { | |
800 | /* If we don't have a callback in flight, post one. */ | |
801 | if (!rbi.inflight) { | |
802 | smp_mb(); /* RCU core before ->inflight = 1. */ | |
803 | rbi.inflight = 1; | |
804 | call_rcu(&rbi.rcu, rcu_torture_boost_cb); | |
805 | if (jiffies - call_rcu_time > | |
806 | test_boost_duration * HZ - HZ / 2) { | |
807 | VERBOSE_PRINTK_STRING("rcu_torture_boost boosting failed"); | |
808 | n_rcu_torture_boost_failure++; | |
809 | } | |
810 | call_rcu_time = jiffies; | |
811 | } | |
812 | cond_resched(); | |
813 | rcu_stutter_wait("rcu_torture_boost"); | |
814 | if (kthread_should_stop() || | |
815 | fullstop != FULLSTOP_DONTSTOP) | |
816 | goto checkwait; | |
817 | } | |
818 | ||
819 | /* | |
820 | * Set the start time of the next test interval. | |
821 | * Yes, this is vulnerable to long delays, but such | |
822 | * delays simply cause a false negative for the next | |
823 | * interval. Besides, we are running at RT priority, | |
824 | * so delays should be relatively rare. | |
825 | */ | |
826 | while (oldstarttime == boost_starttime && | |
827 | !kthread_should_stop()) { | |
828 | if (mutex_trylock(&boost_mutex)) { | |
829 | boost_starttime = jiffies + | |
830 | test_boost_interval * HZ; | |
831 | n_rcu_torture_boosts++; | |
832 | mutex_unlock(&boost_mutex); | |
833 | break; | |
834 | } | |
835 | schedule_timeout_uninterruptible(1); | |
836 | } | |
837 | ||
838 | /* Go do the stutter. */ | |
839 | checkwait: rcu_stutter_wait("rcu_torture_boost"); | |
840 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
841 | ||
842 | /* Clean up and exit. */ | |
843 | VERBOSE_PRINTK_STRING("rcu_torture_boost task stopping"); | |
844 | rcutorture_shutdown_absorb("rcu_torture_boost"); | |
845 | while (!kthread_should_stop() || rbi.inflight) | |
846 | schedule_timeout_uninterruptible(1); | |
847 | smp_mb(); /* order accesses to ->inflight before stack-frame death. */ | |
848 | destroy_rcu_head_on_stack(&rbi.rcu); | |
849 | return 0; | |
850 | } | |
851 | ||
852 | /* | |
853 | * RCU torture force-quiescent-state kthread. Repeatedly induces | |
854 | * bursts of calls to force_quiescent_state(), increasing the probability | |
855 | * of occurrence of some important types of race conditions. | |
856 | */ | |
857 | static int | |
858 | rcu_torture_fqs(void *arg) | |
859 | { | |
860 | unsigned long fqs_resume_time; | |
861 | int fqs_burst_remaining; | |
862 | ||
863 | VERBOSE_PRINTK_STRING("rcu_torture_fqs task started"); | |
864 | do { | |
865 | fqs_resume_time = jiffies + fqs_stutter * HZ; | |
866 | while (ULONG_CMP_LT(jiffies, fqs_resume_time) && | |
867 | !kthread_should_stop()) { | |
868 | schedule_timeout_interruptible(1); | |
869 | } | |
870 | fqs_burst_remaining = fqs_duration; | |
871 | while (fqs_burst_remaining > 0 && | |
872 | !kthread_should_stop()) { | |
873 | cur_ops->fqs(); | |
874 | udelay(fqs_holdoff); | |
875 | fqs_burst_remaining -= fqs_holdoff; | |
876 | } | |
877 | rcu_stutter_wait("rcu_torture_fqs"); | |
878 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
879 | VERBOSE_PRINTK_STRING("rcu_torture_fqs task stopping"); | |
880 | rcutorture_shutdown_absorb("rcu_torture_fqs"); | |
881 | while (!kthread_should_stop()) | |
882 | schedule_timeout_uninterruptible(1); | |
883 | return 0; | |
884 | } | |
885 | ||
886 | /* | |
887 | * RCU torture writer kthread. Repeatedly substitutes a new structure | |
888 | * for that pointed to by rcu_torture_current, freeing the old structure | |
889 | * after a series of grace periods (the "pipeline"). | |
890 | */ | |
891 | static int | |
892 | rcu_torture_writer(void *arg) | |
893 | { | |
894 | int i; | |
895 | long oldbatch = rcu_batches_completed(); | |
896 | struct rcu_torture *rp; | |
897 | struct rcu_torture *old_rp; | |
898 | static DEFINE_RCU_RANDOM(rand); | |
899 | ||
900 | VERBOSE_PRINTK_STRING("rcu_torture_writer task started"); | |
901 | set_user_nice(current, 19); | |
902 | ||
903 | do { | |
904 | schedule_timeout_uninterruptible(1); | |
905 | rp = rcu_torture_alloc(); | |
906 | if (rp == NULL) | |
907 | continue; | |
908 | rp->rtort_pipe_count = 0; | |
909 | udelay(rcu_random(&rand) & 0x3ff); | |
910 | old_rp = rcu_dereference_check(rcu_torture_current, | |
911 | current == writer_task); | |
912 | rp->rtort_mbtest = 1; | |
913 | rcu_assign_pointer(rcu_torture_current, rp); | |
914 | smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */ | |
915 | if (old_rp) { | |
916 | i = old_rp->rtort_pipe_count; | |
917 | if (i > RCU_TORTURE_PIPE_LEN) | |
918 | i = RCU_TORTURE_PIPE_LEN; | |
919 | atomic_inc(&rcu_torture_wcount[i]); | |
920 | old_rp->rtort_pipe_count++; | |
921 | cur_ops->deferred_free(old_rp); | |
922 | } | |
923 | rcutorture_record_progress(++rcu_torture_current_version); | |
924 | oldbatch = cur_ops->completed(); | |
925 | rcu_stutter_wait("rcu_torture_writer"); | |
926 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
927 | VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping"); | |
928 | rcutorture_shutdown_absorb("rcu_torture_writer"); | |
929 | while (!kthread_should_stop()) | |
930 | schedule_timeout_uninterruptible(1); | |
931 | return 0; | |
932 | } | |
933 | ||
934 | /* | |
935 | * RCU torture fake writer kthread. Repeatedly calls sync, with a random | |
936 | * delay between calls. | |
937 | */ | |
938 | static int | |
939 | rcu_torture_fakewriter(void *arg) | |
940 | { | |
941 | DEFINE_RCU_RANDOM(rand); | |
942 | ||
943 | VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task started"); | |
944 | set_user_nice(current, 19); | |
945 | ||
946 | do { | |
947 | schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10); | |
948 | udelay(rcu_random(&rand) & 0x3ff); | |
949 | cur_ops->sync(); | |
950 | rcu_stutter_wait("rcu_torture_fakewriter"); | |
951 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
952 | ||
953 | VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping"); | |
954 | rcutorture_shutdown_absorb("rcu_torture_fakewriter"); | |
955 | while (!kthread_should_stop()) | |
956 | schedule_timeout_uninterruptible(1); | |
957 | return 0; | |
958 | } | |
959 | ||
960 | void rcutorture_trace_dump(void) | |
961 | { | |
962 | static atomic_t beenhere = ATOMIC_INIT(0); | |
963 | ||
964 | if (atomic_read(&beenhere)) | |
965 | return; | |
966 | if (atomic_xchg(&beenhere, 1) != 0) | |
967 | return; | |
968 | do_trace_rcu_torture_read(cur_ops->name, (struct rcu_head *)~0UL); | |
969 | ftrace_dump(DUMP_ALL); | |
970 | } | |
971 | ||
972 | /* | |
973 | * RCU torture reader from timer handler. Dereferences rcu_torture_current, | |
974 | * incrementing the corresponding element of the pipeline array. The | |
975 | * counter in the element should never be greater than 1, otherwise, the | |
976 | * RCU implementation is broken. | |
977 | */ | |
978 | static void rcu_torture_timer(unsigned long unused) | |
979 | { | |
980 | int idx; | |
981 | int completed; | |
982 | static DEFINE_RCU_RANDOM(rand); | |
983 | static DEFINE_SPINLOCK(rand_lock); | |
984 | struct rcu_torture *p; | |
985 | int pipe_count; | |
986 | ||
987 | idx = cur_ops->readlock(); | |
988 | completed = cur_ops->completed(); | |
989 | p = rcu_dereference_check(rcu_torture_current, | |
990 | rcu_read_lock_bh_held() || | |
991 | rcu_read_lock_sched_held() || | |
992 | srcu_read_lock_held(&srcu_ctl)); | |
993 | do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu); | |
994 | if (p == NULL) { | |
995 | /* Leave because rcu_torture_writer is not yet underway */ | |
996 | cur_ops->readunlock(idx); | |
997 | return; | |
998 | } | |
999 | if (p->rtort_mbtest == 0) | |
1000 | atomic_inc(&n_rcu_torture_mberror); | |
1001 | spin_lock(&rand_lock); | |
1002 | cur_ops->read_delay(&rand); | |
1003 | n_rcu_torture_timers++; | |
1004 | spin_unlock(&rand_lock); | |
1005 | preempt_disable(); | |
1006 | pipe_count = p->rtort_pipe_count; | |
1007 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { | |
1008 | /* Should not happen, but... */ | |
1009 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
1010 | } | |
1011 | if (pipe_count > 1) | |
1012 | rcutorture_trace_dump(); | |
1013 | __this_cpu_inc(rcu_torture_count[pipe_count]); | |
1014 | completed = cur_ops->completed() - completed; | |
1015 | if (completed > RCU_TORTURE_PIPE_LEN) { | |
1016 | /* Should not happen, but... */ | |
1017 | completed = RCU_TORTURE_PIPE_LEN; | |
1018 | } | |
1019 | __this_cpu_inc(rcu_torture_batch[completed]); | |
1020 | preempt_enable(); | |
1021 | cur_ops->readunlock(idx); | |
1022 | } | |
1023 | ||
1024 | /* | |
1025 | * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, | |
1026 | * incrementing the corresponding element of the pipeline array. The | |
1027 | * counter in the element should never be greater than 1, otherwise, the | |
1028 | * RCU implementation is broken. | |
1029 | */ | |
1030 | static int | |
1031 | rcu_torture_reader(void *arg) | |
1032 | { | |
1033 | int completed; | |
1034 | int idx; | |
1035 | DEFINE_RCU_RANDOM(rand); | |
1036 | struct rcu_torture *p; | |
1037 | int pipe_count; | |
1038 | struct timer_list t; | |
1039 | ||
1040 | VERBOSE_PRINTK_STRING("rcu_torture_reader task started"); | |
1041 | set_user_nice(current, 19); | |
1042 | if (irqreader && cur_ops->irq_capable) | |
1043 | setup_timer_on_stack(&t, rcu_torture_timer, 0); | |
1044 | ||
1045 | do { | |
1046 | if (irqreader && cur_ops->irq_capable) { | |
1047 | if (!timer_pending(&t)) | |
1048 | mod_timer(&t, jiffies + 1); | |
1049 | } | |
1050 | idx = cur_ops->readlock(); | |
1051 | completed = cur_ops->completed(); | |
1052 | p = rcu_dereference_check(rcu_torture_current, | |
1053 | rcu_read_lock_bh_held() || | |
1054 | rcu_read_lock_sched_held() || | |
1055 | srcu_read_lock_held(&srcu_ctl)); | |
1056 | do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu); | |
1057 | if (p == NULL) { | |
1058 | /* Wait for rcu_torture_writer to get underway */ | |
1059 | cur_ops->readunlock(idx); | |
1060 | schedule_timeout_interruptible(HZ); | |
1061 | continue; | |
1062 | } | |
1063 | if (p->rtort_mbtest == 0) | |
1064 | atomic_inc(&n_rcu_torture_mberror); | |
1065 | cur_ops->read_delay(&rand); | |
1066 | preempt_disable(); | |
1067 | pipe_count = p->rtort_pipe_count; | |
1068 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { | |
1069 | /* Should not happen, but... */ | |
1070 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
1071 | } | |
1072 | if (pipe_count > 1) | |
1073 | rcutorture_trace_dump(); | |
1074 | __this_cpu_inc(rcu_torture_count[pipe_count]); | |
1075 | completed = cur_ops->completed() - completed; | |
1076 | if (completed > RCU_TORTURE_PIPE_LEN) { | |
1077 | /* Should not happen, but... */ | |
1078 | completed = RCU_TORTURE_PIPE_LEN; | |
1079 | } | |
1080 | __this_cpu_inc(rcu_torture_batch[completed]); | |
1081 | preempt_enable(); | |
1082 | cur_ops->readunlock(idx); | |
1083 | schedule(); | |
1084 | rcu_stutter_wait("rcu_torture_reader"); | |
1085 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
1086 | VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping"); | |
1087 | rcutorture_shutdown_absorb("rcu_torture_reader"); | |
1088 | if (irqreader && cur_ops->irq_capable) | |
1089 | del_timer_sync(&t); | |
1090 | while (!kthread_should_stop()) | |
1091 | schedule_timeout_uninterruptible(1); | |
1092 | return 0; | |
1093 | } | |
1094 | ||
1095 | /* | |
1096 | * Create an RCU-torture statistics message in the specified buffer. | |
1097 | */ | |
1098 | static int | |
1099 | rcu_torture_printk(char *page) | |
1100 | { | |
1101 | int cnt = 0; | |
1102 | int cpu; | |
1103 | int i; | |
1104 | long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
1105 | long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
1106 | ||
1107 | for_each_possible_cpu(cpu) { | |
1108 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { | |
1109 | pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i]; | |
1110 | batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i]; | |
1111 | } | |
1112 | } | |
1113 | for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) { | |
1114 | if (pipesummary[i] != 0) | |
1115 | break; | |
1116 | } | |
1117 | cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG); | |
1118 | cnt += sprintf(&page[cnt], | |
1119 | "rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d " | |
1120 | "rtmbe: %d rtbke: %ld rtbre: %ld " | |
1121 | "rtbf: %ld rtb: %ld nt: %ld " | |
1122 | "onoff: %ld/%ld:%ld/%ld", | |
1123 | rcu_torture_current, | |
1124 | rcu_torture_current_version, | |
1125 | list_empty(&rcu_torture_freelist), | |
1126 | atomic_read(&n_rcu_torture_alloc), | |
1127 | atomic_read(&n_rcu_torture_alloc_fail), | |
1128 | atomic_read(&n_rcu_torture_free), | |
1129 | atomic_read(&n_rcu_torture_mberror), | |
1130 | n_rcu_torture_boost_ktrerror, | |
1131 | n_rcu_torture_boost_rterror, | |
1132 | n_rcu_torture_boost_failure, | |
1133 | n_rcu_torture_boosts, | |
1134 | n_rcu_torture_timers, | |
1135 | n_online_successes, | |
1136 | n_online_attempts, | |
1137 | n_offline_successes, | |
1138 | n_offline_attempts); | |
1139 | if (atomic_read(&n_rcu_torture_mberror) != 0 || | |
1140 | n_rcu_torture_boost_ktrerror != 0 || | |
1141 | n_rcu_torture_boost_rterror != 0 || | |
1142 | n_rcu_torture_boost_failure != 0) | |
1143 | cnt += sprintf(&page[cnt], " !!!"); | |
1144 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); | |
1145 | if (i > 1) { | |
1146 | cnt += sprintf(&page[cnt], "!!! "); | |
1147 | atomic_inc(&n_rcu_torture_error); | |
1148 | WARN_ON_ONCE(1); | |
1149 | } | |
1150 | cnt += sprintf(&page[cnt], "Reader Pipe: "); | |
1151 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) | |
1152 | cnt += sprintf(&page[cnt], " %ld", pipesummary[i]); | |
1153 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); | |
1154 | cnt += sprintf(&page[cnt], "Reader Batch: "); | |
1155 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) | |
1156 | cnt += sprintf(&page[cnt], " %ld", batchsummary[i]); | |
1157 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); | |
1158 | cnt += sprintf(&page[cnt], "Free-Block Circulation: "); | |
1159 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { | |
1160 | cnt += sprintf(&page[cnt], " %d", | |
1161 | atomic_read(&rcu_torture_wcount[i])); | |
1162 | } | |
1163 | cnt += sprintf(&page[cnt], "\n"); | |
1164 | if (cur_ops->stats) | |
1165 | cnt += cur_ops->stats(&page[cnt]); | |
1166 | return cnt; | |
1167 | } | |
1168 | ||
1169 | /* | |
1170 | * Print torture statistics. Caller must ensure that there is only | |
1171 | * one call to this function at a given time!!! This is normally | |
1172 | * accomplished by relying on the module system to only have one copy | |
1173 | * of the module loaded, and then by giving the rcu_torture_stats | |
1174 | * kthread full control (or the init/cleanup functions when rcu_torture_stats | |
1175 | * thread is not running). | |
1176 | */ | |
1177 | static void | |
1178 | rcu_torture_stats_print(void) | |
1179 | { | |
1180 | int cnt; | |
1181 | ||
1182 | cnt = rcu_torture_printk(printk_buf); | |
1183 | printk(KERN_ALERT "%s", printk_buf); | |
1184 | } | |
1185 | ||
1186 | /* | |
1187 | * Periodically prints torture statistics, if periodic statistics printing | |
1188 | * was specified via the stat_interval module parameter. | |
1189 | * | |
1190 | * No need to worry about fullstop here, since this one doesn't reference | |
1191 | * volatile state or register callbacks. | |
1192 | */ | |
1193 | static int | |
1194 | rcu_torture_stats(void *arg) | |
1195 | { | |
1196 | VERBOSE_PRINTK_STRING("rcu_torture_stats task started"); | |
1197 | do { | |
1198 | schedule_timeout_interruptible(stat_interval * HZ); | |
1199 | rcu_torture_stats_print(); | |
1200 | rcutorture_shutdown_absorb("rcu_torture_stats"); | |
1201 | } while (!kthread_should_stop()); | |
1202 | VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping"); | |
1203 | return 0; | |
1204 | } | |
1205 | ||
1206 | static int rcu_idle_cpu; /* Force all torture tasks off this CPU */ | |
1207 | ||
1208 | /* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case | |
1209 | * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs. | |
1210 | */ | |
1211 | static void rcu_torture_shuffle_tasks(void) | |
1212 | { | |
1213 | int i; | |
1214 | ||
1215 | cpumask_setall(shuffle_tmp_mask); | |
1216 | get_online_cpus(); | |
1217 | ||
1218 | /* No point in shuffling if there is only one online CPU (ex: UP) */ | |
1219 | if (num_online_cpus() == 1) { | |
1220 | put_online_cpus(); | |
1221 | return; | |
1222 | } | |
1223 | ||
1224 | if (rcu_idle_cpu != -1) | |
1225 | cpumask_clear_cpu(rcu_idle_cpu, shuffle_tmp_mask); | |
1226 | ||
1227 | set_cpus_allowed_ptr(current, shuffle_tmp_mask); | |
1228 | ||
1229 | if (reader_tasks) { | |
1230 | for (i = 0; i < nrealreaders; i++) | |
1231 | if (reader_tasks[i]) | |
1232 | set_cpus_allowed_ptr(reader_tasks[i], | |
1233 | shuffle_tmp_mask); | |
1234 | } | |
1235 | ||
1236 | if (fakewriter_tasks) { | |
1237 | for (i = 0; i < nfakewriters; i++) | |
1238 | if (fakewriter_tasks[i]) | |
1239 | set_cpus_allowed_ptr(fakewriter_tasks[i], | |
1240 | shuffle_tmp_mask); | |
1241 | } | |
1242 | ||
1243 | if (writer_task) | |
1244 | set_cpus_allowed_ptr(writer_task, shuffle_tmp_mask); | |
1245 | ||
1246 | if (stats_task) | |
1247 | set_cpus_allowed_ptr(stats_task, shuffle_tmp_mask); | |
1248 | ||
1249 | if (rcu_idle_cpu == -1) | |
1250 | rcu_idle_cpu = num_online_cpus() - 1; | |
1251 | else | |
1252 | rcu_idle_cpu--; | |
1253 | ||
1254 | put_online_cpus(); | |
1255 | } | |
1256 | ||
1257 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the | |
1258 | * system to become idle at a time and cut off its timer ticks. This is meant | |
1259 | * to test the support for such tickless idle CPU in RCU. | |
1260 | */ | |
1261 | static int | |
1262 | rcu_torture_shuffle(void *arg) | |
1263 | { | |
1264 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started"); | |
1265 | do { | |
1266 | schedule_timeout_interruptible(shuffle_interval * HZ); | |
1267 | rcu_torture_shuffle_tasks(); | |
1268 | rcutorture_shutdown_absorb("rcu_torture_shuffle"); | |
1269 | } while (!kthread_should_stop()); | |
1270 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping"); | |
1271 | return 0; | |
1272 | } | |
1273 | ||
1274 | /* Cause the rcutorture test to "stutter", starting and stopping all | |
1275 | * threads periodically. | |
1276 | */ | |
1277 | static int | |
1278 | rcu_torture_stutter(void *arg) | |
1279 | { | |
1280 | VERBOSE_PRINTK_STRING("rcu_torture_stutter task started"); | |
1281 | do { | |
1282 | schedule_timeout_interruptible(stutter * HZ); | |
1283 | stutter_pause_test = 1; | |
1284 | if (!kthread_should_stop()) | |
1285 | schedule_timeout_interruptible(stutter * HZ); | |
1286 | stutter_pause_test = 0; | |
1287 | rcutorture_shutdown_absorb("rcu_torture_stutter"); | |
1288 | } while (!kthread_should_stop()); | |
1289 | VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping"); | |
1290 | return 0; | |
1291 | } | |
1292 | ||
1293 | static inline void | |
1294 | rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, char *tag) | |
1295 | { | |
1296 | printk(KERN_ALERT "%s" TORTURE_FLAG | |
1297 | "--- %s: nreaders=%d nfakewriters=%d " | |
1298 | "stat_interval=%d verbose=%d test_no_idle_hz=%d " | |
1299 | "shuffle_interval=%d stutter=%d irqreader=%d " | |
1300 | "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d " | |
1301 | "test_boost=%d/%d test_boost_interval=%d " | |
1302 | "test_boost_duration=%d shutdown_secs=%d " | |
1303 | "onoff_interval=%d\n", | |
1304 | torture_type, tag, nrealreaders, nfakewriters, | |
1305 | stat_interval, verbose, test_no_idle_hz, shuffle_interval, | |
1306 | stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter, | |
1307 | test_boost, cur_ops->can_boost, | |
1308 | test_boost_interval, test_boost_duration, shutdown_secs, | |
1309 | onoff_interval); | |
1310 | } | |
1311 | ||
1312 | static struct notifier_block rcutorture_shutdown_nb = { | |
1313 | .notifier_call = rcutorture_shutdown_notify, | |
1314 | }; | |
1315 | ||
1316 | static void rcutorture_booster_cleanup(int cpu) | |
1317 | { | |
1318 | struct task_struct *t; | |
1319 | ||
1320 | if (boost_tasks[cpu] == NULL) | |
1321 | return; | |
1322 | mutex_lock(&boost_mutex); | |
1323 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_boost task"); | |
1324 | t = boost_tasks[cpu]; | |
1325 | boost_tasks[cpu] = NULL; | |
1326 | mutex_unlock(&boost_mutex); | |
1327 | ||
1328 | /* This must be outside of the mutex, otherwise deadlock! */ | |
1329 | kthread_stop(t); | |
1330 | } | |
1331 | ||
1332 | static int rcutorture_booster_init(int cpu) | |
1333 | { | |
1334 | int retval; | |
1335 | ||
1336 | if (boost_tasks[cpu] != NULL) | |
1337 | return 0; /* Already created, nothing more to do. */ | |
1338 | ||
1339 | /* Don't allow time recalculation while creating a new task. */ | |
1340 | mutex_lock(&boost_mutex); | |
1341 | VERBOSE_PRINTK_STRING("Creating rcu_torture_boost task"); | |
1342 | boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL, | |
1343 | cpu_to_node(cpu), | |
1344 | "rcu_torture_boost"); | |
1345 | if (IS_ERR(boost_tasks[cpu])) { | |
1346 | retval = PTR_ERR(boost_tasks[cpu]); | |
1347 | VERBOSE_PRINTK_STRING("rcu_torture_boost task create failed"); | |
1348 | n_rcu_torture_boost_ktrerror++; | |
1349 | boost_tasks[cpu] = NULL; | |
1350 | mutex_unlock(&boost_mutex); | |
1351 | return retval; | |
1352 | } | |
1353 | kthread_bind(boost_tasks[cpu], cpu); | |
1354 | wake_up_process(boost_tasks[cpu]); | |
1355 | mutex_unlock(&boost_mutex); | |
1356 | return 0; | |
1357 | } | |
1358 | ||
1359 | /* | |
1360 | * Cause the rcutorture test to shutdown the system after the test has | |
1361 | * run for the time specified by the shutdown_secs module parameter. | |
1362 | */ | |
1363 | static int | |
1364 | rcu_torture_shutdown(void *arg) | |
1365 | { | |
1366 | long delta; | |
1367 | unsigned long jiffies_snap; | |
1368 | ||
1369 | VERBOSE_PRINTK_STRING("rcu_torture_shutdown task started"); | |
1370 | jiffies_snap = ACCESS_ONCE(jiffies); | |
1371 | while (ULONG_CMP_LT(jiffies_snap, shutdown_time) && | |
1372 | !kthread_should_stop()) { | |
1373 | delta = shutdown_time - jiffies_snap; | |
1374 | if (verbose) | |
1375 | printk(KERN_ALERT "%s" TORTURE_FLAG | |
1376 | "rcu_torture_shutdown task: %lu " | |
1377 | "jiffies remaining\n", | |
1378 | torture_type, delta); | |
1379 | schedule_timeout_interruptible(delta); | |
1380 | jiffies_snap = ACCESS_ONCE(jiffies); | |
1381 | } | |
1382 | if (kthread_should_stop()) { | |
1383 | VERBOSE_PRINTK_STRING("rcu_torture_shutdown task stopping"); | |
1384 | return 0; | |
1385 | } | |
1386 | ||
1387 | /* OK, shut down the system. */ | |
1388 | ||
1389 | VERBOSE_PRINTK_STRING("rcu_torture_shutdown task shutting down system"); | |
1390 | shutdown_task = NULL; /* Avoid self-kill deadlock. */ | |
1391 | rcu_torture_cleanup(); /* Get the success/failure message. */ | |
1392 | kernel_power_off(); /* Shut down the system. */ | |
1393 | return 0; | |
1394 | } | |
1395 | ||
1396 | #ifdef CONFIG_HOTPLUG_CPU | |
1397 | ||
1398 | /* | |
1399 | * Execute random CPU-hotplug operations at the interval specified | |
1400 | * by the onoff_interval. | |
1401 | */ | |
1402 | static int | |
1403 | rcu_torture_onoff(void *arg) | |
1404 | { | |
1405 | int cpu; | |
1406 | int maxcpu = -1; | |
1407 | DEFINE_RCU_RANDOM(rand); | |
1408 | ||
1409 | VERBOSE_PRINTK_STRING("rcu_torture_onoff task started"); | |
1410 | for_each_online_cpu(cpu) | |
1411 | maxcpu = cpu; | |
1412 | WARN_ON(maxcpu < 0); | |
1413 | while (!kthread_should_stop()) { | |
1414 | cpu = (rcu_random(&rand) >> 4) % (maxcpu + 1); | |
1415 | if (cpu_online(cpu) && cpu_is_hotpluggable(cpu)) { | |
1416 | if (verbose) | |
1417 | printk(KERN_ALERT "%s" TORTURE_FLAG | |
1418 | "rcu_torture_onoff task: offlining %d\n", | |
1419 | torture_type, cpu); | |
1420 | n_offline_attempts++; | |
1421 | if (cpu_down(cpu) == 0) { | |
1422 | if (verbose) | |
1423 | printk(KERN_ALERT "%s" TORTURE_FLAG | |
1424 | "rcu_torture_onoff task: " | |
1425 | "offlined %d\n", | |
1426 | torture_type, cpu); | |
1427 | n_offline_successes++; | |
1428 | } | |
1429 | } else if (cpu_is_hotpluggable(cpu)) { | |
1430 | if (verbose) | |
1431 | printk(KERN_ALERT "%s" TORTURE_FLAG | |
1432 | "rcu_torture_onoff task: onlining %d\n", | |
1433 | torture_type, cpu); | |
1434 | n_online_attempts++; | |
1435 | if (cpu_up(cpu) == 0) { | |
1436 | if (verbose) | |
1437 | printk(KERN_ALERT "%s" TORTURE_FLAG | |
1438 | "rcu_torture_onoff task: " | |
1439 | "onlined %d\n", | |
1440 | torture_type, cpu); | |
1441 | n_online_successes++; | |
1442 | } | |
1443 | } | |
1444 | schedule_timeout_interruptible(onoff_interval * HZ); | |
1445 | } | |
1446 | VERBOSE_PRINTK_STRING("rcu_torture_onoff task stopping"); | |
1447 | return 0; | |
1448 | } | |
1449 | ||
1450 | static int | |
1451 | rcu_torture_onoff_init(void) | |
1452 | { | |
1453 | if (onoff_interval <= 0) | |
1454 | return 0; | |
1455 | onoff_task = kthread_run(rcu_torture_onoff, NULL, "rcu_torture_onoff"); | |
1456 | if (IS_ERR(onoff_task)) { | |
1457 | onoff_task = NULL; | |
1458 | return PTR_ERR(onoff_task); | |
1459 | } | |
1460 | return 0; | |
1461 | } | |
1462 | ||
1463 | static void rcu_torture_onoff_cleanup(void) | |
1464 | { | |
1465 | if (onoff_task == NULL) | |
1466 | return; | |
1467 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_onoff task"); | |
1468 | kthread_stop(onoff_task); | |
1469 | } | |
1470 | ||
1471 | #else /* #ifdef CONFIG_HOTPLUG_CPU */ | |
1472 | ||
1473 | static void | |
1474 | rcu_torture_onoff_init(void) | |
1475 | { | |
1476 | } | |
1477 | ||
1478 | static void rcu_torture_onoff_cleanup(void) | |
1479 | { | |
1480 | } | |
1481 | ||
1482 | #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ | |
1483 | ||
1484 | static int rcutorture_cpu_notify(struct notifier_block *self, | |
1485 | unsigned long action, void *hcpu) | |
1486 | { | |
1487 | long cpu = (long)hcpu; | |
1488 | ||
1489 | switch (action) { | |
1490 | case CPU_ONLINE: | |
1491 | case CPU_DOWN_FAILED: | |
1492 | (void)rcutorture_booster_init(cpu); | |
1493 | break; | |
1494 | case CPU_DOWN_PREPARE: | |
1495 | rcutorture_booster_cleanup(cpu); | |
1496 | break; | |
1497 | default: | |
1498 | break; | |
1499 | } | |
1500 | return NOTIFY_OK; | |
1501 | } | |
1502 | ||
1503 | static struct notifier_block rcutorture_cpu_nb = { | |
1504 | .notifier_call = rcutorture_cpu_notify, | |
1505 | }; | |
1506 | ||
1507 | static void | |
1508 | rcu_torture_cleanup(void) | |
1509 | { | |
1510 | int i; | |
1511 | ||
1512 | mutex_lock(&fullstop_mutex); | |
1513 | rcutorture_record_test_transition(); | |
1514 | if (fullstop == FULLSTOP_SHUTDOWN) { | |
1515 | printk(KERN_WARNING /* but going down anyway, so... */ | |
1516 | "Concurrent 'rmmod rcutorture' and shutdown illegal!\n"); | |
1517 | mutex_unlock(&fullstop_mutex); | |
1518 | schedule_timeout_uninterruptible(10); | |
1519 | if (cur_ops->cb_barrier != NULL) | |
1520 | cur_ops->cb_barrier(); | |
1521 | return; | |
1522 | } | |
1523 | fullstop = FULLSTOP_RMMOD; | |
1524 | mutex_unlock(&fullstop_mutex); | |
1525 | unregister_reboot_notifier(&rcutorture_shutdown_nb); | |
1526 | if (stutter_task) { | |
1527 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stutter task"); | |
1528 | kthread_stop(stutter_task); | |
1529 | } | |
1530 | stutter_task = NULL; | |
1531 | if (shuffler_task) { | |
1532 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task"); | |
1533 | kthread_stop(shuffler_task); | |
1534 | free_cpumask_var(shuffle_tmp_mask); | |
1535 | } | |
1536 | shuffler_task = NULL; | |
1537 | ||
1538 | if (writer_task) { | |
1539 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task"); | |
1540 | kthread_stop(writer_task); | |
1541 | } | |
1542 | writer_task = NULL; | |
1543 | ||
1544 | if (reader_tasks) { | |
1545 | for (i = 0; i < nrealreaders; i++) { | |
1546 | if (reader_tasks[i]) { | |
1547 | VERBOSE_PRINTK_STRING( | |
1548 | "Stopping rcu_torture_reader task"); | |
1549 | kthread_stop(reader_tasks[i]); | |
1550 | } | |
1551 | reader_tasks[i] = NULL; | |
1552 | } | |
1553 | kfree(reader_tasks); | |
1554 | reader_tasks = NULL; | |
1555 | } | |
1556 | rcu_torture_current = NULL; | |
1557 | ||
1558 | if (fakewriter_tasks) { | |
1559 | for (i = 0; i < nfakewriters; i++) { | |
1560 | if (fakewriter_tasks[i]) { | |
1561 | VERBOSE_PRINTK_STRING( | |
1562 | "Stopping rcu_torture_fakewriter task"); | |
1563 | kthread_stop(fakewriter_tasks[i]); | |
1564 | } | |
1565 | fakewriter_tasks[i] = NULL; | |
1566 | } | |
1567 | kfree(fakewriter_tasks); | |
1568 | fakewriter_tasks = NULL; | |
1569 | } | |
1570 | ||
1571 | if (stats_task) { | |
1572 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task"); | |
1573 | kthread_stop(stats_task); | |
1574 | } | |
1575 | stats_task = NULL; | |
1576 | ||
1577 | if (fqs_task) { | |
1578 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_fqs task"); | |
1579 | kthread_stop(fqs_task); | |
1580 | } | |
1581 | fqs_task = NULL; | |
1582 | if ((test_boost == 1 && cur_ops->can_boost) || | |
1583 | test_boost == 2) { | |
1584 | unregister_cpu_notifier(&rcutorture_cpu_nb); | |
1585 | for_each_possible_cpu(i) | |
1586 | rcutorture_booster_cleanup(i); | |
1587 | } | |
1588 | if (shutdown_task != NULL) { | |
1589 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_shutdown task"); | |
1590 | kthread_stop(shutdown_task); | |
1591 | } | |
1592 | rcu_torture_onoff_cleanup(); | |
1593 | ||
1594 | /* Wait for all RCU callbacks to fire. */ | |
1595 | ||
1596 | if (cur_ops->cb_barrier != NULL) | |
1597 | cur_ops->cb_barrier(); | |
1598 | ||
1599 | rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ | |
1600 | ||
1601 | if (cur_ops->cleanup) | |
1602 | cur_ops->cleanup(); | |
1603 | if (atomic_read(&n_rcu_torture_error)) | |
1604 | rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE"); | |
1605 | else | |
1606 | rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS"); | |
1607 | } | |
1608 | ||
1609 | static int __init | |
1610 | rcu_torture_init(void) | |
1611 | { | |
1612 | int i; | |
1613 | int cpu; | |
1614 | int firsterr = 0; | |
1615 | static struct rcu_torture_ops *torture_ops[] = | |
1616 | { &rcu_ops, &rcu_sync_ops, &rcu_expedited_ops, | |
1617 | &rcu_bh_ops, &rcu_bh_sync_ops, &rcu_bh_expedited_ops, | |
1618 | &srcu_ops, &srcu_raw_ops, &srcu_expedited_ops, | |
1619 | &sched_ops, &sched_sync_ops, &sched_expedited_ops, }; | |
1620 | ||
1621 | mutex_lock(&fullstop_mutex); | |
1622 | ||
1623 | /* Process args and tell the world that the torturer is on the job. */ | |
1624 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { | |
1625 | cur_ops = torture_ops[i]; | |
1626 | if (strcmp(torture_type, cur_ops->name) == 0) | |
1627 | break; | |
1628 | } | |
1629 | if (i == ARRAY_SIZE(torture_ops)) { | |
1630 | printk(KERN_ALERT "rcu-torture: invalid torture type: \"%s\"\n", | |
1631 | torture_type); | |
1632 | printk(KERN_ALERT "rcu-torture types:"); | |
1633 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) | |
1634 | printk(KERN_ALERT " %s", torture_ops[i]->name); | |
1635 | printk(KERN_ALERT "\n"); | |
1636 | mutex_unlock(&fullstop_mutex); | |
1637 | return -EINVAL; | |
1638 | } | |
1639 | if (cur_ops->fqs == NULL && fqs_duration != 0) { | |
1640 | printk(KERN_ALERT "rcu-torture: ->fqs NULL and non-zero " | |
1641 | "fqs_duration, fqs disabled.\n"); | |
1642 | fqs_duration = 0; | |
1643 | } | |
1644 | if (cur_ops->init) | |
1645 | cur_ops->init(); /* no "goto unwind" prior to this point!!! */ | |
1646 | ||
1647 | if (nreaders >= 0) | |
1648 | nrealreaders = nreaders; | |
1649 | else | |
1650 | nrealreaders = 2 * num_online_cpus(); | |
1651 | rcu_torture_print_module_parms(cur_ops, "Start of test"); | |
1652 | fullstop = FULLSTOP_DONTSTOP; | |
1653 | ||
1654 | /* Set up the freelist. */ | |
1655 | ||
1656 | INIT_LIST_HEAD(&rcu_torture_freelist); | |
1657 | for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) { | |
1658 | rcu_tortures[i].rtort_mbtest = 0; | |
1659 | list_add_tail(&rcu_tortures[i].rtort_free, | |
1660 | &rcu_torture_freelist); | |
1661 | } | |
1662 | ||
1663 | /* Initialize the statistics so that each run gets its own numbers. */ | |
1664 | ||
1665 | rcu_torture_current = NULL; | |
1666 | rcu_torture_current_version = 0; | |
1667 | atomic_set(&n_rcu_torture_alloc, 0); | |
1668 | atomic_set(&n_rcu_torture_alloc_fail, 0); | |
1669 | atomic_set(&n_rcu_torture_free, 0); | |
1670 | atomic_set(&n_rcu_torture_mberror, 0); | |
1671 | atomic_set(&n_rcu_torture_error, 0); | |
1672 | n_rcu_torture_boost_ktrerror = 0; | |
1673 | n_rcu_torture_boost_rterror = 0; | |
1674 | n_rcu_torture_boost_failure = 0; | |
1675 | n_rcu_torture_boosts = 0; | |
1676 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) | |
1677 | atomic_set(&rcu_torture_wcount[i], 0); | |
1678 | for_each_possible_cpu(cpu) { | |
1679 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { | |
1680 | per_cpu(rcu_torture_count, cpu)[i] = 0; | |
1681 | per_cpu(rcu_torture_batch, cpu)[i] = 0; | |
1682 | } | |
1683 | } | |
1684 | ||
1685 | /* Start up the kthreads. */ | |
1686 | ||
1687 | VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task"); | |
1688 | writer_task = kthread_run(rcu_torture_writer, NULL, | |
1689 | "rcu_torture_writer"); | |
1690 | if (IS_ERR(writer_task)) { | |
1691 | firsterr = PTR_ERR(writer_task); | |
1692 | VERBOSE_PRINTK_ERRSTRING("Failed to create writer"); | |
1693 | writer_task = NULL; | |
1694 | goto unwind; | |
1695 | } | |
1696 | fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]), | |
1697 | GFP_KERNEL); | |
1698 | if (fakewriter_tasks == NULL) { | |
1699 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
1700 | firsterr = -ENOMEM; | |
1701 | goto unwind; | |
1702 | } | |
1703 | for (i = 0; i < nfakewriters; i++) { | |
1704 | VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task"); | |
1705 | fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL, | |
1706 | "rcu_torture_fakewriter"); | |
1707 | if (IS_ERR(fakewriter_tasks[i])) { | |
1708 | firsterr = PTR_ERR(fakewriter_tasks[i]); | |
1709 | VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter"); | |
1710 | fakewriter_tasks[i] = NULL; | |
1711 | goto unwind; | |
1712 | } | |
1713 | } | |
1714 | reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]), | |
1715 | GFP_KERNEL); | |
1716 | if (reader_tasks == NULL) { | |
1717 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
1718 | firsterr = -ENOMEM; | |
1719 | goto unwind; | |
1720 | } | |
1721 | for (i = 0; i < nrealreaders; i++) { | |
1722 | VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task"); | |
1723 | reader_tasks[i] = kthread_run(rcu_torture_reader, NULL, | |
1724 | "rcu_torture_reader"); | |
1725 | if (IS_ERR(reader_tasks[i])) { | |
1726 | firsterr = PTR_ERR(reader_tasks[i]); | |
1727 | VERBOSE_PRINTK_ERRSTRING("Failed to create reader"); | |
1728 | reader_tasks[i] = NULL; | |
1729 | goto unwind; | |
1730 | } | |
1731 | } | |
1732 | if (stat_interval > 0) { | |
1733 | VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task"); | |
1734 | stats_task = kthread_run(rcu_torture_stats, NULL, | |
1735 | "rcu_torture_stats"); | |
1736 | if (IS_ERR(stats_task)) { | |
1737 | firsterr = PTR_ERR(stats_task); | |
1738 | VERBOSE_PRINTK_ERRSTRING("Failed to create stats"); | |
1739 | stats_task = NULL; | |
1740 | goto unwind; | |
1741 | } | |
1742 | } | |
1743 | if (test_no_idle_hz) { | |
1744 | rcu_idle_cpu = num_online_cpus() - 1; | |
1745 | ||
1746 | if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) { | |
1747 | firsterr = -ENOMEM; | |
1748 | VERBOSE_PRINTK_ERRSTRING("Failed to alloc mask"); | |
1749 | goto unwind; | |
1750 | } | |
1751 | ||
1752 | /* Create the shuffler thread */ | |
1753 | shuffler_task = kthread_run(rcu_torture_shuffle, NULL, | |
1754 | "rcu_torture_shuffle"); | |
1755 | if (IS_ERR(shuffler_task)) { | |
1756 | free_cpumask_var(shuffle_tmp_mask); | |
1757 | firsterr = PTR_ERR(shuffler_task); | |
1758 | VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler"); | |
1759 | shuffler_task = NULL; | |
1760 | goto unwind; | |
1761 | } | |
1762 | } | |
1763 | if (stutter < 0) | |
1764 | stutter = 0; | |
1765 | if (stutter) { | |
1766 | /* Create the stutter thread */ | |
1767 | stutter_task = kthread_run(rcu_torture_stutter, NULL, | |
1768 | "rcu_torture_stutter"); | |
1769 | if (IS_ERR(stutter_task)) { | |
1770 | firsterr = PTR_ERR(stutter_task); | |
1771 | VERBOSE_PRINTK_ERRSTRING("Failed to create stutter"); | |
1772 | stutter_task = NULL; | |
1773 | goto unwind; | |
1774 | } | |
1775 | } | |
1776 | if (fqs_duration < 0) | |
1777 | fqs_duration = 0; | |
1778 | if (fqs_duration) { | |
1779 | /* Create the stutter thread */ | |
1780 | fqs_task = kthread_run(rcu_torture_fqs, NULL, | |
1781 | "rcu_torture_fqs"); | |
1782 | if (IS_ERR(fqs_task)) { | |
1783 | firsterr = PTR_ERR(fqs_task); | |
1784 | VERBOSE_PRINTK_ERRSTRING("Failed to create fqs"); | |
1785 | fqs_task = NULL; | |
1786 | goto unwind; | |
1787 | } | |
1788 | } | |
1789 | if (test_boost_interval < 1) | |
1790 | test_boost_interval = 1; | |
1791 | if (test_boost_duration < 2) | |
1792 | test_boost_duration = 2; | |
1793 | if ((test_boost == 1 && cur_ops->can_boost) || | |
1794 | test_boost == 2) { | |
1795 | int retval; | |
1796 | ||
1797 | boost_starttime = jiffies + test_boost_interval * HZ; | |
1798 | register_cpu_notifier(&rcutorture_cpu_nb); | |
1799 | for_each_possible_cpu(i) { | |
1800 | if (cpu_is_offline(i)) | |
1801 | continue; /* Heuristic: CPU can go offline. */ | |
1802 | retval = rcutorture_booster_init(i); | |
1803 | if (retval < 0) { | |
1804 | firsterr = retval; | |
1805 | goto unwind; | |
1806 | } | |
1807 | } | |
1808 | } | |
1809 | if (shutdown_secs > 0) { | |
1810 | shutdown_time = jiffies + shutdown_secs * HZ; | |
1811 | shutdown_task = kthread_run(rcu_torture_shutdown, NULL, | |
1812 | "rcu_torture_shutdown"); | |
1813 | if (IS_ERR(shutdown_task)) { | |
1814 | firsterr = PTR_ERR(shutdown_task); | |
1815 | VERBOSE_PRINTK_ERRSTRING("Failed to create shutdown"); | |
1816 | shutdown_task = NULL; | |
1817 | goto unwind; | |
1818 | } | |
1819 | } | |
1820 | rcu_torture_onoff_init(); | |
1821 | register_reboot_notifier(&rcutorture_shutdown_nb); | |
1822 | rcutorture_record_test_transition(); | |
1823 | mutex_unlock(&fullstop_mutex); | |
1824 | return 0; | |
1825 | ||
1826 | unwind: | |
1827 | mutex_unlock(&fullstop_mutex); | |
1828 | rcu_torture_cleanup(); | |
1829 | return firsterr; | |
1830 | } | |
1831 | ||
1832 | module_init(rcu_torture_init); | |
1833 | module_exit(rcu_torture_cleanup); |