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a241ec65 | 1 | /* |
29766f1e | 2 | * Read-Copy Update module-based torture test facility |
a241ec65 PM |
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 | * | |
b772e1dd | 18 | * Copyright (C) IBM Corporation, 2005, 2006 |
a241ec65 PM |
19 | * |
20 | * Authors: Paul E. McKenney <paulmck@us.ibm.com> | |
a71fca58 | 21 | * Josh Triplett <josh@freedesktop.org> |
a241ec65 PM |
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> | |
60063497 | 36 | #include <linux/atomic.h> |
a241ec65 | 37 | #include <linux/bitops.h> |
a241ec65 PM |
38 | #include <linux/completion.h> |
39 | #include <linux/moduleparam.h> | |
40 | #include <linux/percpu.h> | |
41 | #include <linux/notifier.h> | |
343e9099 | 42 | #include <linux/reboot.h> |
83144186 | 43 | #include <linux/freezer.h> |
a241ec65 | 44 | #include <linux/cpu.h> |
a241ec65 | 45 | #include <linux/delay.h> |
a241ec65 | 46 | #include <linux/stat.h> |
b2896d2e | 47 | #include <linux/srcu.h> |
1aeb272c | 48 | #include <linux/slab.h> |
52494535 | 49 | #include <linux/trace_clock.h> |
f07767fd | 50 | #include <asm/byteorder.h> |
a241ec65 PM |
51 | |
52 | MODULE_LICENSE("GPL"); | |
5cf05ad7 | 53 | MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and Josh Triplett <josh@freedesktop.org>"); |
a241ec65 | 54 | |
4102adab PM |
55 | MODULE_ALIAS("rcutorture"); |
56 | #ifdef MODULE_PARAM_PREFIX | |
57 | #undef MODULE_PARAM_PREFIX | |
58 | #endif | |
59 | #define MODULE_PARAM_PREFIX "rcutorture." | |
60 | ||
d10453e9 | 61 | static int fqs_duration; |
bf66f18e | 62 | module_param(fqs_duration, int, 0444); |
d10453e9 PM |
63 | MODULE_PARM_DESC(fqs_duration, "Duration of fqs bursts (us), 0 to disable"); |
64 | static int fqs_holdoff; | |
bf66f18e PM |
65 | module_param(fqs_holdoff, int, 0444); |
66 | MODULE_PARM_DESC(fqs_holdoff, "Holdoff time within fqs bursts (us)"); | |
d10453e9 | 67 | static int fqs_stutter = 3; |
bf66f18e PM |
68 | module_param(fqs_stutter, int, 0444); |
69 | MODULE_PARM_DESC(fqs_stutter, "Wait time between fqs bursts (s)"); | |
d10453e9 | 70 | static bool gp_exp; |
2ec1f2d9 PM |
71 | module_param(gp_exp, bool, 0444); |
72 | MODULE_PARM_DESC(gp_exp, "Use expedited GP wait primitives"); | |
d10453e9 PM |
73 | static bool gp_normal; |
74 | module_param(gp_normal, bool, 0444); | |
75 | MODULE_PARM_DESC(gp_normal, "Use normal (non-expedited) GP wait primitives"); | |
76 | static int irqreader = 1; | |
77 | module_param(irqreader, int, 0444); | |
78 | MODULE_PARM_DESC(irqreader, "Allow RCU readers from irq handlers"); | |
79 | static int n_barrier_cbs; | |
fae4b54f PM |
80 | module_param(n_barrier_cbs, int, 0444); |
81 | MODULE_PARM_DESC(n_barrier_cbs, "# of callbacks/kthreads for barrier testing"); | |
d10453e9 PM |
82 | static int nfakewriters = 4; |
83 | module_param(nfakewriters, int, 0444); | |
84 | MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads"); | |
85 | static int nreaders = -1; | |
86 | module_param(nreaders, int, 0444); | |
87 | MODULE_PARM_DESC(nreaders, "Number of RCU reader threads"); | |
88 | static int object_debug; | |
d2818df1 PM |
89 | module_param(object_debug, int, 0444); |
90 | MODULE_PARM_DESC(object_debug, "Enable debug-object double call_rcu() testing"); | |
d10453e9 | 91 | static int onoff_holdoff; |
9b9ec9b9 PM |
92 | module_param(onoff_holdoff, int, 0444); |
93 | MODULE_PARM_DESC(onoff_holdoff, "Time after boot before CPU hotplugs (s)"); | |
d10453e9 PM |
94 | static int onoff_interval; |
95 | module_param(onoff_interval, int, 0444); | |
96 | MODULE_PARM_DESC(onoff_interval, "Time between CPU hotplugs (s), 0=disable"); | |
97 | static int shuffle_interval = 3; | |
98 | module_param(shuffle_interval, int, 0444); | |
99 | MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles"); | |
100 | static int shutdown_secs; | |
d5f546d8 | 101 | module_param(shutdown_secs, int, 0444); |
d10453e9 PM |
102 | MODULE_PARM_DESC(shutdown_secs, "Shutdown time (s), <= zero to disable."); |
103 | static int stall_cpu; | |
c13f3757 PM |
104 | module_param(stall_cpu, int, 0444); |
105 | MODULE_PARM_DESC(stall_cpu, "Stall duration (s), zero to disable."); | |
d10453e9 | 106 | static int stall_cpu_holdoff = 10; |
c13f3757 PM |
107 | module_param(stall_cpu_holdoff, int, 0444); |
108 | MODULE_PARM_DESC(stall_cpu_holdoff, "Time to wait before starting stall (s)."); | |
d10453e9 PM |
109 | static int stat_interval = 60; |
110 | module_param(stat_interval, int, 0644); | |
111 | MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s"); | |
112 | static int stutter = 5; | |
113 | module_param(stutter, int, 0444); | |
114 | MODULE_PARM_DESC(stutter, "Number of seconds to run/halt test"); | |
115 | static int test_boost = 1; | |
8e8be45e PM |
116 | module_param(test_boost, int, 0444); |
117 | MODULE_PARM_DESC(test_boost, "Test RCU prio boost: 0=no, 1=maybe, 2=yes."); | |
d10453e9 | 118 | static int test_boost_duration = 4; |
8e8be45e PM |
119 | module_param(test_boost_duration, int, 0444); |
120 | MODULE_PARM_DESC(test_boost_duration, "Duration of each boost test, seconds."); | |
d10453e9 PM |
121 | static int test_boost_interval = 7; |
122 | module_param(test_boost_interval, int, 0444); | |
123 | MODULE_PARM_DESC(test_boost_interval, "Interval between boost tests, seconds."); | |
124 | static bool test_no_idle_hz = true; | |
125 | module_param(test_no_idle_hz, bool, 0444); | |
126 | MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs"); | |
127 | static char *torture_type = "rcu"; | |
d6ad6711 | 128 | module_param(torture_type, charp, 0444); |
d10453e9 PM |
129 | MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, ...)"); |
130 | static bool verbose; | |
131 | module_param(verbose, bool, 0444); | |
132 | MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s"); | |
72e9bb54 PM |
133 | |
134 | #define TORTURE_FLAG "-torture:" | |
a241ec65 | 135 | #define PRINTK_STRING(s) \ |
2caa1e44 | 136 | do { pr_alert("%s" TORTURE_FLAG s "\n", torture_type); } while (0) |
a241ec65 | 137 | #define VERBOSE_PRINTK_STRING(s) \ |
2caa1e44 | 138 | do { if (verbose) pr_alert("%s" TORTURE_FLAG s "\n", torture_type); } while (0) |
a241ec65 | 139 | #define VERBOSE_PRINTK_ERRSTRING(s) \ |
2caa1e44 | 140 | do { if (verbose) pr_alert("%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0) |
a241ec65 PM |
141 | |
142 | static char printk_buf[4096]; | |
143 | ||
144 | static int nrealreaders; | |
145 | static struct task_struct *writer_task; | |
b772e1dd | 146 | static struct task_struct **fakewriter_tasks; |
a241ec65 PM |
147 | static struct task_struct **reader_tasks; |
148 | static struct task_struct *stats_task; | |
d84f5203 | 149 | static struct task_struct *shuffler_task; |
d120f65f | 150 | static struct task_struct *stutter_task; |
bf66f18e | 151 | static struct task_struct *fqs_task; |
8e8be45e | 152 | static struct task_struct *boost_tasks[NR_CPUS]; |
d5f546d8 | 153 | static struct task_struct *shutdown_task; |
b58bdcca PM |
154 | #ifdef CONFIG_HOTPLUG_CPU |
155 | static struct task_struct *onoff_task; | |
156 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
c13f3757 | 157 | static struct task_struct *stall_task; |
fae4b54f PM |
158 | static struct task_struct **barrier_cbs_tasks; |
159 | static struct task_struct *barrier_task; | |
a241ec65 PM |
160 | |
161 | #define RCU_TORTURE_PIPE_LEN 10 | |
162 | ||
163 | struct rcu_torture { | |
164 | struct rcu_head rtort_rcu; | |
165 | int rtort_pipe_count; | |
166 | struct list_head rtort_free; | |
996417d2 | 167 | int rtort_mbtest; |
a241ec65 PM |
168 | }; |
169 | ||
a241ec65 | 170 | static LIST_HEAD(rcu_torture_freelist); |
0ddea0ea | 171 | static struct rcu_torture __rcu *rcu_torture_current; |
4a298656 | 172 | static unsigned long rcu_torture_current_version; |
a241ec65 PM |
173 | static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; |
174 | static DEFINE_SPINLOCK(rcu_torture_lock); | |
175 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) = | |
176 | { 0 }; | |
177 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) = | |
178 | { 0 }; | |
179 | static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1]; | |
b2896d2e PM |
180 | static atomic_t n_rcu_torture_alloc; |
181 | static atomic_t n_rcu_torture_alloc_fail; | |
182 | static atomic_t n_rcu_torture_free; | |
183 | static atomic_t n_rcu_torture_mberror; | |
184 | static atomic_t n_rcu_torture_error; | |
fae4b54f | 185 | static long n_rcu_torture_barrier_error; |
8e8be45e PM |
186 | static long n_rcu_torture_boost_ktrerror; |
187 | static long n_rcu_torture_boost_rterror; | |
8e8be45e PM |
188 | static long n_rcu_torture_boost_failure; |
189 | static long n_rcu_torture_boosts; | |
a71fca58 | 190 | static long n_rcu_torture_timers; |
b58bdcca PM |
191 | static long n_offline_attempts; |
192 | static long n_offline_successes; | |
13dbf914 PM |
193 | static unsigned long sum_offline; |
194 | static int min_offline = -1; | |
195 | static int max_offline; | |
b58bdcca PM |
196 | static long n_online_attempts; |
197 | static long n_online_successes; | |
13dbf914 PM |
198 | static unsigned long sum_online; |
199 | static int min_online = -1; | |
200 | static int max_online; | |
fae4b54f PM |
201 | static long n_barrier_attempts; |
202 | static long n_barrier_successes; | |
e3033736 | 203 | static struct list_head rcu_torture_removed; |
73d0a4b1 | 204 | static cpumask_var_t shuffle_tmp_mask; |
a241ec65 | 205 | |
a71fca58 | 206 | static int stutter_pause_test; |
d120f65f | 207 | |
31a72bce PM |
208 | #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE) |
209 | #define RCUTORTURE_RUNNABLE_INIT 1 | |
210 | #else | |
211 | #define RCUTORTURE_RUNNABLE_INIT 0 | |
212 | #endif | |
213 | int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT; | |
bb3bf705 PM |
214 | module_param(rcutorture_runnable, int, 0444); |
215 | MODULE_PARM_DESC(rcutorture_runnable, "Start rcutorture at boot"); | |
31a72bce | 216 | |
3acf4a9a | 217 | #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) |
8e8be45e | 218 | #define rcu_can_boost() 1 |
3acf4a9a | 219 | #else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ |
8e8be45e | 220 | #define rcu_can_boost() 0 |
3acf4a9a | 221 | #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ |
8e8be45e | 222 | |
e4aa0da3 SR |
223 | #ifdef CONFIG_RCU_TRACE |
224 | static u64 notrace rcu_trace_clock_local(void) | |
225 | { | |
226 | u64 ts = trace_clock_local(); | |
227 | unsigned long __maybe_unused ts_rem = do_div(ts, NSEC_PER_USEC); | |
228 | return ts; | |
229 | } | |
230 | #else /* #ifdef CONFIG_RCU_TRACE */ | |
231 | static u64 notrace rcu_trace_clock_local(void) | |
232 | { | |
233 | return 0ULL; | |
234 | } | |
235 | #endif /* #else #ifdef CONFIG_RCU_TRACE */ | |
236 | ||
d5f546d8 | 237 | static unsigned long shutdown_time; /* jiffies to system shutdown. */ |
8e8be45e PM |
238 | static unsigned long boost_starttime; /* jiffies of next boost test start. */ |
239 | DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */ | |
240 | /* and boost task create/destroy. */ | |
fae4b54f | 241 | static atomic_t barrier_cbs_count; /* Barrier callbacks registered. */ |
c6ebcbb6 | 242 | static bool barrier_phase; /* Test phase. */ |
fae4b54f PM |
243 | static atomic_t barrier_cbs_invoked; /* Barrier callbacks invoked. */ |
244 | static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */ | |
245 | static DECLARE_WAIT_QUEUE_HEAD(barrier_wq); | |
8e8be45e | 246 | |
c9d557c1 PM |
247 | /* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */ |
248 | ||
249 | #define FULLSTOP_DONTSTOP 0 /* Normal operation. */ | |
250 | #define FULLSTOP_SHUTDOWN 1 /* System shutdown with rcutorture running. */ | |
251 | #define FULLSTOP_RMMOD 2 /* Normal rmmod of rcutorture. */ | |
252 | static int fullstop = FULLSTOP_RMMOD; | |
0ddea0ea PM |
253 | /* |
254 | * Protect fullstop transitions and spawning of kthreads. | |
255 | */ | |
256 | static DEFINE_MUTEX(fullstop_mutex); | |
343e9099 | 257 | |
d5f546d8 PM |
258 | /* Forward reference. */ |
259 | static void rcu_torture_cleanup(void); | |
260 | ||
343e9099 | 261 | /* |
c9d557c1 | 262 | * Detect and respond to a system shutdown. |
343e9099 PM |
263 | */ |
264 | static int | |
265 | rcutorture_shutdown_notify(struct notifier_block *unused1, | |
266 | unsigned long unused2, void *unused3) | |
267 | { | |
c59ab97e | 268 | mutex_lock(&fullstop_mutex); |
c9d557c1 | 269 | if (fullstop == FULLSTOP_DONTSTOP) |
c59ab97e | 270 | fullstop = FULLSTOP_SHUTDOWN; |
c9d557c1 | 271 | else |
2caa1e44 | 272 | pr_warn(/* but going down anyway, so... */ |
c9d557c1 | 273 | "Concurrent 'rmmod rcutorture' and shutdown illegal!\n"); |
c59ab97e | 274 | mutex_unlock(&fullstop_mutex); |
343e9099 PM |
275 | return NOTIFY_DONE; |
276 | } | |
277 | ||
c9d557c1 PM |
278 | /* |
279 | * Absorb kthreads into a kernel function that won't return, so that | |
280 | * they won't ever access module text or data again. | |
281 | */ | |
e66c33d5 | 282 | static void rcutorture_shutdown_absorb(const char *title) |
c9d557c1 PM |
283 | { |
284 | if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { | |
2caa1e44 | 285 | pr_notice( |
c9d557c1 PM |
286 | "rcutorture thread %s parking due to system shutdown\n", |
287 | title); | |
288 | schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT); | |
289 | } | |
290 | } | |
291 | ||
a241ec65 PM |
292 | /* |
293 | * Allocate an element from the rcu_tortures pool. | |
294 | */ | |
97a41e26 | 295 | static struct rcu_torture * |
a241ec65 PM |
296 | rcu_torture_alloc(void) |
297 | { | |
298 | struct list_head *p; | |
299 | ||
adac1665 | 300 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 PM |
301 | if (list_empty(&rcu_torture_freelist)) { |
302 | atomic_inc(&n_rcu_torture_alloc_fail); | |
adac1665 | 303 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
304 | return NULL; |
305 | } | |
306 | atomic_inc(&n_rcu_torture_alloc); | |
307 | p = rcu_torture_freelist.next; | |
308 | list_del_init(p); | |
adac1665 | 309 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
310 | return container_of(p, struct rcu_torture, rtort_free); |
311 | } | |
312 | ||
313 | /* | |
314 | * Free an element to the rcu_tortures pool. | |
315 | */ | |
316 | static void | |
317 | rcu_torture_free(struct rcu_torture *p) | |
318 | { | |
319 | atomic_inc(&n_rcu_torture_free); | |
adac1665 | 320 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 | 321 | list_add_tail(&p->rtort_free, &rcu_torture_freelist); |
adac1665 | 322 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
323 | } |
324 | ||
a241ec65 PM |
325 | struct rcu_random_state { |
326 | unsigned long rrs_state; | |
75cfef32 | 327 | long rrs_count; |
a241ec65 PM |
328 | }; |
329 | ||
330 | #define RCU_RANDOM_MULT 39916801 /* prime */ | |
331 | #define RCU_RANDOM_ADD 479001701 /* prime */ | |
332 | #define RCU_RANDOM_REFRESH 10000 | |
333 | ||
334 | #define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 } | |
335 | ||
336 | /* | |
337 | * Crude but fast random-number generator. Uses a linear congruential | |
c17ac855 | 338 | * generator, with occasional help from cpu_clock(). |
a241ec65 | 339 | */ |
75cfef32 | 340 | static unsigned long |
a241ec65 PM |
341 | rcu_random(struct rcu_random_state *rrsp) |
342 | { | |
a241ec65 | 343 | if (--rrsp->rrs_count < 0) { |
c676329a | 344 | rrsp->rrs_state += (unsigned long)local_clock(); |
a241ec65 PM |
345 | rrsp->rrs_count = RCU_RANDOM_REFRESH; |
346 | } | |
347 | rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD; | |
348 | return swahw32(rrsp->rrs_state); | |
349 | } | |
350 | ||
d120f65f | 351 | static void |
e66c33d5 | 352 | rcu_stutter_wait(const char *title) |
d120f65f | 353 | { |
c9d557c1 | 354 | while (stutter_pause_test || !rcutorture_runnable) { |
e3d7be27 PM |
355 | if (rcutorture_runnable) |
356 | schedule_timeout_interruptible(1); | |
357 | else | |
3ccf79f4 | 358 | schedule_timeout_interruptible(round_jiffies_relative(HZ)); |
c9d557c1 | 359 | rcutorture_shutdown_absorb(title); |
343e9099 | 360 | } |
d120f65f PM |
361 | } |
362 | ||
72e9bb54 PM |
363 | /* |
364 | * Operations vector for selecting different types of tests. | |
365 | */ | |
366 | ||
367 | struct rcu_torture_ops { | |
368 | void (*init)(void); | |
72e9bb54 | 369 | int (*readlock)(void); |
0acc512c | 370 | void (*read_delay)(struct rcu_random_state *rrsp); |
72e9bb54 PM |
371 | void (*readunlock)(int idx); |
372 | int (*completed)(void); | |
0acc512c | 373 | void (*deferred_free)(struct rcu_torture *p); |
b772e1dd | 374 | void (*sync)(void); |
2ec1f2d9 | 375 | void (*exp_sync)(void); |
fae4b54f | 376 | void (*call)(struct rcu_head *head, void (*func)(struct rcu_head *rcu)); |
2326974d | 377 | void (*cb_barrier)(void); |
bf66f18e | 378 | void (*fqs)(void); |
72e9bb54 | 379 | int (*stats)(char *page); |
0acc512c | 380 | int irq_capable; |
8e8be45e | 381 | int can_boost; |
e66c33d5 | 382 | const char *name; |
72e9bb54 | 383 | }; |
a71fca58 PM |
384 | |
385 | static struct rcu_torture_ops *cur_ops; | |
72e9bb54 PM |
386 | |
387 | /* | |
388 | * Definitions for rcu torture testing. | |
389 | */ | |
390 | ||
a49a4af7 | 391 | static int rcu_torture_read_lock(void) __acquires(RCU) |
72e9bb54 PM |
392 | { |
393 | rcu_read_lock(); | |
394 | return 0; | |
395 | } | |
396 | ||
b2896d2e PM |
397 | static void rcu_read_delay(struct rcu_random_state *rrsp) |
398 | { | |
b8d57a76 JT |
399 | const unsigned long shortdelay_us = 200; |
400 | const unsigned long longdelay_ms = 50; | |
b2896d2e | 401 | |
b8d57a76 JT |
402 | /* We want a short delay sometimes to make a reader delay the grace |
403 | * period, and we want a long delay occasionally to trigger | |
404 | * force_quiescent_state. */ | |
b2896d2e | 405 | |
b8d57a76 JT |
406 | if (!(rcu_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) |
407 | mdelay(longdelay_ms); | |
408 | if (!(rcu_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) | |
409 | udelay(shortdelay_us); | |
e546f485 LJ |
410 | #ifdef CONFIG_PREEMPT |
411 | if (!preempt_count() && !(rcu_random(rrsp) % (nrealreaders * 20000))) | |
412 | preempt_schedule(); /* No QS if preempt_disable() in effect */ | |
413 | #endif | |
b2896d2e PM |
414 | } |
415 | ||
a49a4af7 | 416 | static void rcu_torture_read_unlock(int idx) __releases(RCU) |
72e9bb54 PM |
417 | { |
418 | rcu_read_unlock(); | |
419 | } | |
420 | ||
421 | static int rcu_torture_completed(void) | |
422 | { | |
423 | return rcu_batches_completed(); | |
424 | } | |
425 | ||
426 | static void | |
427 | rcu_torture_cb(struct rcu_head *p) | |
428 | { | |
429 | int i; | |
430 | struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); | |
431 | ||
c9d557c1 | 432 | if (fullstop != FULLSTOP_DONTSTOP) { |
72e9bb54 PM |
433 | /* Test is ending, just drop callbacks on the floor. */ |
434 | /* The next initialization will pick up the pieces. */ | |
435 | return; | |
436 | } | |
437 | i = rp->rtort_pipe_count; | |
438 | if (i > RCU_TORTURE_PIPE_LEN) | |
439 | i = RCU_TORTURE_PIPE_LEN; | |
440 | atomic_inc(&rcu_torture_wcount[i]); | |
441 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
442 | rp->rtort_mbtest = 0; | |
443 | rcu_torture_free(rp); | |
c701d5d9 | 444 | } else { |
0acc512c | 445 | cur_ops->deferred_free(rp); |
c701d5d9 | 446 | } |
72e9bb54 PM |
447 | } |
448 | ||
d9a3da06 PM |
449 | static int rcu_no_completed(void) |
450 | { | |
451 | return 0; | |
452 | } | |
453 | ||
72e9bb54 PM |
454 | static void rcu_torture_deferred_free(struct rcu_torture *p) |
455 | { | |
456 | call_rcu(&p->rtort_rcu, rcu_torture_cb); | |
457 | } | |
458 | ||
e3033736 JT |
459 | static void rcu_sync_torture_init(void) |
460 | { | |
461 | INIT_LIST_HEAD(&rcu_torture_removed); | |
462 | } | |
463 | ||
2ec1f2d9 | 464 | static struct rcu_torture_ops rcu_ops = { |
0acc512c | 465 | .init = rcu_sync_torture_init, |
0acc512c PM |
466 | .readlock = rcu_torture_read_lock, |
467 | .read_delay = rcu_read_delay, | |
468 | .readunlock = rcu_torture_read_unlock, | |
469 | .completed = rcu_torture_completed, | |
2ec1f2d9 | 470 | .deferred_free = rcu_torture_deferred_free, |
0acc512c | 471 | .sync = synchronize_rcu, |
2ec1f2d9 PM |
472 | .exp_sync = synchronize_rcu_expedited, |
473 | .call = call_rcu, | |
474 | .cb_barrier = rcu_barrier, | |
bf66f18e | 475 | .fqs = rcu_force_quiescent_state, |
d9a3da06 PM |
476 | .stats = NULL, |
477 | .irq_capable = 1, | |
8e8be45e | 478 | .can_boost = rcu_can_boost(), |
2ec1f2d9 | 479 | .name = "rcu" |
d9a3da06 PM |
480 | }; |
481 | ||
c32e0660 PM |
482 | /* |
483 | * Definitions for rcu_bh torture testing. | |
484 | */ | |
485 | ||
a49a4af7 | 486 | static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH) |
c32e0660 PM |
487 | { |
488 | rcu_read_lock_bh(); | |
489 | return 0; | |
490 | } | |
491 | ||
a49a4af7 | 492 | static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH) |
c32e0660 PM |
493 | { |
494 | rcu_read_unlock_bh(); | |
495 | } | |
496 | ||
497 | static int rcu_bh_torture_completed(void) | |
498 | { | |
499 | return rcu_batches_completed_bh(); | |
500 | } | |
501 | ||
502 | static void rcu_bh_torture_deferred_free(struct rcu_torture *p) | |
503 | { | |
504 | call_rcu_bh(&p->rtort_rcu, rcu_torture_cb); | |
505 | } | |
506 | ||
507 | static struct rcu_torture_ops rcu_bh_ops = { | |
2ec1f2d9 | 508 | .init = rcu_sync_torture_init, |
0acc512c PM |
509 | .readlock = rcu_bh_torture_read_lock, |
510 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
511 | .readunlock = rcu_bh_torture_read_unlock, | |
512 | .completed = rcu_bh_torture_completed, | |
513 | .deferred_free = rcu_bh_torture_deferred_free, | |
bdf2a436 | 514 | .sync = synchronize_rcu_bh, |
2ec1f2d9 | 515 | .exp_sync = synchronize_rcu_bh_expedited, |
fae4b54f | 516 | .call = call_rcu_bh, |
0acc512c | 517 | .cb_barrier = rcu_barrier_bh, |
bf66f18e | 518 | .fqs = rcu_bh_force_quiescent_state, |
0acc512c PM |
519 | .stats = NULL, |
520 | .irq_capable = 1, | |
521 | .name = "rcu_bh" | |
c32e0660 PM |
522 | }; |
523 | ||
b2896d2e PM |
524 | /* |
525 | * Definitions for srcu torture testing. | |
526 | */ | |
527 | ||
cda4dc81 | 528 | DEFINE_STATIC_SRCU(srcu_ctl); |
b2896d2e | 529 | |
012d3ca8 | 530 | static int srcu_torture_read_lock(void) __acquires(&srcu_ctl) |
b2896d2e PM |
531 | { |
532 | return srcu_read_lock(&srcu_ctl); | |
533 | } | |
534 | ||
535 | static void srcu_read_delay(struct rcu_random_state *rrsp) | |
536 | { | |
537 | long delay; | |
538 | const long uspertick = 1000000 / HZ; | |
539 | const long longdelay = 10; | |
540 | ||
541 | /* We want there to be long-running readers, but not all the time. */ | |
542 | ||
543 | delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick); | |
544 | if (!delay) | |
545 | schedule_timeout_interruptible(longdelay); | |
e546f485 LJ |
546 | else |
547 | rcu_read_delay(rrsp); | |
b2896d2e PM |
548 | } |
549 | ||
012d3ca8 | 550 | static void srcu_torture_read_unlock(int idx) __releases(&srcu_ctl) |
b2896d2e PM |
551 | { |
552 | srcu_read_unlock(&srcu_ctl, idx); | |
553 | } | |
554 | ||
555 | static int srcu_torture_completed(void) | |
556 | { | |
557 | return srcu_batches_completed(&srcu_ctl); | |
558 | } | |
559 | ||
9059c940 LJ |
560 | static void srcu_torture_deferred_free(struct rcu_torture *rp) |
561 | { | |
562 | call_srcu(&srcu_ctl, &rp->rtort_rcu, rcu_torture_cb); | |
563 | } | |
564 | ||
b772e1dd JT |
565 | static void srcu_torture_synchronize(void) |
566 | { | |
567 | synchronize_srcu(&srcu_ctl); | |
568 | } | |
569 | ||
e3f8d378 PM |
570 | static void srcu_torture_call(struct rcu_head *head, |
571 | void (*func)(struct rcu_head *head)) | |
572 | { | |
573 | call_srcu(&srcu_ctl, head, func); | |
574 | } | |
575 | ||
576 | static void srcu_torture_barrier(void) | |
577 | { | |
578 | srcu_barrier(&srcu_ctl); | |
579 | } | |
580 | ||
b2896d2e PM |
581 | static int srcu_torture_stats(char *page) |
582 | { | |
583 | int cnt = 0; | |
584 | int cpu; | |
585 | int idx = srcu_ctl.completed & 0x1; | |
586 | ||
587 | cnt += sprintf(&page[cnt], "%s%s per-CPU(idx=%d):", | |
588 | torture_type, TORTURE_FLAG, idx); | |
589 | for_each_possible_cpu(cpu) { | |
cef50120 | 590 | cnt += sprintf(&page[cnt], " %d(%lu,%lu)", cpu, |
b2896d2e PM |
591 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[!idx], |
592 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[idx]); | |
593 | } | |
594 | cnt += sprintf(&page[cnt], "\n"); | |
595 | return cnt; | |
596 | } | |
597 | ||
2ec1f2d9 PM |
598 | static void srcu_torture_synchronize_expedited(void) |
599 | { | |
600 | synchronize_srcu_expedited(&srcu_ctl); | |
601 | } | |
602 | ||
b2896d2e | 603 | static struct rcu_torture_ops srcu_ops = { |
cda4dc81 | 604 | .init = rcu_sync_torture_init, |
0acc512c PM |
605 | .readlock = srcu_torture_read_lock, |
606 | .read_delay = srcu_read_delay, | |
607 | .readunlock = srcu_torture_read_unlock, | |
608 | .completed = srcu_torture_completed, | |
9059c940 | 609 | .deferred_free = srcu_torture_deferred_free, |
0acc512c | 610 | .sync = srcu_torture_synchronize, |
2ec1f2d9 | 611 | .exp_sync = srcu_torture_synchronize_expedited, |
e3f8d378 PM |
612 | .call = srcu_torture_call, |
613 | .cb_barrier = srcu_torture_barrier, | |
0acc512c PM |
614 | .stats = srcu_torture_stats, |
615 | .name = "srcu" | |
b2896d2e PM |
616 | }; |
617 | ||
4b6c2cca JT |
618 | /* |
619 | * Definitions for sched torture testing. | |
620 | */ | |
621 | ||
622 | static int sched_torture_read_lock(void) | |
623 | { | |
624 | preempt_disable(); | |
625 | return 0; | |
626 | } | |
627 | ||
628 | static void sched_torture_read_unlock(int idx) | |
629 | { | |
630 | preempt_enable(); | |
631 | } | |
632 | ||
2326974d PM |
633 | static void rcu_sched_torture_deferred_free(struct rcu_torture *p) |
634 | { | |
635 | call_rcu_sched(&p->rtort_rcu, rcu_torture_cb); | |
636 | } | |
637 | ||
4b6c2cca | 638 | static struct rcu_torture_ops sched_ops = { |
0acc512c | 639 | .init = rcu_sync_torture_init, |
0acc512c PM |
640 | .readlock = sched_torture_read_lock, |
641 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
642 | .readunlock = sched_torture_read_unlock, | |
d9a3da06 | 643 | .completed = rcu_no_completed, |
0acc512c | 644 | .deferred_free = rcu_sched_torture_deferred_free, |
bdf2a436 | 645 | .sync = synchronize_sched, |
2ec1f2d9 PM |
646 | .exp_sync = synchronize_sched_expedited, |
647 | .call = call_rcu_sched, | |
0acc512c | 648 | .cb_barrier = rcu_barrier_sched, |
bf66f18e | 649 | .fqs = rcu_sched_force_quiescent_state, |
0acc512c PM |
650 | .stats = NULL, |
651 | .irq_capable = 1, | |
652 | .name = "sched" | |
4b6c2cca JT |
653 | }; |
654 | ||
8e8be45e PM |
655 | /* |
656 | * RCU torture priority-boost testing. Runs one real-time thread per | |
657 | * CPU for moderate bursts, repeatedly registering RCU callbacks and | |
658 | * spinning waiting for them to be invoked. If a given callback takes | |
659 | * too long to be invoked, we assume that priority inversion has occurred. | |
660 | */ | |
661 | ||
662 | struct rcu_boost_inflight { | |
663 | struct rcu_head rcu; | |
664 | int inflight; | |
665 | }; | |
666 | ||
667 | static void rcu_torture_boost_cb(struct rcu_head *head) | |
668 | { | |
669 | struct rcu_boost_inflight *rbip = | |
670 | container_of(head, struct rcu_boost_inflight, rcu); | |
671 | ||
672 | smp_mb(); /* Ensure RCU-core accesses precede clearing ->inflight */ | |
673 | rbip->inflight = 0; | |
674 | } | |
675 | ||
676 | static int rcu_torture_boost(void *arg) | |
677 | { | |
678 | unsigned long call_rcu_time; | |
679 | unsigned long endtime; | |
680 | unsigned long oldstarttime; | |
681 | struct rcu_boost_inflight rbi = { .inflight = 0 }; | |
682 | struct sched_param sp; | |
683 | ||
684 | VERBOSE_PRINTK_STRING("rcu_torture_boost started"); | |
685 | ||
686 | /* Set real-time priority. */ | |
687 | sp.sched_priority = 1; | |
688 | if (sched_setscheduler(current, SCHED_FIFO, &sp) < 0) { | |
689 | VERBOSE_PRINTK_STRING("rcu_torture_boost RT prio failed!"); | |
690 | n_rcu_torture_boost_rterror++; | |
691 | } | |
692 | ||
561190e3 | 693 | init_rcu_head_on_stack(&rbi.rcu); |
8e8be45e PM |
694 | /* Each pass through the following loop does one boost-test cycle. */ |
695 | do { | |
696 | /* Wait for the next test interval. */ | |
697 | oldstarttime = boost_starttime; | |
93898fb1 | 698 | while (ULONG_CMP_LT(jiffies, oldstarttime)) { |
0e11c8e8 | 699 | schedule_timeout_interruptible(oldstarttime - jiffies); |
8e8be45e PM |
700 | rcu_stutter_wait("rcu_torture_boost"); |
701 | if (kthread_should_stop() || | |
702 | fullstop != FULLSTOP_DONTSTOP) | |
703 | goto checkwait; | |
704 | } | |
705 | ||
706 | /* Do one boost-test interval. */ | |
707 | endtime = oldstarttime + test_boost_duration * HZ; | |
708 | call_rcu_time = jiffies; | |
93898fb1 | 709 | while (ULONG_CMP_LT(jiffies, endtime)) { |
8e8be45e PM |
710 | /* If we don't have a callback in flight, post one. */ |
711 | if (!rbi.inflight) { | |
712 | smp_mb(); /* RCU core before ->inflight = 1. */ | |
713 | rbi.inflight = 1; | |
714 | call_rcu(&rbi.rcu, rcu_torture_boost_cb); | |
715 | if (jiffies - call_rcu_time > | |
716 | test_boost_duration * HZ - HZ / 2) { | |
717 | VERBOSE_PRINTK_STRING("rcu_torture_boost boosting failed"); | |
718 | n_rcu_torture_boost_failure++; | |
719 | } | |
720 | call_rcu_time = jiffies; | |
721 | } | |
722 | cond_resched(); | |
723 | rcu_stutter_wait("rcu_torture_boost"); | |
724 | if (kthread_should_stop() || | |
725 | fullstop != FULLSTOP_DONTSTOP) | |
726 | goto checkwait; | |
727 | } | |
728 | ||
729 | /* | |
730 | * Set the start time of the next test interval. | |
731 | * Yes, this is vulnerable to long delays, but such | |
732 | * delays simply cause a false negative for the next | |
733 | * interval. Besides, we are running at RT priority, | |
734 | * so delays should be relatively rare. | |
735 | */ | |
ab8f11e5 PM |
736 | while (oldstarttime == boost_starttime && |
737 | !kthread_should_stop()) { | |
8e8be45e PM |
738 | if (mutex_trylock(&boost_mutex)) { |
739 | boost_starttime = jiffies + | |
740 | test_boost_interval * HZ; | |
741 | n_rcu_torture_boosts++; | |
742 | mutex_unlock(&boost_mutex); | |
743 | break; | |
744 | } | |
745 | schedule_timeout_uninterruptible(1); | |
746 | } | |
747 | ||
748 | /* Go do the stutter. */ | |
749 | checkwait: rcu_stutter_wait("rcu_torture_boost"); | |
750 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
751 | ||
752 | /* Clean up and exit. */ | |
753 | VERBOSE_PRINTK_STRING("rcu_torture_boost task stopping"); | |
754 | rcutorture_shutdown_absorb("rcu_torture_boost"); | |
755 | while (!kthread_should_stop() || rbi.inflight) | |
756 | schedule_timeout_uninterruptible(1); | |
757 | smp_mb(); /* order accesses to ->inflight before stack-frame death. */ | |
9d68197c | 758 | destroy_rcu_head_on_stack(&rbi.rcu); |
8e8be45e PM |
759 | return 0; |
760 | } | |
761 | ||
bf66f18e PM |
762 | /* |
763 | * RCU torture force-quiescent-state kthread. Repeatedly induces | |
764 | * bursts of calls to force_quiescent_state(), increasing the probability | |
765 | * of occurrence of some important types of race conditions. | |
766 | */ | |
767 | static int | |
768 | rcu_torture_fqs(void *arg) | |
769 | { | |
770 | unsigned long fqs_resume_time; | |
771 | int fqs_burst_remaining; | |
772 | ||
773 | VERBOSE_PRINTK_STRING("rcu_torture_fqs task started"); | |
774 | do { | |
775 | fqs_resume_time = jiffies + fqs_stutter * HZ; | |
93898fb1 PM |
776 | while (ULONG_CMP_LT(jiffies, fqs_resume_time) && |
777 | !kthread_should_stop()) { | |
bf66f18e PM |
778 | schedule_timeout_interruptible(1); |
779 | } | |
780 | fqs_burst_remaining = fqs_duration; | |
93898fb1 PM |
781 | while (fqs_burst_remaining > 0 && |
782 | !kthread_should_stop()) { | |
bf66f18e PM |
783 | cur_ops->fqs(); |
784 | udelay(fqs_holdoff); | |
785 | fqs_burst_remaining -= fqs_holdoff; | |
786 | } | |
787 | rcu_stutter_wait("rcu_torture_fqs"); | |
788 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
789 | VERBOSE_PRINTK_STRING("rcu_torture_fqs task stopping"); | |
790 | rcutorture_shutdown_absorb("rcu_torture_fqs"); | |
791 | while (!kthread_should_stop()) | |
792 | schedule_timeout_uninterruptible(1); | |
793 | return 0; | |
794 | } | |
795 | ||
a241ec65 PM |
796 | /* |
797 | * RCU torture writer kthread. Repeatedly substitutes a new structure | |
798 | * for that pointed to by rcu_torture_current, freeing the old structure | |
799 | * after a series of grace periods (the "pipeline"). | |
800 | */ | |
801 | static int | |
802 | rcu_torture_writer(void *arg) | |
803 | { | |
2ec1f2d9 | 804 | bool exp; |
a241ec65 | 805 | int i; |
a241ec65 | 806 | struct rcu_torture *rp; |
2ec1f2d9 | 807 | struct rcu_torture *rp1; |
a241ec65 PM |
808 | struct rcu_torture *old_rp; |
809 | static DEFINE_RCU_RANDOM(rand); | |
810 | ||
811 | VERBOSE_PRINTK_STRING("rcu_torture_writer task started"); | |
dbdf65b1 IM |
812 | set_user_nice(current, 19); |
813 | ||
a241ec65 PM |
814 | do { |
815 | schedule_timeout_uninterruptible(1); | |
a71fca58 PM |
816 | rp = rcu_torture_alloc(); |
817 | if (rp == NULL) | |
a241ec65 PM |
818 | continue; |
819 | rp->rtort_pipe_count = 0; | |
820 | udelay(rcu_random(&rand) & 0x3ff); | |
0ddea0ea PM |
821 | old_rp = rcu_dereference_check(rcu_torture_current, |
822 | current == writer_task); | |
996417d2 | 823 | rp->rtort_mbtest = 1; |
a241ec65 | 824 | rcu_assign_pointer(rcu_torture_current, rp); |
9b2619af | 825 | smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */ |
c8e5b163 | 826 | if (old_rp) { |
a241ec65 PM |
827 | i = old_rp->rtort_pipe_count; |
828 | if (i > RCU_TORTURE_PIPE_LEN) | |
829 | i = RCU_TORTURE_PIPE_LEN; | |
830 | atomic_inc(&rcu_torture_wcount[i]); | |
831 | old_rp->rtort_pipe_count++; | |
2ec1f2d9 PM |
832 | if (gp_normal == gp_exp) |
833 | exp = !!(rcu_random(&rand) & 0x80); | |
834 | else | |
835 | exp = gp_exp; | |
836 | if (!exp) { | |
837 | cur_ops->deferred_free(old_rp); | |
838 | } else { | |
839 | cur_ops->exp_sync(); | |
840 | list_add(&old_rp->rtort_free, | |
841 | &rcu_torture_removed); | |
842 | list_for_each_entry_safe(rp, rp1, | |
843 | &rcu_torture_removed, | |
844 | rtort_free) { | |
845 | i = rp->rtort_pipe_count; | |
846 | if (i > RCU_TORTURE_PIPE_LEN) | |
847 | i = RCU_TORTURE_PIPE_LEN; | |
848 | atomic_inc(&rcu_torture_wcount[i]); | |
849 | if (++rp->rtort_pipe_count >= | |
850 | RCU_TORTURE_PIPE_LEN) { | |
851 | rp->rtort_mbtest = 0; | |
852 | list_del(&rp->rtort_free); | |
853 | rcu_torture_free(rp); | |
854 | } | |
855 | } | |
856 | } | |
a241ec65 | 857 | } |
4a298656 | 858 | rcutorture_record_progress(++rcu_torture_current_version); |
c9d557c1 PM |
859 | rcu_stutter_wait("rcu_torture_writer"); |
860 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
a241ec65 | 861 | VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping"); |
c9d557c1 PM |
862 | rcutorture_shutdown_absorb("rcu_torture_writer"); |
863 | while (!kthread_should_stop()) | |
a241ec65 PM |
864 | schedule_timeout_uninterruptible(1); |
865 | return 0; | |
866 | } | |
867 | ||
b772e1dd JT |
868 | /* |
869 | * RCU torture fake writer kthread. Repeatedly calls sync, with a random | |
870 | * delay between calls. | |
871 | */ | |
872 | static int | |
873 | rcu_torture_fakewriter(void *arg) | |
874 | { | |
875 | DEFINE_RCU_RANDOM(rand); | |
876 | ||
877 | VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task started"); | |
878 | set_user_nice(current, 19); | |
879 | ||
880 | do { | |
881 | schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10); | |
882 | udelay(rcu_random(&rand) & 0x3ff); | |
72472a02 | 883 | if (cur_ops->cb_barrier != NULL && |
2ec1f2d9 | 884 | rcu_random(&rand) % (nfakewriters * 8) == 0) { |
72472a02 | 885 | cur_ops->cb_barrier(); |
2ec1f2d9 PM |
886 | } else if (gp_normal == gp_exp) { |
887 | if (rcu_random(&rand) & 0x80) | |
888 | cur_ops->sync(); | |
889 | else | |
890 | cur_ops->exp_sync(); | |
891 | } else if (gp_normal) { | |
72472a02 | 892 | cur_ops->sync(); |
2ec1f2d9 PM |
893 | } else { |
894 | cur_ops->exp_sync(); | |
895 | } | |
c9d557c1 PM |
896 | rcu_stutter_wait("rcu_torture_fakewriter"); |
897 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
b772e1dd JT |
898 | |
899 | VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping"); | |
c9d557c1 PM |
900 | rcutorture_shutdown_absorb("rcu_torture_fakewriter"); |
901 | while (!kthread_should_stop()) | |
b772e1dd JT |
902 | schedule_timeout_uninterruptible(1); |
903 | return 0; | |
904 | } | |
905 | ||
91afaf30 PM |
906 | void rcutorture_trace_dump(void) |
907 | { | |
908 | static atomic_t beenhere = ATOMIC_INIT(0); | |
909 | ||
910 | if (atomic_read(&beenhere)) | |
911 | return; | |
912 | if (atomic_xchg(&beenhere, 1) != 0) | |
913 | return; | |
91afaf30 PM |
914 | ftrace_dump(DUMP_ALL); |
915 | } | |
916 | ||
0729fbf3 PM |
917 | /* |
918 | * RCU torture reader from timer handler. Dereferences rcu_torture_current, | |
919 | * incrementing the corresponding element of the pipeline array. The | |
920 | * counter in the element should never be greater than 1, otherwise, the | |
921 | * RCU implementation is broken. | |
922 | */ | |
923 | static void rcu_torture_timer(unsigned long unused) | |
924 | { | |
925 | int idx; | |
926 | int completed; | |
52494535 | 927 | int completed_end; |
0729fbf3 PM |
928 | static DEFINE_RCU_RANDOM(rand); |
929 | static DEFINE_SPINLOCK(rand_lock); | |
930 | struct rcu_torture *p; | |
931 | int pipe_count; | |
52494535 | 932 | unsigned long long ts; |
0729fbf3 PM |
933 | |
934 | idx = cur_ops->readlock(); | |
935 | completed = cur_ops->completed(); | |
e4aa0da3 | 936 | ts = rcu_trace_clock_local(); |
632ee200 | 937 | p = rcu_dereference_check(rcu_torture_current, |
632ee200 PM |
938 | rcu_read_lock_bh_held() || |
939 | rcu_read_lock_sched_held() || | |
940 | srcu_read_lock_held(&srcu_ctl)); | |
0729fbf3 PM |
941 | if (p == NULL) { |
942 | /* Leave because rcu_torture_writer is not yet underway */ | |
943 | cur_ops->readunlock(idx); | |
944 | return; | |
945 | } | |
946 | if (p->rtort_mbtest == 0) | |
947 | atomic_inc(&n_rcu_torture_mberror); | |
948 | spin_lock(&rand_lock); | |
0acc512c | 949 | cur_ops->read_delay(&rand); |
0729fbf3 PM |
950 | n_rcu_torture_timers++; |
951 | spin_unlock(&rand_lock); | |
952 | preempt_disable(); | |
953 | pipe_count = p->rtort_pipe_count; | |
954 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { | |
955 | /* Should not happen, but... */ | |
956 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
957 | } | |
52494535 PM |
958 | completed_end = cur_ops->completed(); |
959 | if (pipe_count > 1) { | |
52494535 PM |
960 | do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, ts, |
961 | completed, completed_end); | |
91afaf30 | 962 | rcutorture_trace_dump(); |
52494535 | 963 | } |
dd17c8f7 | 964 | __this_cpu_inc(rcu_torture_count[pipe_count]); |
52494535 | 965 | completed = completed_end - completed; |
0729fbf3 PM |
966 | if (completed > RCU_TORTURE_PIPE_LEN) { |
967 | /* Should not happen, but... */ | |
968 | completed = RCU_TORTURE_PIPE_LEN; | |
969 | } | |
dd17c8f7 | 970 | __this_cpu_inc(rcu_torture_batch[completed]); |
0729fbf3 PM |
971 | preempt_enable(); |
972 | cur_ops->readunlock(idx); | |
973 | } | |
974 | ||
a241ec65 PM |
975 | /* |
976 | * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, | |
977 | * incrementing the corresponding element of the pipeline array. The | |
978 | * counter in the element should never be greater than 1, otherwise, the | |
979 | * RCU implementation is broken. | |
980 | */ | |
981 | static int | |
982 | rcu_torture_reader(void *arg) | |
983 | { | |
984 | int completed; | |
52494535 | 985 | int completed_end; |
72e9bb54 | 986 | int idx; |
a241ec65 PM |
987 | DEFINE_RCU_RANDOM(rand); |
988 | struct rcu_torture *p; | |
989 | int pipe_count; | |
0729fbf3 | 990 | struct timer_list t; |
52494535 | 991 | unsigned long long ts; |
a241ec65 PM |
992 | |
993 | VERBOSE_PRINTK_STRING("rcu_torture_reader task started"); | |
dbdf65b1 | 994 | set_user_nice(current, 19); |
0acc512c | 995 | if (irqreader && cur_ops->irq_capable) |
0729fbf3 | 996 | setup_timer_on_stack(&t, rcu_torture_timer, 0); |
dbdf65b1 | 997 | |
a241ec65 | 998 | do { |
0acc512c | 999 | if (irqreader && cur_ops->irq_capable) { |
0729fbf3 | 1000 | if (!timer_pending(&t)) |
6155fec9 | 1001 | mod_timer(&t, jiffies + 1); |
0729fbf3 | 1002 | } |
72e9bb54 PM |
1003 | idx = cur_ops->readlock(); |
1004 | completed = cur_ops->completed(); | |
e4aa0da3 | 1005 | ts = rcu_trace_clock_local(); |
632ee200 | 1006 | p = rcu_dereference_check(rcu_torture_current, |
632ee200 PM |
1007 | rcu_read_lock_bh_held() || |
1008 | rcu_read_lock_sched_held() || | |
1009 | srcu_read_lock_held(&srcu_ctl)); | |
a241ec65 PM |
1010 | if (p == NULL) { |
1011 | /* Wait for rcu_torture_writer to get underway */ | |
72e9bb54 | 1012 | cur_ops->readunlock(idx); |
a241ec65 PM |
1013 | schedule_timeout_interruptible(HZ); |
1014 | continue; | |
1015 | } | |
996417d2 PM |
1016 | if (p->rtort_mbtest == 0) |
1017 | atomic_inc(&n_rcu_torture_mberror); | |
0acc512c | 1018 | cur_ops->read_delay(&rand); |
a241ec65 PM |
1019 | preempt_disable(); |
1020 | pipe_count = p->rtort_pipe_count; | |
1021 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { | |
1022 | /* Should not happen, but... */ | |
1023 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
1024 | } | |
52494535 PM |
1025 | completed_end = cur_ops->completed(); |
1026 | if (pipe_count > 1) { | |
52494535 PM |
1027 | do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, |
1028 | ts, completed, completed_end); | |
91afaf30 | 1029 | rcutorture_trace_dump(); |
52494535 | 1030 | } |
dd17c8f7 | 1031 | __this_cpu_inc(rcu_torture_count[pipe_count]); |
52494535 | 1032 | completed = completed_end - completed; |
a241ec65 PM |
1033 | if (completed > RCU_TORTURE_PIPE_LEN) { |
1034 | /* Should not happen, but... */ | |
1035 | completed = RCU_TORTURE_PIPE_LEN; | |
1036 | } | |
dd17c8f7 | 1037 | __this_cpu_inc(rcu_torture_batch[completed]); |
a241ec65 | 1038 | preempt_enable(); |
72e9bb54 | 1039 | cur_ops->readunlock(idx); |
a241ec65 | 1040 | schedule(); |
c9d557c1 PM |
1041 | rcu_stutter_wait("rcu_torture_reader"); |
1042 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
a241ec65 | 1043 | VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping"); |
c9d557c1 | 1044 | rcutorture_shutdown_absorb("rcu_torture_reader"); |
0acc512c | 1045 | if (irqreader && cur_ops->irq_capable) |
0729fbf3 | 1046 | del_timer_sync(&t); |
c9d557c1 | 1047 | while (!kthread_should_stop()) |
a241ec65 PM |
1048 | schedule_timeout_uninterruptible(1); |
1049 | return 0; | |
1050 | } | |
1051 | ||
1052 | /* | |
1053 | * Create an RCU-torture statistics message in the specified buffer. | |
1054 | */ | |
1055 | static int | |
1056 | rcu_torture_printk(char *page) | |
1057 | { | |
1058 | int cnt = 0; | |
1059 | int cpu; | |
1060 | int i; | |
1061 | long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
1062 | long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
1063 | ||
0a945022 | 1064 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
1065 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
1066 | pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i]; | |
1067 | batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i]; | |
1068 | } | |
1069 | } | |
1070 | for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) { | |
1071 | if (pipesummary[i] != 0) | |
1072 | break; | |
1073 | } | |
72e9bb54 | 1074 | cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 | 1075 | cnt += sprintf(&page[cnt], |
5cf05ad7 | 1076 | "rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ", |
a241ec65 PM |
1077 | rcu_torture_current, |
1078 | rcu_torture_current_version, | |
1079 | list_empty(&rcu_torture_freelist), | |
1080 | atomic_read(&n_rcu_torture_alloc), | |
1081 | atomic_read(&n_rcu_torture_alloc_fail), | |
5cf05ad7 PM |
1082 | atomic_read(&n_rcu_torture_free)); |
1083 | cnt += sprintf(&page[cnt], "rtmbe: %d rtbke: %ld rtbre: %ld ", | |
0729fbf3 | 1084 | atomic_read(&n_rcu_torture_mberror), |
8e8be45e | 1085 | n_rcu_torture_boost_ktrerror, |
5cf05ad7 PM |
1086 | n_rcu_torture_boost_rterror); |
1087 | cnt += sprintf(&page[cnt], "rtbf: %ld rtb: %ld nt: %ld ", | |
8e8be45e PM |
1088 | n_rcu_torture_boost_failure, |
1089 | n_rcu_torture_boosts, | |
5cf05ad7 | 1090 | n_rcu_torture_timers); |
13dbf914 PM |
1091 | cnt += sprintf(&page[cnt], |
1092 | "onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ", | |
1093 | n_online_successes, n_online_attempts, | |
1094 | n_offline_successes, n_offline_attempts, | |
1095 | min_online, max_online, | |
1096 | min_offline, max_offline, | |
1097 | sum_online, sum_offline, HZ); | |
5cf05ad7 | 1098 | cnt += sprintf(&page[cnt], "barrier: %ld/%ld:%ld", |
fae4b54f PM |
1099 | n_barrier_successes, |
1100 | n_barrier_attempts, | |
1101 | n_rcu_torture_barrier_error); | |
1102 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); | |
8e8be45e | 1103 | if (atomic_read(&n_rcu_torture_mberror) != 0 || |
fae4b54f | 1104 | n_rcu_torture_barrier_error != 0 || |
8e8be45e PM |
1105 | n_rcu_torture_boost_ktrerror != 0 || |
1106 | n_rcu_torture_boost_rterror != 0 || | |
fae4b54f PM |
1107 | n_rcu_torture_boost_failure != 0 || |
1108 | i > 1) { | |
a241ec65 | 1109 | cnt += sprintf(&page[cnt], "!!! "); |
996417d2 | 1110 | atomic_inc(&n_rcu_torture_error); |
5af970a4 | 1111 | WARN_ON_ONCE(1); |
996417d2 | 1112 | } |
a241ec65 PM |
1113 | cnt += sprintf(&page[cnt], "Reader Pipe: "); |
1114 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) | |
1115 | cnt += sprintf(&page[cnt], " %ld", pipesummary[i]); | |
72e9bb54 | 1116 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 | 1117 | cnt += sprintf(&page[cnt], "Reader Batch: "); |
72e9bb54 | 1118 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
a241ec65 | 1119 | cnt += sprintf(&page[cnt], " %ld", batchsummary[i]); |
72e9bb54 | 1120 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 PM |
1121 | cnt += sprintf(&page[cnt], "Free-Block Circulation: "); |
1122 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { | |
1123 | cnt += sprintf(&page[cnt], " %d", | |
1124 | atomic_read(&rcu_torture_wcount[i])); | |
1125 | } | |
1126 | cnt += sprintf(&page[cnt], "\n"); | |
c8e5b163 | 1127 | if (cur_ops->stats) |
72e9bb54 | 1128 | cnt += cur_ops->stats(&page[cnt]); |
a241ec65 PM |
1129 | return cnt; |
1130 | } | |
1131 | ||
1132 | /* | |
1133 | * Print torture statistics. Caller must ensure that there is only | |
1134 | * one call to this function at a given time!!! This is normally | |
1135 | * accomplished by relying on the module system to only have one copy | |
1136 | * of the module loaded, and then by giving the rcu_torture_stats | |
1137 | * kthread full control (or the init/cleanup functions when rcu_torture_stats | |
1138 | * thread is not running). | |
1139 | */ | |
1140 | static void | |
1141 | rcu_torture_stats_print(void) | |
1142 | { | |
1143 | int cnt; | |
1144 | ||
1145 | cnt = rcu_torture_printk(printk_buf); | |
2caa1e44 | 1146 | pr_alert("%s", printk_buf); |
a241ec65 PM |
1147 | } |
1148 | ||
1149 | /* | |
1150 | * Periodically prints torture statistics, if periodic statistics printing | |
1151 | * was specified via the stat_interval module parameter. | |
1152 | * | |
1153 | * No need to worry about fullstop here, since this one doesn't reference | |
1154 | * volatile state or register callbacks. | |
1155 | */ | |
1156 | static int | |
1157 | rcu_torture_stats(void *arg) | |
1158 | { | |
1159 | VERBOSE_PRINTK_STRING("rcu_torture_stats task started"); | |
1160 | do { | |
1161 | schedule_timeout_interruptible(stat_interval * HZ); | |
1162 | rcu_torture_stats_print(); | |
c9d557c1 PM |
1163 | rcutorture_shutdown_absorb("rcu_torture_stats"); |
1164 | } while (!kthread_should_stop()); | |
a241ec65 PM |
1165 | VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping"); |
1166 | return 0; | |
1167 | } | |
1168 | ||
d84f5203 SV |
1169 | static int rcu_idle_cpu; /* Force all torture tasks off this CPU */ |
1170 | ||
1171 | /* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case | |
1172 | * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs. | |
1173 | */ | |
b2896d2e | 1174 | static void rcu_torture_shuffle_tasks(void) |
d84f5203 | 1175 | { |
d84f5203 SV |
1176 | int i; |
1177 | ||
73d0a4b1 | 1178 | cpumask_setall(shuffle_tmp_mask); |
86ef5c9a | 1179 | get_online_cpus(); |
d84f5203 SV |
1180 | |
1181 | /* No point in shuffling if there is only one online CPU (ex: UP) */ | |
c9d557c1 PM |
1182 | if (num_online_cpus() == 1) { |
1183 | put_online_cpus(); | |
1184 | return; | |
1185 | } | |
d84f5203 SV |
1186 | |
1187 | if (rcu_idle_cpu != -1) | |
73d0a4b1 | 1188 | cpumask_clear_cpu(rcu_idle_cpu, shuffle_tmp_mask); |
d84f5203 | 1189 | |
73d0a4b1 | 1190 | set_cpus_allowed_ptr(current, shuffle_tmp_mask); |
d84f5203 | 1191 | |
c8e5b163 | 1192 | if (reader_tasks) { |
d84f5203 SV |
1193 | for (i = 0; i < nrealreaders; i++) |
1194 | if (reader_tasks[i]) | |
f70316da | 1195 | set_cpus_allowed_ptr(reader_tasks[i], |
73d0a4b1 | 1196 | shuffle_tmp_mask); |
d84f5203 | 1197 | } |
c8e5b163 | 1198 | if (fakewriter_tasks) { |
b772e1dd JT |
1199 | for (i = 0; i < nfakewriters; i++) |
1200 | if (fakewriter_tasks[i]) | |
f70316da | 1201 | set_cpus_allowed_ptr(fakewriter_tasks[i], |
73d0a4b1 | 1202 | shuffle_tmp_mask); |
b772e1dd | 1203 | } |
d84f5203 | 1204 | if (writer_task) |
73d0a4b1 | 1205 | set_cpus_allowed_ptr(writer_task, shuffle_tmp_mask); |
d84f5203 | 1206 | if (stats_task) |
73d0a4b1 | 1207 | set_cpus_allowed_ptr(stats_task, shuffle_tmp_mask); |
0e11c8e8 PM |
1208 | if (stutter_task) |
1209 | set_cpus_allowed_ptr(stutter_task, shuffle_tmp_mask); | |
1210 | if (fqs_task) | |
1211 | set_cpus_allowed_ptr(fqs_task, shuffle_tmp_mask); | |
1212 | if (shutdown_task) | |
1213 | set_cpus_allowed_ptr(shutdown_task, shuffle_tmp_mask); | |
1214 | #ifdef CONFIG_HOTPLUG_CPU | |
1215 | if (onoff_task) | |
1216 | set_cpus_allowed_ptr(onoff_task, shuffle_tmp_mask); | |
1217 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
1218 | if (stall_task) | |
1219 | set_cpus_allowed_ptr(stall_task, shuffle_tmp_mask); | |
1220 | if (barrier_cbs_tasks) | |
1221 | for (i = 0; i < n_barrier_cbs; i++) | |
1222 | if (barrier_cbs_tasks[i]) | |
1223 | set_cpus_allowed_ptr(barrier_cbs_tasks[i], | |
1224 | shuffle_tmp_mask); | |
1225 | if (barrier_task) | |
1226 | set_cpus_allowed_ptr(barrier_task, shuffle_tmp_mask); | |
d84f5203 SV |
1227 | |
1228 | if (rcu_idle_cpu == -1) | |
1229 | rcu_idle_cpu = num_online_cpus() - 1; | |
1230 | else | |
1231 | rcu_idle_cpu--; | |
1232 | ||
86ef5c9a | 1233 | put_online_cpus(); |
d84f5203 SV |
1234 | } |
1235 | ||
1236 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the | |
1237 | * system to become idle at a time and cut off its timer ticks. This is meant | |
1238 | * to test the support for such tickless idle CPU in RCU. | |
1239 | */ | |
1240 | static int | |
1241 | rcu_torture_shuffle(void *arg) | |
1242 | { | |
1243 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started"); | |
1244 | do { | |
1245 | schedule_timeout_interruptible(shuffle_interval * HZ); | |
1246 | rcu_torture_shuffle_tasks(); | |
c9d557c1 PM |
1247 | rcutorture_shutdown_absorb("rcu_torture_shuffle"); |
1248 | } while (!kthread_should_stop()); | |
d84f5203 SV |
1249 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping"); |
1250 | return 0; | |
1251 | } | |
1252 | ||
d120f65f PM |
1253 | /* Cause the rcutorture test to "stutter", starting and stopping all |
1254 | * threads periodically. | |
1255 | */ | |
1256 | static int | |
1257 | rcu_torture_stutter(void *arg) | |
1258 | { | |
1259 | VERBOSE_PRINTK_STRING("rcu_torture_stutter task started"); | |
1260 | do { | |
1261 | schedule_timeout_interruptible(stutter * HZ); | |
1262 | stutter_pause_test = 1; | |
c9d557c1 | 1263 | if (!kthread_should_stop()) |
d120f65f PM |
1264 | schedule_timeout_interruptible(stutter * HZ); |
1265 | stutter_pause_test = 0; | |
c9d557c1 PM |
1266 | rcutorture_shutdown_absorb("rcu_torture_stutter"); |
1267 | } while (!kthread_should_stop()); | |
d120f65f PM |
1268 | VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping"); |
1269 | return 0; | |
1270 | } | |
1271 | ||
95c38322 | 1272 | static inline void |
e66c33d5 | 1273 | rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag) |
95c38322 | 1274 | { |
2caa1e44 PM |
1275 | pr_alert("%s" TORTURE_FLAG |
1276 | "--- %s: nreaders=%d nfakewriters=%d " | |
1277 | "stat_interval=%d verbose=%d test_no_idle_hz=%d " | |
1278 | "shuffle_interval=%d stutter=%d irqreader=%d " | |
1279 | "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d " | |
1280 | "test_boost=%d/%d test_boost_interval=%d " | |
1281 | "test_boost_duration=%d shutdown_secs=%d " | |
67afeed2 PM |
1282 | "stall_cpu=%d stall_cpu_holdoff=%d " |
1283 | "n_barrier_cbs=%d " | |
2caa1e44 PM |
1284 | "onoff_interval=%d onoff_holdoff=%d\n", |
1285 | torture_type, tag, nrealreaders, nfakewriters, | |
1286 | stat_interval, verbose, test_no_idle_hz, shuffle_interval, | |
1287 | stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter, | |
1288 | test_boost, cur_ops->can_boost, | |
1289 | test_boost_interval, test_boost_duration, shutdown_secs, | |
67afeed2 PM |
1290 | stall_cpu, stall_cpu_holdoff, |
1291 | n_barrier_cbs, | |
2caa1e44 | 1292 | onoff_interval, onoff_holdoff); |
95c38322 PM |
1293 | } |
1294 | ||
8e8be45e | 1295 | static struct notifier_block rcutorture_shutdown_nb = { |
343e9099 PM |
1296 | .notifier_call = rcutorture_shutdown_notify, |
1297 | }; | |
1298 | ||
8e8be45e PM |
1299 | static void rcutorture_booster_cleanup(int cpu) |
1300 | { | |
1301 | struct task_struct *t; | |
1302 | ||
1303 | if (boost_tasks[cpu] == NULL) | |
1304 | return; | |
1305 | mutex_lock(&boost_mutex); | |
1306 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_boost task"); | |
1307 | t = boost_tasks[cpu]; | |
1308 | boost_tasks[cpu] = NULL; | |
1309 | mutex_unlock(&boost_mutex); | |
1310 | ||
1311 | /* This must be outside of the mutex, otherwise deadlock! */ | |
1312 | kthread_stop(t); | |
37e377d2 | 1313 | boost_tasks[cpu] = NULL; |
8e8be45e PM |
1314 | } |
1315 | ||
1316 | static int rcutorture_booster_init(int cpu) | |
1317 | { | |
1318 | int retval; | |
1319 | ||
1320 | if (boost_tasks[cpu] != NULL) | |
1321 | return 0; /* Already created, nothing more to do. */ | |
1322 | ||
1323 | /* Don't allow time recalculation while creating a new task. */ | |
1324 | mutex_lock(&boost_mutex); | |
1325 | VERBOSE_PRINTK_STRING("Creating rcu_torture_boost task"); | |
1f288094 ED |
1326 | boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL, |
1327 | cpu_to_node(cpu), | |
1328 | "rcu_torture_boost"); | |
8e8be45e PM |
1329 | if (IS_ERR(boost_tasks[cpu])) { |
1330 | retval = PTR_ERR(boost_tasks[cpu]); | |
1331 | VERBOSE_PRINTK_STRING("rcu_torture_boost task create failed"); | |
1332 | n_rcu_torture_boost_ktrerror++; | |
1333 | boost_tasks[cpu] = NULL; | |
1334 | mutex_unlock(&boost_mutex); | |
1335 | return retval; | |
1336 | } | |
1337 | kthread_bind(boost_tasks[cpu], cpu); | |
1338 | wake_up_process(boost_tasks[cpu]); | |
1339 | mutex_unlock(&boost_mutex); | |
1340 | return 0; | |
1341 | } | |
1342 | ||
d5f546d8 PM |
1343 | /* |
1344 | * Cause the rcutorture test to shutdown the system after the test has | |
1345 | * run for the time specified by the shutdown_secs module parameter. | |
1346 | */ | |
1347 | static int | |
1348 | rcu_torture_shutdown(void *arg) | |
1349 | { | |
1350 | long delta; | |
1351 | unsigned long jiffies_snap; | |
1352 | ||
1353 | VERBOSE_PRINTK_STRING("rcu_torture_shutdown task started"); | |
1354 | jiffies_snap = ACCESS_ONCE(jiffies); | |
1355 | while (ULONG_CMP_LT(jiffies_snap, shutdown_time) && | |
1356 | !kthread_should_stop()) { | |
1357 | delta = shutdown_time - jiffies_snap; | |
1358 | if (verbose) | |
2caa1e44 PM |
1359 | pr_alert("%s" TORTURE_FLAG |
1360 | "rcu_torture_shutdown task: %lu jiffies remaining\n", | |
1361 | torture_type, delta); | |
d5f546d8 PM |
1362 | schedule_timeout_interruptible(delta); |
1363 | jiffies_snap = ACCESS_ONCE(jiffies); | |
1364 | } | |
b58bdcca | 1365 | if (kthread_should_stop()) { |
d5f546d8 PM |
1366 | VERBOSE_PRINTK_STRING("rcu_torture_shutdown task stopping"); |
1367 | return 0; | |
1368 | } | |
1369 | ||
1370 | /* OK, shut down the system. */ | |
1371 | ||
1372 | VERBOSE_PRINTK_STRING("rcu_torture_shutdown task shutting down system"); | |
1373 | shutdown_task = NULL; /* Avoid self-kill deadlock. */ | |
1374 | rcu_torture_cleanup(); /* Get the success/failure message. */ | |
1375 | kernel_power_off(); /* Shut down the system. */ | |
1376 | return 0; | |
1377 | } | |
1378 | ||
b58bdcca PM |
1379 | #ifdef CONFIG_HOTPLUG_CPU |
1380 | ||
1381 | /* | |
1382 | * Execute random CPU-hotplug operations at the interval specified | |
1383 | * by the onoff_interval. | |
1384 | */ | |
49fb4c62 | 1385 | static int |
b58bdcca PM |
1386 | rcu_torture_onoff(void *arg) |
1387 | { | |
1388 | int cpu; | |
13dbf914 | 1389 | unsigned long delta; |
b58bdcca PM |
1390 | int maxcpu = -1; |
1391 | DEFINE_RCU_RANDOM(rand); | |
48983260 | 1392 | int ret; |
13dbf914 | 1393 | unsigned long starttime; |
b58bdcca PM |
1394 | |
1395 | VERBOSE_PRINTK_STRING("rcu_torture_onoff task started"); | |
1396 | for_each_online_cpu(cpu) | |
1397 | maxcpu = cpu; | |
1398 | WARN_ON(maxcpu < 0); | |
9b9ec9b9 PM |
1399 | if (onoff_holdoff > 0) { |
1400 | VERBOSE_PRINTK_STRING("rcu_torture_onoff begin holdoff"); | |
1401 | schedule_timeout_interruptible(onoff_holdoff * HZ); | |
1402 | VERBOSE_PRINTK_STRING("rcu_torture_onoff end holdoff"); | |
1403 | } | |
b58bdcca PM |
1404 | while (!kthread_should_stop()) { |
1405 | cpu = (rcu_random(&rand) >> 4) % (maxcpu + 1); | |
f220242a | 1406 | if (cpu_online(cpu) && cpu_is_hotpluggable(cpu)) { |
b58bdcca | 1407 | if (verbose) |
2caa1e44 PM |
1408 | pr_alert("%s" TORTURE_FLAG |
1409 | "rcu_torture_onoff task: offlining %d\n", | |
1410 | torture_type, cpu); | |
13dbf914 | 1411 | starttime = jiffies; |
b58bdcca | 1412 | n_offline_attempts++; |
48983260 PM |
1413 | ret = cpu_down(cpu); |
1414 | if (ret) { | |
1415 | if (verbose) | |
1416 | pr_alert("%s" TORTURE_FLAG | |
1417 | "rcu_torture_onoff task: offline %d failed: errno %d\n", | |
1418 | torture_type, cpu, ret); | |
1419 | } else { | |
b58bdcca | 1420 | if (verbose) |
2caa1e44 PM |
1421 | pr_alert("%s" TORTURE_FLAG |
1422 | "rcu_torture_onoff task: offlined %d\n", | |
1423 | torture_type, cpu); | |
b58bdcca | 1424 | n_offline_successes++; |
13dbf914 PM |
1425 | delta = jiffies - starttime; |
1426 | sum_offline += delta; | |
1427 | if (min_offline < 0) { | |
1428 | min_offline = delta; | |
1429 | max_offline = delta; | |
1430 | } | |
1431 | if (min_offline > delta) | |
1432 | min_offline = delta; | |
1433 | if (max_offline < delta) | |
1434 | max_offline = delta; | |
b58bdcca | 1435 | } |
f220242a | 1436 | } else if (cpu_is_hotpluggable(cpu)) { |
b58bdcca | 1437 | if (verbose) |
2caa1e44 PM |
1438 | pr_alert("%s" TORTURE_FLAG |
1439 | "rcu_torture_onoff task: onlining %d\n", | |
1440 | torture_type, cpu); | |
13dbf914 | 1441 | starttime = jiffies; |
b58bdcca | 1442 | n_online_attempts++; |
7a6a4107 PM |
1443 | ret = cpu_up(cpu); |
1444 | if (ret) { | |
1445 | if (verbose) | |
1446 | pr_alert("%s" TORTURE_FLAG | |
1447 | "rcu_torture_onoff task: online %d failed: errno %d\n", | |
1448 | torture_type, cpu, ret); | |
1449 | } else { | |
b58bdcca | 1450 | if (verbose) |
2caa1e44 PM |
1451 | pr_alert("%s" TORTURE_FLAG |
1452 | "rcu_torture_onoff task: onlined %d\n", | |
1453 | torture_type, cpu); | |
b58bdcca | 1454 | n_online_successes++; |
13dbf914 PM |
1455 | delta = jiffies - starttime; |
1456 | sum_online += delta; | |
1457 | if (min_online < 0) { | |
1458 | min_online = delta; | |
1459 | max_online = delta; | |
1460 | } | |
1461 | if (min_online > delta) | |
1462 | min_online = delta; | |
1463 | if (max_online < delta) | |
1464 | max_online = delta; | |
b58bdcca PM |
1465 | } |
1466 | } | |
1467 | schedule_timeout_interruptible(onoff_interval * HZ); | |
1468 | } | |
1469 | VERBOSE_PRINTK_STRING("rcu_torture_onoff task stopping"); | |
1470 | return 0; | |
1471 | } | |
1472 | ||
49fb4c62 | 1473 | static int |
b58bdcca PM |
1474 | rcu_torture_onoff_init(void) |
1475 | { | |
3c1b1ce0 JL |
1476 | int ret; |
1477 | ||
b58bdcca PM |
1478 | if (onoff_interval <= 0) |
1479 | return 0; | |
1480 | onoff_task = kthread_run(rcu_torture_onoff, NULL, "rcu_torture_onoff"); | |
1481 | if (IS_ERR(onoff_task)) { | |
3c1b1ce0 | 1482 | ret = PTR_ERR(onoff_task); |
b58bdcca | 1483 | onoff_task = NULL; |
3c1b1ce0 | 1484 | return ret; |
b58bdcca PM |
1485 | } |
1486 | return 0; | |
1487 | } | |
1488 | ||
1489 | static void rcu_torture_onoff_cleanup(void) | |
1490 | { | |
1491 | if (onoff_task == NULL) | |
1492 | return; | |
1493 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_onoff task"); | |
1494 | kthread_stop(onoff_task); | |
37e377d2 | 1495 | onoff_task = NULL; |
b58bdcca PM |
1496 | } |
1497 | ||
1498 | #else /* #ifdef CONFIG_HOTPLUG_CPU */ | |
1499 | ||
37e377d2 | 1500 | static int |
b58bdcca PM |
1501 | rcu_torture_onoff_init(void) |
1502 | { | |
37e377d2 | 1503 | return 0; |
b58bdcca PM |
1504 | } |
1505 | ||
1506 | static void rcu_torture_onoff_cleanup(void) | |
1507 | { | |
1508 | } | |
1509 | ||
1510 | #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ | |
1511 | ||
c13f3757 PM |
1512 | /* |
1513 | * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then | |
1514 | * induces a CPU stall for the time specified by stall_cpu. | |
1515 | */ | |
49fb4c62 | 1516 | static int rcu_torture_stall(void *args) |
c13f3757 PM |
1517 | { |
1518 | unsigned long stop_at; | |
1519 | ||
1520 | VERBOSE_PRINTK_STRING("rcu_torture_stall task started"); | |
1521 | if (stall_cpu_holdoff > 0) { | |
1522 | VERBOSE_PRINTK_STRING("rcu_torture_stall begin holdoff"); | |
1523 | schedule_timeout_interruptible(stall_cpu_holdoff * HZ); | |
1524 | VERBOSE_PRINTK_STRING("rcu_torture_stall end holdoff"); | |
1525 | } | |
1526 | if (!kthread_should_stop()) { | |
1527 | stop_at = get_seconds() + stall_cpu; | |
1528 | /* RCU CPU stall is expected behavior in following code. */ | |
2caa1e44 | 1529 | pr_alert("rcu_torture_stall start.\n"); |
c13f3757 PM |
1530 | rcu_read_lock(); |
1531 | preempt_disable(); | |
1532 | while (ULONG_CMP_LT(get_seconds(), stop_at)) | |
1533 | continue; /* Induce RCU CPU stall warning. */ | |
1534 | preempt_enable(); | |
1535 | rcu_read_unlock(); | |
2caa1e44 | 1536 | pr_alert("rcu_torture_stall end.\n"); |
c13f3757 PM |
1537 | } |
1538 | rcutorture_shutdown_absorb("rcu_torture_stall"); | |
1539 | while (!kthread_should_stop()) | |
1540 | schedule_timeout_interruptible(10 * HZ); | |
1541 | return 0; | |
1542 | } | |
1543 | ||
1544 | /* Spawn CPU-stall kthread, if stall_cpu specified. */ | |
1545 | static int __init rcu_torture_stall_init(void) | |
1546 | { | |
1547 | int ret; | |
1548 | ||
1549 | if (stall_cpu <= 0) | |
1550 | return 0; | |
1551 | stall_task = kthread_run(rcu_torture_stall, NULL, "rcu_torture_stall"); | |
1552 | if (IS_ERR(stall_task)) { | |
1553 | ret = PTR_ERR(stall_task); | |
1554 | stall_task = NULL; | |
1555 | return ret; | |
1556 | } | |
1557 | return 0; | |
1558 | } | |
1559 | ||
1560 | /* Clean up after the CPU-stall kthread, if one was spawned. */ | |
1561 | static void rcu_torture_stall_cleanup(void) | |
1562 | { | |
1563 | if (stall_task == NULL) | |
1564 | return; | |
1565 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stall_task."); | |
1566 | kthread_stop(stall_task); | |
37e377d2 | 1567 | stall_task = NULL; |
c13f3757 PM |
1568 | } |
1569 | ||
fae4b54f PM |
1570 | /* Callback function for RCU barrier testing. */ |
1571 | void rcu_torture_barrier_cbf(struct rcu_head *rcu) | |
1572 | { | |
1573 | atomic_inc(&barrier_cbs_invoked); | |
1574 | } | |
1575 | ||
1576 | /* kthread function to register callbacks used to test RCU barriers. */ | |
1577 | static int rcu_torture_barrier_cbs(void *arg) | |
1578 | { | |
1579 | long myid = (long)arg; | |
c6ebcbb6 | 1580 | bool lastphase = 0; |
78e4bc34 | 1581 | bool newphase; |
fae4b54f PM |
1582 | struct rcu_head rcu; |
1583 | ||
1584 | init_rcu_head_on_stack(&rcu); | |
1585 | VERBOSE_PRINTK_STRING("rcu_torture_barrier_cbs task started"); | |
1586 | set_user_nice(current, 19); | |
1587 | do { | |
1588 | wait_event(barrier_cbs_wq[myid], | |
78e4bc34 PM |
1589 | (newphase = |
1590 | ACCESS_ONCE(barrier_phase)) != lastphase || | |
fae4b54f PM |
1591 | kthread_should_stop() || |
1592 | fullstop != FULLSTOP_DONTSTOP); | |
78e4bc34 | 1593 | lastphase = newphase; |
c6ebcbb6 | 1594 | smp_mb(); /* ensure barrier_phase load before ->call(). */ |
fae4b54f PM |
1595 | if (kthread_should_stop() || fullstop != FULLSTOP_DONTSTOP) |
1596 | break; | |
1597 | cur_ops->call(&rcu, rcu_torture_barrier_cbf); | |
1598 | if (atomic_dec_and_test(&barrier_cbs_count)) | |
1599 | wake_up(&barrier_wq); | |
1600 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
1601 | VERBOSE_PRINTK_STRING("rcu_torture_barrier_cbs task stopping"); | |
1602 | rcutorture_shutdown_absorb("rcu_torture_barrier_cbs"); | |
1603 | while (!kthread_should_stop()) | |
1604 | schedule_timeout_interruptible(1); | |
1605 | cur_ops->cb_barrier(); | |
1606 | destroy_rcu_head_on_stack(&rcu); | |
1607 | return 0; | |
1608 | } | |
1609 | ||
1610 | /* kthread function to drive and coordinate RCU barrier testing. */ | |
1611 | static int rcu_torture_barrier(void *arg) | |
1612 | { | |
1613 | int i; | |
1614 | ||
1615 | VERBOSE_PRINTK_STRING("rcu_torture_barrier task starting"); | |
1616 | do { | |
1617 | atomic_set(&barrier_cbs_invoked, 0); | |
1618 | atomic_set(&barrier_cbs_count, n_barrier_cbs); | |
c6ebcbb6 PM |
1619 | smp_mb(); /* Ensure barrier_phase after prior assignments. */ |
1620 | barrier_phase = !barrier_phase; | |
fae4b54f PM |
1621 | for (i = 0; i < n_barrier_cbs; i++) |
1622 | wake_up(&barrier_cbs_wq[i]); | |
1623 | wait_event(barrier_wq, | |
1624 | atomic_read(&barrier_cbs_count) == 0 || | |
1625 | kthread_should_stop() || | |
1626 | fullstop != FULLSTOP_DONTSTOP); | |
1627 | if (kthread_should_stop() || fullstop != FULLSTOP_DONTSTOP) | |
1628 | break; | |
1629 | n_barrier_attempts++; | |
78e4bc34 | 1630 | cur_ops->cb_barrier(); /* Implies smp_mb() for wait_event(). */ |
fae4b54f PM |
1631 | if (atomic_read(&barrier_cbs_invoked) != n_barrier_cbs) { |
1632 | n_rcu_torture_barrier_error++; | |
1633 | WARN_ON_ONCE(1); | |
1634 | } | |
1635 | n_barrier_successes++; | |
1636 | schedule_timeout_interruptible(HZ / 10); | |
1637 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
1638 | VERBOSE_PRINTK_STRING("rcu_torture_barrier task stopping"); | |
143aa672 | 1639 | rcutorture_shutdown_absorb("rcu_torture_barrier"); |
fae4b54f PM |
1640 | while (!kthread_should_stop()) |
1641 | schedule_timeout_interruptible(1); | |
1642 | return 0; | |
1643 | } | |
1644 | ||
1645 | /* Initialize RCU barrier testing. */ | |
1646 | static int rcu_torture_barrier_init(void) | |
1647 | { | |
1648 | int i; | |
1649 | int ret; | |
1650 | ||
1651 | if (n_barrier_cbs == 0) | |
1652 | return 0; | |
1653 | if (cur_ops->call == NULL || cur_ops->cb_barrier == NULL) { | |
2caa1e44 PM |
1654 | pr_alert("%s" TORTURE_FLAG |
1655 | " Call or barrier ops missing for %s,\n", | |
1656 | torture_type, cur_ops->name); | |
1657 | pr_alert("%s" TORTURE_FLAG | |
1658 | " RCU barrier testing omitted from run.\n", | |
1659 | torture_type); | |
fae4b54f PM |
1660 | return 0; |
1661 | } | |
1662 | atomic_set(&barrier_cbs_count, 0); | |
1663 | atomic_set(&barrier_cbs_invoked, 0); | |
1664 | barrier_cbs_tasks = | |
1665 | kzalloc(n_barrier_cbs * sizeof(barrier_cbs_tasks[0]), | |
1666 | GFP_KERNEL); | |
1667 | barrier_cbs_wq = | |
1668 | kzalloc(n_barrier_cbs * sizeof(barrier_cbs_wq[0]), | |
1669 | GFP_KERNEL); | |
de5e6437 | 1670 | if (barrier_cbs_tasks == NULL || !barrier_cbs_wq) |
fae4b54f PM |
1671 | return -ENOMEM; |
1672 | for (i = 0; i < n_barrier_cbs; i++) { | |
1673 | init_waitqueue_head(&barrier_cbs_wq[i]); | |
1674 | barrier_cbs_tasks[i] = kthread_run(rcu_torture_barrier_cbs, | |
9059c940 | 1675 | (void *)(long)i, |
fae4b54f PM |
1676 | "rcu_torture_barrier_cbs"); |
1677 | if (IS_ERR(barrier_cbs_tasks[i])) { | |
1678 | ret = PTR_ERR(barrier_cbs_tasks[i]); | |
1679 | VERBOSE_PRINTK_ERRSTRING("Failed to create rcu_torture_barrier_cbs"); | |
1680 | barrier_cbs_tasks[i] = NULL; | |
1681 | return ret; | |
1682 | } | |
1683 | } | |
1684 | barrier_task = kthread_run(rcu_torture_barrier, NULL, | |
1685 | "rcu_torture_barrier"); | |
1686 | if (IS_ERR(barrier_task)) { | |
1687 | ret = PTR_ERR(barrier_task); | |
1688 | VERBOSE_PRINTK_ERRSTRING("Failed to create rcu_torture_barrier"); | |
1689 | barrier_task = NULL; | |
1690 | } | |
1691 | return 0; | |
1692 | } | |
1693 | ||
1694 | /* Clean up after RCU barrier testing. */ | |
1695 | static void rcu_torture_barrier_cleanup(void) | |
1696 | { | |
1697 | int i; | |
1698 | ||
1699 | if (barrier_task != NULL) { | |
1700 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_barrier task"); | |
1701 | kthread_stop(barrier_task); | |
1702 | barrier_task = NULL; | |
1703 | } | |
1704 | if (barrier_cbs_tasks != NULL) { | |
1705 | for (i = 0; i < n_barrier_cbs; i++) { | |
1706 | if (barrier_cbs_tasks[i] != NULL) { | |
1707 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_barrier_cbs task"); | |
1708 | kthread_stop(barrier_cbs_tasks[i]); | |
1709 | barrier_cbs_tasks[i] = NULL; | |
1710 | } | |
1711 | } | |
1712 | kfree(barrier_cbs_tasks); | |
1713 | barrier_cbs_tasks = NULL; | |
1714 | } | |
1715 | if (barrier_cbs_wq != NULL) { | |
1716 | kfree(barrier_cbs_wq); | |
1717 | barrier_cbs_wq = NULL; | |
1718 | } | |
1719 | } | |
1720 | ||
8e8be45e PM |
1721 | static int rcutorture_cpu_notify(struct notifier_block *self, |
1722 | unsigned long action, void *hcpu) | |
1723 | { | |
1724 | long cpu = (long)hcpu; | |
1725 | ||
1726 | switch (action) { | |
1727 | case CPU_ONLINE: | |
1728 | case CPU_DOWN_FAILED: | |
1729 | (void)rcutorture_booster_init(cpu); | |
1730 | break; | |
1731 | case CPU_DOWN_PREPARE: | |
1732 | rcutorture_booster_cleanup(cpu); | |
1733 | break; | |
1734 | default: | |
1735 | break; | |
1736 | } | |
1737 | return NOTIFY_OK; | |
1738 | } | |
1739 | ||
1740 | static struct notifier_block rcutorture_cpu_nb = { | |
1741 | .notifier_call = rcutorture_cpu_notify, | |
1742 | }; | |
1743 | ||
a241ec65 PM |
1744 | static void |
1745 | rcu_torture_cleanup(void) | |
1746 | { | |
1747 | int i; | |
1748 | ||
343e9099 | 1749 | mutex_lock(&fullstop_mutex); |
4a298656 | 1750 | rcutorture_record_test_transition(); |
c9d557c1 | 1751 | if (fullstop == FULLSTOP_SHUTDOWN) { |
2caa1e44 | 1752 | pr_warn(/* but going down anyway, so... */ |
c9d557c1 | 1753 | "Concurrent 'rmmod rcutorture' and shutdown illegal!\n"); |
343e9099 | 1754 | mutex_unlock(&fullstop_mutex); |
c9d557c1 | 1755 | schedule_timeout_uninterruptible(10); |
343e9099 PM |
1756 | if (cur_ops->cb_barrier != NULL) |
1757 | cur_ops->cb_barrier(); | |
1758 | return; | |
1759 | } | |
c9d557c1 | 1760 | fullstop = FULLSTOP_RMMOD; |
343e9099 | 1761 | mutex_unlock(&fullstop_mutex); |
8e8be45e | 1762 | unregister_reboot_notifier(&rcutorture_shutdown_nb); |
fae4b54f | 1763 | rcu_torture_barrier_cleanup(); |
c13f3757 | 1764 | rcu_torture_stall_cleanup(); |
d120f65f PM |
1765 | if (stutter_task) { |
1766 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stutter task"); | |
1767 | kthread_stop(stutter_task); | |
1768 | } | |
1769 | stutter_task = NULL; | |
c8e5b163 | 1770 | if (shuffler_task) { |
d84f5203 SV |
1771 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task"); |
1772 | kthread_stop(shuffler_task); | |
73d0a4b1 | 1773 | free_cpumask_var(shuffle_tmp_mask); |
d84f5203 SV |
1774 | } |
1775 | shuffler_task = NULL; | |
1776 | ||
c8e5b163 | 1777 | if (writer_task) { |
a241ec65 PM |
1778 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task"); |
1779 | kthread_stop(writer_task); | |
1780 | } | |
1781 | writer_task = NULL; | |
1782 | ||
c8e5b163 | 1783 | if (reader_tasks) { |
a241ec65 | 1784 | for (i = 0; i < nrealreaders; i++) { |
c8e5b163 | 1785 | if (reader_tasks[i]) { |
a241ec65 PM |
1786 | VERBOSE_PRINTK_STRING( |
1787 | "Stopping rcu_torture_reader task"); | |
1788 | kthread_stop(reader_tasks[i]); | |
1789 | } | |
1790 | reader_tasks[i] = NULL; | |
1791 | } | |
1792 | kfree(reader_tasks); | |
1793 | reader_tasks = NULL; | |
1794 | } | |
1795 | rcu_torture_current = NULL; | |
1796 | ||
c8e5b163 | 1797 | if (fakewriter_tasks) { |
b772e1dd | 1798 | for (i = 0; i < nfakewriters; i++) { |
c8e5b163 | 1799 | if (fakewriter_tasks[i]) { |
b772e1dd JT |
1800 | VERBOSE_PRINTK_STRING( |
1801 | "Stopping rcu_torture_fakewriter task"); | |
1802 | kthread_stop(fakewriter_tasks[i]); | |
1803 | } | |
1804 | fakewriter_tasks[i] = NULL; | |
1805 | } | |
1806 | kfree(fakewriter_tasks); | |
1807 | fakewriter_tasks = NULL; | |
1808 | } | |
1809 | ||
c8e5b163 | 1810 | if (stats_task) { |
a241ec65 PM |
1811 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task"); |
1812 | kthread_stop(stats_task); | |
1813 | } | |
1814 | stats_task = NULL; | |
1815 | ||
bf66f18e PM |
1816 | if (fqs_task) { |
1817 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_fqs task"); | |
1818 | kthread_stop(fqs_task); | |
1819 | } | |
1820 | fqs_task = NULL; | |
8e8be45e PM |
1821 | if ((test_boost == 1 && cur_ops->can_boost) || |
1822 | test_boost == 2) { | |
1823 | unregister_cpu_notifier(&rcutorture_cpu_nb); | |
1824 | for_each_possible_cpu(i) | |
1825 | rcutorture_booster_cleanup(i); | |
1826 | } | |
d5f546d8 PM |
1827 | if (shutdown_task != NULL) { |
1828 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_shutdown task"); | |
1829 | kthread_stop(shutdown_task); | |
1830 | } | |
37e377d2 | 1831 | shutdown_task = NULL; |
b58bdcca | 1832 | rcu_torture_onoff_cleanup(); |
bf66f18e | 1833 | |
a241ec65 | 1834 | /* Wait for all RCU callbacks to fire. */ |
2326974d PM |
1835 | |
1836 | if (cur_ops->cb_barrier != NULL) | |
1837 | cur_ops->cb_barrier(); | |
a241ec65 | 1838 | |
a241ec65 | 1839 | rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ |
72e9bb54 | 1840 | |
fae4b54f | 1841 | if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error) |
8e8be45e | 1842 | rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE"); |
091541bb PM |
1843 | else if (n_online_successes != n_online_attempts || |
1844 | n_offline_successes != n_offline_attempts) | |
1845 | rcu_torture_print_module_parms(cur_ops, | |
1846 | "End of test: RCU_HOTPLUG"); | |
95c38322 | 1847 | else |
8e8be45e | 1848 | rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS"); |
a241ec65 PM |
1849 | } |
1850 | ||
d2818df1 PM |
1851 | #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD |
1852 | static void rcu_torture_leak_cb(struct rcu_head *rhp) | |
1853 | { | |
1854 | } | |
1855 | ||
1856 | static void rcu_torture_err_cb(struct rcu_head *rhp) | |
1857 | { | |
1858 | /* | |
1859 | * This -might- happen due to race conditions, but is unlikely. | |
1860 | * The scenario that leads to this happening is that the | |
1861 | * first of the pair of duplicate callbacks is queued, | |
1862 | * someone else starts a grace period that includes that | |
1863 | * callback, then the second of the pair must wait for the | |
1864 | * next grace period. Unlikely, but can happen. If it | |
1865 | * does happen, the debug-objects subsystem won't have splatted. | |
1866 | */ | |
1867 | pr_alert("rcutorture: duplicated callback was invoked.\n"); | |
1868 | } | |
1869 | #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ | |
1870 | ||
1871 | /* | |
1872 | * Verify that double-free causes debug-objects to complain, but only | |
1873 | * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test | |
1874 | * cannot be carried out. | |
1875 | */ | |
1876 | static void rcu_test_debug_objects(void) | |
1877 | { | |
1878 | #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD | |
1879 | struct rcu_head rh1; | |
1880 | struct rcu_head rh2; | |
1881 | ||
1882 | init_rcu_head_on_stack(&rh1); | |
1883 | init_rcu_head_on_stack(&rh2); | |
1884 | pr_alert("rcutorture: WARN: Duplicate call_rcu() test starting.\n"); | |
1885 | ||
1886 | /* Try to queue the rh2 pair of callbacks for the same grace period. */ | |
1887 | preempt_disable(); /* Prevent preemption from interrupting test. */ | |
1888 | rcu_read_lock(); /* Make it impossible to finish a grace period. */ | |
1889 | call_rcu(&rh1, rcu_torture_leak_cb); /* Start grace period. */ | |
1890 | local_irq_disable(); /* Make it harder to start a new grace period. */ | |
1891 | call_rcu(&rh2, rcu_torture_leak_cb); | |
1892 | call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */ | |
1893 | local_irq_enable(); | |
1894 | rcu_read_unlock(); | |
1895 | preempt_enable(); | |
1896 | ||
1897 | /* Wait for them all to get done so we can safely return. */ | |
1898 | rcu_barrier(); | |
1899 | pr_alert("rcutorture: WARN: Duplicate call_rcu() test complete.\n"); | |
1900 | destroy_rcu_head_on_stack(&rh1); | |
1901 | destroy_rcu_head_on_stack(&rh2); | |
1902 | #else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ | |
1903 | pr_alert("rcutorture: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n"); | |
1904 | #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ | |
1905 | } | |
1906 | ||
6f8bc500 | 1907 | static int __init |
a241ec65 PM |
1908 | rcu_torture_init(void) |
1909 | { | |
1910 | int i; | |
1911 | int cpu; | |
1912 | int firsterr = 0; | |
fae4b54f | 1913 | int retval; |
2ec1f2d9 PM |
1914 | static struct rcu_torture_ops *torture_ops[] = { |
1915 | &rcu_ops, &rcu_bh_ops, &srcu_ops, &sched_ops, | |
1916 | }; | |
a241ec65 | 1917 | |
343e9099 PM |
1918 | mutex_lock(&fullstop_mutex); |
1919 | ||
a241ec65 | 1920 | /* Process args and tell the world that the torturer is on the job. */ |
ade5fb81 | 1921 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { |
72e9bb54 | 1922 | cur_ops = torture_ops[i]; |
ade5fb81 | 1923 | if (strcmp(torture_type, cur_ops->name) == 0) |
72e9bb54 | 1924 | break; |
72e9bb54 | 1925 | } |
ade5fb81 | 1926 | if (i == ARRAY_SIZE(torture_ops)) { |
2caa1e44 PM |
1927 | pr_alert("rcu-torture: invalid torture type: \"%s\"\n", |
1928 | torture_type); | |
1929 | pr_alert("rcu-torture types:"); | |
cf886c44 | 1930 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) |
2caa1e44 PM |
1931 | pr_alert(" %s", torture_ops[i]->name); |
1932 | pr_alert("\n"); | |
343e9099 | 1933 | mutex_unlock(&fullstop_mutex); |
a71fca58 | 1934 | return -EINVAL; |
72e9bb54 | 1935 | } |
bf66f18e | 1936 | if (cur_ops->fqs == NULL && fqs_duration != 0) { |
2caa1e44 | 1937 | pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n"); |
bf66f18e PM |
1938 | fqs_duration = 0; |
1939 | } | |
c8e5b163 | 1940 | if (cur_ops->init) |
72e9bb54 PM |
1941 | cur_ops->init(); /* no "goto unwind" prior to this point!!! */ |
1942 | ||
a241ec65 PM |
1943 | if (nreaders >= 0) |
1944 | nrealreaders = nreaders; | |
1945 | else | |
1946 | nrealreaders = 2 * num_online_cpus(); | |
8e8be45e | 1947 | rcu_torture_print_module_parms(cur_ops, "Start of test"); |
c9d557c1 | 1948 | fullstop = FULLSTOP_DONTSTOP; |
a241ec65 PM |
1949 | |
1950 | /* Set up the freelist. */ | |
1951 | ||
1952 | INIT_LIST_HEAD(&rcu_torture_freelist); | |
788e770e | 1953 | for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) { |
996417d2 | 1954 | rcu_tortures[i].rtort_mbtest = 0; |
a241ec65 PM |
1955 | list_add_tail(&rcu_tortures[i].rtort_free, |
1956 | &rcu_torture_freelist); | |
1957 | } | |
1958 | ||
1959 | /* Initialize the statistics so that each run gets its own numbers. */ | |
1960 | ||
1961 | rcu_torture_current = NULL; | |
1962 | rcu_torture_current_version = 0; | |
1963 | atomic_set(&n_rcu_torture_alloc, 0); | |
1964 | atomic_set(&n_rcu_torture_alloc_fail, 0); | |
1965 | atomic_set(&n_rcu_torture_free, 0); | |
996417d2 PM |
1966 | atomic_set(&n_rcu_torture_mberror, 0); |
1967 | atomic_set(&n_rcu_torture_error, 0); | |
fae4b54f | 1968 | n_rcu_torture_barrier_error = 0; |
8e8be45e PM |
1969 | n_rcu_torture_boost_ktrerror = 0; |
1970 | n_rcu_torture_boost_rterror = 0; | |
8e8be45e PM |
1971 | n_rcu_torture_boost_failure = 0; |
1972 | n_rcu_torture_boosts = 0; | |
a241ec65 PM |
1973 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
1974 | atomic_set(&rcu_torture_wcount[i], 0); | |
0a945022 | 1975 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
1976 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
1977 | per_cpu(rcu_torture_count, cpu)[i] = 0; | |
1978 | per_cpu(rcu_torture_batch, cpu)[i] = 0; | |
1979 | } | |
1980 | } | |
1981 | ||
1982 | /* Start up the kthreads. */ | |
1983 | ||
1984 | VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task"); | |
60f53782 PM |
1985 | writer_task = kthread_create(rcu_torture_writer, NULL, |
1986 | "rcu_torture_writer"); | |
a241ec65 PM |
1987 | if (IS_ERR(writer_task)) { |
1988 | firsterr = PTR_ERR(writer_task); | |
1989 | VERBOSE_PRINTK_ERRSTRING("Failed to create writer"); | |
1990 | writer_task = NULL; | |
1991 | goto unwind; | |
1992 | } | |
60f53782 | 1993 | wake_up_process(writer_task); |
b772e1dd | 1994 | fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]), |
a71fca58 | 1995 | GFP_KERNEL); |
b772e1dd JT |
1996 | if (fakewriter_tasks == NULL) { |
1997 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
1998 | firsterr = -ENOMEM; | |
1999 | goto unwind; | |
2000 | } | |
2001 | for (i = 0; i < nfakewriters; i++) { | |
2002 | VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task"); | |
2003 | fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL, | |
a71fca58 | 2004 | "rcu_torture_fakewriter"); |
b772e1dd JT |
2005 | if (IS_ERR(fakewriter_tasks[i])) { |
2006 | firsterr = PTR_ERR(fakewriter_tasks[i]); | |
2007 | VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter"); | |
2008 | fakewriter_tasks[i] = NULL; | |
2009 | goto unwind; | |
2010 | } | |
2011 | } | |
2860aaba | 2012 | reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]), |
a241ec65 PM |
2013 | GFP_KERNEL); |
2014 | if (reader_tasks == NULL) { | |
2015 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
2016 | firsterr = -ENOMEM; | |
2017 | goto unwind; | |
2018 | } | |
2019 | for (i = 0; i < nrealreaders; i++) { | |
2020 | VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task"); | |
2021 | reader_tasks[i] = kthread_run(rcu_torture_reader, NULL, | |
2022 | "rcu_torture_reader"); | |
2023 | if (IS_ERR(reader_tasks[i])) { | |
2024 | firsterr = PTR_ERR(reader_tasks[i]); | |
2025 | VERBOSE_PRINTK_ERRSTRING("Failed to create reader"); | |
2026 | reader_tasks[i] = NULL; | |
2027 | goto unwind; | |
2028 | } | |
2029 | } | |
2030 | if (stat_interval > 0) { | |
2031 | VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task"); | |
2032 | stats_task = kthread_run(rcu_torture_stats, NULL, | |
2033 | "rcu_torture_stats"); | |
2034 | if (IS_ERR(stats_task)) { | |
2035 | firsterr = PTR_ERR(stats_task); | |
2036 | VERBOSE_PRINTK_ERRSTRING("Failed to create stats"); | |
2037 | stats_task = NULL; | |
2038 | goto unwind; | |
2039 | } | |
2040 | } | |
d84f5203 SV |
2041 | if (test_no_idle_hz) { |
2042 | rcu_idle_cpu = num_online_cpus() - 1; | |
73d0a4b1 RR |
2043 | |
2044 | if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) { | |
2045 | firsterr = -ENOMEM; | |
2046 | VERBOSE_PRINTK_ERRSTRING("Failed to alloc mask"); | |
2047 | goto unwind; | |
2048 | } | |
2049 | ||
d84f5203 SV |
2050 | /* Create the shuffler thread */ |
2051 | shuffler_task = kthread_run(rcu_torture_shuffle, NULL, | |
2052 | "rcu_torture_shuffle"); | |
2053 | if (IS_ERR(shuffler_task)) { | |
73d0a4b1 | 2054 | free_cpumask_var(shuffle_tmp_mask); |
d84f5203 SV |
2055 | firsterr = PTR_ERR(shuffler_task); |
2056 | VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler"); | |
2057 | shuffler_task = NULL; | |
2058 | goto unwind; | |
2059 | } | |
2060 | } | |
d120f65f PM |
2061 | if (stutter < 0) |
2062 | stutter = 0; | |
2063 | if (stutter) { | |
2064 | /* Create the stutter thread */ | |
2065 | stutter_task = kthread_run(rcu_torture_stutter, NULL, | |
2066 | "rcu_torture_stutter"); | |
2067 | if (IS_ERR(stutter_task)) { | |
2068 | firsterr = PTR_ERR(stutter_task); | |
2069 | VERBOSE_PRINTK_ERRSTRING("Failed to create stutter"); | |
2070 | stutter_task = NULL; | |
2071 | goto unwind; | |
2072 | } | |
2073 | } | |
bf66f18e PM |
2074 | if (fqs_duration < 0) |
2075 | fqs_duration = 0; | |
2076 | if (fqs_duration) { | |
2077 | /* Create the stutter thread */ | |
2078 | fqs_task = kthread_run(rcu_torture_fqs, NULL, | |
2079 | "rcu_torture_fqs"); | |
2080 | if (IS_ERR(fqs_task)) { | |
2081 | firsterr = PTR_ERR(fqs_task); | |
2082 | VERBOSE_PRINTK_ERRSTRING("Failed to create fqs"); | |
2083 | fqs_task = NULL; | |
2084 | goto unwind; | |
2085 | } | |
2086 | } | |
8e8be45e PM |
2087 | if (test_boost_interval < 1) |
2088 | test_boost_interval = 1; | |
2089 | if (test_boost_duration < 2) | |
2090 | test_boost_duration = 2; | |
2091 | if ((test_boost == 1 && cur_ops->can_boost) || | |
2092 | test_boost == 2) { | |
8e8be45e PM |
2093 | |
2094 | boost_starttime = jiffies + test_boost_interval * HZ; | |
2095 | register_cpu_notifier(&rcutorture_cpu_nb); | |
2096 | for_each_possible_cpu(i) { | |
2097 | if (cpu_is_offline(i)) | |
2098 | continue; /* Heuristic: CPU can go offline. */ | |
2099 | retval = rcutorture_booster_init(i); | |
2100 | if (retval < 0) { | |
2101 | firsterr = retval; | |
2102 | goto unwind; | |
2103 | } | |
2104 | } | |
2105 | } | |
d5f546d8 PM |
2106 | if (shutdown_secs > 0) { |
2107 | shutdown_time = jiffies + shutdown_secs * HZ; | |
60f53782 PM |
2108 | shutdown_task = kthread_create(rcu_torture_shutdown, NULL, |
2109 | "rcu_torture_shutdown"); | |
d5f546d8 PM |
2110 | if (IS_ERR(shutdown_task)) { |
2111 | firsterr = PTR_ERR(shutdown_task); | |
2112 | VERBOSE_PRINTK_ERRSTRING("Failed to create shutdown"); | |
2113 | shutdown_task = NULL; | |
2114 | goto unwind; | |
2115 | } | |
60f53782 | 2116 | wake_up_process(shutdown_task); |
d5f546d8 | 2117 | } |
37e377d2 PM |
2118 | i = rcu_torture_onoff_init(); |
2119 | if (i != 0) { | |
2120 | firsterr = i; | |
2121 | goto unwind; | |
2122 | } | |
8e8be45e | 2123 | register_reboot_notifier(&rcutorture_shutdown_nb); |
37e377d2 PM |
2124 | i = rcu_torture_stall_init(); |
2125 | if (i != 0) { | |
2126 | firsterr = i; | |
2127 | goto unwind; | |
2128 | } | |
fae4b54f PM |
2129 | retval = rcu_torture_barrier_init(); |
2130 | if (retval != 0) { | |
2131 | firsterr = retval; | |
2132 | goto unwind; | |
2133 | } | |
d2818df1 PM |
2134 | if (object_debug) |
2135 | rcu_test_debug_objects(); | |
4a298656 | 2136 | rcutorture_record_test_transition(); |
343e9099 | 2137 | mutex_unlock(&fullstop_mutex); |
a241ec65 PM |
2138 | return 0; |
2139 | ||
2140 | unwind: | |
343e9099 | 2141 | mutex_unlock(&fullstop_mutex); |
a241ec65 PM |
2142 | rcu_torture_cleanup(); |
2143 | return firsterr; | |
2144 | } | |
2145 | ||
2146 | module_init(rcu_torture_init); | |
2147 | module_exit(rcu_torture_cleanup); |