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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 | 141 | |
a241ec65 PM |
142 | static int nrealreaders; |
143 | static struct task_struct *writer_task; | |
b772e1dd | 144 | static struct task_struct **fakewriter_tasks; |
a241ec65 PM |
145 | static struct task_struct **reader_tasks; |
146 | static struct task_struct *stats_task; | |
d84f5203 | 147 | static struct task_struct *shuffler_task; |
d120f65f | 148 | static struct task_struct *stutter_task; |
bf66f18e | 149 | static struct task_struct *fqs_task; |
8e8be45e | 150 | static struct task_struct *boost_tasks[NR_CPUS]; |
d5f546d8 | 151 | static struct task_struct *shutdown_task; |
b58bdcca PM |
152 | #ifdef CONFIG_HOTPLUG_CPU |
153 | static struct task_struct *onoff_task; | |
154 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
c13f3757 | 155 | static struct task_struct *stall_task; |
fae4b54f PM |
156 | static struct task_struct **barrier_cbs_tasks; |
157 | static struct task_struct *barrier_task; | |
a241ec65 PM |
158 | |
159 | #define RCU_TORTURE_PIPE_LEN 10 | |
160 | ||
161 | struct rcu_torture { | |
162 | struct rcu_head rtort_rcu; | |
163 | int rtort_pipe_count; | |
164 | struct list_head rtort_free; | |
996417d2 | 165 | int rtort_mbtest; |
a241ec65 PM |
166 | }; |
167 | ||
a241ec65 | 168 | static LIST_HEAD(rcu_torture_freelist); |
0ddea0ea | 169 | static struct rcu_torture __rcu *rcu_torture_current; |
4a298656 | 170 | static unsigned long rcu_torture_current_version; |
a241ec65 PM |
171 | static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; |
172 | static DEFINE_SPINLOCK(rcu_torture_lock); | |
806274c0 PM |
173 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], |
174 | rcu_torture_count) = { 0 }; | |
175 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], | |
176 | rcu_torture_batch) = { 0 }; | |
a241ec65 | 177 | static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1]; |
b2896d2e PM |
178 | static atomic_t n_rcu_torture_alloc; |
179 | static atomic_t n_rcu_torture_alloc_fail; | |
180 | static atomic_t n_rcu_torture_free; | |
181 | static atomic_t n_rcu_torture_mberror; | |
182 | static atomic_t n_rcu_torture_error; | |
fae4b54f | 183 | static long n_rcu_torture_barrier_error; |
8e8be45e PM |
184 | static long n_rcu_torture_boost_ktrerror; |
185 | static long n_rcu_torture_boost_rterror; | |
8e8be45e PM |
186 | static long n_rcu_torture_boost_failure; |
187 | static long n_rcu_torture_boosts; | |
a71fca58 | 188 | static long n_rcu_torture_timers; |
b58bdcca PM |
189 | static long n_offline_attempts; |
190 | static long n_offline_successes; | |
13dbf914 PM |
191 | static unsigned long sum_offline; |
192 | static int min_offline = -1; | |
193 | static int max_offline; | |
b58bdcca PM |
194 | static long n_online_attempts; |
195 | static long n_online_successes; | |
13dbf914 PM |
196 | static unsigned long sum_online; |
197 | static int min_online = -1; | |
198 | static int max_online; | |
fae4b54f PM |
199 | static long n_barrier_attempts; |
200 | static long n_barrier_successes; | |
e3033736 | 201 | static struct list_head rcu_torture_removed; |
73d0a4b1 | 202 | static cpumask_var_t shuffle_tmp_mask; |
a241ec65 | 203 | |
a71fca58 | 204 | static int stutter_pause_test; |
d120f65f | 205 | |
31a72bce PM |
206 | #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE) |
207 | #define RCUTORTURE_RUNNABLE_INIT 1 | |
208 | #else | |
209 | #define RCUTORTURE_RUNNABLE_INIT 0 | |
210 | #endif | |
211 | int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT; | |
bb3bf705 PM |
212 | module_param(rcutorture_runnable, int, 0444); |
213 | MODULE_PARM_DESC(rcutorture_runnable, "Start rcutorture at boot"); | |
31a72bce | 214 | |
3acf4a9a | 215 | #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) |
8e8be45e | 216 | #define rcu_can_boost() 1 |
3acf4a9a | 217 | #else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ |
8e8be45e | 218 | #define rcu_can_boost() 0 |
3acf4a9a | 219 | #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ |
8e8be45e | 220 | |
e4aa0da3 SR |
221 | #ifdef CONFIG_RCU_TRACE |
222 | static u64 notrace rcu_trace_clock_local(void) | |
223 | { | |
224 | u64 ts = trace_clock_local(); | |
225 | unsigned long __maybe_unused ts_rem = do_div(ts, NSEC_PER_USEC); | |
226 | return ts; | |
227 | } | |
228 | #else /* #ifdef CONFIG_RCU_TRACE */ | |
229 | static u64 notrace rcu_trace_clock_local(void) | |
230 | { | |
231 | return 0ULL; | |
232 | } | |
233 | #endif /* #else #ifdef CONFIG_RCU_TRACE */ | |
234 | ||
d5f546d8 | 235 | static unsigned long shutdown_time; /* jiffies to system shutdown. */ |
8e8be45e PM |
236 | static unsigned long boost_starttime; /* jiffies of next boost test start. */ |
237 | DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */ | |
238 | /* and boost task create/destroy. */ | |
fae4b54f | 239 | static atomic_t barrier_cbs_count; /* Barrier callbacks registered. */ |
c6ebcbb6 | 240 | static bool barrier_phase; /* Test phase. */ |
fae4b54f PM |
241 | static atomic_t barrier_cbs_invoked; /* Barrier callbacks invoked. */ |
242 | static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */ | |
243 | static DECLARE_WAIT_QUEUE_HEAD(barrier_wq); | |
8e8be45e | 244 | |
c9d557c1 PM |
245 | /* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */ |
246 | ||
247 | #define FULLSTOP_DONTSTOP 0 /* Normal operation. */ | |
248 | #define FULLSTOP_SHUTDOWN 1 /* System shutdown with rcutorture running. */ | |
249 | #define FULLSTOP_RMMOD 2 /* Normal rmmod of rcutorture. */ | |
250 | static int fullstop = FULLSTOP_RMMOD; | |
0ddea0ea PM |
251 | /* |
252 | * Protect fullstop transitions and spawning of kthreads. | |
253 | */ | |
254 | static DEFINE_MUTEX(fullstop_mutex); | |
343e9099 | 255 | |
d5f546d8 PM |
256 | /* Forward reference. */ |
257 | static void rcu_torture_cleanup(void); | |
258 | ||
343e9099 | 259 | /* |
c9d557c1 | 260 | * Detect and respond to a system shutdown. |
343e9099 PM |
261 | */ |
262 | static int | |
263 | rcutorture_shutdown_notify(struct notifier_block *unused1, | |
264 | unsigned long unused2, void *unused3) | |
265 | { | |
c59ab97e | 266 | mutex_lock(&fullstop_mutex); |
c9d557c1 | 267 | if (fullstop == FULLSTOP_DONTSTOP) |
c59ab97e | 268 | fullstop = FULLSTOP_SHUTDOWN; |
c9d557c1 | 269 | else |
2caa1e44 | 270 | pr_warn(/* but going down anyway, so... */ |
c9d557c1 | 271 | "Concurrent 'rmmod rcutorture' and shutdown illegal!\n"); |
c59ab97e | 272 | mutex_unlock(&fullstop_mutex); |
343e9099 PM |
273 | return NOTIFY_DONE; |
274 | } | |
275 | ||
c9d557c1 PM |
276 | /* |
277 | * Absorb kthreads into a kernel function that won't return, so that | |
278 | * they won't ever access module text or data again. | |
279 | */ | |
e66c33d5 | 280 | static void rcutorture_shutdown_absorb(const char *title) |
c9d557c1 PM |
281 | { |
282 | if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { | |
2caa1e44 | 283 | pr_notice( |
c9d557c1 PM |
284 | "rcutorture thread %s parking due to system shutdown\n", |
285 | title); | |
286 | schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT); | |
287 | } | |
288 | } | |
289 | ||
a241ec65 PM |
290 | /* |
291 | * Allocate an element from the rcu_tortures pool. | |
292 | */ | |
97a41e26 | 293 | static struct rcu_torture * |
a241ec65 PM |
294 | rcu_torture_alloc(void) |
295 | { | |
296 | struct list_head *p; | |
297 | ||
adac1665 | 298 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 PM |
299 | if (list_empty(&rcu_torture_freelist)) { |
300 | atomic_inc(&n_rcu_torture_alloc_fail); | |
adac1665 | 301 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
302 | return NULL; |
303 | } | |
304 | atomic_inc(&n_rcu_torture_alloc); | |
305 | p = rcu_torture_freelist.next; | |
306 | list_del_init(p); | |
adac1665 | 307 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
308 | return container_of(p, struct rcu_torture, rtort_free); |
309 | } | |
310 | ||
311 | /* | |
312 | * Free an element to the rcu_tortures pool. | |
313 | */ | |
314 | static void | |
315 | rcu_torture_free(struct rcu_torture *p) | |
316 | { | |
317 | atomic_inc(&n_rcu_torture_free); | |
adac1665 | 318 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 | 319 | list_add_tail(&p->rtort_free, &rcu_torture_freelist); |
adac1665 | 320 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
321 | } |
322 | ||
a241ec65 PM |
323 | struct rcu_random_state { |
324 | unsigned long rrs_state; | |
75cfef32 | 325 | long rrs_count; |
a241ec65 PM |
326 | }; |
327 | ||
328 | #define RCU_RANDOM_MULT 39916801 /* prime */ | |
329 | #define RCU_RANDOM_ADD 479001701 /* prime */ | |
330 | #define RCU_RANDOM_REFRESH 10000 | |
331 | ||
332 | #define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 } | |
333 | ||
334 | /* | |
335 | * Crude but fast random-number generator. Uses a linear congruential | |
c17ac855 | 336 | * generator, with occasional help from cpu_clock(). |
a241ec65 | 337 | */ |
75cfef32 | 338 | static unsigned long |
a241ec65 PM |
339 | rcu_random(struct rcu_random_state *rrsp) |
340 | { | |
a241ec65 | 341 | if (--rrsp->rrs_count < 0) { |
c676329a | 342 | rrsp->rrs_state += (unsigned long)local_clock(); |
a241ec65 PM |
343 | rrsp->rrs_count = RCU_RANDOM_REFRESH; |
344 | } | |
345 | rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD; | |
346 | return swahw32(rrsp->rrs_state); | |
347 | } | |
348 | ||
d120f65f | 349 | static void |
e66c33d5 | 350 | rcu_stutter_wait(const char *title) |
d120f65f | 351 | { |
c9d557c1 | 352 | while (stutter_pause_test || !rcutorture_runnable) { |
e3d7be27 PM |
353 | if (rcutorture_runnable) |
354 | schedule_timeout_interruptible(1); | |
355 | else | |
3ccf79f4 | 356 | schedule_timeout_interruptible(round_jiffies_relative(HZ)); |
c9d557c1 | 357 | rcutorture_shutdown_absorb(title); |
343e9099 | 358 | } |
d120f65f PM |
359 | } |
360 | ||
72e9bb54 PM |
361 | /* |
362 | * Operations vector for selecting different types of tests. | |
363 | */ | |
364 | ||
365 | struct rcu_torture_ops { | |
366 | void (*init)(void); | |
72e9bb54 | 367 | int (*readlock)(void); |
0acc512c | 368 | void (*read_delay)(struct rcu_random_state *rrsp); |
72e9bb54 PM |
369 | void (*readunlock)(int idx); |
370 | int (*completed)(void); | |
0acc512c | 371 | void (*deferred_free)(struct rcu_torture *p); |
b772e1dd | 372 | void (*sync)(void); |
2ec1f2d9 | 373 | void (*exp_sync)(void); |
fae4b54f | 374 | void (*call)(struct rcu_head *head, void (*func)(struct rcu_head *rcu)); |
2326974d | 375 | void (*cb_barrier)(void); |
bf66f18e | 376 | void (*fqs)(void); |
d1008950 | 377 | void (*stats)(char *page); |
0acc512c | 378 | int irq_capable; |
8e8be45e | 379 | int can_boost; |
e66c33d5 | 380 | const char *name; |
72e9bb54 | 381 | }; |
a71fca58 PM |
382 | |
383 | static struct rcu_torture_ops *cur_ops; | |
72e9bb54 PM |
384 | |
385 | /* | |
386 | * Definitions for rcu torture testing. | |
387 | */ | |
388 | ||
a49a4af7 | 389 | static int rcu_torture_read_lock(void) __acquires(RCU) |
72e9bb54 PM |
390 | { |
391 | rcu_read_lock(); | |
392 | return 0; | |
393 | } | |
394 | ||
b2896d2e PM |
395 | static void rcu_read_delay(struct rcu_random_state *rrsp) |
396 | { | |
b8d57a76 JT |
397 | const unsigned long shortdelay_us = 200; |
398 | const unsigned long longdelay_ms = 50; | |
b2896d2e | 399 | |
b8d57a76 JT |
400 | /* We want a short delay sometimes to make a reader delay the grace |
401 | * period, and we want a long delay occasionally to trigger | |
402 | * force_quiescent_state. */ | |
b2896d2e | 403 | |
b8d57a76 JT |
404 | if (!(rcu_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) |
405 | mdelay(longdelay_ms); | |
406 | if (!(rcu_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) | |
407 | udelay(shortdelay_us); | |
e546f485 LJ |
408 | #ifdef CONFIG_PREEMPT |
409 | if (!preempt_count() && !(rcu_random(rrsp) % (nrealreaders * 20000))) | |
410 | preempt_schedule(); /* No QS if preempt_disable() in effect */ | |
411 | #endif | |
b2896d2e PM |
412 | } |
413 | ||
a49a4af7 | 414 | static void rcu_torture_read_unlock(int idx) __releases(RCU) |
72e9bb54 PM |
415 | { |
416 | rcu_read_unlock(); | |
417 | } | |
418 | ||
419 | static int rcu_torture_completed(void) | |
420 | { | |
421 | return rcu_batches_completed(); | |
422 | } | |
423 | ||
424 | static void | |
425 | rcu_torture_cb(struct rcu_head *p) | |
426 | { | |
427 | int i; | |
428 | struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); | |
429 | ||
c9d557c1 | 430 | if (fullstop != FULLSTOP_DONTSTOP) { |
72e9bb54 PM |
431 | /* Test is ending, just drop callbacks on the floor. */ |
432 | /* The next initialization will pick up the pieces. */ | |
433 | return; | |
434 | } | |
435 | i = rp->rtort_pipe_count; | |
436 | if (i > RCU_TORTURE_PIPE_LEN) | |
437 | i = RCU_TORTURE_PIPE_LEN; | |
438 | atomic_inc(&rcu_torture_wcount[i]); | |
439 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
440 | rp->rtort_mbtest = 0; | |
441 | rcu_torture_free(rp); | |
c701d5d9 | 442 | } else { |
0acc512c | 443 | cur_ops->deferred_free(rp); |
c701d5d9 | 444 | } |
72e9bb54 PM |
445 | } |
446 | ||
d9a3da06 PM |
447 | static int rcu_no_completed(void) |
448 | { | |
449 | return 0; | |
450 | } | |
451 | ||
72e9bb54 PM |
452 | static void rcu_torture_deferred_free(struct rcu_torture *p) |
453 | { | |
454 | call_rcu(&p->rtort_rcu, rcu_torture_cb); | |
455 | } | |
456 | ||
e3033736 JT |
457 | static void rcu_sync_torture_init(void) |
458 | { | |
459 | INIT_LIST_HEAD(&rcu_torture_removed); | |
460 | } | |
461 | ||
2ec1f2d9 | 462 | static struct rcu_torture_ops rcu_ops = { |
0acc512c | 463 | .init = rcu_sync_torture_init, |
0acc512c PM |
464 | .readlock = rcu_torture_read_lock, |
465 | .read_delay = rcu_read_delay, | |
466 | .readunlock = rcu_torture_read_unlock, | |
467 | .completed = rcu_torture_completed, | |
2ec1f2d9 | 468 | .deferred_free = rcu_torture_deferred_free, |
0acc512c | 469 | .sync = synchronize_rcu, |
2ec1f2d9 PM |
470 | .exp_sync = synchronize_rcu_expedited, |
471 | .call = call_rcu, | |
472 | .cb_barrier = rcu_barrier, | |
bf66f18e | 473 | .fqs = rcu_force_quiescent_state, |
d9a3da06 PM |
474 | .stats = NULL, |
475 | .irq_capable = 1, | |
8e8be45e | 476 | .can_boost = rcu_can_boost(), |
2ec1f2d9 | 477 | .name = "rcu" |
d9a3da06 PM |
478 | }; |
479 | ||
c32e0660 PM |
480 | /* |
481 | * Definitions for rcu_bh torture testing. | |
482 | */ | |
483 | ||
a49a4af7 | 484 | static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH) |
c32e0660 PM |
485 | { |
486 | rcu_read_lock_bh(); | |
487 | return 0; | |
488 | } | |
489 | ||
a49a4af7 | 490 | static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH) |
c32e0660 PM |
491 | { |
492 | rcu_read_unlock_bh(); | |
493 | } | |
494 | ||
495 | static int rcu_bh_torture_completed(void) | |
496 | { | |
497 | return rcu_batches_completed_bh(); | |
498 | } | |
499 | ||
500 | static void rcu_bh_torture_deferred_free(struct rcu_torture *p) | |
501 | { | |
502 | call_rcu_bh(&p->rtort_rcu, rcu_torture_cb); | |
503 | } | |
504 | ||
505 | static struct rcu_torture_ops rcu_bh_ops = { | |
2ec1f2d9 | 506 | .init = rcu_sync_torture_init, |
0acc512c PM |
507 | .readlock = rcu_bh_torture_read_lock, |
508 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
509 | .readunlock = rcu_bh_torture_read_unlock, | |
510 | .completed = rcu_bh_torture_completed, | |
511 | .deferred_free = rcu_bh_torture_deferred_free, | |
bdf2a436 | 512 | .sync = synchronize_rcu_bh, |
2ec1f2d9 | 513 | .exp_sync = synchronize_rcu_bh_expedited, |
fae4b54f | 514 | .call = call_rcu_bh, |
0acc512c | 515 | .cb_barrier = rcu_barrier_bh, |
bf66f18e | 516 | .fqs = rcu_bh_force_quiescent_state, |
0acc512c PM |
517 | .stats = NULL, |
518 | .irq_capable = 1, | |
519 | .name = "rcu_bh" | |
c32e0660 PM |
520 | }; |
521 | ||
b2896d2e PM |
522 | /* |
523 | * Definitions for srcu torture testing. | |
524 | */ | |
525 | ||
cda4dc81 | 526 | DEFINE_STATIC_SRCU(srcu_ctl); |
b2896d2e | 527 | |
012d3ca8 | 528 | static int srcu_torture_read_lock(void) __acquires(&srcu_ctl) |
b2896d2e PM |
529 | { |
530 | return srcu_read_lock(&srcu_ctl); | |
531 | } | |
532 | ||
533 | static void srcu_read_delay(struct rcu_random_state *rrsp) | |
534 | { | |
535 | long delay; | |
536 | const long uspertick = 1000000 / HZ; | |
537 | const long longdelay = 10; | |
538 | ||
539 | /* We want there to be long-running readers, but not all the time. */ | |
540 | ||
541 | delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick); | |
542 | if (!delay) | |
543 | schedule_timeout_interruptible(longdelay); | |
e546f485 LJ |
544 | else |
545 | rcu_read_delay(rrsp); | |
b2896d2e PM |
546 | } |
547 | ||
012d3ca8 | 548 | static void srcu_torture_read_unlock(int idx) __releases(&srcu_ctl) |
b2896d2e PM |
549 | { |
550 | srcu_read_unlock(&srcu_ctl, idx); | |
551 | } | |
552 | ||
553 | static int srcu_torture_completed(void) | |
554 | { | |
555 | return srcu_batches_completed(&srcu_ctl); | |
556 | } | |
557 | ||
9059c940 LJ |
558 | static void srcu_torture_deferred_free(struct rcu_torture *rp) |
559 | { | |
560 | call_srcu(&srcu_ctl, &rp->rtort_rcu, rcu_torture_cb); | |
561 | } | |
562 | ||
b772e1dd JT |
563 | static void srcu_torture_synchronize(void) |
564 | { | |
565 | synchronize_srcu(&srcu_ctl); | |
566 | } | |
567 | ||
e3f8d378 PM |
568 | static void srcu_torture_call(struct rcu_head *head, |
569 | void (*func)(struct rcu_head *head)) | |
570 | { | |
571 | call_srcu(&srcu_ctl, head, func); | |
572 | } | |
573 | ||
574 | static void srcu_torture_barrier(void) | |
575 | { | |
576 | srcu_barrier(&srcu_ctl); | |
577 | } | |
578 | ||
d1008950 | 579 | static void srcu_torture_stats(char *page) |
b2896d2e | 580 | { |
b2896d2e PM |
581 | int cpu; |
582 | int idx = srcu_ctl.completed & 0x1; | |
583 | ||
d1008950 | 584 | page += sprintf(page, "%s%s per-CPU(idx=%d):", |
b2896d2e PM |
585 | torture_type, TORTURE_FLAG, idx); |
586 | for_each_possible_cpu(cpu) { | |
d1008950 | 587 | page += sprintf(page, " %d(%lu,%lu)", cpu, |
b2896d2e PM |
588 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[!idx], |
589 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[idx]); | |
590 | } | |
d1008950 | 591 | sprintf(page, "\n"); |
b2896d2e PM |
592 | } |
593 | ||
2ec1f2d9 PM |
594 | static void srcu_torture_synchronize_expedited(void) |
595 | { | |
596 | synchronize_srcu_expedited(&srcu_ctl); | |
597 | } | |
598 | ||
b2896d2e | 599 | static struct rcu_torture_ops srcu_ops = { |
cda4dc81 | 600 | .init = rcu_sync_torture_init, |
0acc512c PM |
601 | .readlock = srcu_torture_read_lock, |
602 | .read_delay = srcu_read_delay, | |
603 | .readunlock = srcu_torture_read_unlock, | |
604 | .completed = srcu_torture_completed, | |
9059c940 | 605 | .deferred_free = srcu_torture_deferred_free, |
0acc512c | 606 | .sync = srcu_torture_synchronize, |
2ec1f2d9 | 607 | .exp_sync = srcu_torture_synchronize_expedited, |
e3f8d378 PM |
608 | .call = srcu_torture_call, |
609 | .cb_barrier = srcu_torture_barrier, | |
0acc512c PM |
610 | .stats = srcu_torture_stats, |
611 | .name = "srcu" | |
b2896d2e PM |
612 | }; |
613 | ||
4b6c2cca JT |
614 | /* |
615 | * Definitions for sched torture testing. | |
616 | */ | |
617 | ||
618 | static int sched_torture_read_lock(void) | |
619 | { | |
620 | preempt_disable(); | |
621 | return 0; | |
622 | } | |
623 | ||
624 | static void sched_torture_read_unlock(int idx) | |
625 | { | |
626 | preempt_enable(); | |
627 | } | |
628 | ||
2326974d PM |
629 | static void rcu_sched_torture_deferred_free(struct rcu_torture *p) |
630 | { | |
631 | call_rcu_sched(&p->rtort_rcu, rcu_torture_cb); | |
632 | } | |
633 | ||
4b6c2cca | 634 | static struct rcu_torture_ops sched_ops = { |
0acc512c | 635 | .init = rcu_sync_torture_init, |
0acc512c PM |
636 | .readlock = sched_torture_read_lock, |
637 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
638 | .readunlock = sched_torture_read_unlock, | |
d9a3da06 | 639 | .completed = rcu_no_completed, |
0acc512c | 640 | .deferred_free = rcu_sched_torture_deferred_free, |
bdf2a436 | 641 | .sync = synchronize_sched, |
2ec1f2d9 PM |
642 | .exp_sync = synchronize_sched_expedited, |
643 | .call = call_rcu_sched, | |
0acc512c | 644 | .cb_barrier = rcu_barrier_sched, |
bf66f18e | 645 | .fqs = rcu_sched_force_quiescent_state, |
0acc512c PM |
646 | .stats = NULL, |
647 | .irq_capable = 1, | |
648 | .name = "sched" | |
4b6c2cca JT |
649 | }; |
650 | ||
8e8be45e PM |
651 | /* |
652 | * RCU torture priority-boost testing. Runs one real-time thread per | |
653 | * CPU for moderate bursts, repeatedly registering RCU callbacks and | |
654 | * spinning waiting for them to be invoked. If a given callback takes | |
655 | * too long to be invoked, we assume that priority inversion has occurred. | |
656 | */ | |
657 | ||
658 | struct rcu_boost_inflight { | |
659 | struct rcu_head rcu; | |
660 | int inflight; | |
661 | }; | |
662 | ||
663 | static void rcu_torture_boost_cb(struct rcu_head *head) | |
664 | { | |
665 | struct rcu_boost_inflight *rbip = | |
666 | container_of(head, struct rcu_boost_inflight, rcu); | |
667 | ||
668 | smp_mb(); /* Ensure RCU-core accesses precede clearing ->inflight */ | |
669 | rbip->inflight = 0; | |
670 | } | |
671 | ||
672 | static int rcu_torture_boost(void *arg) | |
673 | { | |
674 | unsigned long call_rcu_time; | |
675 | unsigned long endtime; | |
676 | unsigned long oldstarttime; | |
677 | struct rcu_boost_inflight rbi = { .inflight = 0 }; | |
678 | struct sched_param sp; | |
679 | ||
680 | VERBOSE_PRINTK_STRING("rcu_torture_boost started"); | |
681 | ||
682 | /* Set real-time priority. */ | |
683 | sp.sched_priority = 1; | |
684 | if (sched_setscheduler(current, SCHED_FIFO, &sp) < 0) { | |
685 | VERBOSE_PRINTK_STRING("rcu_torture_boost RT prio failed!"); | |
686 | n_rcu_torture_boost_rterror++; | |
687 | } | |
688 | ||
561190e3 | 689 | init_rcu_head_on_stack(&rbi.rcu); |
8e8be45e PM |
690 | /* Each pass through the following loop does one boost-test cycle. */ |
691 | do { | |
692 | /* Wait for the next test interval. */ | |
693 | oldstarttime = boost_starttime; | |
93898fb1 | 694 | while (ULONG_CMP_LT(jiffies, oldstarttime)) { |
0e11c8e8 | 695 | schedule_timeout_interruptible(oldstarttime - jiffies); |
8e8be45e PM |
696 | rcu_stutter_wait("rcu_torture_boost"); |
697 | if (kthread_should_stop() || | |
698 | fullstop != FULLSTOP_DONTSTOP) | |
699 | goto checkwait; | |
700 | } | |
701 | ||
702 | /* Do one boost-test interval. */ | |
703 | endtime = oldstarttime + test_boost_duration * HZ; | |
704 | call_rcu_time = jiffies; | |
93898fb1 | 705 | while (ULONG_CMP_LT(jiffies, endtime)) { |
8e8be45e PM |
706 | /* If we don't have a callback in flight, post one. */ |
707 | if (!rbi.inflight) { | |
708 | smp_mb(); /* RCU core before ->inflight = 1. */ | |
709 | rbi.inflight = 1; | |
710 | call_rcu(&rbi.rcu, rcu_torture_boost_cb); | |
711 | if (jiffies - call_rcu_time > | |
712 | test_boost_duration * HZ - HZ / 2) { | |
713 | VERBOSE_PRINTK_STRING("rcu_torture_boost boosting failed"); | |
714 | n_rcu_torture_boost_failure++; | |
715 | } | |
716 | call_rcu_time = jiffies; | |
717 | } | |
718 | cond_resched(); | |
719 | rcu_stutter_wait("rcu_torture_boost"); | |
720 | if (kthread_should_stop() || | |
721 | fullstop != FULLSTOP_DONTSTOP) | |
722 | goto checkwait; | |
723 | } | |
724 | ||
725 | /* | |
726 | * Set the start time of the next test interval. | |
727 | * Yes, this is vulnerable to long delays, but such | |
728 | * delays simply cause a false negative for the next | |
729 | * interval. Besides, we are running at RT priority, | |
730 | * so delays should be relatively rare. | |
731 | */ | |
ab8f11e5 PM |
732 | while (oldstarttime == boost_starttime && |
733 | !kthread_should_stop()) { | |
8e8be45e PM |
734 | if (mutex_trylock(&boost_mutex)) { |
735 | boost_starttime = jiffies + | |
736 | test_boost_interval * HZ; | |
737 | n_rcu_torture_boosts++; | |
738 | mutex_unlock(&boost_mutex); | |
739 | break; | |
740 | } | |
741 | schedule_timeout_uninterruptible(1); | |
742 | } | |
743 | ||
744 | /* Go do the stutter. */ | |
745 | checkwait: rcu_stutter_wait("rcu_torture_boost"); | |
746 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
747 | ||
748 | /* Clean up and exit. */ | |
749 | VERBOSE_PRINTK_STRING("rcu_torture_boost task stopping"); | |
750 | rcutorture_shutdown_absorb("rcu_torture_boost"); | |
751 | while (!kthread_should_stop() || rbi.inflight) | |
752 | schedule_timeout_uninterruptible(1); | |
753 | smp_mb(); /* order accesses to ->inflight before stack-frame death. */ | |
9d68197c | 754 | destroy_rcu_head_on_stack(&rbi.rcu); |
8e8be45e PM |
755 | return 0; |
756 | } | |
757 | ||
bf66f18e PM |
758 | /* |
759 | * RCU torture force-quiescent-state kthread. Repeatedly induces | |
760 | * bursts of calls to force_quiescent_state(), increasing the probability | |
761 | * of occurrence of some important types of race conditions. | |
762 | */ | |
763 | static int | |
764 | rcu_torture_fqs(void *arg) | |
765 | { | |
766 | unsigned long fqs_resume_time; | |
767 | int fqs_burst_remaining; | |
768 | ||
769 | VERBOSE_PRINTK_STRING("rcu_torture_fqs task started"); | |
770 | do { | |
771 | fqs_resume_time = jiffies + fqs_stutter * HZ; | |
93898fb1 PM |
772 | while (ULONG_CMP_LT(jiffies, fqs_resume_time) && |
773 | !kthread_should_stop()) { | |
bf66f18e PM |
774 | schedule_timeout_interruptible(1); |
775 | } | |
776 | fqs_burst_remaining = fqs_duration; | |
93898fb1 PM |
777 | while (fqs_burst_remaining > 0 && |
778 | !kthread_should_stop()) { | |
bf66f18e PM |
779 | cur_ops->fqs(); |
780 | udelay(fqs_holdoff); | |
781 | fqs_burst_remaining -= fqs_holdoff; | |
782 | } | |
783 | rcu_stutter_wait("rcu_torture_fqs"); | |
784 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
785 | VERBOSE_PRINTK_STRING("rcu_torture_fqs task stopping"); | |
786 | rcutorture_shutdown_absorb("rcu_torture_fqs"); | |
787 | while (!kthread_should_stop()) | |
788 | schedule_timeout_uninterruptible(1); | |
789 | return 0; | |
790 | } | |
791 | ||
a241ec65 PM |
792 | /* |
793 | * RCU torture writer kthread. Repeatedly substitutes a new structure | |
794 | * for that pointed to by rcu_torture_current, freeing the old structure | |
795 | * after a series of grace periods (the "pipeline"). | |
796 | */ | |
797 | static int | |
798 | rcu_torture_writer(void *arg) | |
799 | { | |
2ec1f2d9 | 800 | bool exp; |
a241ec65 | 801 | int i; |
a241ec65 | 802 | struct rcu_torture *rp; |
2ec1f2d9 | 803 | struct rcu_torture *rp1; |
a241ec65 PM |
804 | struct rcu_torture *old_rp; |
805 | static DEFINE_RCU_RANDOM(rand); | |
806 | ||
807 | VERBOSE_PRINTK_STRING("rcu_torture_writer task started"); | |
dbdf65b1 IM |
808 | set_user_nice(current, 19); |
809 | ||
a241ec65 PM |
810 | do { |
811 | schedule_timeout_uninterruptible(1); | |
a71fca58 PM |
812 | rp = rcu_torture_alloc(); |
813 | if (rp == NULL) | |
a241ec65 PM |
814 | continue; |
815 | rp->rtort_pipe_count = 0; | |
816 | udelay(rcu_random(&rand) & 0x3ff); | |
0ddea0ea PM |
817 | old_rp = rcu_dereference_check(rcu_torture_current, |
818 | current == writer_task); | |
996417d2 | 819 | rp->rtort_mbtest = 1; |
a241ec65 | 820 | rcu_assign_pointer(rcu_torture_current, rp); |
9b2619af | 821 | smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */ |
c8e5b163 | 822 | if (old_rp) { |
a241ec65 PM |
823 | i = old_rp->rtort_pipe_count; |
824 | if (i > RCU_TORTURE_PIPE_LEN) | |
825 | i = RCU_TORTURE_PIPE_LEN; | |
826 | atomic_inc(&rcu_torture_wcount[i]); | |
827 | old_rp->rtort_pipe_count++; | |
2ec1f2d9 PM |
828 | if (gp_normal == gp_exp) |
829 | exp = !!(rcu_random(&rand) & 0x80); | |
830 | else | |
831 | exp = gp_exp; | |
832 | if (!exp) { | |
833 | cur_ops->deferred_free(old_rp); | |
834 | } else { | |
835 | cur_ops->exp_sync(); | |
836 | list_add(&old_rp->rtort_free, | |
837 | &rcu_torture_removed); | |
838 | list_for_each_entry_safe(rp, rp1, | |
839 | &rcu_torture_removed, | |
840 | rtort_free) { | |
841 | i = rp->rtort_pipe_count; | |
842 | if (i > RCU_TORTURE_PIPE_LEN) | |
843 | i = RCU_TORTURE_PIPE_LEN; | |
844 | atomic_inc(&rcu_torture_wcount[i]); | |
845 | if (++rp->rtort_pipe_count >= | |
846 | RCU_TORTURE_PIPE_LEN) { | |
847 | rp->rtort_mbtest = 0; | |
848 | list_del(&rp->rtort_free); | |
849 | rcu_torture_free(rp); | |
850 | } | |
851 | } | |
852 | } | |
a241ec65 | 853 | } |
4a298656 | 854 | rcutorture_record_progress(++rcu_torture_current_version); |
c9d557c1 PM |
855 | rcu_stutter_wait("rcu_torture_writer"); |
856 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
a241ec65 | 857 | VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping"); |
c9d557c1 PM |
858 | rcutorture_shutdown_absorb("rcu_torture_writer"); |
859 | while (!kthread_should_stop()) | |
a241ec65 PM |
860 | schedule_timeout_uninterruptible(1); |
861 | return 0; | |
862 | } | |
863 | ||
b772e1dd JT |
864 | /* |
865 | * RCU torture fake writer kthread. Repeatedly calls sync, with a random | |
866 | * delay between calls. | |
867 | */ | |
868 | static int | |
869 | rcu_torture_fakewriter(void *arg) | |
870 | { | |
871 | DEFINE_RCU_RANDOM(rand); | |
872 | ||
873 | VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task started"); | |
874 | set_user_nice(current, 19); | |
875 | ||
876 | do { | |
877 | schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10); | |
878 | udelay(rcu_random(&rand) & 0x3ff); | |
72472a02 | 879 | if (cur_ops->cb_barrier != NULL && |
2ec1f2d9 | 880 | rcu_random(&rand) % (nfakewriters * 8) == 0) { |
72472a02 | 881 | cur_ops->cb_barrier(); |
2ec1f2d9 PM |
882 | } else if (gp_normal == gp_exp) { |
883 | if (rcu_random(&rand) & 0x80) | |
884 | cur_ops->sync(); | |
885 | else | |
886 | cur_ops->exp_sync(); | |
887 | } else if (gp_normal) { | |
72472a02 | 888 | cur_ops->sync(); |
2ec1f2d9 PM |
889 | } else { |
890 | cur_ops->exp_sync(); | |
891 | } | |
c9d557c1 PM |
892 | rcu_stutter_wait("rcu_torture_fakewriter"); |
893 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
b772e1dd JT |
894 | |
895 | VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping"); | |
c9d557c1 PM |
896 | rcutorture_shutdown_absorb("rcu_torture_fakewriter"); |
897 | while (!kthread_should_stop()) | |
b772e1dd JT |
898 | schedule_timeout_uninterruptible(1); |
899 | return 0; | |
900 | } | |
901 | ||
91afaf30 PM |
902 | void rcutorture_trace_dump(void) |
903 | { | |
904 | static atomic_t beenhere = ATOMIC_INIT(0); | |
905 | ||
906 | if (atomic_read(&beenhere)) | |
907 | return; | |
908 | if (atomic_xchg(&beenhere, 1) != 0) | |
909 | return; | |
91afaf30 PM |
910 | ftrace_dump(DUMP_ALL); |
911 | } | |
912 | ||
0729fbf3 PM |
913 | /* |
914 | * RCU torture reader from timer handler. Dereferences rcu_torture_current, | |
915 | * incrementing the corresponding element of the pipeline array. The | |
916 | * counter in the element should never be greater than 1, otherwise, the | |
917 | * RCU implementation is broken. | |
918 | */ | |
919 | static void rcu_torture_timer(unsigned long unused) | |
920 | { | |
921 | int idx; | |
922 | int completed; | |
52494535 | 923 | int completed_end; |
0729fbf3 PM |
924 | static DEFINE_RCU_RANDOM(rand); |
925 | static DEFINE_SPINLOCK(rand_lock); | |
926 | struct rcu_torture *p; | |
927 | int pipe_count; | |
52494535 | 928 | unsigned long long ts; |
0729fbf3 PM |
929 | |
930 | idx = cur_ops->readlock(); | |
931 | completed = cur_ops->completed(); | |
e4aa0da3 | 932 | ts = rcu_trace_clock_local(); |
632ee200 | 933 | p = rcu_dereference_check(rcu_torture_current, |
632ee200 PM |
934 | rcu_read_lock_bh_held() || |
935 | rcu_read_lock_sched_held() || | |
936 | srcu_read_lock_held(&srcu_ctl)); | |
0729fbf3 PM |
937 | if (p == NULL) { |
938 | /* Leave because rcu_torture_writer is not yet underway */ | |
939 | cur_ops->readunlock(idx); | |
940 | return; | |
941 | } | |
942 | if (p->rtort_mbtest == 0) | |
943 | atomic_inc(&n_rcu_torture_mberror); | |
944 | spin_lock(&rand_lock); | |
0acc512c | 945 | cur_ops->read_delay(&rand); |
0729fbf3 PM |
946 | n_rcu_torture_timers++; |
947 | spin_unlock(&rand_lock); | |
948 | preempt_disable(); | |
949 | pipe_count = p->rtort_pipe_count; | |
950 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { | |
951 | /* Should not happen, but... */ | |
952 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
953 | } | |
52494535 PM |
954 | completed_end = cur_ops->completed(); |
955 | if (pipe_count > 1) { | |
52494535 PM |
956 | do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, ts, |
957 | completed, completed_end); | |
91afaf30 | 958 | rcutorture_trace_dump(); |
52494535 | 959 | } |
dd17c8f7 | 960 | __this_cpu_inc(rcu_torture_count[pipe_count]); |
52494535 | 961 | completed = completed_end - completed; |
0729fbf3 PM |
962 | if (completed > RCU_TORTURE_PIPE_LEN) { |
963 | /* Should not happen, but... */ | |
964 | completed = RCU_TORTURE_PIPE_LEN; | |
965 | } | |
dd17c8f7 | 966 | __this_cpu_inc(rcu_torture_batch[completed]); |
0729fbf3 PM |
967 | preempt_enable(); |
968 | cur_ops->readunlock(idx); | |
969 | } | |
970 | ||
a241ec65 PM |
971 | /* |
972 | * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, | |
973 | * incrementing the corresponding element of the pipeline array. The | |
974 | * counter in the element should never be greater than 1, otherwise, the | |
975 | * RCU implementation is broken. | |
976 | */ | |
977 | static int | |
978 | rcu_torture_reader(void *arg) | |
979 | { | |
980 | int completed; | |
52494535 | 981 | int completed_end; |
72e9bb54 | 982 | int idx; |
a241ec65 PM |
983 | DEFINE_RCU_RANDOM(rand); |
984 | struct rcu_torture *p; | |
985 | int pipe_count; | |
0729fbf3 | 986 | struct timer_list t; |
52494535 | 987 | unsigned long long ts; |
a241ec65 PM |
988 | |
989 | VERBOSE_PRINTK_STRING("rcu_torture_reader task started"); | |
dbdf65b1 | 990 | set_user_nice(current, 19); |
0acc512c | 991 | if (irqreader && cur_ops->irq_capable) |
0729fbf3 | 992 | setup_timer_on_stack(&t, rcu_torture_timer, 0); |
dbdf65b1 | 993 | |
a241ec65 | 994 | do { |
0acc512c | 995 | if (irqreader && cur_ops->irq_capable) { |
0729fbf3 | 996 | if (!timer_pending(&t)) |
6155fec9 | 997 | mod_timer(&t, jiffies + 1); |
0729fbf3 | 998 | } |
72e9bb54 PM |
999 | idx = cur_ops->readlock(); |
1000 | completed = cur_ops->completed(); | |
e4aa0da3 | 1001 | ts = rcu_trace_clock_local(); |
632ee200 | 1002 | p = rcu_dereference_check(rcu_torture_current, |
632ee200 PM |
1003 | rcu_read_lock_bh_held() || |
1004 | rcu_read_lock_sched_held() || | |
1005 | srcu_read_lock_held(&srcu_ctl)); | |
a241ec65 PM |
1006 | if (p == NULL) { |
1007 | /* Wait for rcu_torture_writer to get underway */ | |
72e9bb54 | 1008 | cur_ops->readunlock(idx); |
a241ec65 PM |
1009 | schedule_timeout_interruptible(HZ); |
1010 | continue; | |
1011 | } | |
996417d2 PM |
1012 | if (p->rtort_mbtest == 0) |
1013 | atomic_inc(&n_rcu_torture_mberror); | |
0acc512c | 1014 | cur_ops->read_delay(&rand); |
a241ec65 PM |
1015 | preempt_disable(); |
1016 | pipe_count = p->rtort_pipe_count; | |
1017 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { | |
1018 | /* Should not happen, but... */ | |
1019 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
1020 | } | |
52494535 PM |
1021 | completed_end = cur_ops->completed(); |
1022 | if (pipe_count > 1) { | |
52494535 PM |
1023 | do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, |
1024 | ts, completed, completed_end); | |
91afaf30 | 1025 | rcutorture_trace_dump(); |
52494535 | 1026 | } |
dd17c8f7 | 1027 | __this_cpu_inc(rcu_torture_count[pipe_count]); |
52494535 | 1028 | completed = completed_end - completed; |
a241ec65 PM |
1029 | if (completed > RCU_TORTURE_PIPE_LEN) { |
1030 | /* Should not happen, but... */ | |
1031 | completed = RCU_TORTURE_PIPE_LEN; | |
1032 | } | |
dd17c8f7 | 1033 | __this_cpu_inc(rcu_torture_batch[completed]); |
a241ec65 | 1034 | preempt_enable(); |
72e9bb54 | 1035 | cur_ops->readunlock(idx); |
a241ec65 | 1036 | schedule(); |
c9d557c1 PM |
1037 | rcu_stutter_wait("rcu_torture_reader"); |
1038 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
a241ec65 | 1039 | VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping"); |
c9d557c1 | 1040 | rcutorture_shutdown_absorb("rcu_torture_reader"); |
0acc512c | 1041 | if (irqreader && cur_ops->irq_capable) |
0729fbf3 | 1042 | del_timer_sync(&t); |
c9d557c1 | 1043 | while (!kthread_should_stop()) |
a241ec65 PM |
1044 | schedule_timeout_uninterruptible(1); |
1045 | return 0; | |
1046 | } | |
1047 | ||
1048 | /* | |
1049 | * Create an RCU-torture statistics message in the specified buffer. | |
1050 | */ | |
d1008950 | 1051 | static void |
a241ec65 PM |
1052 | rcu_torture_printk(char *page) |
1053 | { | |
a241ec65 PM |
1054 | int cpu; |
1055 | int i; | |
1056 | long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
1057 | long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
1058 | ||
0a945022 | 1059 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
1060 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
1061 | pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i]; | |
1062 | batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i]; | |
1063 | } | |
1064 | } | |
1065 | for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) { | |
1066 | if (pipesummary[i] != 0) | |
1067 | break; | |
1068 | } | |
d1008950 CG |
1069 | page += sprintf(page, "%s%s ", torture_type, TORTURE_FLAG); |
1070 | page += sprintf(page, | |
5cf05ad7 | 1071 | "rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ", |
a241ec65 PM |
1072 | rcu_torture_current, |
1073 | rcu_torture_current_version, | |
1074 | list_empty(&rcu_torture_freelist), | |
1075 | atomic_read(&n_rcu_torture_alloc), | |
1076 | atomic_read(&n_rcu_torture_alloc_fail), | |
5cf05ad7 | 1077 | atomic_read(&n_rcu_torture_free)); |
d1008950 | 1078 | page += sprintf(page, "rtmbe: %d rtbke: %ld rtbre: %ld ", |
0729fbf3 | 1079 | atomic_read(&n_rcu_torture_mberror), |
8e8be45e | 1080 | n_rcu_torture_boost_ktrerror, |
5cf05ad7 | 1081 | n_rcu_torture_boost_rterror); |
d1008950 | 1082 | page += sprintf(page, "rtbf: %ld rtb: %ld nt: %ld ", |
8e8be45e PM |
1083 | n_rcu_torture_boost_failure, |
1084 | n_rcu_torture_boosts, | |
5cf05ad7 | 1085 | n_rcu_torture_timers); |
d1008950 | 1086 | page += sprintf(page, |
13dbf914 PM |
1087 | "onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ", |
1088 | n_online_successes, n_online_attempts, | |
1089 | n_offline_successes, n_offline_attempts, | |
1090 | min_online, max_online, | |
1091 | min_offline, max_offline, | |
1092 | sum_online, sum_offline, HZ); | |
d1008950 | 1093 | page += sprintf(page, "barrier: %ld/%ld:%ld", |
fae4b54f PM |
1094 | n_barrier_successes, |
1095 | n_barrier_attempts, | |
1096 | n_rcu_torture_barrier_error); | |
d1008950 | 1097 | page += sprintf(page, "\n%s%s ", torture_type, TORTURE_FLAG); |
8e8be45e | 1098 | if (atomic_read(&n_rcu_torture_mberror) != 0 || |
fae4b54f | 1099 | n_rcu_torture_barrier_error != 0 || |
8e8be45e PM |
1100 | n_rcu_torture_boost_ktrerror != 0 || |
1101 | n_rcu_torture_boost_rterror != 0 || | |
fae4b54f PM |
1102 | n_rcu_torture_boost_failure != 0 || |
1103 | i > 1) { | |
d1008950 | 1104 | page += sprintf(page, "!!! "); |
996417d2 | 1105 | atomic_inc(&n_rcu_torture_error); |
5af970a4 | 1106 | WARN_ON_ONCE(1); |
996417d2 | 1107 | } |
d1008950 | 1108 | page += sprintf(page, "Reader Pipe: "); |
a241ec65 | 1109 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
d1008950 CG |
1110 | page += sprintf(page, " %ld", pipesummary[i]); |
1111 | page += sprintf(page, "\n%s%s ", torture_type, TORTURE_FLAG); | |
1112 | page += sprintf(page, "Reader Batch: "); | |
72e9bb54 | 1113 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
d1008950 CG |
1114 | page += sprintf(page, " %ld", batchsummary[i]); |
1115 | page += sprintf(page, "\n%s%s ", torture_type, TORTURE_FLAG); | |
1116 | page += sprintf(page, "Free-Block Circulation: "); | |
a241ec65 | 1117 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
d1008950 | 1118 | page += sprintf(page, " %d", |
a241ec65 PM |
1119 | atomic_read(&rcu_torture_wcount[i])); |
1120 | } | |
d1008950 | 1121 | page += sprintf(page, "\n"); |
c8e5b163 | 1122 | if (cur_ops->stats) |
d1008950 | 1123 | cur_ops->stats(page); |
a241ec65 PM |
1124 | } |
1125 | ||
1126 | /* | |
1127 | * Print torture statistics. Caller must ensure that there is only | |
1128 | * one call to this function at a given time!!! This is normally | |
1129 | * accomplished by relying on the module system to only have one copy | |
1130 | * of the module loaded, and then by giving the rcu_torture_stats | |
1131 | * kthread full control (or the init/cleanup functions when rcu_torture_stats | |
1132 | * thread is not running). | |
1133 | */ | |
1134 | static void | |
1135 | rcu_torture_stats_print(void) | |
1136 | { | |
d1008950 CG |
1137 | int size = nr_cpu_ids * 200 + 8192; |
1138 | char *buf; | |
a241ec65 | 1139 | |
d1008950 CG |
1140 | buf = kmalloc(size, GFP_KERNEL); |
1141 | if (!buf) { | |
1142 | pr_err("rcu-torture: Out of memory, need: %d", size); | |
1143 | return; | |
1144 | } | |
1145 | rcu_torture_printk(buf); | |
1146 | pr_alert("%s", buf); | |
1147 | kfree(buf); | |
a241ec65 PM |
1148 | } |
1149 | ||
1150 | /* | |
1151 | * Periodically prints torture statistics, if periodic statistics printing | |
1152 | * was specified via the stat_interval module parameter. | |
1153 | * | |
1154 | * No need to worry about fullstop here, since this one doesn't reference | |
1155 | * volatile state or register callbacks. | |
1156 | */ | |
1157 | static int | |
1158 | rcu_torture_stats(void *arg) | |
1159 | { | |
1160 | VERBOSE_PRINTK_STRING("rcu_torture_stats task started"); | |
1161 | do { | |
1162 | schedule_timeout_interruptible(stat_interval * HZ); | |
1163 | rcu_torture_stats_print(); | |
c9d557c1 PM |
1164 | rcutorture_shutdown_absorb("rcu_torture_stats"); |
1165 | } while (!kthread_should_stop()); | |
a241ec65 PM |
1166 | VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping"); |
1167 | return 0; | |
1168 | } | |
1169 | ||
d84f5203 SV |
1170 | static int rcu_idle_cpu; /* Force all torture tasks off this CPU */ |
1171 | ||
1172 | /* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case | |
1173 | * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs. | |
1174 | */ | |
b2896d2e | 1175 | static void rcu_torture_shuffle_tasks(void) |
d84f5203 | 1176 | { |
d84f5203 SV |
1177 | int i; |
1178 | ||
73d0a4b1 | 1179 | cpumask_setall(shuffle_tmp_mask); |
86ef5c9a | 1180 | get_online_cpus(); |
d84f5203 SV |
1181 | |
1182 | /* No point in shuffling if there is only one online CPU (ex: UP) */ | |
c9d557c1 PM |
1183 | if (num_online_cpus() == 1) { |
1184 | put_online_cpus(); | |
1185 | return; | |
1186 | } | |
d84f5203 SV |
1187 | |
1188 | if (rcu_idle_cpu != -1) | |
73d0a4b1 | 1189 | cpumask_clear_cpu(rcu_idle_cpu, shuffle_tmp_mask); |
d84f5203 | 1190 | |
73d0a4b1 | 1191 | set_cpus_allowed_ptr(current, shuffle_tmp_mask); |
d84f5203 | 1192 | |
c8e5b163 | 1193 | if (reader_tasks) { |
d84f5203 SV |
1194 | for (i = 0; i < nrealreaders; i++) |
1195 | if (reader_tasks[i]) | |
f70316da | 1196 | set_cpus_allowed_ptr(reader_tasks[i], |
73d0a4b1 | 1197 | shuffle_tmp_mask); |
d84f5203 | 1198 | } |
c8e5b163 | 1199 | if (fakewriter_tasks) { |
b772e1dd JT |
1200 | for (i = 0; i < nfakewriters; i++) |
1201 | if (fakewriter_tasks[i]) | |
f70316da | 1202 | set_cpus_allowed_ptr(fakewriter_tasks[i], |
73d0a4b1 | 1203 | shuffle_tmp_mask); |
b772e1dd | 1204 | } |
d84f5203 | 1205 | if (writer_task) |
73d0a4b1 | 1206 | set_cpus_allowed_ptr(writer_task, shuffle_tmp_mask); |
d84f5203 | 1207 | if (stats_task) |
73d0a4b1 | 1208 | set_cpus_allowed_ptr(stats_task, shuffle_tmp_mask); |
0e11c8e8 PM |
1209 | if (stutter_task) |
1210 | set_cpus_allowed_ptr(stutter_task, shuffle_tmp_mask); | |
1211 | if (fqs_task) | |
1212 | set_cpus_allowed_ptr(fqs_task, shuffle_tmp_mask); | |
1213 | if (shutdown_task) | |
1214 | set_cpus_allowed_ptr(shutdown_task, shuffle_tmp_mask); | |
1215 | #ifdef CONFIG_HOTPLUG_CPU | |
1216 | if (onoff_task) | |
1217 | set_cpus_allowed_ptr(onoff_task, shuffle_tmp_mask); | |
1218 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
1219 | if (stall_task) | |
1220 | set_cpus_allowed_ptr(stall_task, shuffle_tmp_mask); | |
1221 | if (barrier_cbs_tasks) | |
1222 | for (i = 0; i < n_barrier_cbs; i++) | |
1223 | if (barrier_cbs_tasks[i]) | |
1224 | set_cpus_allowed_ptr(barrier_cbs_tasks[i], | |
1225 | shuffle_tmp_mask); | |
1226 | if (barrier_task) | |
1227 | set_cpus_allowed_ptr(barrier_task, shuffle_tmp_mask); | |
d84f5203 SV |
1228 | |
1229 | if (rcu_idle_cpu == -1) | |
1230 | rcu_idle_cpu = num_online_cpus() - 1; | |
1231 | else | |
1232 | rcu_idle_cpu--; | |
1233 | ||
86ef5c9a | 1234 | put_online_cpus(); |
d84f5203 SV |
1235 | } |
1236 | ||
1237 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the | |
1238 | * system to become idle at a time and cut off its timer ticks. This is meant | |
1239 | * to test the support for such tickless idle CPU in RCU. | |
1240 | */ | |
1241 | static int | |
1242 | rcu_torture_shuffle(void *arg) | |
1243 | { | |
1244 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started"); | |
1245 | do { | |
1246 | schedule_timeout_interruptible(shuffle_interval * HZ); | |
1247 | rcu_torture_shuffle_tasks(); | |
c9d557c1 PM |
1248 | rcutorture_shutdown_absorb("rcu_torture_shuffle"); |
1249 | } while (!kthread_should_stop()); | |
d84f5203 SV |
1250 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping"); |
1251 | return 0; | |
1252 | } | |
1253 | ||
d120f65f PM |
1254 | /* Cause the rcutorture test to "stutter", starting and stopping all |
1255 | * threads periodically. | |
1256 | */ | |
1257 | static int | |
1258 | rcu_torture_stutter(void *arg) | |
1259 | { | |
1260 | VERBOSE_PRINTK_STRING("rcu_torture_stutter task started"); | |
1261 | do { | |
1262 | schedule_timeout_interruptible(stutter * HZ); | |
1263 | stutter_pause_test = 1; | |
c9d557c1 | 1264 | if (!kthread_should_stop()) |
d120f65f PM |
1265 | schedule_timeout_interruptible(stutter * HZ); |
1266 | stutter_pause_test = 0; | |
c9d557c1 PM |
1267 | rcutorture_shutdown_absorb("rcu_torture_stutter"); |
1268 | } while (!kthread_should_stop()); | |
d120f65f PM |
1269 | VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping"); |
1270 | return 0; | |
1271 | } | |
1272 | ||
95c38322 | 1273 | static inline void |
e66c33d5 | 1274 | rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag) |
95c38322 | 1275 | { |
2caa1e44 PM |
1276 | pr_alert("%s" TORTURE_FLAG |
1277 | "--- %s: nreaders=%d nfakewriters=%d " | |
1278 | "stat_interval=%d verbose=%d test_no_idle_hz=%d " | |
1279 | "shuffle_interval=%d stutter=%d irqreader=%d " | |
1280 | "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d " | |
1281 | "test_boost=%d/%d test_boost_interval=%d " | |
1282 | "test_boost_duration=%d shutdown_secs=%d " | |
67afeed2 PM |
1283 | "stall_cpu=%d stall_cpu_holdoff=%d " |
1284 | "n_barrier_cbs=%d " | |
2caa1e44 PM |
1285 | "onoff_interval=%d onoff_holdoff=%d\n", |
1286 | torture_type, tag, nrealreaders, nfakewriters, | |
1287 | stat_interval, verbose, test_no_idle_hz, shuffle_interval, | |
1288 | stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter, | |
1289 | test_boost, cur_ops->can_boost, | |
1290 | test_boost_interval, test_boost_duration, shutdown_secs, | |
67afeed2 PM |
1291 | stall_cpu, stall_cpu_holdoff, |
1292 | n_barrier_cbs, | |
2caa1e44 | 1293 | onoff_interval, onoff_holdoff); |
95c38322 PM |
1294 | } |
1295 | ||
8e8be45e | 1296 | static struct notifier_block rcutorture_shutdown_nb = { |
343e9099 PM |
1297 | .notifier_call = rcutorture_shutdown_notify, |
1298 | }; | |
1299 | ||
8e8be45e PM |
1300 | static void rcutorture_booster_cleanup(int cpu) |
1301 | { | |
1302 | struct task_struct *t; | |
1303 | ||
1304 | if (boost_tasks[cpu] == NULL) | |
1305 | return; | |
1306 | mutex_lock(&boost_mutex); | |
1307 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_boost task"); | |
1308 | t = boost_tasks[cpu]; | |
1309 | boost_tasks[cpu] = NULL; | |
1310 | mutex_unlock(&boost_mutex); | |
1311 | ||
1312 | /* This must be outside of the mutex, otherwise deadlock! */ | |
1313 | kthread_stop(t); | |
37e377d2 | 1314 | boost_tasks[cpu] = NULL; |
8e8be45e PM |
1315 | } |
1316 | ||
1317 | static int rcutorture_booster_init(int cpu) | |
1318 | { | |
1319 | int retval; | |
1320 | ||
1321 | if (boost_tasks[cpu] != NULL) | |
1322 | return 0; /* Already created, nothing more to do. */ | |
1323 | ||
1324 | /* Don't allow time recalculation while creating a new task. */ | |
1325 | mutex_lock(&boost_mutex); | |
1326 | VERBOSE_PRINTK_STRING("Creating rcu_torture_boost task"); | |
1f288094 ED |
1327 | boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL, |
1328 | cpu_to_node(cpu), | |
1329 | "rcu_torture_boost"); | |
8e8be45e PM |
1330 | if (IS_ERR(boost_tasks[cpu])) { |
1331 | retval = PTR_ERR(boost_tasks[cpu]); | |
1332 | VERBOSE_PRINTK_STRING("rcu_torture_boost task create failed"); | |
1333 | n_rcu_torture_boost_ktrerror++; | |
1334 | boost_tasks[cpu] = NULL; | |
1335 | mutex_unlock(&boost_mutex); | |
1336 | return retval; | |
1337 | } | |
1338 | kthread_bind(boost_tasks[cpu], cpu); | |
1339 | wake_up_process(boost_tasks[cpu]); | |
1340 | mutex_unlock(&boost_mutex); | |
1341 | return 0; | |
1342 | } | |
1343 | ||
d5f546d8 PM |
1344 | /* |
1345 | * Cause the rcutorture test to shutdown the system after the test has | |
1346 | * run for the time specified by the shutdown_secs module parameter. | |
1347 | */ | |
1348 | static int | |
1349 | rcu_torture_shutdown(void *arg) | |
1350 | { | |
1351 | long delta; | |
1352 | unsigned long jiffies_snap; | |
1353 | ||
1354 | VERBOSE_PRINTK_STRING("rcu_torture_shutdown task started"); | |
1355 | jiffies_snap = ACCESS_ONCE(jiffies); | |
1356 | while (ULONG_CMP_LT(jiffies_snap, shutdown_time) && | |
1357 | !kthread_should_stop()) { | |
1358 | delta = shutdown_time - jiffies_snap; | |
1359 | if (verbose) | |
2caa1e44 PM |
1360 | pr_alert("%s" TORTURE_FLAG |
1361 | "rcu_torture_shutdown task: %lu jiffies remaining\n", | |
1362 | torture_type, delta); | |
d5f546d8 PM |
1363 | schedule_timeout_interruptible(delta); |
1364 | jiffies_snap = ACCESS_ONCE(jiffies); | |
1365 | } | |
b58bdcca | 1366 | if (kthread_should_stop()) { |
d5f546d8 PM |
1367 | VERBOSE_PRINTK_STRING("rcu_torture_shutdown task stopping"); |
1368 | return 0; | |
1369 | } | |
1370 | ||
1371 | /* OK, shut down the system. */ | |
1372 | ||
1373 | VERBOSE_PRINTK_STRING("rcu_torture_shutdown task shutting down system"); | |
1374 | shutdown_task = NULL; /* Avoid self-kill deadlock. */ | |
1375 | rcu_torture_cleanup(); /* Get the success/failure message. */ | |
1376 | kernel_power_off(); /* Shut down the system. */ | |
1377 | return 0; | |
1378 | } | |
1379 | ||
b58bdcca PM |
1380 | #ifdef CONFIG_HOTPLUG_CPU |
1381 | ||
1382 | /* | |
1383 | * Execute random CPU-hotplug operations at the interval specified | |
1384 | * by the onoff_interval. | |
1385 | */ | |
49fb4c62 | 1386 | static int |
b58bdcca PM |
1387 | rcu_torture_onoff(void *arg) |
1388 | { | |
1389 | int cpu; | |
13dbf914 | 1390 | unsigned long delta; |
b58bdcca PM |
1391 | int maxcpu = -1; |
1392 | DEFINE_RCU_RANDOM(rand); | |
48983260 | 1393 | int ret; |
13dbf914 | 1394 | unsigned long starttime; |
b58bdcca PM |
1395 | |
1396 | VERBOSE_PRINTK_STRING("rcu_torture_onoff task started"); | |
1397 | for_each_online_cpu(cpu) | |
1398 | maxcpu = cpu; | |
1399 | WARN_ON(maxcpu < 0); | |
9b9ec9b9 PM |
1400 | if (onoff_holdoff > 0) { |
1401 | VERBOSE_PRINTK_STRING("rcu_torture_onoff begin holdoff"); | |
1402 | schedule_timeout_interruptible(onoff_holdoff * HZ); | |
1403 | VERBOSE_PRINTK_STRING("rcu_torture_onoff end holdoff"); | |
1404 | } | |
b58bdcca PM |
1405 | while (!kthread_should_stop()) { |
1406 | cpu = (rcu_random(&rand) >> 4) % (maxcpu + 1); | |
f220242a | 1407 | if (cpu_online(cpu) && cpu_is_hotpluggable(cpu)) { |
b58bdcca | 1408 | if (verbose) |
2caa1e44 PM |
1409 | pr_alert("%s" TORTURE_FLAG |
1410 | "rcu_torture_onoff task: offlining %d\n", | |
1411 | torture_type, cpu); | |
13dbf914 | 1412 | starttime = jiffies; |
b58bdcca | 1413 | n_offline_attempts++; |
48983260 PM |
1414 | ret = cpu_down(cpu); |
1415 | if (ret) { | |
1416 | if (verbose) | |
1417 | pr_alert("%s" TORTURE_FLAG | |
1418 | "rcu_torture_onoff task: offline %d failed: errno %d\n", | |
1419 | torture_type, cpu, ret); | |
1420 | } else { | |
b58bdcca | 1421 | if (verbose) |
2caa1e44 PM |
1422 | pr_alert("%s" TORTURE_FLAG |
1423 | "rcu_torture_onoff task: offlined %d\n", | |
1424 | torture_type, cpu); | |
b58bdcca | 1425 | n_offline_successes++; |
13dbf914 PM |
1426 | delta = jiffies - starttime; |
1427 | sum_offline += delta; | |
1428 | if (min_offline < 0) { | |
1429 | min_offline = delta; | |
1430 | max_offline = delta; | |
1431 | } | |
1432 | if (min_offline > delta) | |
1433 | min_offline = delta; | |
1434 | if (max_offline < delta) | |
1435 | max_offline = delta; | |
b58bdcca | 1436 | } |
f220242a | 1437 | } else if (cpu_is_hotpluggable(cpu)) { |
b58bdcca | 1438 | if (verbose) |
2caa1e44 PM |
1439 | pr_alert("%s" TORTURE_FLAG |
1440 | "rcu_torture_onoff task: onlining %d\n", | |
1441 | torture_type, cpu); | |
13dbf914 | 1442 | starttime = jiffies; |
b58bdcca | 1443 | n_online_attempts++; |
7a6a4107 PM |
1444 | ret = cpu_up(cpu); |
1445 | if (ret) { | |
1446 | if (verbose) | |
1447 | pr_alert("%s" TORTURE_FLAG | |
1448 | "rcu_torture_onoff task: online %d failed: errno %d\n", | |
1449 | torture_type, cpu, ret); | |
1450 | } else { | |
b58bdcca | 1451 | if (verbose) |
2caa1e44 PM |
1452 | pr_alert("%s" TORTURE_FLAG |
1453 | "rcu_torture_onoff task: onlined %d\n", | |
1454 | torture_type, cpu); | |
b58bdcca | 1455 | n_online_successes++; |
13dbf914 PM |
1456 | delta = jiffies - starttime; |
1457 | sum_online += delta; | |
1458 | if (min_online < 0) { | |
1459 | min_online = delta; | |
1460 | max_online = delta; | |
1461 | } | |
1462 | if (min_online > delta) | |
1463 | min_online = delta; | |
1464 | if (max_online < delta) | |
1465 | max_online = delta; | |
b58bdcca PM |
1466 | } |
1467 | } | |
1468 | schedule_timeout_interruptible(onoff_interval * HZ); | |
1469 | } | |
1470 | VERBOSE_PRINTK_STRING("rcu_torture_onoff task stopping"); | |
1471 | return 0; | |
1472 | } | |
1473 | ||
49fb4c62 | 1474 | static int |
b58bdcca PM |
1475 | rcu_torture_onoff_init(void) |
1476 | { | |
3c1b1ce0 JL |
1477 | int ret; |
1478 | ||
b58bdcca PM |
1479 | if (onoff_interval <= 0) |
1480 | return 0; | |
1481 | onoff_task = kthread_run(rcu_torture_onoff, NULL, "rcu_torture_onoff"); | |
1482 | if (IS_ERR(onoff_task)) { | |
3c1b1ce0 | 1483 | ret = PTR_ERR(onoff_task); |
b58bdcca | 1484 | onoff_task = NULL; |
3c1b1ce0 | 1485 | return ret; |
b58bdcca PM |
1486 | } |
1487 | return 0; | |
1488 | } | |
1489 | ||
1490 | static void rcu_torture_onoff_cleanup(void) | |
1491 | { | |
1492 | if (onoff_task == NULL) | |
1493 | return; | |
1494 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_onoff task"); | |
1495 | kthread_stop(onoff_task); | |
37e377d2 | 1496 | onoff_task = NULL; |
b58bdcca PM |
1497 | } |
1498 | ||
1499 | #else /* #ifdef CONFIG_HOTPLUG_CPU */ | |
1500 | ||
37e377d2 | 1501 | static int |
b58bdcca PM |
1502 | rcu_torture_onoff_init(void) |
1503 | { | |
37e377d2 | 1504 | return 0; |
b58bdcca PM |
1505 | } |
1506 | ||
1507 | static void rcu_torture_onoff_cleanup(void) | |
1508 | { | |
1509 | } | |
1510 | ||
1511 | #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ | |
1512 | ||
c13f3757 PM |
1513 | /* |
1514 | * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then | |
1515 | * induces a CPU stall for the time specified by stall_cpu. | |
1516 | */ | |
49fb4c62 | 1517 | static int rcu_torture_stall(void *args) |
c13f3757 PM |
1518 | { |
1519 | unsigned long stop_at; | |
1520 | ||
1521 | VERBOSE_PRINTK_STRING("rcu_torture_stall task started"); | |
1522 | if (stall_cpu_holdoff > 0) { | |
1523 | VERBOSE_PRINTK_STRING("rcu_torture_stall begin holdoff"); | |
1524 | schedule_timeout_interruptible(stall_cpu_holdoff * HZ); | |
1525 | VERBOSE_PRINTK_STRING("rcu_torture_stall end holdoff"); | |
1526 | } | |
1527 | if (!kthread_should_stop()) { | |
1528 | stop_at = get_seconds() + stall_cpu; | |
1529 | /* RCU CPU stall is expected behavior in following code. */ | |
2caa1e44 | 1530 | pr_alert("rcu_torture_stall start.\n"); |
c13f3757 PM |
1531 | rcu_read_lock(); |
1532 | preempt_disable(); | |
1533 | while (ULONG_CMP_LT(get_seconds(), stop_at)) | |
1534 | continue; /* Induce RCU CPU stall warning. */ | |
1535 | preempt_enable(); | |
1536 | rcu_read_unlock(); | |
2caa1e44 | 1537 | pr_alert("rcu_torture_stall end.\n"); |
c13f3757 PM |
1538 | } |
1539 | rcutorture_shutdown_absorb("rcu_torture_stall"); | |
1540 | while (!kthread_should_stop()) | |
1541 | schedule_timeout_interruptible(10 * HZ); | |
1542 | return 0; | |
1543 | } | |
1544 | ||
1545 | /* Spawn CPU-stall kthread, if stall_cpu specified. */ | |
1546 | static int __init rcu_torture_stall_init(void) | |
1547 | { | |
1548 | int ret; | |
1549 | ||
1550 | if (stall_cpu <= 0) | |
1551 | return 0; | |
1552 | stall_task = kthread_run(rcu_torture_stall, NULL, "rcu_torture_stall"); | |
1553 | if (IS_ERR(stall_task)) { | |
1554 | ret = PTR_ERR(stall_task); | |
1555 | stall_task = NULL; | |
1556 | return ret; | |
1557 | } | |
1558 | return 0; | |
1559 | } | |
1560 | ||
1561 | /* Clean up after the CPU-stall kthread, if one was spawned. */ | |
1562 | static void rcu_torture_stall_cleanup(void) | |
1563 | { | |
1564 | if (stall_task == NULL) | |
1565 | return; | |
1566 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stall_task."); | |
1567 | kthread_stop(stall_task); | |
37e377d2 | 1568 | stall_task = NULL; |
c13f3757 PM |
1569 | } |
1570 | ||
fae4b54f PM |
1571 | /* Callback function for RCU barrier testing. */ |
1572 | void rcu_torture_barrier_cbf(struct rcu_head *rcu) | |
1573 | { | |
1574 | atomic_inc(&barrier_cbs_invoked); | |
1575 | } | |
1576 | ||
1577 | /* kthread function to register callbacks used to test RCU barriers. */ | |
1578 | static int rcu_torture_barrier_cbs(void *arg) | |
1579 | { | |
1580 | long myid = (long)arg; | |
c6ebcbb6 | 1581 | bool lastphase = 0; |
78e4bc34 | 1582 | bool newphase; |
fae4b54f PM |
1583 | struct rcu_head rcu; |
1584 | ||
1585 | init_rcu_head_on_stack(&rcu); | |
1586 | VERBOSE_PRINTK_STRING("rcu_torture_barrier_cbs task started"); | |
1587 | set_user_nice(current, 19); | |
1588 | do { | |
1589 | wait_event(barrier_cbs_wq[myid], | |
78e4bc34 PM |
1590 | (newphase = |
1591 | ACCESS_ONCE(barrier_phase)) != lastphase || | |
fae4b54f PM |
1592 | kthread_should_stop() || |
1593 | fullstop != FULLSTOP_DONTSTOP); | |
78e4bc34 | 1594 | lastphase = newphase; |
c6ebcbb6 | 1595 | smp_mb(); /* ensure barrier_phase load before ->call(). */ |
fae4b54f PM |
1596 | if (kthread_should_stop() || fullstop != FULLSTOP_DONTSTOP) |
1597 | break; | |
1598 | cur_ops->call(&rcu, rcu_torture_barrier_cbf); | |
1599 | if (atomic_dec_and_test(&barrier_cbs_count)) | |
1600 | wake_up(&barrier_wq); | |
1601 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
1602 | VERBOSE_PRINTK_STRING("rcu_torture_barrier_cbs task stopping"); | |
1603 | rcutorture_shutdown_absorb("rcu_torture_barrier_cbs"); | |
1604 | while (!kthread_should_stop()) | |
1605 | schedule_timeout_interruptible(1); | |
1606 | cur_ops->cb_barrier(); | |
1607 | destroy_rcu_head_on_stack(&rcu); | |
1608 | return 0; | |
1609 | } | |
1610 | ||
1611 | /* kthread function to drive and coordinate RCU barrier testing. */ | |
1612 | static int rcu_torture_barrier(void *arg) | |
1613 | { | |
1614 | int i; | |
1615 | ||
1616 | VERBOSE_PRINTK_STRING("rcu_torture_barrier task starting"); | |
1617 | do { | |
1618 | atomic_set(&barrier_cbs_invoked, 0); | |
1619 | atomic_set(&barrier_cbs_count, n_barrier_cbs); | |
c6ebcbb6 PM |
1620 | smp_mb(); /* Ensure barrier_phase after prior assignments. */ |
1621 | barrier_phase = !barrier_phase; | |
fae4b54f PM |
1622 | for (i = 0; i < n_barrier_cbs; i++) |
1623 | wake_up(&barrier_cbs_wq[i]); | |
1624 | wait_event(barrier_wq, | |
1625 | atomic_read(&barrier_cbs_count) == 0 || | |
1626 | kthread_should_stop() || | |
1627 | fullstop != FULLSTOP_DONTSTOP); | |
1628 | if (kthread_should_stop() || fullstop != FULLSTOP_DONTSTOP) | |
1629 | break; | |
1630 | n_barrier_attempts++; | |
78e4bc34 | 1631 | cur_ops->cb_barrier(); /* Implies smp_mb() for wait_event(). */ |
fae4b54f PM |
1632 | if (atomic_read(&barrier_cbs_invoked) != n_barrier_cbs) { |
1633 | n_rcu_torture_barrier_error++; | |
1634 | WARN_ON_ONCE(1); | |
1635 | } | |
1636 | n_barrier_successes++; | |
1637 | schedule_timeout_interruptible(HZ / 10); | |
1638 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
1639 | VERBOSE_PRINTK_STRING("rcu_torture_barrier task stopping"); | |
143aa672 | 1640 | rcutorture_shutdown_absorb("rcu_torture_barrier"); |
fae4b54f PM |
1641 | while (!kthread_should_stop()) |
1642 | schedule_timeout_interruptible(1); | |
1643 | return 0; | |
1644 | } | |
1645 | ||
1646 | /* Initialize RCU barrier testing. */ | |
1647 | static int rcu_torture_barrier_init(void) | |
1648 | { | |
1649 | int i; | |
1650 | int ret; | |
1651 | ||
1652 | if (n_barrier_cbs == 0) | |
1653 | return 0; | |
1654 | if (cur_ops->call == NULL || cur_ops->cb_barrier == NULL) { | |
2caa1e44 PM |
1655 | pr_alert("%s" TORTURE_FLAG |
1656 | " Call or barrier ops missing for %s,\n", | |
1657 | torture_type, cur_ops->name); | |
1658 | pr_alert("%s" TORTURE_FLAG | |
1659 | " RCU barrier testing omitted from run.\n", | |
1660 | torture_type); | |
fae4b54f PM |
1661 | return 0; |
1662 | } | |
1663 | atomic_set(&barrier_cbs_count, 0); | |
1664 | atomic_set(&barrier_cbs_invoked, 0); | |
1665 | barrier_cbs_tasks = | |
1666 | kzalloc(n_barrier_cbs * sizeof(barrier_cbs_tasks[0]), | |
1667 | GFP_KERNEL); | |
1668 | barrier_cbs_wq = | |
1669 | kzalloc(n_barrier_cbs * sizeof(barrier_cbs_wq[0]), | |
1670 | GFP_KERNEL); | |
de5e6437 | 1671 | if (barrier_cbs_tasks == NULL || !barrier_cbs_wq) |
fae4b54f PM |
1672 | return -ENOMEM; |
1673 | for (i = 0; i < n_barrier_cbs; i++) { | |
1674 | init_waitqueue_head(&barrier_cbs_wq[i]); | |
1675 | barrier_cbs_tasks[i] = kthread_run(rcu_torture_barrier_cbs, | |
9059c940 | 1676 | (void *)(long)i, |
fae4b54f PM |
1677 | "rcu_torture_barrier_cbs"); |
1678 | if (IS_ERR(barrier_cbs_tasks[i])) { | |
1679 | ret = PTR_ERR(barrier_cbs_tasks[i]); | |
1680 | VERBOSE_PRINTK_ERRSTRING("Failed to create rcu_torture_barrier_cbs"); | |
1681 | barrier_cbs_tasks[i] = NULL; | |
1682 | return ret; | |
1683 | } | |
1684 | } | |
1685 | barrier_task = kthread_run(rcu_torture_barrier, NULL, | |
1686 | "rcu_torture_barrier"); | |
1687 | if (IS_ERR(barrier_task)) { | |
1688 | ret = PTR_ERR(barrier_task); | |
1689 | VERBOSE_PRINTK_ERRSTRING("Failed to create rcu_torture_barrier"); | |
1690 | barrier_task = NULL; | |
1691 | } | |
1692 | return 0; | |
1693 | } | |
1694 | ||
1695 | /* Clean up after RCU barrier testing. */ | |
1696 | static void rcu_torture_barrier_cleanup(void) | |
1697 | { | |
1698 | int i; | |
1699 | ||
1700 | if (barrier_task != NULL) { | |
1701 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_barrier task"); | |
1702 | kthread_stop(barrier_task); | |
1703 | barrier_task = NULL; | |
1704 | } | |
1705 | if (barrier_cbs_tasks != NULL) { | |
1706 | for (i = 0; i < n_barrier_cbs; i++) { | |
1707 | if (barrier_cbs_tasks[i] != NULL) { | |
1708 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_barrier_cbs task"); | |
1709 | kthread_stop(barrier_cbs_tasks[i]); | |
1710 | barrier_cbs_tasks[i] = NULL; | |
1711 | } | |
1712 | } | |
1713 | kfree(barrier_cbs_tasks); | |
1714 | barrier_cbs_tasks = NULL; | |
1715 | } | |
1716 | if (barrier_cbs_wq != NULL) { | |
1717 | kfree(barrier_cbs_wq); | |
1718 | barrier_cbs_wq = NULL; | |
1719 | } | |
1720 | } | |
1721 | ||
8e8be45e PM |
1722 | static int rcutorture_cpu_notify(struct notifier_block *self, |
1723 | unsigned long action, void *hcpu) | |
1724 | { | |
1725 | long cpu = (long)hcpu; | |
1726 | ||
1727 | switch (action) { | |
1728 | case CPU_ONLINE: | |
1729 | case CPU_DOWN_FAILED: | |
1730 | (void)rcutorture_booster_init(cpu); | |
1731 | break; | |
1732 | case CPU_DOWN_PREPARE: | |
1733 | rcutorture_booster_cleanup(cpu); | |
1734 | break; | |
1735 | default: | |
1736 | break; | |
1737 | } | |
1738 | return NOTIFY_OK; | |
1739 | } | |
1740 | ||
1741 | static struct notifier_block rcutorture_cpu_nb = { | |
1742 | .notifier_call = rcutorture_cpu_notify, | |
1743 | }; | |
1744 | ||
a241ec65 PM |
1745 | static void |
1746 | rcu_torture_cleanup(void) | |
1747 | { | |
1748 | int i; | |
1749 | ||
343e9099 | 1750 | mutex_lock(&fullstop_mutex); |
4a298656 | 1751 | rcutorture_record_test_transition(); |
c9d557c1 | 1752 | if (fullstop == FULLSTOP_SHUTDOWN) { |
2caa1e44 | 1753 | pr_warn(/* but going down anyway, so... */ |
c9d557c1 | 1754 | "Concurrent 'rmmod rcutorture' and shutdown illegal!\n"); |
343e9099 | 1755 | mutex_unlock(&fullstop_mutex); |
c9d557c1 | 1756 | schedule_timeout_uninterruptible(10); |
343e9099 PM |
1757 | if (cur_ops->cb_barrier != NULL) |
1758 | cur_ops->cb_barrier(); | |
1759 | return; | |
1760 | } | |
c9d557c1 | 1761 | fullstop = FULLSTOP_RMMOD; |
343e9099 | 1762 | mutex_unlock(&fullstop_mutex); |
8e8be45e | 1763 | unregister_reboot_notifier(&rcutorture_shutdown_nb); |
fae4b54f | 1764 | rcu_torture_barrier_cleanup(); |
c13f3757 | 1765 | rcu_torture_stall_cleanup(); |
d120f65f PM |
1766 | if (stutter_task) { |
1767 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stutter task"); | |
1768 | kthread_stop(stutter_task); | |
1769 | } | |
1770 | stutter_task = NULL; | |
c8e5b163 | 1771 | if (shuffler_task) { |
d84f5203 SV |
1772 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task"); |
1773 | kthread_stop(shuffler_task); | |
73d0a4b1 | 1774 | free_cpumask_var(shuffle_tmp_mask); |
d84f5203 SV |
1775 | } |
1776 | shuffler_task = NULL; | |
1777 | ||
c8e5b163 | 1778 | if (writer_task) { |
a241ec65 PM |
1779 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task"); |
1780 | kthread_stop(writer_task); | |
1781 | } | |
1782 | writer_task = NULL; | |
1783 | ||
c8e5b163 | 1784 | if (reader_tasks) { |
a241ec65 | 1785 | for (i = 0; i < nrealreaders; i++) { |
c8e5b163 | 1786 | if (reader_tasks[i]) { |
a241ec65 PM |
1787 | VERBOSE_PRINTK_STRING( |
1788 | "Stopping rcu_torture_reader task"); | |
1789 | kthread_stop(reader_tasks[i]); | |
1790 | } | |
1791 | reader_tasks[i] = NULL; | |
1792 | } | |
1793 | kfree(reader_tasks); | |
1794 | reader_tasks = NULL; | |
1795 | } | |
1796 | rcu_torture_current = NULL; | |
1797 | ||
c8e5b163 | 1798 | if (fakewriter_tasks) { |
b772e1dd | 1799 | for (i = 0; i < nfakewriters; i++) { |
c8e5b163 | 1800 | if (fakewriter_tasks[i]) { |
b772e1dd JT |
1801 | VERBOSE_PRINTK_STRING( |
1802 | "Stopping rcu_torture_fakewriter task"); | |
1803 | kthread_stop(fakewriter_tasks[i]); | |
1804 | } | |
1805 | fakewriter_tasks[i] = NULL; | |
1806 | } | |
1807 | kfree(fakewriter_tasks); | |
1808 | fakewriter_tasks = NULL; | |
1809 | } | |
1810 | ||
c8e5b163 | 1811 | if (stats_task) { |
a241ec65 PM |
1812 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task"); |
1813 | kthread_stop(stats_task); | |
1814 | } | |
1815 | stats_task = NULL; | |
1816 | ||
bf66f18e PM |
1817 | if (fqs_task) { |
1818 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_fqs task"); | |
1819 | kthread_stop(fqs_task); | |
1820 | } | |
1821 | fqs_task = NULL; | |
8e8be45e PM |
1822 | if ((test_boost == 1 && cur_ops->can_boost) || |
1823 | test_boost == 2) { | |
1824 | unregister_cpu_notifier(&rcutorture_cpu_nb); | |
1825 | for_each_possible_cpu(i) | |
1826 | rcutorture_booster_cleanup(i); | |
1827 | } | |
d5f546d8 PM |
1828 | if (shutdown_task != NULL) { |
1829 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_shutdown task"); | |
1830 | kthread_stop(shutdown_task); | |
1831 | } | |
37e377d2 | 1832 | shutdown_task = NULL; |
b58bdcca | 1833 | rcu_torture_onoff_cleanup(); |
bf66f18e | 1834 | |
a241ec65 | 1835 | /* Wait for all RCU callbacks to fire. */ |
2326974d PM |
1836 | |
1837 | if (cur_ops->cb_barrier != NULL) | |
1838 | cur_ops->cb_barrier(); | |
a241ec65 | 1839 | |
a241ec65 | 1840 | rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ |
72e9bb54 | 1841 | |
fae4b54f | 1842 | if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error) |
8e8be45e | 1843 | rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE"); |
091541bb PM |
1844 | else if (n_online_successes != n_online_attempts || |
1845 | n_offline_successes != n_offline_attempts) | |
1846 | rcu_torture_print_module_parms(cur_ops, | |
1847 | "End of test: RCU_HOTPLUG"); | |
95c38322 | 1848 | else |
8e8be45e | 1849 | rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS"); |
a241ec65 PM |
1850 | } |
1851 | ||
d2818df1 PM |
1852 | #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD |
1853 | static void rcu_torture_leak_cb(struct rcu_head *rhp) | |
1854 | { | |
1855 | } | |
1856 | ||
1857 | static void rcu_torture_err_cb(struct rcu_head *rhp) | |
1858 | { | |
1859 | /* | |
1860 | * This -might- happen due to race conditions, but is unlikely. | |
1861 | * The scenario that leads to this happening is that the | |
1862 | * first of the pair of duplicate callbacks is queued, | |
1863 | * someone else starts a grace period that includes that | |
1864 | * callback, then the second of the pair must wait for the | |
1865 | * next grace period. Unlikely, but can happen. If it | |
1866 | * does happen, the debug-objects subsystem won't have splatted. | |
1867 | */ | |
1868 | pr_alert("rcutorture: duplicated callback was invoked.\n"); | |
1869 | } | |
1870 | #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ | |
1871 | ||
1872 | /* | |
1873 | * Verify that double-free causes debug-objects to complain, but only | |
1874 | * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test | |
1875 | * cannot be carried out. | |
1876 | */ | |
1877 | static void rcu_test_debug_objects(void) | |
1878 | { | |
1879 | #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD | |
1880 | struct rcu_head rh1; | |
1881 | struct rcu_head rh2; | |
1882 | ||
1883 | init_rcu_head_on_stack(&rh1); | |
1884 | init_rcu_head_on_stack(&rh2); | |
1885 | pr_alert("rcutorture: WARN: Duplicate call_rcu() test starting.\n"); | |
1886 | ||
1887 | /* Try to queue the rh2 pair of callbacks for the same grace period. */ | |
1888 | preempt_disable(); /* Prevent preemption from interrupting test. */ | |
1889 | rcu_read_lock(); /* Make it impossible to finish a grace period. */ | |
1890 | call_rcu(&rh1, rcu_torture_leak_cb); /* Start grace period. */ | |
1891 | local_irq_disable(); /* Make it harder to start a new grace period. */ | |
1892 | call_rcu(&rh2, rcu_torture_leak_cb); | |
1893 | call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */ | |
1894 | local_irq_enable(); | |
1895 | rcu_read_unlock(); | |
1896 | preempt_enable(); | |
1897 | ||
1898 | /* Wait for them all to get done so we can safely return. */ | |
1899 | rcu_barrier(); | |
1900 | pr_alert("rcutorture: WARN: Duplicate call_rcu() test complete.\n"); | |
1901 | destroy_rcu_head_on_stack(&rh1); | |
1902 | destroy_rcu_head_on_stack(&rh2); | |
1903 | #else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ | |
1904 | pr_alert("rcutorture: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n"); | |
1905 | #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ | |
1906 | } | |
1907 | ||
6f8bc500 | 1908 | static int __init |
a241ec65 PM |
1909 | rcu_torture_init(void) |
1910 | { | |
1911 | int i; | |
1912 | int cpu; | |
1913 | int firsterr = 0; | |
fae4b54f | 1914 | int retval; |
2ec1f2d9 PM |
1915 | static struct rcu_torture_ops *torture_ops[] = { |
1916 | &rcu_ops, &rcu_bh_ops, &srcu_ops, &sched_ops, | |
1917 | }; | |
a241ec65 | 1918 | |
343e9099 PM |
1919 | mutex_lock(&fullstop_mutex); |
1920 | ||
a241ec65 | 1921 | /* Process args and tell the world that the torturer is on the job. */ |
ade5fb81 | 1922 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { |
72e9bb54 | 1923 | cur_ops = torture_ops[i]; |
ade5fb81 | 1924 | if (strcmp(torture_type, cur_ops->name) == 0) |
72e9bb54 | 1925 | break; |
72e9bb54 | 1926 | } |
ade5fb81 | 1927 | if (i == ARRAY_SIZE(torture_ops)) { |
2caa1e44 PM |
1928 | pr_alert("rcu-torture: invalid torture type: \"%s\"\n", |
1929 | torture_type); | |
1930 | pr_alert("rcu-torture types:"); | |
cf886c44 | 1931 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) |
2caa1e44 PM |
1932 | pr_alert(" %s", torture_ops[i]->name); |
1933 | pr_alert("\n"); | |
343e9099 | 1934 | mutex_unlock(&fullstop_mutex); |
a71fca58 | 1935 | return -EINVAL; |
72e9bb54 | 1936 | } |
bf66f18e | 1937 | if (cur_ops->fqs == NULL && fqs_duration != 0) { |
2caa1e44 | 1938 | pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n"); |
bf66f18e PM |
1939 | fqs_duration = 0; |
1940 | } | |
c8e5b163 | 1941 | if (cur_ops->init) |
72e9bb54 PM |
1942 | cur_ops->init(); /* no "goto unwind" prior to this point!!! */ |
1943 | ||
a241ec65 PM |
1944 | if (nreaders >= 0) |
1945 | nrealreaders = nreaders; | |
1946 | else | |
1947 | nrealreaders = 2 * num_online_cpus(); | |
8e8be45e | 1948 | rcu_torture_print_module_parms(cur_ops, "Start of test"); |
c9d557c1 | 1949 | fullstop = FULLSTOP_DONTSTOP; |
a241ec65 PM |
1950 | |
1951 | /* Set up the freelist. */ | |
1952 | ||
1953 | INIT_LIST_HEAD(&rcu_torture_freelist); | |
788e770e | 1954 | for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) { |
996417d2 | 1955 | rcu_tortures[i].rtort_mbtest = 0; |
a241ec65 PM |
1956 | list_add_tail(&rcu_tortures[i].rtort_free, |
1957 | &rcu_torture_freelist); | |
1958 | } | |
1959 | ||
1960 | /* Initialize the statistics so that each run gets its own numbers. */ | |
1961 | ||
1962 | rcu_torture_current = NULL; | |
1963 | rcu_torture_current_version = 0; | |
1964 | atomic_set(&n_rcu_torture_alloc, 0); | |
1965 | atomic_set(&n_rcu_torture_alloc_fail, 0); | |
1966 | atomic_set(&n_rcu_torture_free, 0); | |
996417d2 PM |
1967 | atomic_set(&n_rcu_torture_mberror, 0); |
1968 | atomic_set(&n_rcu_torture_error, 0); | |
fae4b54f | 1969 | n_rcu_torture_barrier_error = 0; |
8e8be45e PM |
1970 | n_rcu_torture_boost_ktrerror = 0; |
1971 | n_rcu_torture_boost_rterror = 0; | |
8e8be45e PM |
1972 | n_rcu_torture_boost_failure = 0; |
1973 | n_rcu_torture_boosts = 0; | |
a241ec65 PM |
1974 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
1975 | atomic_set(&rcu_torture_wcount[i], 0); | |
0a945022 | 1976 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
1977 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
1978 | per_cpu(rcu_torture_count, cpu)[i] = 0; | |
1979 | per_cpu(rcu_torture_batch, cpu)[i] = 0; | |
1980 | } | |
1981 | } | |
1982 | ||
1983 | /* Start up the kthreads. */ | |
1984 | ||
1985 | VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task"); | |
60f53782 PM |
1986 | writer_task = kthread_create(rcu_torture_writer, NULL, |
1987 | "rcu_torture_writer"); | |
a241ec65 PM |
1988 | if (IS_ERR(writer_task)) { |
1989 | firsterr = PTR_ERR(writer_task); | |
1990 | VERBOSE_PRINTK_ERRSTRING("Failed to create writer"); | |
1991 | writer_task = NULL; | |
1992 | goto unwind; | |
1993 | } | |
60f53782 | 1994 | wake_up_process(writer_task); |
b772e1dd | 1995 | fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]), |
a71fca58 | 1996 | GFP_KERNEL); |
b772e1dd JT |
1997 | if (fakewriter_tasks == NULL) { |
1998 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
1999 | firsterr = -ENOMEM; | |
2000 | goto unwind; | |
2001 | } | |
2002 | for (i = 0; i < nfakewriters; i++) { | |
2003 | VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task"); | |
2004 | fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL, | |
a71fca58 | 2005 | "rcu_torture_fakewriter"); |
b772e1dd JT |
2006 | if (IS_ERR(fakewriter_tasks[i])) { |
2007 | firsterr = PTR_ERR(fakewriter_tasks[i]); | |
2008 | VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter"); | |
2009 | fakewriter_tasks[i] = NULL; | |
2010 | goto unwind; | |
2011 | } | |
2012 | } | |
2860aaba | 2013 | reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]), |
a241ec65 PM |
2014 | GFP_KERNEL); |
2015 | if (reader_tasks == NULL) { | |
2016 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
2017 | firsterr = -ENOMEM; | |
2018 | goto unwind; | |
2019 | } | |
2020 | for (i = 0; i < nrealreaders; i++) { | |
2021 | VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task"); | |
2022 | reader_tasks[i] = kthread_run(rcu_torture_reader, NULL, | |
2023 | "rcu_torture_reader"); | |
2024 | if (IS_ERR(reader_tasks[i])) { | |
2025 | firsterr = PTR_ERR(reader_tasks[i]); | |
2026 | VERBOSE_PRINTK_ERRSTRING("Failed to create reader"); | |
2027 | reader_tasks[i] = NULL; | |
2028 | goto unwind; | |
2029 | } | |
2030 | } | |
2031 | if (stat_interval > 0) { | |
2032 | VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task"); | |
2033 | stats_task = kthread_run(rcu_torture_stats, NULL, | |
2034 | "rcu_torture_stats"); | |
2035 | if (IS_ERR(stats_task)) { | |
2036 | firsterr = PTR_ERR(stats_task); | |
2037 | VERBOSE_PRINTK_ERRSTRING("Failed to create stats"); | |
2038 | stats_task = NULL; | |
2039 | goto unwind; | |
2040 | } | |
2041 | } | |
d84f5203 SV |
2042 | if (test_no_idle_hz) { |
2043 | rcu_idle_cpu = num_online_cpus() - 1; | |
73d0a4b1 RR |
2044 | |
2045 | if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) { | |
2046 | firsterr = -ENOMEM; | |
2047 | VERBOSE_PRINTK_ERRSTRING("Failed to alloc mask"); | |
2048 | goto unwind; | |
2049 | } | |
2050 | ||
d84f5203 SV |
2051 | /* Create the shuffler thread */ |
2052 | shuffler_task = kthread_run(rcu_torture_shuffle, NULL, | |
2053 | "rcu_torture_shuffle"); | |
2054 | if (IS_ERR(shuffler_task)) { | |
73d0a4b1 | 2055 | free_cpumask_var(shuffle_tmp_mask); |
d84f5203 SV |
2056 | firsterr = PTR_ERR(shuffler_task); |
2057 | VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler"); | |
2058 | shuffler_task = NULL; | |
2059 | goto unwind; | |
2060 | } | |
2061 | } | |
d120f65f PM |
2062 | if (stutter < 0) |
2063 | stutter = 0; | |
2064 | if (stutter) { | |
2065 | /* Create the stutter thread */ | |
2066 | stutter_task = kthread_run(rcu_torture_stutter, NULL, | |
2067 | "rcu_torture_stutter"); | |
2068 | if (IS_ERR(stutter_task)) { | |
2069 | firsterr = PTR_ERR(stutter_task); | |
2070 | VERBOSE_PRINTK_ERRSTRING("Failed to create stutter"); | |
2071 | stutter_task = NULL; | |
2072 | goto unwind; | |
2073 | } | |
2074 | } | |
bf66f18e PM |
2075 | if (fqs_duration < 0) |
2076 | fqs_duration = 0; | |
2077 | if (fqs_duration) { | |
2078 | /* Create the stutter thread */ | |
2079 | fqs_task = kthread_run(rcu_torture_fqs, NULL, | |
2080 | "rcu_torture_fqs"); | |
2081 | if (IS_ERR(fqs_task)) { | |
2082 | firsterr = PTR_ERR(fqs_task); | |
2083 | VERBOSE_PRINTK_ERRSTRING("Failed to create fqs"); | |
2084 | fqs_task = NULL; | |
2085 | goto unwind; | |
2086 | } | |
2087 | } | |
8e8be45e PM |
2088 | if (test_boost_interval < 1) |
2089 | test_boost_interval = 1; | |
2090 | if (test_boost_duration < 2) | |
2091 | test_boost_duration = 2; | |
2092 | if ((test_boost == 1 && cur_ops->can_boost) || | |
2093 | test_boost == 2) { | |
8e8be45e PM |
2094 | |
2095 | boost_starttime = jiffies + test_boost_interval * HZ; | |
2096 | register_cpu_notifier(&rcutorture_cpu_nb); | |
2097 | for_each_possible_cpu(i) { | |
2098 | if (cpu_is_offline(i)) | |
2099 | continue; /* Heuristic: CPU can go offline. */ | |
2100 | retval = rcutorture_booster_init(i); | |
2101 | if (retval < 0) { | |
2102 | firsterr = retval; | |
2103 | goto unwind; | |
2104 | } | |
2105 | } | |
2106 | } | |
d5f546d8 PM |
2107 | if (shutdown_secs > 0) { |
2108 | shutdown_time = jiffies + shutdown_secs * HZ; | |
60f53782 PM |
2109 | shutdown_task = kthread_create(rcu_torture_shutdown, NULL, |
2110 | "rcu_torture_shutdown"); | |
d5f546d8 PM |
2111 | if (IS_ERR(shutdown_task)) { |
2112 | firsterr = PTR_ERR(shutdown_task); | |
2113 | VERBOSE_PRINTK_ERRSTRING("Failed to create shutdown"); | |
2114 | shutdown_task = NULL; | |
2115 | goto unwind; | |
2116 | } | |
60f53782 | 2117 | wake_up_process(shutdown_task); |
d5f546d8 | 2118 | } |
37e377d2 PM |
2119 | i = rcu_torture_onoff_init(); |
2120 | if (i != 0) { | |
2121 | firsterr = i; | |
2122 | goto unwind; | |
2123 | } | |
8e8be45e | 2124 | register_reboot_notifier(&rcutorture_shutdown_nb); |
37e377d2 PM |
2125 | i = rcu_torture_stall_init(); |
2126 | if (i != 0) { | |
2127 | firsterr = i; | |
2128 | goto unwind; | |
2129 | } | |
fae4b54f PM |
2130 | retval = rcu_torture_barrier_init(); |
2131 | if (retval != 0) { | |
2132 | firsterr = retval; | |
2133 | goto unwind; | |
2134 | } | |
d2818df1 PM |
2135 | if (object_debug) |
2136 | rcu_test_debug_objects(); | |
4a298656 | 2137 | rcutorture_record_test_transition(); |
343e9099 | 2138 | mutex_unlock(&fullstop_mutex); |
a241ec65 PM |
2139 | return 0; |
2140 | ||
2141 | unwind: | |
343e9099 | 2142 | mutex_unlock(&fullstop_mutex); |
a241ec65 PM |
2143 | rcu_torture_cleanup(); |
2144 | return firsterr; | |
2145 | } | |
2146 | ||
2147 | module_init(rcu_torture_init); | |
2148 | module_exit(rcu_torture_cleanup); |