Commit | Line | Data |
---|---|---|
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 | * | |
18 | * Copyright (C) IBM Corporation, 2005 | |
19 | * | |
20 | * Authors: Paul E. McKenney <paulmck@us.ibm.com> | |
21 | * | |
22 | * See also: Documentation/RCU/torture.txt | |
23 | */ | |
24 | #include <linux/types.h> | |
25 | #include <linux/kernel.h> | |
26 | #include <linux/init.h> | |
27 | #include <linux/module.h> | |
28 | #include <linux/kthread.h> | |
29 | #include <linux/err.h> | |
30 | #include <linux/spinlock.h> | |
31 | #include <linux/smp.h> | |
32 | #include <linux/rcupdate.h> | |
33 | #include <linux/interrupt.h> | |
34 | #include <linux/sched.h> | |
35 | #include <asm/atomic.h> | |
36 | #include <linux/bitops.h> | |
37 | #include <linux/module.h> | |
38 | #include <linux/completion.h> | |
39 | #include <linux/moduleparam.h> | |
40 | #include <linux/percpu.h> | |
41 | #include <linux/notifier.h> | |
a241ec65 PM |
42 | #include <linux/cpu.h> |
43 | #include <linux/random.h> | |
44 | #include <linux/delay.h> | |
45 | #include <linux/byteorder/swabb.h> | |
46 | #include <linux/stat.h> | |
b2896d2e | 47 | #include <linux/srcu.h> |
a241ec65 PM |
48 | |
49 | MODULE_LICENSE("GPL"); | |
ff2c93a5 | 50 | MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>"); |
a241ec65 | 51 | |
4802211c | 52 | static int nreaders = -1; /* # reader threads, defaults to 2*ncpus */ |
d84f5203 | 53 | static int stat_interval; /* Interval between stats, in seconds. */ |
a241ec65 | 54 | /* Defaults to "only at end of test". */ |
d84f5203 SV |
55 | static int verbose; /* Print more debug info. */ |
56 | static int test_no_idle_hz; /* Test RCU's support for tickless idle CPUs. */ | |
57 | static int shuffle_interval = 5; /* Interval between shuffles (in sec)*/ | |
3c29e03d | 58 | static char *torture_type = "rcu"; /* What to torture: rcu, rcu_bh, srcu. */ |
a241ec65 | 59 | |
8d3b33f6 | 60 | module_param(nreaders, int, 0); |
a241ec65 | 61 | MODULE_PARM_DESC(nreaders, "Number of RCU reader threads"); |
8d3b33f6 | 62 | module_param(stat_interval, int, 0); |
a241ec65 | 63 | MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s"); |
8d3b33f6 | 64 | module_param(verbose, bool, 0); |
a241ec65 | 65 | MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s"); |
8d3b33f6 | 66 | module_param(test_no_idle_hz, bool, 0); |
d84f5203 | 67 | MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs"); |
8d3b33f6 | 68 | module_param(shuffle_interval, int, 0); |
d84f5203 | 69 | MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles"); |
72e9bb54 | 70 | module_param(torture_type, charp, 0); |
b2896d2e | 71 | MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)"); |
72e9bb54 PM |
72 | |
73 | #define TORTURE_FLAG "-torture:" | |
a241ec65 | 74 | #define PRINTK_STRING(s) \ |
72e9bb54 | 75 | do { printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0) |
a241ec65 | 76 | #define VERBOSE_PRINTK_STRING(s) \ |
72e9bb54 | 77 | do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0) |
a241ec65 | 78 | #define VERBOSE_PRINTK_ERRSTRING(s) \ |
72e9bb54 | 79 | do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0) |
a241ec65 PM |
80 | |
81 | static char printk_buf[4096]; | |
82 | ||
83 | static int nrealreaders; | |
84 | static struct task_struct *writer_task; | |
85 | static struct task_struct **reader_tasks; | |
86 | static struct task_struct *stats_task; | |
d84f5203 | 87 | static struct task_struct *shuffler_task; |
a241ec65 PM |
88 | |
89 | #define RCU_TORTURE_PIPE_LEN 10 | |
90 | ||
91 | struct rcu_torture { | |
92 | struct rcu_head rtort_rcu; | |
93 | int rtort_pipe_count; | |
94 | struct list_head rtort_free; | |
996417d2 | 95 | int rtort_mbtest; |
a241ec65 PM |
96 | }; |
97 | ||
98 | static int fullstop = 0; /* stop generating callbacks at test end. */ | |
99 | static LIST_HEAD(rcu_torture_freelist); | |
100 | static struct rcu_torture *rcu_torture_current = NULL; | |
101 | static long rcu_torture_current_version = 0; | |
102 | static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; | |
103 | static DEFINE_SPINLOCK(rcu_torture_lock); | |
104 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) = | |
105 | { 0 }; | |
106 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) = | |
107 | { 0 }; | |
108 | static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1]; | |
b2896d2e PM |
109 | static atomic_t n_rcu_torture_alloc; |
110 | static atomic_t n_rcu_torture_alloc_fail; | |
111 | static atomic_t n_rcu_torture_free; | |
112 | static atomic_t n_rcu_torture_mberror; | |
113 | static atomic_t n_rcu_torture_error; | |
a241ec65 PM |
114 | |
115 | /* | |
116 | * Allocate an element from the rcu_tortures pool. | |
117 | */ | |
97a41e26 | 118 | static struct rcu_torture * |
a241ec65 PM |
119 | rcu_torture_alloc(void) |
120 | { | |
121 | struct list_head *p; | |
122 | ||
adac1665 | 123 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 PM |
124 | if (list_empty(&rcu_torture_freelist)) { |
125 | atomic_inc(&n_rcu_torture_alloc_fail); | |
adac1665 | 126 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
127 | return NULL; |
128 | } | |
129 | atomic_inc(&n_rcu_torture_alloc); | |
130 | p = rcu_torture_freelist.next; | |
131 | list_del_init(p); | |
adac1665 | 132 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
133 | return container_of(p, struct rcu_torture, rtort_free); |
134 | } | |
135 | ||
136 | /* | |
137 | * Free an element to the rcu_tortures pool. | |
138 | */ | |
139 | static void | |
140 | rcu_torture_free(struct rcu_torture *p) | |
141 | { | |
142 | atomic_inc(&n_rcu_torture_free); | |
adac1665 | 143 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 | 144 | list_add_tail(&p->rtort_free, &rcu_torture_freelist); |
adac1665 | 145 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
146 | } |
147 | ||
a241ec65 PM |
148 | struct rcu_random_state { |
149 | unsigned long rrs_state; | |
75cfef32 | 150 | long rrs_count; |
a241ec65 PM |
151 | }; |
152 | ||
153 | #define RCU_RANDOM_MULT 39916801 /* prime */ | |
154 | #define RCU_RANDOM_ADD 479001701 /* prime */ | |
155 | #define RCU_RANDOM_REFRESH 10000 | |
156 | ||
157 | #define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 } | |
158 | ||
159 | /* | |
160 | * Crude but fast random-number generator. Uses a linear congruential | |
161 | * generator, with occasional help from get_random_bytes(). | |
162 | */ | |
75cfef32 | 163 | static unsigned long |
a241ec65 PM |
164 | rcu_random(struct rcu_random_state *rrsp) |
165 | { | |
166 | long refresh; | |
167 | ||
168 | if (--rrsp->rrs_count < 0) { | |
169 | get_random_bytes(&refresh, sizeof(refresh)); | |
170 | rrsp->rrs_state += refresh; | |
171 | rrsp->rrs_count = RCU_RANDOM_REFRESH; | |
172 | } | |
173 | rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD; | |
174 | return swahw32(rrsp->rrs_state); | |
175 | } | |
176 | ||
72e9bb54 PM |
177 | /* |
178 | * Operations vector for selecting different types of tests. | |
179 | */ | |
180 | ||
181 | struct rcu_torture_ops { | |
182 | void (*init)(void); | |
183 | void (*cleanup)(void); | |
184 | int (*readlock)(void); | |
b2896d2e | 185 | void (*readdelay)(struct rcu_random_state *rrsp); |
72e9bb54 PM |
186 | void (*readunlock)(int idx); |
187 | int (*completed)(void); | |
188 | void (*deferredfree)(struct rcu_torture *p); | |
189 | int (*stats)(char *page); | |
190 | char *name; | |
191 | }; | |
192 | static struct rcu_torture_ops *cur_ops = NULL; | |
193 | ||
194 | /* | |
195 | * Definitions for rcu torture testing. | |
196 | */ | |
197 | ||
a49a4af7 | 198 | static int rcu_torture_read_lock(void) __acquires(RCU) |
72e9bb54 PM |
199 | { |
200 | rcu_read_lock(); | |
201 | return 0; | |
202 | } | |
203 | ||
b2896d2e PM |
204 | static void rcu_read_delay(struct rcu_random_state *rrsp) |
205 | { | |
206 | long delay; | |
207 | const long longdelay = 200; | |
208 | ||
209 | /* We want there to be long-running readers, but not all the time. */ | |
210 | ||
211 | delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay); | |
212 | if (!delay) | |
213 | udelay(longdelay); | |
214 | } | |
215 | ||
a49a4af7 | 216 | static void rcu_torture_read_unlock(int idx) __releases(RCU) |
72e9bb54 PM |
217 | { |
218 | rcu_read_unlock(); | |
219 | } | |
220 | ||
221 | static int rcu_torture_completed(void) | |
222 | { | |
223 | return rcu_batches_completed(); | |
224 | } | |
225 | ||
226 | static void | |
227 | rcu_torture_cb(struct rcu_head *p) | |
228 | { | |
229 | int i; | |
230 | struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); | |
231 | ||
232 | if (fullstop) { | |
233 | /* Test is ending, just drop callbacks on the floor. */ | |
234 | /* The next initialization will pick up the pieces. */ | |
235 | return; | |
236 | } | |
237 | i = rp->rtort_pipe_count; | |
238 | if (i > RCU_TORTURE_PIPE_LEN) | |
239 | i = RCU_TORTURE_PIPE_LEN; | |
240 | atomic_inc(&rcu_torture_wcount[i]); | |
241 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
242 | rp->rtort_mbtest = 0; | |
243 | rcu_torture_free(rp); | |
244 | } else | |
245 | cur_ops->deferredfree(rp); | |
246 | } | |
247 | ||
248 | static void rcu_torture_deferred_free(struct rcu_torture *p) | |
249 | { | |
250 | call_rcu(&p->rtort_rcu, rcu_torture_cb); | |
251 | } | |
252 | ||
253 | static struct rcu_torture_ops rcu_ops = { | |
254 | .init = NULL, | |
255 | .cleanup = NULL, | |
256 | .readlock = rcu_torture_read_lock, | |
b2896d2e | 257 | .readdelay = rcu_read_delay, |
72e9bb54 PM |
258 | .readunlock = rcu_torture_read_unlock, |
259 | .completed = rcu_torture_completed, | |
260 | .deferredfree = rcu_torture_deferred_free, | |
261 | .stats = NULL, | |
262 | .name = "rcu" | |
263 | }; | |
264 | ||
c32e0660 PM |
265 | /* |
266 | * Definitions for rcu_bh torture testing. | |
267 | */ | |
268 | ||
a49a4af7 | 269 | static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH) |
c32e0660 PM |
270 | { |
271 | rcu_read_lock_bh(); | |
272 | return 0; | |
273 | } | |
274 | ||
a49a4af7 | 275 | static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH) |
c32e0660 PM |
276 | { |
277 | rcu_read_unlock_bh(); | |
278 | } | |
279 | ||
280 | static int rcu_bh_torture_completed(void) | |
281 | { | |
282 | return rcu_batches_completed_bh(); | |
283 | } | |
284 | ||
285 | static void rcu_bh_torture_deferred_free(struct rcu_torture *p) | |
286 | { | |
287 | call_rcu_bh(&p->rtort_rcu, rcu_torture_cb); | |
288 | } | |
289 | ||
290 | static struct rcu_torture_ops rcu_bh_ops = { | |
291 | .init = NULL, | |
292 | .cleanup = NULL, | |
293 | .readlock = rcu_bh_torture_read_lock, | |
b2896d2e | 294 | .readdelay = rcu_read_delay, /* just reuse rcu's version. */ |
c32e0660 PM |
295 | .readunlock = rcu_bh_torture_read_unlock, |
296 | .completed = rcu_bh_torture_completed, | |
297 | .deferredfree = rcu_bh_torture_deferred_free, | |
298 | .stats = NULL, | |
299 | .name = "rcu_bh" | |
300 | }; | |
301 | ||
b2896d2e PM |
302 | /* |
303 | * Definitions for srcu torture testing. | |
304 | */ | |
305 | ||
306 | static struct srcu_struct srcu_ctl; | |
307 | static struct list_head srcu_removed; | |
308 | ||
309 | static void srcu_torture_init(void) | |
310 | { | |
311 | init_srcu_struct(&srcu_ctl); | |
312 | INIT_LIST_HEAD(&srcu_removed); | |
313 | } | |
314 | ||
315 | static void srcu_torture_cleanup(void) | |
316 | { | |
317 | synchronize_srcu(&srcu_ctl); | |
318 | cleanup_srcu_struct(&srcu_ctl); | |
319 | } | |
320 | ||
321 | static int srcu_torture_read_lock(void) | |
322 | { | |
323 | return srcu_read_lock(&srcu_ctl); | |
324 | } | |
325 | ||
326 | static void srcu_read_delay(struct rcu_random_state *rrsp) | |
327 | { | |
328 | long delay; | |
329 | const long uspertick = 1000000 / HZ; | |
330 | const long longdelay = 10; | |
331 | ||
332 | /* We want there to be long-running readers, but not all the time. */ | |
333 | ||
334 | delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick); | |
335 | if (!delay) | |
336 | schedule_timeout_interruptible(longdelay); | |
337 | } | |
338 | ||
339 | static void srcu_torture_read_unlock(int idx) | |
340 | { | |
341 | srcu_read_unlock(&srcu_ctl, idx); | |
342 | } | |
343 | ||
344 | static int srcu_torture_completed(void) | |
345 | { | |
346 | return srcu_batches_completed(&srcu_ctl); | |
347 | } | |
348 | ||
349 | static void srcu_torture_deferred_free(struct rcu_torture *p) | |
350 | { | |
351 | int i; | |
352 | struct rcu_torture *rp; | |
353 | struct rcu_torture *rp1; | |
354 | ||
355 | synchronize_srcu(&srcu_ctl); | |
356 | list_add(&p->rtort_free, &srcu_removed); | |
357 | list_for_each_entry_safe(rp, rp1, &srcu_removed, rtort_free) { | |
358 | i = rp->rtort_pipe_count; | |
359 | if (i > RCU_TORTURE_PIPE_LEN) | |
360 | i = RCU_TORTURE_PIPE_LEN; | |
361 | atomic_inc(&rcu_torture_wcount[i]); | |
362 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
363 | rp->rtort_mbtest = 0; | |
364 | list_del(&rp->rtort_free); | |
365 | rcu_torture_free(rp); | |
366 | } | |
367 | } | |
368 | } | |
369 | ||
370 | static int srcu_torture_stats(char *page) | |
371 | { | |
372 | int cnt = 0; | |
373 | int cpu; | |
374 | int idx = srcu_ctl.completed & 0x1; | |
375 | ||
376 | cnt += sprintf(&page[cnt], "%s%s per-CPU(idx=%d):", | |
377 | torture_type, TORTURE_FLAG, idx); | |
378 | for_each_possible_cpu(cpu) { | |
379 | cnt += sprintf(&page[cnt], " %d(%d,%d)", cpu, | |
380 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[!idx], | |
381 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[idx]); | |
382 | } | |
383 | cnt += sprintf(&page[cnt], "\n"); | |
384 | return cnt; | |
385 | } | |
386 | ||
387 | static struct rcu_torture_ops srcu_ops = { | |
388 | .init = srcu_torture_init, | |
389 | .cleanup = srcu_torture_cleanup, | |
390 | .readlock = srcu_torture_read_lock, | |
391 | .readdelay = srcu_read_delay, | |
392 | .readunlock = srcu_torture_read_unlock, | |
393 | .completed = srcu_torture_completed, | |
394 | .deferredfree = srcu_torture_deferred_free, | |
395 | .stats = srcu_torture_stats, | |
396 | .name = "srcu" | |
397 | }; | |
398 | ||
72e9bb54 | 399 | static struct rcu_torture_ops *torture_ops[] = |
b2896d2e | 400 | { &rcu_ops, &rcu_bh_ops, &srcu_ops, NULL }; |
72e9bb54 | 401 | |
a241ec65 PM |
402 | /* |
403 | * RCU torture writer kthread. Repeatedly substitutes a new structure | |
404 | * for that pointed to by rcu_torture_current, freeing the old structure | |
405 | * after a series of grace periods (the "pipeline"). | |
406 | */ | |
407 | static int | |
408 | rcu_torture_writer(void *arg) | |
409 | { | |
410 | int i; | |
411 | long oldbatch = rcu_batches_completed(); | |
412 | struct rcu_torture *rp; | |
413 | struct rcu_torture *old_rp; | |
414 | static DEFINE_RCU_RANDOM(rand); | |
415 | ||
416 | VERBOSE_PRINTK_STRING("rcu_torture_writer task started"); | |
dbdf65b1 IM |
417 | set_user_nice(current, 19); |
418 | ||
a241ec65 PM |
419 | do { |
420 | schedule_timeout_uninterruptible(1); | |
a241ec65 PM |
421 | if ((rp = rcu_torture_alloc()) == NULL) |
422 | continue; | |
423 | rp->rtort_pipe_count = 0; | |
424 | udelay(rcu_random(&rand) & 0x3ff); | |
425 | old_rp = rcu_torture_current; | |
996417d2 | 426 | rp->rtort_mbtest = 1; |
a241ec65 PM |
427 | rcu_assign_pointer(rcu_torture_current, rp); |
428 | smp_wmb(); | |
429 | if (old_rp != NULL) { | |
430 | i = old_rp->rtort_pipe_count; | |
431 | if (i > RCU_TORTURE_PIPE_LEN) | |
432 | i = RCU_TORTURE_PIPE_LEN; | |
433 | atomic_inc(&rcu_torture_wcount[i]); | |
434 | old_rp->rtort_pipe_count++; | |
72e9bb54 | 435 | cur_ops->deferredfree(old_rp); |
a241ec65 PM |
436 | } |
437 | rcu_torture_current_version++; | |
72e9bb54 | 438 | oldbatch = cur_ops->completed(); |
a241ec65 PM |
439 | } while (!kthread_should_stop() && !fullstop); |
440 | VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping"); | |
441 | while (!kthread_should_stop()) | |
442 | schedule_timeout_uninterruptible(1); | |
443 | return 0; | |
444 | } | |
445 | ||
446 | /* | |
447 | * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, | |
448 | * incrementing the corresponding element of the pipeline array. The | |
449 | * counter in the element should never be greater than 1, otherwise, the | |
450 | * RCU implementation is broken. | |
451 | */ | |
452 | static int | |
453 | rcu_torture_reader(void *arg) | |
454 | { | |
455 | int completed; | |
72e9bb54 | 456 | int idx; |
a241ec65 PM |
457 | DEFINE_RCU_RANDOM(rand); |
458 | struct rcu_torture *p; | |
459 | int pipe_count; | |
460 | ||
461 | VERBOSE_PRINTK_STRING("rcu_torture_reader task started"); | |
dbdf65b1 IM |
462 | set_user_nice(current, 19); |
463 | ||
a241ec65 | 464 | do { |
72e9bb54 PM |
465 | idx = cur_ops->readlock(); |
466 | completed = cur_ops->completed(); | |
a241ec65 PM |
467 | p = rcu_dereference(rcu_torture_current); |
468 | if (p == NULL) { | |
469 | /* Wait for rcu_torture_writer to get underway */ | |
72e9bb54 | 470 | cur_ops->readunlock(idx); |
a241ec65 PM |
471 | schedule_timeout_interruptible(HZ); |
472 | continue; | |
473 | } | |
996417d2 PM |
474 | if (p->rtort_mbtest == 0) |
475 | atomic_inc(&n_rcu_torture_mberror); | |
b2896d2e | 476 | cur_ops->readdelay(&rand); |
a241ec65 PM |
477 | preempt_disable(); |
478 | pipe_count = p->rtort_pipe_count; | |
479 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { | |
480 | /* Should not happen, but... */ | |
481 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
482 | } | |
483 | ++__get_cpu_var(rcu_torture_count)[pipe_count]; | |
72e9bb54 | 484 | completed = cur_ops->completed() - completed; |
a241ec65 PM |
485 | if (completed > RCU_TORTURE_PIPE_LEN) { |
486 | /* Should not happen, but... */ | |
487 | completed = RCU_TORTURE_PIPE_LEN; | |
488 | } | |
489 | ++__get_cpu_var(rcu_torture_batch)[completed]; | |
490 | preempt_enable(); | |
72e9bb54 | 491 | cur_ops->readunlock(idx); |
a241ec65 PM |
492 | schedule(); |
493 | } while (!kthread_should_stop() && !fullstop); | |
494 | VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping"); | |
495 | while (!kthread_should_stop()) | |
496 | schedule_timeout_uninterruptible(1); | |
497 | return 0; | |
498 | } | |
499 | ||
500 | /* | |
501 | * Create an RCU-torture statistics message in the specified buffer. | |
502 | */ | |
503 | static int | |
504 | rcu_torture_printk(char *page) | |
505 | { | |
506 | int cnt = 0; | |
507 | int cpu; | |
508 | int i; | |
509 | long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
510 | long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
511 | ||
0a945022 | 512 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
513 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
514 | pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i]; | |
515 | batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i]; | |
516 | } | |
517 | } | |
518 | for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) { | |
519 | if (pipesummary[i] != 0) | |
520 | break; | |
521 | } | |
72e9bb54 | 522 | cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 | 523 | cnt += sprintf(&page[cnt], |
996417d2 PM |
524 | "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d " |
525 | "rtmbe: %d", | |
a241ec65 PM |
526 | rcu_torture_current, |
527 | rcu_torture_current_version, | |
528 | list_empty(&rcu_torture_freelist), | |
529 | atomic_read(&n_rcu_torture_alloc), | |
530 | atomic_read(&n_rcu_torture_alloc_fail), | |
996417d2 PM |
531 | atomic_read(&n_rcu_torture_free), |
532 | atomic_read(&n_rcu_torture_mberror)); | |
533 | if (atomic_read(&n_rcu_torture_mberror) != 0) | |
534 | cnt += sprintf(&page[cnt], " !!!"); | |
72e9bb54 | 535 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
996417d2 | 536 | if (i > 1) { |
a241ec65 | 537 | cnt += sprintf(&page[cnt], "!!! "); |
996417d2 PM |
538 | atomic_inc(&n_rcu_torture_error); |
539 | } | |
a241ec65 PM |
540 | cnt += sprintf(&page[cnt], "Reader Pipe: "); |
541 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) | |
542 | cnt += sprintf(&page[cnt], " %ld", pipesummary[i]); | |
72e9bb54 | 543 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 | 544 | cnt += sprintf(&page[cnt], "Reader Batch: "); |
72e9bb54 | 545 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
a241ec65 | 546 | cnt += sprintf(&page[cnt], " %ld", batchsummary[i]); |
72e9bb54 | 547 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 PM |
548 | cnt += sprintf(&page[cnt], "Free-Block Circulation: "); |
549 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { | |
550 | cnt += sprintf(&page[cnt], " %d", | |
551 | atomic_read(&rcu_torture_wcount[i])); | |
552 | } | |
553 | cnt += sprintf(&page[cnt], "\n"); | |
72e9bb54 PM |
554 | if (cur_ops->stats != NULL) |
555 | cnt += cur_ops->stats(&page[cnt]); | |
a241ec65 PM |
556 | return cnt; |
557 | } | |
558 | ||
559 | /* | |
560 | * Print torture statistics. Caller must ensure that there is only | |
561 | * one call to this function at a given time!!! This is normally | |
562 | * accomplished by relying on the module system to only have one copy | |
563 | * of the module loaded, and then by giving the rcu_torture_stats | |
564 | * kthread full control (or the init/cleanup functions when rcu_torture_stats | |
565 | * thread is not running). | |
566 | */ | |
567 | static void | |
568 | rcu_torture_stats_print(void) | |
569 | { | |
570 | int cnt; | |
571 | ||
572 | cnt = rcu_torture_printk(printk_buf); | |
573 | printk(KERN_ALERT "%s", printk_buf); | |
574 | } | |
575 | ||
576 | /* | |
577 | * Periodically prints torture statistics, if periodic statistics printing | |
578 | * was specified via the stat_interval module parameter. | |
579 | * | |
580 | * No need to worry about fullstop here, since this one doesn't reference | |
581 | * volatile state or register callbacks. | |
582 | */ | |
583 | static int | |
584 | rcu_torture_stats(void *arg) | |
585 | { | |
586 | VERBOSE_PRINTK_STRING("rcu_torture_stats task started"); | |
587 | do { | |
588 | schedule_timeout_interruptible(stat_interval * HZ); | |
589 | rcu_torture_stats_print(); | |
590 | } while (!kthread_should_stop()); | |
591 | VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping"); | |
592 | return 0; | |
593 | } | |
594 | ||
d84f5203 SV |
595 | static int rcu_idle_cpu; /* Force all torture tasks off this CPU */ |
596 | ||
597 | /* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case | |
598 | * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs. | |
599 | */ | |
b2896d2e | 600 | static void rcu_torture_shuffle_tasks(void) |
d84f5203 SV |
601 | { |
602 | cpumask_t tmp_mask = CPU_MASK_ALL; | |
603 | int i; | |
604 | ||
605 | lock_cpu_hotplug(); | |
606 | ||
607 | /* No point in shuffling if there is only one online CPU (ex: UP) */ | |
608 | if (num_online_cpus() == 1) { | |
609 | unlock_cpu_hotplug(); | |
610 | return; | |
611 | } | |
612 | ||
613 | if (rcu_idle_cpu != -1) | |
614 | cpu_clear(rcu_idle_cpu, tmp_mask); | |
615 | ||
616 | set_cpus_allowed(current, tmp_mask); | |
617 | ||
618 | if (reader_tasks != NULL) { | |
619 | for (i = 0; i < nrealreaders; i++) | |
620 | if (reader_tasks[i]) | |
621 | set_cpus_allowed(reader_tasks[i], tmp_mask); | |
622 | } | |
623 | ||
624 | if (writer_task) | |
625 | set_cpus_allowed(writer_task, tmp_mask); | |
626 | ||
627 | if (stats_task) | |
628 | set_cpus_allowed(stats_task, tmp_mask); | |
629 | ||
630 | if (rcu_idle_cpu == -1) | |
631 | rcu_idle_cpu = num_online_cpus() - 1; | |
632 | else | |
633 | rcu_idle_cpu--; | |
634 | ||
635 | unlock_cpu_hotplug(); | |
636 | } | |
637 | ||
638 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the | |
639 | * system to become idle at a time and cut off its timer ticks. This is meant | |
640 | * to test the support for such tickless idle CPU in RCU. | |
641 | */ | |
642 | static int | |
643 | rcu_torture_shuffle(void *arg) | |
644 | { | |
645 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started"); | |
646 | do { | |
647 | schedule_timeout_interruptible(shuffle_interval * HZ); | |
648 | rcu_torture_shuffle_tasks(); | |
649 | } while (!kthread_should_stop()); | |
650 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping"); | |
651 | return 0; | |
652 | } | |
653 | ||
95c38322 PM |
654 | static inline void |
655 | rcu_torture_print_module_parms(char *tag) | |
656 | { | |
72e9bb54 | 657 | printk(KERN_ALERT "%s" TORTURE_FLAG "--- %s: nreaders=%d " |
95c38322 PM |
658 | "stat_interval=%d verbose=%d test_no_idle_hz=%d " |
659 | "shuffle_interval = %d\n", | |
72e9bb54 PM |
660 | torture_type, tag, nrealreaders, stat_interval, verbose, |
661 | test_no_idle_hz, shuffle_interval); | |
95c38322 PM |
662 | } |
663 | ||
a241ec65 PM |
664 | static void |
665 | rcu_torture_cleanup(void) | |
666 | { | |
667 | int i; | |
668 | ||
669 | fullstop = 1; | |
d84f5203 SV |
670 | if (shuffler_task != NULL) { |
671 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task"); | |
672 | kthread_stop(shuffler_task); | |
673 | } | |
674 | shuffler_task = NULL; | |
675 | ||
a241ec65 PM |
676 | if (writer_task != NULL) { |
677 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task"); | |
678 | kthread_stop(writer_task); | |
679 | } | |
680 | writer_task = NULL; | |
681 | ||
682 | if (reader_tasks != NULL) { | |
683 | for (i = 0; i < nrealreaders; i++) { | |
684 | if (reader_tasks[i] != NULL) { | |
685 | VERBOSE_PRINTK_STRING( | |
686 | "Stopping rcu_torture_reader task"); | |
687 | kthread_stop(reader_tasks[i]); | |
688 | } | |
689 | reader_tasks[i] = NULL; | |
690 | } | |
691 | kfree(reader_tasks); | |
692 | reader_tasks = NULL; | |
693 | } | |
694 | rcu_torture_current = NULL; | |
695 | ||
696 | if (stats_task != NULL) { | |
697 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task"); | |
698 | kthread_stop(stats_task); | |
699 | } | |
700 | stats_task = NULL; | |
701 | ||
702 | /* Wait for all RCU callbacks to fire. */ | |
89d46b87 | 703 | rcu_barrier(); |
a241ec65 | 704 | |
a241ec65 | 705 | rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ |
72e9bb54 PM |
706 | |
707 | if (cur_ops->cleanup != NULL) | |
708 | cur_ops->cleanup(); | |
95c38322 PM |
709 | if (atomic_read(&n_rcu_torture_error)) |
710 | rcu_torture_print_module_parms("End of test: FAILURE"); | |
711 | else | |
712 | rcu_torture_print_module_parms("End of test: SUCCESS"); | |
a241ec65 PM |
713 | } |
714 | ||
715 | static int | |
716 | rcu_torture_init(void) | |
717 | { | |
718 | int i; | |
719 | int cpu; | |
720 | int firsterr = 0; | |
721 | ||
722 | /* Process args and tell the world that the torturer is on the job. */ | |
723 | ||
72e9bb54 PM |
724 | for (i = 0; cur_ops = torture_ops[i], cur_ops != NULL; i++) { |
725 | cur_ops = torture_ops[i]; | |
726 | if (strcmp(torture_type, cur_ops->name) == 0) { | |
727 | break; | |
728 | } | |
729 | } | |
730 | if (cur_ops == NULL) { | |
731 | printk(KERN_ALERT "rcutorture: invalid torture type: \"%s\"\n", | |
732 | torture_type); | |
733 | return (-EINVAL); | |
734 | } | |
735 | if (cur_ops->init != NULL) | |
736 | cur_ops->init(); /* no "goto unwind" prior to this point!!! */ | |
737 | ||
a241ec65 PM |
738 | if (nreaders >= 0) |
739 | nrealreaders = nreaders; | |
740 | else | |
741 | nrealreaders = 2 * num_online_cpus(); | |
95c38322 | 742 | rcu_torture_print_module_parms("Start of test"); |
a241ec65 PM |
743 | fullstop = 0; |
744 | ||
745 | /* Set up the freelist. */ | |
746 | ||
747 | INIT_LIST_HEAD(&rcu_torture_freelist); | |
748 | for (i = 0; i < sizeof(rcu_tortures) / sizeof(rcu_tortures[0]); i++) { | |
996417d2 | 749 | rcu_tortures[i].rtort_mbtest = 0; |
a241ec65 PM |
750 | list_add_tail(&rcu_tortures[i].rtort_free, |
751 | &rcu_torture_freelist); | |
752 | } | |
753 | ||
754 | /* Initialize the statistics so that each run gets its own numbers. */ | |
755 | ||
756 | rcu_torture_current = NULL; | |
757 | rcu_torture_current_version = 0; | |
758 | atomic_set(&n_rcu_torture_alloc, 0); | |
759 | atomic_set(&n_rcu_torture_alloc_fail, 0); | |
760 | atomic_set(&n_rcu_torture_free, 0); | |
996417d2 PM |
761 | atomic_set(&n_rcu_torture_mberror, 0); |
762 | atomic_set(&n_rcu_torture_error, 0); | |
a241ec65 PM |
763 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
764 | atomic_set(&rcu_torture_wcount[i], 0); | |
0a945022 | 765 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
766 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
767 | per_cpu(rcu_torture_count, cpu)[i] = 0; | |
768 | per_cpu(rcu_torture_batch, cpu)[i] = 0; | |
769 | } | |
770 | } | |
771 | ||
772 | /* Start up the kthreads. */ | |
773 | ||
774 | VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task"); | |
775 | writer_task = kthread_run(rcu_torture_writer, NULL, | |
776 | "rcu_torture_writer"); | |
777 | if (IS_ERR(writer_task)) { | |
778 | firsterr = PTR_ERR(writer_task); | |
779 | VERBOSE_PRINTK_ERRSTRING("Failed to create writer"); | |
780 | writer_task = NULL; | |
781 | goto unwind; | |
782 | } | |
2860aaba | 783 | reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]), |
a241ec65 PM |
784 | GFP_KERNEL); |
785 | if (reader_tasks == NULL) { | |
786 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
787 | firsterr = -ENOMEM; | |
788 | goto unwind; | |
789 | } | |
790 | for (i = 0; i < nrealreaders; i++) { | |
791 | VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task"); | |
792 | reader_tasks[i] = kthread_run(rcu_torture_reader, NULL, | |
793 | "rcu_torture_reader"); | |
794 | if (IS_ERR(reader_tasks[i])) { | |
795 | firsterr = PTR_ERR(reader_tasks[i]); | |
796 | VERBOSE_PRINTK_ERRSTRING("Failed to create reader"); | |
797 | reader_tasks[i] = NULL; | |
798 | goto unwind; | |
799 | } | |
800 | } | |
801 | if (stat_interval > 0) { | |
802 | VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task"); | |
803 | stats_task = kthread_run(rcu_torture_stats, NULL, | |
804 | "rcu_torture_stats"); | |
805 | if (IS_ERR(stats_task)) { | |
806 | firsterr = PTR_ERR(stats_task); | |
807 | VERBOSE_PRINTK_ERRSTRING("Failed to create stats"); | |
808 | stats_task = NULL; | |
809 | goto unwind; | |
810 | } | |
811 | } | |
d84f5203 SV |
812 | if (test_no_idle_hz) { |
813 | rcu_idle_cpu = num_online_cpus() - 1; | |
814 | /* Create the shuffler thread */ | |
815 | shuffler_task = kthread_run(rcu_torture_shuffle, NULL, | |
816 | "rcu_torture_shuffle"); | |
817 | if (IS_ERR(shuffler_task)) { | |
818 | firsterr = PTR_ERR(shuffler_task); | |
819 | VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler"); | |
820 | shuffler_task = NULL; | |
821 | goto unwind; | |
822 | } | |
823 | } | |
a241ec65 PM |
824 | return 0; |
825 | ||
826 | unwind: | |
827 | rcu_torture_cleanup(); | |
828 | return firsterr; | |
829 | } | |
830 | ||
831 | module_init(rcu_torture_init); | |
832 | module_exit(rcu_torture_cleanup); |