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