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a241ec65 PM |
1 | /* |
2 | * Read-Copy Update /proc-based torture test facility | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
17 | * | |
18 | * Copyright (C) IBM Corporation, 2005 | |
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> | |
47 | ||
48 | MODULE_LICENSE("GPL"); | |
49 | ||
50 | static int nreaders = -1; /* # reader threads, defaults to 4*ncpus */ | |
d84f5203 | 51 | static int stat_interval; /* Interval between stats, in seconds. */ |
a241ec65 | 52 | /* Defaults to "only at end of test". */ |
d84f5203 SV |
53 | static int verbose; /* Print more debug info. */ |
54 | static int test_no_idle_hz; /* Test RCU's support for tickless idle CPUs. */ | |
55 | static int shuffle_interval = 5; /* Interval between shuffles (in sec)*/ | |
a241ec65 PM |
56 | |
57 | MODULE_PARM(nreaders, "i"); | |
58 | MODULE_PARM_DESC(nreaders, "Number of RCU reader threads"); | |
59 | MODULE_PARM(stat_interval, "i"); | |
60 | MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s"); | |
61 | MODULE_PARM(verbose, "i"); | |
62 | MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s"); | |
d84f5203 SV |
63 | MODULE_PARM(test_no_idle_hz, "i"); |
64 | MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs"); | |
65 | MODULE_PARM(shuffle_interval, "i"); | |
66 | MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles"); | |
a241ec65 PM |
67 | #define TORTURE_FLAG "rcutorture: " |
68 | #define PRINTK_STRING(s) \ | |
69 | do { printk(KERN_ALERT TORTURE_FLAG s "\n"); } while (0) | |
70 | #define VERBOSE_PRINTK_STRING(s) \ | |
71 | do { if (verbose) printk(KERN_ALERT TORTURE_FLAG s "\n"); } while (0) | |
72 | #define VERBOSE_PRINTK_ERRSTRING(s) \ | |
73 | do { if (verbose) printk(KERN_ALERT TORTURE_FLAG "!!! " s "\n"); } while (0) | |
74 | ||
75 | static char printk_buf[4096]; | |
76 | ||
77 | static int nrealreaders; | |
78 | static struct task_struct *writer_task; | |
79 | static struct task_struct **reader_tasks; | |
80 | static struct task_struct *stats_task; | |
d84f5203 | 81 | static struct task_struct *shuffler_task; |
a241ec65 PM |
82 | |
83 | #define RCU_TORTURE_PIPE_LEN 10 | |
84 | ||
85 | struct rcu_torture { | |
86 | struct rcu_head rtort_rcu; | |
87 | int rtort_pipe_count; | |
88 | struct list_head rtort_free; | |
996417d2 | 89 | int rtort_mbtest; |
a241ec65 PM |
90 | }; |
91 | ||
92 | static int fullstop = 0; /* stop generating callbacks at test end. */ | |
93 | static LIST_HEAD(rcu_torture_freelist); | |
94 | static struct rcu_torture *rcu_torture_current = NULL; | |
95 | static long rcu_torture_current_version = 0; | |
96 | static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; | |
97 | static DEFINE_SPINLOCK(rcu_torture_lock); | |
98 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) = | |
99 | { 0 }; | |
100 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) = | |
101 | { 0 }; | |
102 | static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1]; | |
103 | atomic_t n_rcu_torture_alloc; | |
104 | atomic_t n_rcu_torture_alloc_fail; | |
105 | atomic_t n_rcu_torture_free; | |
996417d2 PM |
106 | atomic_t n_rcu_torture_mberror; |
107 | atomic_t n_rcu_torture_error; | |
a241ec65 PM |
108 | |
109 | /* | |
110 | * Allocate an element from the rcu_tortures pool. | |
111 | */ | |
97a41e26 | 112 | static struct rcu_torture * |
a241ec65 PM |
113 | rcu_torture_alloc(void) |
114 | { | |
115 | struct list_head *p; | |
116 | ||
adac1665 | 117 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 PM |
118 | if (list_empty(&rcu_torture_freelist)) { |
119 | atomic_inc(&n_rcu_torture_alloc_fail); | |
adac1665 | 120 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
121 | return NULL; |
122 | } | |
123 | atomic_inc(&n_rcu_torture_alloc); | |
124 | p = rcu_torture_freelist.next; | |
125 | list_del_init(p); | |
adac1665 | 126 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
127 | return container_of(p, struct rcu_torture, rtort_free); |
128 | } | |
129 | ||
130 | /* | |
131 | * Free an element to the rcu_tortures pool. | |
132 | */ | |
133 | static void | |
134 | rcu_torture_free(struct rcu_torture *p) | |
135 | { | |
136 | atomic_inc(&n_rcu_torture_free); | |
adac1665 | 137 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 | 138 | list_add_tail(&p->rtort_free, &rcu_torture_freelist); |
adac1665 | 139 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
140 | } |
141 | ||
142 | static void | |
143 | rcu_torture_cb(struct rcu_head *p) | |
144 | { | |
145 | int i; | |
146 | struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); | |
147 | ||
148 | if (fullstop) { | |
149 | /* Test is ending, just drop callbacks on the floor. */ | |
150 | /* The next initialization will pick up the pieces. */ | |
151 | return; | |
152 | } | |
153 | i = rp->rtort_pipe_count; | |
154 | if (i > RCU_TORTURE_PIPE_LEN) | |
155 | i = RCU_TORTURE_PIPE_LEN; | |
156 | atomic_inc(&rcu_torture_wcount[i]); | |
996417d2 PM |
157 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { |
158 | rp->rtort_mbtest = 0; | |
a241ec65 | 159 | rcu_torture_free(rp); |
996417d2 | 160 | } else |
a241ec65 PM |
161 | call_rcu(p, rcu_torture_cb); |
162 | } | |
163 | ||
164 | struct rcu_random_state { | |
165 | unsigned long rrs_state; | |
166 | unsigned long rrs_count; | |
167 | }; | |
168 | ||
169 | #define RCU_RANDOM_MULT 39916801 /* prime */ | |
170 | #define RCU_RANDOM_ADD 479001701 /* prime */ | |
171 | #define RCU_RANDOM_REFRESH 10000 | |
172 | ||
173 | #define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 } | |
174 | ||
175 | /* | |
176 | * Crude but fast random-number generator. Uses a linear congruential | |
177 | * generator, with occasional help from get_random_bytes(). | |
178 | */ | |
179 | static long | |
180 | rcu_random(struct rcu_random_state *rrsp) | |
181 | { | |
182 | long refresh; | |
183 | ||
184 | if (--rrsp->rrs_count < 0) { | |
185 | get_random_bytes(&refresh, sizeof(refresh)); | |
186 | rrsp->rrs_state += refresh; | |
187 | rrsp->rrs_count = RCU_RANDOM_REFRESH; | |
188 | } | |
189 | rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD; | |
190 | return swahw32(rrsp->rrs_state); | |
191 | } | |
192 | ||
193 | /* | |
194 | * RCU torture writer kthread. Repeatedly substitutes a new structure | |
195 | * for that pointed to by rcu_torture_current, freeing the old structure | |
196 | * after a series of grace periods (the "pipeline"). | |
197 | */ | |
198 | static int | |
199 | rcu_torture_writer(void *arg) | |
200 | { | |
201 | int i; | |
202 | long oldbatch = rcu_batches_completed(); | |
203 | struct rcu_torture *rp; | |
204 | struct rcu_torture *old_rp; | |
205 | static DEFINE_RCU_RANDOM(rand); | |
206 | ||
207 | VERBOSE_PRINTK_STRING("rcu_torture_writer task started"); | |
dbdf65b1 IM |
208 | set_user_nice(current, 19); |
209 | ||
a241ec65 PM |
210 | do { |
211 | schedule_timeout_uninterruptible(1); | |
212 | if (rcu_batches_completed() == oldbatch) | |
213 | continue; | |
214 | if ((rp = rcu_torture_alloc()) == NULL) | |
215 | continue; | |
216 | rp->rtort_pipe_count = 0; | |
217 | udelay(rcu_random(&rand) & 0x3ff); | |
218 | old_rp = rcu_torture_current; | |
996417d2 | 219 | rp->rtort_mbtest = 1; |
a241ec65 PM |
220 | rcu_assign_pointer(rcu_torture_current, rp); |
221 | smp_wmb(); | |
222 | if (old_rp != NULL) { | |
223 | i = old_rp->rtort_pipe_count; | |
224 | if (i > RCU_TORTURE_PIPE_LEN) | |
225 | i = RCU_TORTURE_PIPE_LEN; | |
226 | atomic_inc(&rcu_torture_wcount[i]); | |
227 | old_rp->rtort_pipe_count++; | |
228 | call_rcu(&old_rp->rtort_rcu, rcu_torture_cb); | |
229 | } | |
230 | rcu_torture_current_version++; | |
231 | oldbatch = rcu_batches_completed(); | |
232 | } while (!kthread_should_stop() && !fullstop); | |
233 | VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping"); | |
234 | while (!kthread_should_stop()) | |
235 | schedule_timeout_uninterruptible(1); | |
236 | return 0; | |
237 | } | |
238 | ||
239 | /* | |
240 | * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, | |
241 | * incrementing the corresponding element of the pipeline array. The | |
242 | * counter in the element should never be greater than 1, otherwise, the | |
243 | * RCU implementation is broken. | |
244 | */ | |
245 | static int | |
246 | rcu_torture_reader(void *arg) | |
247 | { | |
248 | int completed; | |
249 | DEFINE_RCU_RANDOM(rand); | |
250 | struct rcu_torture *p; | |
251 | int pipe_count; | |
252 | ||
253 | VERBOSE_PRINTK_STRING("rcu_torture_reader task started"); | |
dbdf65b1 IM |
254 | set_user_nice(current, 19); |
255 | ||
a241ec65 PM |
256 | do { |
257 | rcu_read_lock(); | |
258 | completed = rcu_batches_completed(); | |
259 | p = rcu_dereference(rcu_torture_current); | |
260 | if (p == NULL) { | |
261 | /* Wait for rcu_torture_writer to get underway */ | |
262 | rcu_read_unlock(); | |
263 | schedule_timeout_interruptible(HZ); | |
264 | continue; | |
265 | } | |
996417d2 PM |
266 | if (p->rtort_mbtest == 0) |
267 | atomic_inc(&n_rcu_torture_mberror); | |
a241ec65 PM |
268 | udelay(rcu_random(&rand) & 0x7f); |
269 | preempt_disable(); | |
270 | pipe_count = p->rtort_pipe_count; | |
271 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { | |
272 | /* Should not happen, but... */ | |
273 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
274 | } | |
275 | ++__get_cpu_var(rcu_torture_count)[pipe_count]; | |
276 | completed = rcu_batches_completed() - completed; | |
277 | if (completed > RCU_TORTURE_PIPE_LEN) { | |
278 | /* Should not happen, but... */ | |
279 | completed = RCU_TORTURE_PIPE_LEN; | |
280 | } | |
281 | ++__get_cpu_var(rcu_torture_batch)[completed]; | |
282 | preempt_enable(); | |
283 | rcu_read_unlock(); | |
284 | schedule(); | |
285 | } while (!kthread_should_stop() && !fullstop); | |
286 | VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping"); | |
287 | while (!kthread_should_stop()) | |
288 | schedule_timeout_uninterruptible(1); | |
289 | return 0; | |
290 | } | |
291 | ||
292 | /* | |
293 | * Create an RCU-torture statistics message in the specified buffer. | |
294 | */ | |
295 | static int | |
296 | rcu_torture_printk(char *page) | |
297 | { | |
298 | int cnt = 0; | |
299 | int cpu; | |
300 | int i; | |
301 | long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
302 | long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
303 | ||
304 | for_each_cpu(cpu) { | |
305 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { | |
306 | pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i]; | |
307 | batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i]; | |
308 | } | |
309 | } | |
310 | for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) { | |
311 | if (pipesummary[i] != 0) | |
312 | break; | |
313 | } | |
314 | cnt += sprintf(&page[cnt], "rcutorture: "); | |
315 | cnt += sprintf(&page[cnt], | |
996417d2 PM |
316 | "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d " |
317 | "rtmbe: %d", | |
a241ec65 PM |
318 | rcu_torture_current, |
319 | rcu_torture_current_version, | |
320 | list_empty(&rcu_torture_freelist), | |
321 | atomic_read(&n_rcu_torture_alloc), | |
322 | atomic_read(&n_rcu_torture_alloc_fail), | |
996417d2 PM |
323 | atomic_read(&n_rcu_torture_free), |
324 | atomic_read(&n_rcu_torture_mberror)); | |
325 | if (atomic_read(&n_rcu_torture_mberror) != 0) | |
326 | cnt += sprintf(&page[cnt], " !!!"); | |
a241ec65 | 327 | cnt += sprintf(&page[cnt], "\nrcutorture: "); |
996417d2 | 328 | if (i > 1) { |
a241ec65 | 329 | cnt += sprintf(&page[cnt], "!!! "); |
996417d2 PM |
330 | atomic_inc(&n_rcu_torture_error); |
331 | } | |
a241ec65 PM |
332 | cnt += sprintf(&page[cnt], "Reader Pipe: "); |
333 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) | |
334 | cnt += sprintf(&page[cnt], " %ld", pipesummary[i]); | |
335 | cnt += sprintf(&page[cnt], "\nrcutorture: "); | |
336 | cnt += sprintf(&page[cnt], "Reader Batch: "); | |
337 | for (i = 0; i < RCU_TORTURE_PIPE_LEN; i++) | |
338 | cnt += sprintf(&page[cnt], " %ld", batchsummary[i]); | |
339 | cnt += sprintf(&page[cnt], "\nrcutorture: "); | |
340 | cnt += sprintf(&page[cnt], "Free-Block Circulation: "); | |
341 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { | |
342 | cnt += sprintf(&page[cnt], " %d", | |
343 | atomic_read(&rcu_torture_wcount[i])); | |
344 | } | |
345 | cnt += sprintf(&page[cnt], "\n"); | |
346 | return cnt; | |
347 | } | |
348 | ||
349 | /* | |
350 | * Print torture statistics. Caller must ensure that there is only | |
351 | * one call to this function at a given time!!! This is normally | |
352 | * accomplished by relying on the module system to only have one copy | |
353 | * of the module loaded, and then by giving the rcu_torture_stats | |
354 | * kthread full control (or the init/cleanup functions when rcu_torture_stats | |
355 | * thread is not running). | |
356 | */ | |
357 | static void | |
358 | rcu_torture_stats_print(void) | |
359 | { | |
360 | int cnt; | |
361 | ||
362 | cnt = rcu_torture_printk(printk_buf); | |
363 | printk(KERN_ALERT "%s", printk_buf); | |
364 | } | |
365 | ||
366 | /* | |
367 | * Periodically prints torture statistics, if periodic statistics printing | |
368 | * was specified via the stat_interval module parameter. | |
369 | * | |
370 | * No need to worry about fullstop here, since this one doesn't reference | |
371 | * volatile state or register callbacks. | |
372 | */ | |
373 | static int | |
374 | rcu_torture_stats(void *arg) | |
375 | { | |
376 | VERBOSE_PRINTK_STRING("rcu_torture_stats task started"); | |
377 | do { | |
378 | schedule_timeout_interruptible(stat_interval * HZ); | |
379 | rcu_torture_stats_print(); | |
380 | } while (!kthread_should_stop()); | |
381 | VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping"); | |
382 | return 0; | |
383 | } | |
384 | ||
d84f5203 SV |
385 | static int rcu_idle_cpu; /* Force all torture tasks off this CPU */ |
386 | ||
387 | /* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case | |
388 | * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs. | |
389 | */ | |
390 | void rcu_torture_shuffle_tasks(void) | |
391 | { | |
392 | cpumask_t tmp_mask = CPU_MASK_ALL; | |
393 | int i; | |
394 | ||
395 | lock_cpu_hotplug(); | |
396 | ||
397 | /* No point in shuffling if there is only one online CPU (ex: UP) */ | |
398 | if (num_online_cpus() == 1) { | |
399 | unlock_cpu_hotplug(); | |
400 | return; | |
401 | } | |
402 | ||
403 | if (rcu_idle_cpu != -1) | |
404 | cpu_clear(rcu_idle_cpu, tmp_mask); | |
405 | ||
406 | set_cpus_allowed(current, tmp_mask); | |
407 | ||
408 | if (reader_tasks != NULL) { | |
409 | for (i = 0; i < nrealreaders; i++) | |
410 | if (reader_tasks[i]) | |
411 | set_cpus_allowed(reader_tasks[i], tmp_mask); | |
412 | } | |
413 | ||
414 | if (writer_task) | |
415 | set_cpus_allowed(writer_task, tmp_mask); | |
416 | ||
417 | if (stats_task) | |
418 | set_cpus_allowed(stats_task, tmp_mask); | |
419 | ||
420 | if (rcu_idle_cpu == -1) | |
421 | rcu_idle_cpu = num_online_cpus() - 1; | |
422 | else | |
423 | rcu_idle_cpu--; | |
424 | ||
425 | unlock_cpu_hotplug(); | |
426 | } | |
427 | ||
428 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the | |
429 | * system to become idle at a time and cut off its timer ticks. This is meant | |
430 | * to test the support for such tickless idle CPU in RCU. | |
431 | */ | |
432 | static int | |
433 | rcu_torture_shuffle(void *arg) | |
434 | { | |
435 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started"); | |
436 | do { | |
437 | schedule_timeout_interruptible(shuffle_interval * HZ); | |
438 | rcu_torture_shuffle_tasks(); | |
439 | } while (!kthread_should_stop()); | |
440 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping"); | |
441 | return 0; | |
442 | } | |
443 | ||
a241ec65 PM |
444 | static void |
445 | rcu_torture_cleanup(void) | |
446 | { | |
447 | int i; | |
448 | ||
449 | fullstop = 1; | |
d84f5203 SV |
450 | if (shuffler_task != NULL) { |
451 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task"); | |
452 | kthread_stop(shuffler_task); | |
453 | } | |
454 | shuffler_task = NULL; | |
455 | ||
a241ec65 PM |
456 | if (writer_task != NULL) { |
457 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task"); | |
458 | kthread_stop(writer_task); | |
459 | } | |
460 | writer_task = NULL; | |
461 | ||
462 | if (reader_tasks != NULL) { | |
463 | for (i = 0; i < nrealreaders; i++) { | |
464 | if (reader_tasks[i] != NULL) { | |
465 | VERBOSE_PRINTK_STRING( | |
466 | "Stopping rcu_torture_reader task"); | |
467 | kthread_stop(reader_tasks[i]); | |
468 | } | |
469 | reader_tasks[i] = NULL; | |
470 | } | |
471 | kfree(reader_tasks); | |
472 | reader_tasks = NULL; | |
473 | } | |
474 | rcu_torture_current = NULL; | |
475 | ||
476 | if (stats_task != NULL) { | |
477 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task"); | |
478 | kthread_stop(stats_task); | |
479 | } | |
480 | stats_task = NULL; | |
481 | ||
482 | /* Wait for all RCU callbacks to fire. */ | |
89d46b87 | 483 | rcu_barrier(); |
a241ec65 | 484 | |
a241ec65 | 485 | rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ |
996417d2 PM |
486 | printk(KERN_ALERT TORTURE_FLAG |
487 | "--- End of test: %s\n", | |
488 | atomic_read(&n_rcu_torture_error) == 0 ? "SUCCESS" : "FAILURE"); | |
a241ec65 PM |
489 | } |
490 | ||
491 | static int | |
492 | rcu_torture_init(void) | |
493 | { | |
494 | int i; | |
495 | int cpu; | |
496 | int firsterr = 0; | |
497 | ||
498 | /* Process args and tell the world that the torturer is on the job. */ | |
499 | ||
500 | if (nreaders >= 0) | |
501 | nrealreaders = nreaders; | |
502 | else | |
503 | nrealreaders = 2 * num_online_cpus(); | |
d84f5203 SV |
504 | printk(KERN_ALERT TORTURE_FLAG "--- Start of test: nreaders=%d " |
505 | "stat_interval=%d verbose=%d test_no_idle_hz=%d " | |
506 | "shuffle_interval = %d\n", | |
507 | nrealreaders, stat_interval, verbose, test_no_idle_hz, | |
508 | shuffle_interval); | |
a241ec65 PM |
509 | fullstop = 0; |
510 | ||
511 | /* Set up the freelist. */ | |
512 | ||
513 | INIT_LIST_HEAD(&rcu_torture_freelist); | |
514 | for (i = 0; i < sizeof(rcu_tortures) / sizeof(rcu_tortures[0]); i++) { | |
996417d2 | 515 | rcu_tortures[i].rtort_mbtest = 0; |
a241ec65 PM |
516 | list_add_tail(&rcu_tortures[i].rtort_free, |
517 | &rcu_torture_freelist); | |
518 | } | |
519 | ||
520 | /* Initialize the statistics so that each run gets its own numbers. */ | |
521 | ||
522 | rcu_torture_current = NULL; | |
523 | rcu_torture_current_version = 0; | |
524 | atomic_set(&n_rcu_torture_alloc, 0); | |
525 | atomic_set(&n_rcu_torture_alloc_fail, 0); | |
526 | atomic_set(&n_rcu_torture_free, 0); | |
996417d2 PM |
527 | atomic_set(&n_rcu_torture_mberror, 0); |
528 | atomic_set(&n_rcu_torture_error, 0); | |
a241ec65 PM |
529 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
530 | atomic_set(&rcu_torture_wcount[i], 0); | |
531 | for_each_cpu(cpu) { | |
532 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { | |
533 | per_cpu(rcu_torture_count, cpu)[i] = 0; | |
534 | per_cpu(rcu_torture_batch, cpu)[i] = 0; | |
535 | } | |
536 | } | |
537 | ||
538 | /* Start up the kthreads. */ | |
539 | ||
540 | VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task"); | |
541 | writer_task = kthread_run(rcu_torture_writer, NULL, | |
542 | "rcu_torture_writer"); | |
543 | if (IS_ERR(writer_task)) { | |
544 | firsterr = PTR_ERR(writer_task); | |
545 | VERBOSE_PRINTK_ERRSTRING("Failed to create writer"); | |
546 | writer_task = NULL; | |
547 | goto unwind; | |
548 | } | |
549 | reader_tasks = kmalloc(nrealreaders * sizeof(reader_tasks[0]), | |
550 | GFP_KERNEL); | |
551 | if (reader_tasks == NULL) { | |
552 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
553 | firsterr = -ENOMEM; | |
554 | goto unwind; | |
555 | } | |
556 | for (i = 0; i < nrealreaders; i++) { | |
557 | VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task"); | |
558 | reader_tasks[i] = kthread_run(rcu_torture_reader, NULL, | |
559 | "rcu_torture_reader"); | |
560 | if (IS_ERR(reader_tasks[i])) { | |
561 | firsterr = PTR_ERR(reader_tasks[i]); | |
562 | VERBOSE_PRINTK_ERRSTRING("Failed to create reader"); | |
563 | reader_tasks[i] = NULL; | |
564 | goto unwind; | |
565 | } | |
566 | } | |
567 | if (stat_interval > 0) { | |
568 | VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task"); | |
569 | stats_task = kthread_run(rcu_torture_stats, NULL, | |
570 | "rcu_torture_stats"); | |
571 | if (IS_ERR(stats_task)) { | |
572 | firsterr = PTR_ERR(stats_task); | |
573 | VERBOSE_PRINTK_ERRSTRING("Failed to create stats"); | |
574 | stats_task = NULL; | |
575 | goto unwind; | |
576 | } | |
577 | } | |
d84f5203 SV |
578 | if (test_no_idle_hz) { |
579 | rcu_idle_cpu = num_online_cpus() - 1; | |
580 | /* Create the shuffler thread */ | |
581 | shuffler_task = kthread_run(rcu_torture_shuffle, NULL, | |
582 | "rcu_torture_shuffle"); | |
583 | if (IS_ERR(shuffler_task)) { | |
584 | firsterr = PTR_ERR(shuffler_task); | |
585 | VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler"); | |
586 | shuffler_task = NULL; | |
587 | goto unwind; | |
588 | } | |
589 | } | |
a241ec65 PM |
590 | return 0; |
591 | ||
592 | unwind: | |
593 | rcu_torture_cleanup(); | |
594 | return firsterr; | |
595 | } | |
596 | ||
597 | module_init(rcu_torture_init); | |
598 | module_exit(rcu_torture_cleanup); |