Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 1 | /* |
Paul E. McKenney | 29766f1 | 2006-06-27 02:54:02 -0700 | [diff] [blame] | 2 | * Read-Copy Update module-based torture test facility |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 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> |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 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 */ |
Srivatsa Vaddagiri | d84f520 | 2006-01-08 01:03:42 -0800 | [diff] [blame] | 51 | static int stat_interval; /* Interval between stats, in seconds. */ |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 52 | /* Defaults to "only at end of test". */ |
Srivatsa Vaddagiri | d84f520 | 2006-01-08 01:03:42 -0800 | [diff] [blame] | 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)*/ |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 56 | static char *torture_type = "rcu"; /* What to torture. */ |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 57 | |
Rusty Russell | 8d3b33f | 2006-03-25 03:07:05 -0800 | [diff] [blame] | 58 | module_param(nreaders, int, 0); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 59 | MODULE_PARM_DESC(nreaders, "Number of RCU reader threads"); |
Rusty Russell | 8d3b33f | 2006-03-25 03:07:05 -0800 | [diff] [blame] | 60 | module_param(stat_interval, int, 0); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 61 | MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s"); |
Rusty Russell | 8d3b33f | 2006-03-25 03:07:05 -0800 | [diff] [blame] | 62 | module_param(verbose, bool, 0); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 63 | MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s"); |
Rusty Russell | 8d3b33f | 2006-03-25 03:07:05 -0800 | [diff] [blame] | 64 | module_param(test_no_idle_hz, bool, 0); |
Srivatsa Vaddagiri | d84f520 | 2006-01-08 01:03:42 -0800 | [diff] [blame] | 65 | MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs"); |
Rusty Russell | 8d3b33f | 2006-03-25 03:07:05 -0800 | [diff] [blame] | 66 | module_param(shuffle_interval, int, 0); |
Srivatsa Vaddagiri | d84f520 | 2006-01-08 01:03:42 -0800 | [diff] [blame] | 67 | MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles"); |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 68 | module_param(torture_type, charp, 0); |
Paul E. McKenney | c32e066 | 2006-06-27 02:54:04 -0700 | [diff] [blame] | 69 | MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh)"); |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 70 | |
| 71 | #define TORTURE_FLAG "-torture:" |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 72 | #define PRINTK_STRING(s) \ |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 73 | do { printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0) |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 74 | #define VERBOSE_PRINTK_STRING(s) \ |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 75 | do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0) |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 76 | #define VERBOSE_PRINTK_ERRSTRING(s) \ |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 77 | do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0) |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 78 | |
| 79 | static char printk_buf[4096]; |
| 80 | |
| 81 | static int nrealreaders; |
| 82 | static struct task_struct *writer_task; |
| 83 | static struct task_struct **reader_tasks; |
| 84 | static struct task_struct *stats_task; |
Srivatsa Vaddagiri | d84f520 | 2006-01-08 01:03:42 -0800 | [diff] [blame] | 85 | static struct task_struct *shuffler_task; |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 86 | |
| 87 | #define RCU_TORTURE_PIPE_LEN 10 |
| 88 | |
| 89 | struct rcu_torture { |
| 90 | struct rcu_head rtort_rcu; |
| 91 | int rtort_pipe_count; |
| 92 | struct list_head rtort_free; |
Paul E. McKenney | 996417d | 2005-11-18 01:10:50 -0800 | [diff] [blame] | 93 | int rtort_mbtest; |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 94 | }; |
| 95 | |
| 96 | static int fullstop = 0; /* stop generating callbacks at test end. */ |
| 97 | static LIST_HEAD(rcu_torture_freelist); |
| 98 | static struct rcu_torture *rcu_torture_current = NULL; |
| 99 | static long rcu_torture_current_version = 0; |
| 100 | static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; |
| 101 | static DEFINE_SPINLOCK(rcu_torture_lock); |
| 102 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) = |
| 103 | { 0 }; |
| 104 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) = |
| 105 | { 0 }; |
| 106 | static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1]; |
| 107 | atomic_t n_rcu_torture_alloc; |
| 108 | atomic_t n_rcu_torture_alloc_fail; |
| 109 | atomic_t n_rcu_torture_free; |
Paul E. McKenney | 996417d | 2005-11-18 01:10:50 -0800 | [diff] [blame] | 110 | atomic_t n_rcu_torture_mberror; |
| 111 | atomic_t n_rcu_torture_error; |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 112 | |
| 113 | /* |
| 114 | * Allocate an element from the rcu_tortures pool. |
| 115 | */ |
Adrian Bunk | 97a41e2 | 2006-01-08 01:02:17 -0800 | [diff] [blame] | 116 | static struct rcu_torture * |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 117 | rcu_torture_alloc(void) |
| 118 | { |
| 119 | struct list_head *p; |
| 120 | |
Ingo Molnar | adac166 | 2006-01-25 19:50:12 +0100 | [diff] [blame] | 121 | spin_lock_bh(&rcu_torture_lock); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 122 | if (list_empty(&rcu_torture_freelist)) { |
| 123 | atomic_inc(&n_rcu_torture_alloc_fail); |
Ingo Molnar | adac166 | 2006-01-25 19:50:12 +0100 | [diff] [blame] | 124 | spin_unlock_bh(&rcu_torture_lock); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 125 | return NULL; |
| 126 | } |
| 127 | atomic_inc(&n_rcu_torture_alloc); |
| 128 | p = rcu_torture_freelist.next; |
| 129 | list_del_init(p); |
Ingo Molnar | adac166 | 2006-01-25 19:50:12 +0100 | [diff] [blame] | 130 | spin_unlock_bh(&rcu_torture_lock); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 131 | return container_of(p, struct rcu_torture, rtort_free); |
| 132 | } |
| 133 | |
| 134 | /* |
| 135 | * Free an element to the rcu_tortures pool. |
| 136 | */ |
| 137 | static void |
| 138 | rcu_torture_free(struct rcu_torture *p) |
| 139 | { |
| 140 | atomic_inc(&n_rcu_torture_free); |
Ingo Molnar | adac166 | 2006-01-25 19:50:12 +0100 | [diff] [blame] | 141 | spin_lock_bh(&rcu_torture_lock); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 142 | list_add_tail(&p->rtort_free, &rcu_torture_freelist); |
Ingo Molnar | adac166 | 2006-01-25 19:50:12 +0100 | [diff] [blame] | 143 | spin_unlock_bh(&rcu_torture_lock); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 144 | } |
| 145 | |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 146 | struct rcu_random_state { |
| 147 | unsigned long rrs_state; |
| 148 | unsigned long rrs_count; |
| 149 | }; |
| 150 | |
| 151 | #define RCU_RANDOM_MULT 39916801 /* prime */ |
| 152 | #define RCU_RANDOM_ADD 479001701 /* prime */ |
| 153 | #define RCU_RANDOM_REFRESH 10000 |
| 154 | |
| 155 | #define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 } |
| 156 | |
| 157 | /* |
| 158 | * Crude but fast random-number generator. Uses a linear congruential |
| 159 | * generator, with occasional help from get_random_bytes(). |
| 160 | */ |
| 161 | static long |
| 162 | rcu_random(struct rcu_random_state *rrsp) |
| 163 | { |
| 164 | long refresh; |
| 165 | |
| 166 | if (--rrsp->rrs_count < 0) { |
| 167 | get_random_bytes(&refresh, sizeof(refresh)); |
| 168 | rrsp->rrs_state += refresh; |
| 169 | rrsp->rrs_count = RCU_RANDOM_REFRESH; |
| 170 | } |
| 171 | rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD; |
| 172 | return swahw32(rrsp->rrs_state); |
| 173 | } |
| 174 | |
| 175 | /* |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 176 | * Operations vector for selecting different types of tests. |
| 177 | */ |
| 178 | |
| 179 | struct rcu_torture_ops { |
| 180 | void (*init)(void); |
| 181 | void (*cleanup)(void); |
| 182 | int (*readlock)(void); |
| 183 | void (*readunlock)(int idx); |
| 184 | int (*completed)(void); |
| 185 | void (*deferredfree)(struct rcu_torture *p); |
| 186 | int (*stats)(char *page); |
| 187 | char *name; |
| 188 | }; |
| 189 | static struct rcu_torture_ops *cur_ops = NULL; |
| 190 | |
| 191 | /* |
| 192 | * Definitions for rcu torture testing. |
| 193 | */ |
| 194 | |
| 195 | static int rcu_torture_read_lock(void) |
| 196 | { |
| 197 | rcu_read_lock(); |
| 198 | return 0; |
| 199 | } |
| 200 | |
| 201 | static void rcu_torture_read_unlock(int idx) |
| 202 | { |
| 203 | rcu_read_unlock(); |
| 204 | } |
| 205 | |
| 206 | static int rcu_torture_completed(void) |
| 207 | { |
| 208 | return rcu_batches_completed(); |
| 209 | } |
| 210 | |
| 211 | static void |
| 212 | rcu_torture_cb(struct rcu_head *p) |
| 213 | { |
| 214 | int i; |
| 215 | struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); |
| 216 | |
| 217 | if (fullstop) { |
| 218 | /* Test is ending, just drop callbacks on the floor. */ |
| 219 | /* The next initialization will pick up the pieces. */ |
| 220 | return; |
| 221 | } |
| 222 | i = rp->rtort_pipe_count; |
| 223 | if (i > RCU_TORTURE_PIPE_LEN) |
| 224 | i = RCU_TORTURE_PIPE_LEN; |
| 225 | atomic_inc(&rcu_torture_wcount[i]); |
| 226 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { |
| 227 | rp->rtort_mbtest = 0; |
| 228 | rcu_torture_free(rp); |
| 229 | } else |
| 230 | cur_ops->deferredfree(rp); |
| 231 | } |
| 232 | |
| 233 | static void rcu_torture_deferred_free(struct rcu_torture *p) |
| 234 | { |
| 235 | call_rcu(&p->rtort_rcu, rcu_torture_cb); |
| 236 | } |
| 237 | |
| 238 | static struct rcu_torture_ops rcu_ops = { |
| 239 | .init = NULL, |
| 240 | .cleanup = NULL, |
| 241 | .readlock = rcu_torture_read_lock, |
| 242 | .readunlock = rcu_torture_read_unlock, |
| 243 | .completed = rcu_torture_completed, |
| 244 | .deferredfree = rcu_torture_deferred_free, |
| 245 | .stats = NULL, |
| 246 | .name = "rcu" |
| 247 | }; |
| 248 | |
Paul E. McKenney | c32e066 | 2006-06-27 02:54:04 -0700 | [diff] [blame] | 249 | /* |
| 250 | * Definitions for rcu_bh torture testing. |
| 251 | */ |
| 252 | |
| 253 | static int rcu_bh_torture_read_lock(void) |
| 254 | { |
| 255 | rcu_read_lock_bh(); |
| 256 | return 0; |
| 257 | } |
| 258 | |
| 259 | static void rcu_bh_torture_read_unlock(int idx) |
| 260 | { |
| 261 | rcu_read_unlock_bh(); |
| 262 | } |
| 263 | |
| 264 | static int rcu_bh_torture_completed(void) |
| 265 | { |
| 266 | return rcu_batches_completed_bh(); |
| 267 | } |
| 268 | |
| 269 | static void rcu_bh_torture_deferred_free(struct rcu_torture *p) |
| 270 | { |
| 271 | call_rcu_bh(&p->rtort_rcu, rcu_torture_cb); |
| 272 | } |
| 273 | |
| 274 | static struct rcu_torture_ops rcu_bh_ops = { |
| 275 | .init = NULL, |
| 276 | .cleanup = NULL, |
| 277 | .readlock = rcu_bh_torture_read_lock, |
| 278 | .readunlock = rcu_bh_torture_read_unlock, |
| 279 | .completed = rcu_bh_torture_completed, |
| 280 | .deferredfree = rcu_bh_torture_deferred_free, |
| 281 | .stats = NULL, |
| 282 | .name = "rcu_bh" |
| 283 | }; |
| 284 | |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 285 | static struct rcu_torture_ops *torture_ops[] = |
Paul E. McKenney | c32e066 | 2006-06-27 02:54:04 -0700 | [diff] [blame] | 286 | { &rcu_ops, &rcu_bh_ops, NULL }; |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 287 | |
| 288 | /* |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 289 | * RCU torture writer kthread. Repeatedly substitutes a new structure |
| 290 | * for that pointed to by rcu_torture_current, freeing the old structure |
| 291 | * after a series of grace periods (the "pipeline"). |
| 292 | */ |
| 293 | static int |
| 294 | rcu_torture_writer(void *arg) |
| 295 | { |
| 296 | int i; |
| 297 | long oldbatch = rcu_batches_completed(); |
| 298 | struct rcu_torture *rp; |
| 299 | struct rcu_torture *old_rp; |
| 300 | static DEFINE_RCU_RANDOM(rand); |
| 301 | |
| 302 | VERBOSE_PRINTK_STRING("rcu_torture_writer task started"); |
Ingo Molnar | dbdf65b | 2005-11-13 16:07:22 -0800 | [diff] [blame] | 303 | set_user_nice(current, 19); |
| 304 | |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 305 | do { |
| 306 | schedule_timeout_uninterruptible(1); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 307 | if ((rp = rcu_torture_alloc()) == NULL) |
| 308 | continue; |
| 309 | rp->rtort_pipe_count = 0; |
| 310 | udelay(rcu_random(&rand) & 0x3ff); |
| 311 | old_rp = rcu_torture_current; |
Paul E. McKenney | 996417d | 2005-11-18 01:10:50 -0800 | [diff] [blame] | 312 | rp->rtort_mbtest = 1; |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 313 | rcu_assign_pointer(rcu_torture_current, rp); |
| 314 | smp_wmb(); |
| 315 | if (old_rp != NULL) { |
| 316 | i = old_rp->rtort_pipe_count; |
| 317 | if (i > RCU_TORTURE_PIPE_LEN) |
| 318 | i = RCU_TORTURE_PIPE_LEN; |
| 319 | atomic_inc(&rcu_torture_wcount[i]); |
| 320 | old_rp->rtort_pipe_count++; |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 321 | cur_ops->deferredfree(old_rp); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 322 | } |
| 323 | rcu_torture_current_version++; |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 324 | oldbatch = cur_ops->completed(); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 325 | } while (!kthread_should_stop() && !fullstop); |
| 326 | VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping"); |
| 327 | while (!kthread_should_stop()) |
| 328 | schedule_timeout_uninterruptible(1); |
| 329 | return 0; |
| 330 | } |
| 331 | |
| 332 | /* |
| 333 | * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, |
| 334 | * incrementing the corresponding element of the pipeline array. The |
| 335 | * counter in the element should never be greater than 1, otherwise, the |
| 336 | * RCU implementation is broken. |
| 337 | */ |
| 338 | static int |
| 339 | rcu_torture_reader(void *arg) |
| 340 | { |
| 341 | int completed; |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 342 | int idx; |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 343 | DEFINE_RCU_RANDOM(rand); |
| 344 | struct rcu_torture *p; |
| 345 | int pipe_count; |
| 346 | |
| 347 | VERBOSE_PRINTK_STRING("rcu_torture_reader task started"); |
Ingo Molnar | dbdf65b | 2005-11-13 16:07:22 -0800 | [diff] [blame] | 348 | set_user_nice(current, 19); |
| 349 | |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 350 | do { |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 351 | idx = cur_ops->readlock(); |
| 352 | completed = cur_ops->completed(); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 353 | p = rcu_dereference(rcu_torture_current); |
| 354 | if (p == NULL) { |
| 355 | /* Wait for rcu_torture_writer to get underway */ |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 356 | cur_ops->readunlock(idx); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 357 | schedule_timeout_interruptible(HZ); |
| 358 | continue; |
| 359 | } |
Paul E. McKenney | 996417d | 2005-11-18 01:10:50 -0800 | [diff] [blame] | 360 | if (p->rtort_mbtest == 0) |
| 361 | atomic_inc(&n_rcu_torture_mberror); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 362 | udelay(rcu_random(&rand) & 0x7f); |
| 363 | preempt_disable(); |
| 364 | pipe_count = p->rtort_pipe_count; |
| 365 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { |
| 366 | /* Should not happen, but... */ |
| 367 | pipe_count = RCU_TORTURE_PIPE_LEN; |
| 368 | } |
| 369 | ++__get_cpu_var(rcu_torture_count)[pipe_count]; |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 370 | completed = cur_ops->completed() - completed; |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 371 | if (completed > RCU_TORTURE_PIPE_LEN) { |
| 372 | /* Should not happen, but... */ |
| 373 | completed = RCU_TORTURE_PIPE_LEN; |
| 374 | } |
| 375 | ++__get_cpu_var(rcu_torture_batch)[completed]; |
| 376 | preempt_enable(); |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 377 | cur_ops->readunlock(idx); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 378 | schedule(); |
| 379 | } while (!kthread_should_stop() && !fullstop); |
| 380 | VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping"); |
| 381 | while (!kthread_should_stop()) |
| 382 | schedule_timeout_uninterruptible(1); |
| 383 | return 0; |
| 384 | } |
| 385 | |
| 386 | /* |
| 387 | * Create an RCU-torture statistics message in the specified buffer. |
| 388 | */ |
| 389 | static int |
| 390 | rcu_torture_printk(char *page) |
| 391 | { |
| 392 | int cnt = 0; |
| 393 | int cpu; |
| 394 | int i; |
| 395 | long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; |
| 396 | long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; |
| 397 | |
KAMEZAWA Hiroyuki | 0a94502 | 2006-03-28 01:56:37 -0800 | [diff] [blame] | 398 | for_each_possible_cpu(cpu) { |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 399 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
| 400 | pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i]; |
| 401 | batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i]; |
| 402 | } |
| 403 | } |
| 404 | for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) { |
| 405 | if (pipesummary[i] != 0) |
| 406 | break; |
| 407 | } |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 408 | cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 409 | cnt += sprintf(&page[cnt], |
Paul E. McKenney | 996417d | 2005-11-18 01:10:50 -0800 | [diff] [blame] | 410 | "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d " |
| 411 | "rtmbe: %d", |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 412 | rcu_torture_current, |
| 413 | rcu_torture_current_version, |
| 414 | list_empty(&rcu_torture_freelist), |
| 415 | atomic_read(&n_rcu_torture_alloc), |
| 416 | atomic_read(&n_rcu_torture_alloc_fail), |
Paul E. McKenney | 996417d | 2005-11-18 01:10:50 -0800 | [diff] [blame] | 417 | atomic_read(&n_rcu_torture_free), |
| 418 | atomic_read(&n_rcu_torture_mberror)); |
| 419 | if (atomic_read(&n_rcu_torture_mberror) != 0) |
| 420 | cnt += sprintf(&page[cnt], " !!!"); |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 421 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
Paul E. McKenney | 996417d | 2005-11-18 01:10:50 -0800 | [diff] [blame] | 422 | if (i > 1) { |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 423 | cnt += sprintf(&page[cnt], "!!! "); |
Paul E. McKenney | 996417d | 2005-11-18 01:10:50 -0800 | [diff] [blame] | 424 | atomic_inc(&n_rcu_torture_error); |
| 425 | } |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 426 | cnt += sprintf(&page[cnt], "Reader Pipe: "); |
| 427 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
| 428 | cnt += sprintf(&page[cnt], " %ld", pipesummary[i]); |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 429 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 430 | cnt += sprintf(&page[cnt], "Reader Batch: "); |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 431 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 432 | cnt += sprintf(&page[cnt], " %ld", batchsummary[i]); |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 433 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 434 | cnt += sprintf(&page[cnt], "Free-Block Circulation: "); |
| 435 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
| 436 | cnt += sprintf(&page[cnt], " %d", |
| 437 | atomic_read(&rcu_torture_wcount[i])); |
| 438 | } |
| 439 | cnt += sprintf(&page[cnt], "\n"); |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 440 | if (cur_ops->stats != NULL) |
| 441 | cnt += cur_ops->stats(&page[cnt]); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 442 | return cnt; |
| 443 | } |
| 444 | |
| 445 | /* |
| 446 | * Print torture statistics. Caller must ensure that there is only |
| 447 | * one call to this function at a given time!!! This is normally |
| 448 | * accomplished by relying on the module system to only have one copy |
| 449 | * of the module loaded, and then by giving the rcu_torture_stats |
| 450 | * kthread full control (or the init/cleanup functions when rcu_torture_stats |
| 451 | * thread is not running). |
| 452 | */ |
| 453 | static void |
| 454 | rcu_torture_stats_print(void) |
| 455 | { |
| 456 | int cnt; |
| 457 | |
| 458 | cnt = rcu_torture_printk(printk_buf); |
| 459 | printk(KERN_ALERT "%s", printk_buf); |
| 460 | } |
| 461 | |
| 462 | /* |
| 463 | * Periodically prints torture statistics, if periodic statistics printing |
| 464 | * was specified via the stat_interval module parameter. |
| 465 | * |
| 466 | * No need to worry about fullstop here, since this one doesn't reference |
| 467 | * volatile state or register callbacks. |
| 468 | */ |
| 469 | static int |
| 470 | rcu_torture_stats(void *arg) |
| 471 | { |
| 472 | VERBOSE_PRINTK_STRING("rcu_torture_stats task started"); |
| 473 | do { |
| 474 | schedule_timeout_interruptible(stat_interval * HZ); |
| 475 | rcu_torture_stats_print(); |
| 476 | } while (!kthread_should_stop()); |
| 477 | VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping"); |
| 478 | return 0; |
| 479 | } |
| 480 | |
Srivatsa Vaddagiri | d84f520 | 2006-01-08 01:03:42 -0800 | [diff] [blame] | 481 | static int rcu_idle_cpu; /* Force all torture tasks off this CPU */ |
| 482 | |
| 483 | /* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case |
| 484 | * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs. |
| 485 | */ |
| 486 | void rcu_torture_shuffle_tasks(void) |
| 487 | { |
| 488 | cpumask_t tmp_mask = CPU_MASK_ALL; |
| 489 | int i; |
| 490 | |
| 491 | lock_cpu_hotplug(); |
| 492 | |
| 493 | /* No point in shuffling if there is only one online CPU (ex: UP) */ |
| 494 | if (num_online_cpus() == 1) { |
| 495 | unlock_cpu_hotplug(); |
| 496 | return; |
| 497 | } |
| 498 | |
| 499 | if (rcu_idle_cpu != -1) |
| 500 | cpu_clear(rcu_idle_cpu, tmp_mask); |
| 501 | |
| 502 | set_cpus_allowed(current, tmp_mask); |
| 503 | |
| 504 | if (reader_tasks != NULL) { |
| 505 | for (i = 0; i < nrealreaders; i++) |
| 506 | if (reader_tasks[i]) |
| 507 | set_cpus_allowed(reader_tasks[i], tmp_mask); |
| 508 | } |
| 509 | |
| 510 | if (writer_task) |
| 511 | set_cpus_allowed(writer_task, tmp_mask); |
| 512 | |
| 513 | if (stats_task) |
| 514 | set_cpus_allowed(stats_task, tmp_mask); |
| 515 | |
| 516 | if (rcu_idle_cpu == -1) |
| 517 | rcu_idle_cpu = num_online_cpus() - 1; |
| 518 | else |
| 519 | rcu_idle_cpu--; |
| 520 | |
| 521 | unlock_cpu_hotplug(); |
| 522 | } |
| 523 | |
| 524 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the |
| 525 | * system to become idle at a time and cut off its timer ticks. This is meant |
| 526 | * to test the support for such tickless idle CPU in RCU. |
| 527 | */ |
| 528 | static int |
| 529 | rcu_torture_shuffle(void *arg) |
| 530 | { |
| 531 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started"); |
| 532 | do { |
| 533 | schedule_timeout_interruptible(shuffle_interval * HZ); |
| 534 | rcu_torture_shuffle_tasks(); |
| 535 | } while (!kthread_should_stop()); |
| 536 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping"); |
| 537 | return 0; |
| 538 | } |
| 539 | |
Paul E. McKenney | 95c3832 | 2006-03-24 03:15:58 -0800 | [diff] [blame] | 540 | static inline void |
| 541 | rcu_torture_print_module_parms(char *tag) |
| 542 | { |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 543 | printk(KERN_ALERT "%s" TORTURE_FLAG "--- %s: nreaders=%d " |
Paul E. McKenney | 95c3832 | 2006-03-24 03:15:58 -0800 | [diff] [blame] | 544 | "stat_interval=%d verbose=%d test_no_idle_hz=%d " |
| 545 | "shuffle_interval = %d\n", |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 546 | torture_type, tag, nrealreaders, stat_interval, verbose, |
| 547 | test_no_idle_hz, shuffle_interval); |
Paul E. McKenney | 95c3832 | 2006-03-24 03:15:58 -0800 | [diff] [blame] | 548 | } |
| 549 | |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 550 | static void |
| 551 | rcu_torture_cleanup(void) |
| 552 | { |
| 553 | int i; |
| 554 | |
| 555 | fullstop = 1; |
Srivatsa Vaddagiri | d84f520 | 2006-01-08 01:03:42 -0800 | [diff] [blame] | 556 | if (shuffler_task != NULL) { |
| 557 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task"); |
| 558 | kthread_stop(shuffler_task); |
| 559 | } |
| 560 | shuffler_task = NULL; |
| 561 | |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 562 | if (writer_task != NULL) { |
| 563 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task"); |
| 564 | kthread_stop(writer_task); |
| 565 | } |
| 566 | writer_task = NULL; |
| 567 | |
| 568 | if (reader_tasks != NULL) { |
| 569 | for (i = 0; i < nrealreaders; i++) { |
| 570 | if (reader_tasks[i] != NULL) { |
| 571 | VERBOSE_PRINTK_STRING( |
| 572 | "Stopping rcu_torture_reader task"); |
| 573 | kthread_stop(reader_tasks[i]); |
| 574 | } |
| 575 | reader_tasks[i] = NULL; |
| 576 | } |
| 577 | kfree(reader_tasks); |
| 578 | reader_tasks = NULL; |
| 579 | } |
| 580 | rcu_torture_current = NULL; |
| 581 | |
| 582 | if (stats_task != NULL) { |
| 583 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task"); |
| 584 | kthread_stop(stats_task); |
| 585 | } |
| 586 | stats_task = NULL; |
| 587 | |
| 588 | /* Wait for all RCU callbacks to fire. */ |
Srivatsa Vaddagiri | 89d46b8 | 2005-12-12 00:37:06 -0800 | [diff] [blame] | 589 | rcu_barrier(); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 590 | |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 591 | rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 592 | |
| 593 | if (cur_ops->cleanup != NULL) |
| 594 | cur_ops->cleanup(); |
Paul E. McKenney | 95c3832 | 2006-03-24 03:15:58 -0800 | [diff] [blame] | 595 | if (atomic_read(&n_rcu_torture_error)) |
| 596 | rcu_torture_print_module_parms("End of test: FAILURE"); |
| 597 | else |
| 598 | rcu_torture_print_module_parms("End of test: SUCCESS"); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 599 | } |
| 600 | |
| 601 | static int |
| 602 | rcu_torture_init(void) |
| 603 | { |
| 604 | int i; |
| 605 | int cpu; |
| 606 | int firsterr = 0; |
| 607 | |
| 608 | /* Process args and tell the world that the torturer is on the job. */ |
| 609 | |
Paul E. McKenney | 72e9bb5 | 2006-06-27 02:54:03 -0700 | [diff] [blame] | 610 | for (i = 0; cur_ops = torture_ops[i], cur_ops != NULL; i++) { |
| 611 | cur_ops = torture_ops[i]; |
| 612 | if (strcmp(torture_type, cur_ops->name) == 0) { |
| 613 | break; |
| 614 | } |
| 615 | } |
| 616 | if (cur_ops == NULL) { |
| 617 | printk(KERN_ALERT "rcutorture: invalid torture type: \"%s\"\n", |
| 618 | torture_type); |
| 619 | return (-EINVAL); |
| 620 | } |
| 621 | if (cur_ops->init != NULL) |
| 622 | cur_ops->init(); /* no "goto unwind" prior to this point!!! */ |
| 623 | |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 624 | if (nreaders >= 0) |
| 625 | nrealreaders = nreaders; |
| 626 | else |
| 627 | nrealreaders = 2 * num_online_cpus(); |
Paul E. McKenney | 95c3832 | 2006-03-24 03:15:58 -0800 | [diff] [blame] | 628 | rcu_torture_print_module_parms("Start of test"); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 629 | fullstop = 0; |
| 630 | |
| 631 | /* Set up the freelist. */ |
| 632 | |
| 633 | INIT_LIST_HEAD(&rcu_torture_freelist); |
| 634 | for (i = 0; i < sizeof(rcu_tortures) / sizeof(rcu_tortures[0]); i++) { |
Paul E. McKenney | 996417d | 2005-11-18 01:10:50 -0800 | [diff] [blame] | 635 | rcu_tortures[i].rtort_mbtest = 0; |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 636 | list_add_tail(&rcu_tortures[i].rtort_free, |
| 637 | &rcu_torture_freelist); |
| 638 | } |
| 639 | |
| 640 | /* Initialize the statistics so that each run gets its own numbers. */ |
| 641 | |
| 642 | rcu_torture_current = NULL; |
| 643 | rcu_torture_current_version = 0; |
| 644 | atomic_set(&n_rcu_torture_alloc, 0); |
| 645 | atomic_set(&n_rcu_torture_alloc_fail, 0); |
| 646 | atomic_set(&n_rcu_torture_free, 0); |
Paul E. McKenney | 996417d | 2005-11-18 01:10:50 -0800 | [diff] [blame] | 647 | atomic_set(&n_rcu_torture_mberror, 0); |
| 648 | atomic_set(&n_rcu_torture_error, 0); |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 649 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
| 650 | atomic_set(&rcu_torture_wcount[i], 0); |
KAMEZAWA Hiroyuki | 0a94502 | 2006-03-28 01:56:37 -0800 | [diff] [blame] | 651 | for_each_possible_cpu(cpu) { |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 652 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
| 653 | per_cpu(rcu_torture_count, cpu)[i] = 0; |
| 654 | per_cpu(rcu_torture_batch, cpu)[i] = 0; |
| 655 | } |
| 656 | } |
| 657 | |
| 658 | /* Start up the kthreads. */ |
| 659 | |
| 660 | VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task"); |
| 661 | writer_task = kthread_run(rcu_torture_writer, NULL, |
| 662 | "rcu_torture_writer"); |
| 663 | if (IS_ERR(writer_task)) { |
| 664 | firsterr = PTR_ERR(writer_task); |
| 665 | VERBOSE_PRINTK_ERRSTRING("Failed to create writer"); |
| 666 | writer_task = NULL; |
| 667 | goto unwind; |
| 668 | } |
| 669 | reader_tasks = kmalloc(nrealreaders * sizeof(reader_tasks[0]), |
| 670 | GFP_KERNEL); |
| 671 | if (reader_tasks == NULL) { |
| 672 | VERBOSE_PRINTK_ERRSTRING("out of memory"); |
| 673 | firsterr = -ENOMEM; |
| 674 | goto unwind; |
| 675 | } |
| 676 | for (i = 0; i < nrealreaders; i++) { |
| 677 | VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task"); |
| 678 | reader_tasks[i] = kthread_run(rcu_torture_reader, NULL, |
| 679 | "rcu_torture_reader"); |
| 680 | if (IS_ERR(reader_tasks[i])) { |
| 681 | firsterr = PTR_ERR(reader_tasks[i]); |
| 682 | VERBOSE_PRINTK_ERRSTRING("Failed to create reader"); |
| 683 | reader_tasks[i] = NULL; |
| 684 | goto unwind; |
| 685 | } |
| 686 | } |
| 687 | if (stat_interval > 0) { |
| 688 | VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task"); |
| 689 | stats_task = kthread_run(rcu_torture_stats, NULL, |
| 690 | "rcu_torture_stats"); |
| 691 | if (IS_ERR(stats_task)) { |
| 692 | firsterr = PTR_ERR(stats_task); |
| 693 | VERBOSE_PRINTK_ERRSTRING("Failed to create stats"); |
| 694 | stats_task = NULL; |
| 695 | goto unwind; |
| 696 | } |
| 697 | } |
Srivatsa Vaddagiri | d84f520 | 2006-01-08 01:03:42 -0800 | [diff] [blame] | 698 | if (test_no_idle_hz) { |
| 699 | rcu_idle_cpu = num_online_cpus() - 1; |
| 700 | /* Create the shuffler thread */ |
| 701 | shuffler_task = kthread_run(rcu_torture_shuffle, NULL, |
| 702 | "rcu_torture_shuffle"); |
| 703 | if (IS_ERR(shuffler_task)) { |
| 704 | firsterr = PTR_ERR(shuffler_task); |
| 705 | VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler"); |
| 706 | shuffler_task = NULL; |
| 707 | goto unwind; |
| 708 | } |
| 709 | } |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 710 | return 0; |
| 711 | |
| 712 | unwind: |
| 713 | rcu_torture_cleanup(); |
| 714 | return firsterr; |
| 715 | } |
| 716 | |
| 717 | module_init(rcu_torture_init); |
| 718 | module_exit(rcu_torture_cleanup); |