1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * Read-Copy Update definitions shared among RCU implementations. 4 * 5 * Copyright IBM Corporation, 2011 6 * 7 * Author: Paul E. McKenney <paulmck@linux.ibm.com> 8 */ 9 10 #ifndef __LINUX_RCU_H 11 #define __LINUX_RCU_H 12 13 #include <trace/events/rcu.h> 14 15 /* 16 * Grace-period counter management. 17 */ 18 19 #define RCU_SEQ_CTR_SHIFT 2 20 #define RCU_SEQ_STATE_MASK ((1 << RCU_SEQ_CTR_SHIFT) - 1) 21 22 /* Low-order bit definition for polled grace-period APIs. */ 23 #define RCU_GET_STATE_COMPLETED 0x1 24 25 extern int sysctl_sched_rt_runtime; 26 27 /* 28 * Return the counter portion of a sequence number previously returned 29 * by rcu_seq_snap() or rcu_seq_current(). 30 */ 31 static inline unsigned long rcu_seq_ctr(unsigned long s) 32 { 33 return s >> RCU_SEQ_CTR_SHIFT; 34 } 35 36 /* 37 * Return the state portion of a sequence number previously returned 38 * by rcu_seq_snap() or rcu_seq_current(). 39 */ 40 static inline int rcu_seq_state(unsigned long s) 41 { 42 return s & RCU_SEQ_STATE_MASK; 43 } 44 45 /* 46 * Set the state portion of the pointed-to sequence number. 47 * The caller is responsible for preventing conflicting updates. 48 */ 49 static inline void rcu_seq_set_state(unsigned long *sp, int newstate) 50 { 51 WARN_ON_ONCE(newstate & ~RCU_SEQ_STATE_MASK); 52 WRITE_ONCE(*sp, (*sp & ~RCU_SEQ_STATE_MASK) + newstate); 53 } 54 55 /* Adjust sequence number for start of update-side operation. */ 56 static inline void rcu_seq_start(unsigned long *sp) 57 { 58 WRITE_ONCE(*sp, *sp + 1); 59 smp_mb(); /* Ensure update-side operation after counter increment. */ 60 WARN_ON_ONCE(rcu_seq_state(*sp) != 1); 61 } 62 63 /* Compute the end-of-grace-period value for the specified sequence number. */ 64 static inline unsigned long rcu_seq_endval(unsigned long *sp) 65 { 66 return (*sp | RCU_SEQ_STATE_MASK) + 1; 67 } 68 69 /* Adjust sequence number for end of update-side operation. */ 70 static inline void rcu_seq_end(unsigned long *sp) 71 { 72 smp_mb(); /* Ensure update-side operation before counter increment. */ 73 WARN_ON_ONCE(!rcu_seq_state(*sp)); 74 WRITE_ONCE(*sp, rcu_seq_endval(sp)); 75 } 76 77 /* 78 * rcu_seq_snap - Take a snapshot of the update side's sequence number. 79 * 80 * This function returns the earliest value of the grace-period sequence number 81 * that will indicate that a full grace period has elapsed since the current 82 * time. Once the grace-period sequence number has reached this value, it will 83 * be safe to invoke all callbacks that have been registered prior to the 84 * current time. This value is the current grace-period number plus two to the 85 * power of the number of low-order bits reserved for state, then rounded up to 86 * the next value in which the state bits are all zero. 87 */ 88 static inline unsigned long rcu_seq_snap(unsigned long *sp) 89 { 90 unsigned long s; 91 92 s = (READ_ONCE(*sp) + 2 * RCU_SEQ_STATE_MASK + 1) & ~RCU_SEQ_STATE_MASK; 93 smp_mb(); /* Above access must not bleed into critical section. */ 94 return s; 95 } 96 97 /* Return the current value the update side's sequence number, no ordering. */ 98 static inline unsigned long rcu_seq_current(unsigned long *sp) 99 { 100 return READ_ONCE(*sp); 101 } 102 103 /* 104 * Given a snapshot from rcu_seq_snap(), determine whether or not the 105 * corresponding update-side operation has started. 106 */ 107 static inline bool rcu_seq_started(unsigned long *sp, unsigned long s) 108 { 109 return ULONG_CMP_LT((s - 1) & ~RCU_SEQ_STATE_MASK, READ_ONCE(*sp)); 110 } 111 112 /* 113 * Given a snapshot from rcu_seq_snap(), determine whether or not a 114 * full update-side operation has occurred. 115 */ 116 static inline bool rcu_seq_done(unsigned long *sp, unsigned long s) 117 { 118 return ULONG_CMP_GE(READ_ONCE(*sp), s); 119 } 120 121 /* 122 * Given a snapshot from rcu_seq_snap(), determine whether or not a 123 * full update-side operation has occurred, but do not allow the 124 * (ULONG_MAX / 2) safety-factor/guard-band. 125 */ 126 static inline bool rcu_seq_done_exact(unsigned long *sp, unsigned long s) 127 { 128 unsigned long cur_s = READ_ONCE(*sp); 129 130 return ULONG_CMP_GE(cur_s, s) || ULONG_CMP_LT(cur_s, s - (2 * RCU_SEQ_STATE_MASK + 1)); 131 } 132 133 /* 134 * Has a grace period completed since the time the old gp_seq was collected? 135 */ 136 static inline bool rcu_seq_completed_gp(unsigned long old, unsigned long new) 137 { 138 return ULONG_CMP_LT(old, new & ~RCU_SEQ_STATE_MASK); 139 } 140 141 /* 142 * Has a grace period started since the time the old gp_seq was collected? 143 */ 144 static inline bool rcu_seq_new_gp(unsigned long old, unsigned long new) 145 { 146 return ULONG_CMP_LT((old + RCU_SEQ_STATE_MASK) & ~RCU_SEQ_STATE_MASK, 147 new); 148 } 149 150 /* 151 * Roughly how many full grace periods have elapsed between the collection 152 * of the two specified grace periods? 153 */ 154 static inline unsigned long rcu_seq_diff(unsigned long new, unsigned long old) 155 { 156 unsigned long rnd_diff; 157 158 if (old == new) 159 return 0; 160 /* 161 * Compute the number of grace periods (still shifted up), plus 162 * one if either of new and old is not an exact grace period. 163 */ 164 rnd_diff = (new & ~RCU_SEQ_STATE_MASK) - 165 ((old + RCU_SEQ_STATE_MASK) & ~RCU_SEQ_STATE_MASK) + 166 ((new & RCU_SEQ_STATE_MASK) || (old & RCU_SEQ_STATE_MASK)); 167 if (ULONG_CMP_GE(RCU_SEQ_STATE_MASK, rnd_diff)) 168 return 1; /* Definitely no grace period has elapsed. */ 169 return ((rnd_diff - RCU_SEQ_STATE_MASK - 1) >> RCU_SEQ_CTR_SHIFT) + 2; 170 } 171 172 /* 173 * debug_rcu_head_queue()/debug_rcu_head_unqueue() are used internally 174 * by call_rcu() and rcu callback execution, and are therefore not part 175 * of the RCU API. These are in rcupdate.h because they are used by all 176 * RCU implementations. 177 */ 178 179 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD 180 # define STATE_RCU_HEAD_READY 0 181 # define STATE_RCU_HEAD_QUEUED 1 182 183 extern const struct debug_obj_descr rcuhead_debug_descr; 184 185 static inline int debug_rcu_head_queue(struct rcu_head *head) 186 { 187 int r1; 188 189 r1 = debug_object_activate(head, &rcuhead_debug_descr); 190 debug_object_active_state(head, &rcuhead_debug_descr, 191 STATE_RCU_HEAD_READY, 192 STATE_RCU_HEAD_QUEUED); 193 return r1; 194 } 195 196 static inline void debug_rcu_head_unqueue(struct rcu_head *head) 197 { 198 debug_object_active_state(head, &rcuhead_debug_descr, 199 STATE_RCU_HEAD_QUEUED, 200 STATE_RCU_HEAD_READY); 201 debug_object_deactivate(head, &rcuhead_debug_descr); 202 } 203 #else /* !CONFIG_DEBUG_OBJECTS_RCU_HEAD */ 204 static inline int debug_rcu_head_queue(struct rcu_head *head) 205 { 206 return 0; 207 } 208 209 static inline void debug_rcu_head_unqueue(struct rcu_head *head) 210 { 211 } 212 #endif /* #else !CONFIG_DEBUG_OBJECTS_RCU_HEAD */ 213 214 extern int rcu_cpu_stall_suppress_at_boot; 215 216 static inline bool rcu_stall_is_suppressed_at_boot(void) 217 { 218 return rcu_cpu_stall_suppress_at_boot && !rcu_inkernel_boot_has_ended(); 219 } 220 221 #ifdef CONFIG_RCU_STALL_COMMON 222 223 extern int rcu_cpu_stall_ftrace_dump; 224 extern int rcu_cpu_stall_suppress; 225 extern int rcu_cpu_stall_timeout; 226 extern int rcu_exp_cpu_stall_timeout; 227 int rcu_jiffies_till_stall_check(void); 228 int rcu_exp_jiffies_till_stall_check(void); 229 230 static inline bool rcu_stall_is_suppressed(void) 231 { 232 return rcu_stall_is_suppressed_at_boot() || rcu_cpu_stall_suppress; 233 } 234 235 #define rcu_ftrace_dump_stall_suppress() \ 236 do { \ 237 if (!rcu_cpu_stall_suppress) \ 238 rcu_cpu_stall_suppress = 3; \ 239 } while (0) 240 241 #define rcu_ftrace_dump_stall_unsuppress() \ 242 do { \ 243 if (rcu_cpu_stall_suppress == 3) \ 244 rcu_cpu_stall_suppress = 0; \ 245 } while (0) 246 247 #else /* #endif #ifdef CONFIG_RCU_STALL_COMMON */ 248 249 static inline bool rcu_stall_is_suppressed(void) 250 { 251 return rcu_stall_is_suppressed_at_boot(); 252 } 253 #define rcu_ftrace_dump_stall_suppress() 254 #define rcu_ftrace_dump_stall_unsuppress() 255 #endif /* #ifdef CONFIG_RCU_STALL_COMMON */ 256 257 /* 258 * Strings used in tracepoints need to be exported via the 259 * tracing system such that tools like perf and trace-cmd can 260 * translate the string address pointers to actual text. 261 */ 262 #define TPS(x) tracepoint_string(x) 263 264 /* 265 * Dump the ftrace buffer, but only one time per callsite per boot. 266 */ 267 #define rcu_ftrace_dump(oops_dump_mode) \ 268 do { \ 269 static atomic_t ___rfd_beenhere = ATOMIC_INIT(0); \ 270 \ 271 if (!atomic_read(&___rfd_beenhere) && \ 272 !atomic_xchg(&___rfd_beenhere, 1)) { \ 273 tracing_off(); \ 274 rcu_ftrace_dump_stall_suppress(); \ 275 ftrace_dump(oops_dump_mode); \ 276 rcu_ftrace_dump_stall_unsuppress(); \ 277 } \ 278 } while (0) 279 280 void rcu_early_boot_tests(void); 281 void rcu_test_sync_prims(void); 282 283 /* 284 * This function really isn't for public consumption, but RCU is special in 285 * that context switches can allow the state machine to make progress. 286 */ 287 extern void resched_cpu(int cpu); 288 289 #if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU) 290 291 #include <linux/rcu_node_tree.h> 292 293 extern int rcu_num_lvls; 294 extern int num_rcu_lvl[]; 295 extern int rcu_num_nodes; 296 static bool rcu_fanout_exact; 297 static int rcu_fanout_leaf; 298 299 /* 300 * Compute the per-level fanout, either using the exact fanout specified 301 * or balancing the tree, depending on the rcu_fanout_exact boot parameter. 302 */ 303 static inline void rcu_init_levelspread(int *levelspread, const int *levelcnt) 304 { 305 int i; 306 307 for (i = 0; i < RCU_NUM_LVLS; i++) 308 levelspread[i] = INT_MIN; 309 if (rcu_fanout_exact) { 310 levelspread[rcu_num_lvls - 1] = rcu_fanout_leaf; 311 for (i = rcu_num_lvls - 2; i >= 0; i--) 312 levelspread[i] = RCU_FANOUT; 313 } else { 314 int ccur; 315 int cprv; 316 317 cprv = nr_cpu_ids; 318 for (i = rcu_num_lvls - 1; i >= 0; i--) { 319 ccur = levelcnt[i]; 320 levelspread[i] = (cprv + ccur - 1) / ccur; 321 cprv = ccur; 322 } 323 } 324 } 325 326 extern void rcu_init_geometry(void); 327 328 /* Returns a pointer to the first leaf rcu_node structure. */ 329 #define rcu_first_leaf_node() (rcu_state.level[rcu_num_lvls - 1]) 330 331 /* Is this rcu_node a leaf? */ 332 #define rcu_is_leaf_node(rnp) ((rnp)->level == rcu_num_lvls - 1) 333 334 /* Is this rcu_node the last leaf? */ 335 #define rcu_is_last_leaf_node(rnp) ((rnp) == &rcu_state.node[rcu_num_nodes - 1]) 336 337 /* 338 * Do a full breadth-first scan of the {s,}rcu_node structures for the 339 * specified state structure (for SRCU) or the only rcu_state structure 340 * (for RCU). 341 */ 342 #define srcu_for_each_node_breadth_first(sp, rnp) \ 343 for ((rnp) = &(sp)->node[0]; \ 344 (rnp) < &(sp)->node[rcu_num_nodes]; (rnp)++) 345 #define rcu_for_each_node_breadth_first(rnp) \ 346 srcu_for_each_node_breadth_first(&rcu_state, rnp) 347 348 /* 349 * Scan the leaves of the rcu_node hierarchy for the rcu_state structure. 350 * Note that if there is a singleton rcu_node tree with but one rcu_node 351 * structure, this loop -will- visit the rcu_node structure. It is still 352 * a leaf node, even if it is also the root node. 353 */ 354 #define rcu_for_each_leaf_node(rnp) \ 355 for ((rnp) = rcu_first_leaf_node(); \ 356 (rnp) < &rcu_state.node[rcu_num_nodes]; (rnp)++) 357 358 /* 359 * Iterate over all possible CPUs in a leaf RCU node. 360 */ 361 #define for_each_leaf_node_possible_cpu(rnp, cpu) \ 362 for (WARN_ON_ONCE(!rcu_is_leaf_node(rnp)), \ 363 (cpu) = cpumask_next((rnp)->grplo - 1, cpu_possible_mask); \ 364 (cpu) <= rnp->grphi; \ 365 (cpu) = cpumask_next((cpu), cpu_possible_mask)) 366 367 /* 368 * Iterate over all CPUs in a leaf RCU node's specified mask. 369 */ 370 #define rcu_find_next_bit(rnp, cpu, mask) \ 371 ((rnp)->grplo + find_next_bit(&(mask), BITS_PER_LONG, (cpu))) 372 #define for_each_leaf_node_cpu_mask(rnp, cpu, mask) \ 373 for (WARN_ON_ONCE(!rcu_is_leaf_node(rnp)), \ 374 (cpu) = rcu_find_next_bit((rnp), 0, (mask)); \ 375 (cpu) <= rnp->grphi; \ 376 (cpu) = rcu_find_next_bit((rnp), (cpu) + 1 - (rnp->grplo), (mask))) 377 378 /* 379 * Wrappers for the rcu_node::lock acquire and release. 380 * 381 * Because the rcu_nodes form a tree, the tree traversal locking will observe 382 * different lock values, this in turn means that an UNLOCK of one level 383 * followed by a LOCK of another level does not imply a full memory barrier; 384 * and most importantly transitivity is lost. 385 * 386 * In order to restore full ordering between tree levels, augment the regular 387 * lock acquire functions with smp_mb__after_unlock_lock(). 388 * 389 * As ->lock of struct rcu_node is a __private field, therefore one should use 390 * these wrappers rather than directly call raw_spin_{lock,unlock}* on ->lock. 391 */ 392 #define raw_spin_lock_rcu_node(p) \ 393 do { \ 394 raw_spin_lock(&ACCESS_PRIVATE(p, lock)); \ 395 smp_mb__after_unlock_lock(); \ 396 } while (0) 397 398 #define raw_spin_unlock_rcu_node(p) \ 399 do { \ 400 lockdep_assert_irqs_disabled(); \ 401 raw_spin_unlock(&ACCESS_PRIVATE(p, lock)); \ 402 } while (0) 403 404 #define raw_spin_lock_irq_rcu_node(p) \ 405 do { \ 406 raw_spin_lock_irq(&ACCESS_PRIVATE(p, lock)); \ 407 smp_mb__after_unlock_lock(); \ 408 } while (0) 409 410 #define raw_spin_unlock_irq_rcu_node(p) \ 411 do { \ 412 lockdep_assert_irqs_disabled(); \ 413 raw_spin_unlock_irq(&ACCESS_PRIVATE(p, lock)); \ 414 } while (0) 415 416 #define raw_spin_lock_irqsave_rcu_node(p, flags) \ 417 do { \ 418 raw_spin_lock_irqsave(&ACCESS_PRIVATE(p, lock), flags); \ 419 smp_mb__after_unlock_lock(); \ 420 } while (0) 421 422 #define raw_spin_unlock_irqrestore_rcu_node(p, flags) \ 423 do { \ 424 lockdep_assert_irqs_disabled(); \ 425 raw_spin_unlock_irqrestore(&ACCESS_PRIVATE(p, lock), flags); \ 426 } while (0) 427 428 #define raw_spin_trylock_rcu_node(p) \ 429 ({ \ 430 bool ___locked = raw_spin_trylock(&ACCESS_PRIVATE(p, lock)); \ 431 \ 432 if (___locked) \ 433 smp_mb__after_unlock_lock(); \ 434 ___locked; \ 435 }) 436 437 #define raw_lockdep_assert_held_rcu_node(p) \ 438 lockdep_assert_held(&ACCESS_PRIVATE(p, lock)) 439 440 #endif /* #if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU) */ 441 442 #ifdef CONFIG_TINY_RCU 443 /* Tiny RCU doesn't expedite, as its purpose in life is instead to be tiny. */ 444 static inline bool rcu_gp_is_normal(void) { return true; } 445 static inline bool rcu_gp_is_expedited(void) { return false; } 446 static inline void rcu_expedite_gp(void) { } 447 static inline void rcu_unexpedite_gp(void) { } 448 static inline void rcu_request_urgent_qs_task(struct task_struct *t) { } 449 #else /* #ifdef CONFIG_TINY_RCU */ 450 bool rcu_gp_is_normal(void); /* Internal RCU use. */ 451 bool rcu_gp_is_expedited(void); /* Internal RCU use. */ 452 void rcu_expedite_gp(void); 453 void rcu_unexpedite_gp(void); 454 void rcupdate_announce_bootup_oddness(void); 455 #ifdef CONFIG_TASKS_RCU_GENERIC 456 void show_rcu_tasks_gp_kthreads(void); 457 #else /* #ifdef CONFIG_TASKS_RCU_GENERIC */ 458 static inline void show_rcu_tasks_gp_kthreads(void) {} 459 #endif /* #else #ifdef CONFIG_TASKS_RCU_GENERIC */ 460 void rcu_request_urgent_qs_task(struct task_struct *t); 461 #endif /* #else #ifdef CONFIG_TINY_RCU */ 462 463 #define RCU_SCHEDULER_INACTIVE 0 464 #define RCU_SCHEDULER_INIT 1 465 #define RCU_SCHEDULER_RUNNING 2 466 467 enum rcutorture_type { 468 RCU_FLAVOR, 469 RCU_TASKS_FLAVOR, 470 RCU_TASKS_RUDE_FLAVOR, 471 RCU_TASKS_TRACING_FLAVOR, 472 RCU_TRIVIAL_FLAVOR, 473 SRCU_FLAVOR, 474 INVALID_RCU_FLAVOR 475 }; 476 477 #if defined(CONFIG_TREE_RCU) 478 void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags, 479 unsigned long *gp_seq); 480 void do_trace_rcu_torture_read(const char *rcutorturename, 481 struct rcu_head *rhp, 482 unsigned long secs, 483 unsigned long c_old, 484 unsigned long c); 485 void rcu_gp_set_torture_wait(int duration); 486 #else 487 static inline void rcutorture_get_gp_data(enum rcutorture_type test_type, 488 int *flags, unsigned long *gp_seq) 489 { 490 *flags = 0; 491 *gp_seq = 0; 492 } 493 #ifdef CONFIG_RCU_TRACE 494 void do_trace_rcu_torture_read(const char *rcutorturename, 495 struct rcu_head *rhp, 496 unsigned long secs, 497 unsigned long c_old, 498 unsigned long c); 499 #else 500 #define do_trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \ 501 do { } while (0) 502 #endif 503 static inline void rcu_gp_set_torture_wait(int duration) { } 504 #endif 505 506 #if IS_ENABLED(CONFIG_RCU_TORTURE_TEST) || IS_MODULE(CONFIG_RCU_TORTURE_TEST) 507 long rcutorture_sched_setaffinity(pid_t pid, const struct cpumask *in_mask); 508 #endif 509 510 #ifdef CONFIG_TINY_SRCU 511 512 static inline void srcutorture_get_gp_data(enum rcutorture_type test_type, 513 struct srcu_struct *sp, int *flags, 514 unsigned long *gp_seq) 515 { 516 if (test_type != SRCU_FLAVOR) 517 return; 518 *flags = 0; 519 *gp_seq = sp->srcu_idx; 520 } 521 522 #elif defined(CONFIG_TREE_SRCU) 523 524 void srcutorture_get_gp_data(enum rcutorture_type test_type, 525 struct srcu_struct *sp, int *flags, 526 unsigned long *gp_seq); 527 528 #endif 529 530 #ifdef CONFIG_TINY_RCU 531 static inline bool rcu_dynticks_zero_in_eqs(int cpu, int *vp) { return false; } 532 static inline unsigned long rcu_get_gp_seq(void) { return 0; } 533 static inline unsigned long rcu_exp_batches_completed(void) { return 0; } 534 static inline unsigned long 535 srcu_batches_completed(struct srcu_struct *sp) { return 0; } 536 static inline void rcu_force_quiescent_state(void) { } 537 static inline bool rcu_check_boost_fail(unsigned long gp_state, int *cpup) { return true; } 538 static inline void show_rcu_gp_kthreads(void) { } 539 static inline int rcu_get_gp_kthreads_prio(void) { return 0; } 540 static inline void rcu_fwd_progress_check(unsigned long j) { } 541 static inline void rcu_gp_slow_register(atomic_t *rgssp) { } 542 static inline void rcu_gp_slow_unregister(atomic_t *rgssp) { } 543 #else /* #ifdef CONFIG_TINY_RCU */ 544 bool rcu_dynticks_zero_in_eqs(int cpu, int *vp); 545 unsigned long rcu_get_gp_seq(void); 546 unsigned long rcu_exp_batches_completed(void); 547 unsigned long srcu_batches_completed(struct srcu_struct *sp); 548 bool rcu_check_boost_fail(unsigned long gp_state, int *cpup); 549 void show_rcu_gp_kthreads(void); 550 int rcu_get_gp_kthreads_prio(void); 551 void rcu_fwd_progress_check(unsigned long j); 552 void rcu_force_quiescent_state(void); 553 extern struct workqueue_struct *rcu_gp_wq; 554 #ifdef CONFIG_RCU_EXP_KTHREAD 555 extern struct kthread_worker *rcu_exp_gp_kworker; 556 extern struct kthread_worker *rcu_exp_par_gp_kworker; 557 #else /* !CONFIG_RCU_EXP_KTHREAD */ 558 extern struct workqueue_struct *rcu_par_gp_wq; 559 #endif /* CONFIG_RCU_EXP_KTHREAD */ 560 void rcu_gp_slow_register(atomic_t *rgssp); 561 void rcu_gp_slow_unregister(atomic_t *rgssp); 562 #endif /* #else #ifdef CONFIG_TINY_RCU */ 563 564 #ifdef CONFIG_RCU_NOCB_CPU 565 void rcu_bind_current_to_nocb(void); 566 #else 567 static inline void rcu_bind_current_to_nocb(void) { } 568 #endif 569 570 #if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_RCU) 571 void show_rcu_tasks_classic_gp_kthread(void); 572 #else 573 static inline void show_rcu_tasks_classic_gp_kthread(void) {} 574 #endif 575 #if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_RUDE_RCU) 576 void show_rcu_tasks_rude_gp_kthread(void); 577 #else 578 static inline void show_rcu_tasks_rude_gp_kthread(void) {} 579 #endif 580 #if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_TRACE_RCU) 581 void show_rcu_tasks_trace_gp_kthread(void); 582 #else 583 static inline void show_rcu_tasks_trace_gp_kthread(void) {} 584 #endif 585 586 #endif /* __LINUX_RCU_H */ 587