1 /* 2 * Read-Copy Update mechanism for mutual exclusion (tree-based version) 3 * Internal non-public definitions. 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, you can access it online at 17 * http://www.gnu.org/licenses/gpl-2.0.html. 18 * 19 * Copyright IBM Corporation, 2008 20 * 21 * Author: Ingo Molnar <mingo@elte.hu> 22 * Paul E. McKenney <paulmck@linux.vnet.ibm.com> 23 */ 24 25 #include <linux/cache.h> 26 #include <linux/spinlock.h> 27 #include <linux/rtmutex.h> 28 #include <linux/threads.h> 29 #include <linux/cpumask.h> 30 #include <linux/seqlock.h> 31 #include <linux/swait.h> 32 #include <linux/stop_machine.h> 33 #include <linux/rcu_node_tree.h> 34 35 #include "rcu_segcblist.h" 36 37 /* 38 * Dynticks per-CPU state. 39 */ 40 struct rcu_dynticks { 41 long dynticks_nesting; /* Track process nesting level. */ 42 long dynticks_nmi_nesting; /* Track irq/NMI nesting level. */ 43 atomic_t dynticks; /* Even value for idle, else odd. */ 44 bool rcu_need_heavy_qs; /* GP old, need heavy quiescent state. */ 45 unsigned long rcu_qs_ctr; /* Light universal quiescent state ctr. */ 46 bool rcu_urgent_qs; /* GP old need light quiescent state. */ 47 #ifdef CONFIG_RCU_FAST_NO_HZ 48 bool all_lazy; /* Are all CPU's CBs lazy? */ 49 unsigned long nonlazy_posted; 50 /* # times non-lazy CBs posted to CPU. */ 51 unsigned long nonlazy_posted_snap; 52 /* idle-period nonlazy_posted snapshot. */ 53 unsigned long last_accelerate; 54 /* Last jiffy CBs were accelerated. */ 55 unsigned long last_advance_all; 56 /* Last jiffy CBs were all advanced. */ 57 int tick_nohz_enabled_snap; /* Previously seen value from sysfs. */ 58 #endif /* #ifdef CONFIG_RCU_FAST_NO_HZ */ 59 }; 60 61 /* Communicate arguments to a workqueue handler. */ 62 struct rcu_exp_work { 63 smp_call_func_t rew_func; 64 struct rcu_state *rew_rsp; 65 unsigned long rew_s; 66 struct work_struct rew_work; 67 }; 68 69 /* RCU's kthread states for tracing. */ 70 #define RCU_KTHREAD_STOPPED 0 71 #define RCU_KTHREAD_RUNNING 1 72 #define RCU_KTHREAD_WAITING 2 73 #define RCU_KTHREAD_OFFCPU 3 74 #define RCU_KTHREAD_YIELDING 4 75 #define RCU_KTHREAD_MAX 4 76 77 /* 78 * Definition for node within the RCU grace-period-detection hierarchy. 79 */ 80 struct rcu_node { 81 raw_spinlock_t __private lock; /* Root rcu_node's lock protects */ 82 /* some rcu_state fields as well as */ 83 /* following. */ 84 unsigned long gpnum; /* Current grace period for this node. */ 85 /* This will either be equal to or one */ 86 /* behind the root rcu_node's gpnum. */ 87 unsigned long completed; /* Last GP completed for this node. */ 88 /* This will either be equal to or one */ 89 /* behind the root rcu_node's gpnum. */ 90 unsigned long qsmask; /* CPUs or groups that need to switch in */ 91 /* order for current grace period to proceed.*/ 92 /* In leaf rcu_node, each bit corresponds to */ 93 /* an rcu_data structure, otherwise, each */ 94 /* bit corresponds to a child rcu_node */ 95 /* structure. */ 96 unsigned long qsmaskinit; 97 /* Per-GP initial value for qsmask. */ 98 /* Initialized from ->qsmaskinitnext at the */ 99 /* beginning of each grace period. */ 100 unsigned long qsmaskinitnext; 101 /* Online CPUs for next grace period. */ 102 unsigned long expmask; /* CPUs or groups that need to check in */ 103 /* to allow the current expedited GP */ 104 /* to complete. */ 105 unsigned long expmaskinit; 106 /* Per-GP initial values for expmask. */ 107 /* Initialized from ->expmaskinitnext at the */ 108 /* beginning of each expedited GP. */ 109 unsigned long expmaskinitnext; 110 /* Online CPUs for next expedited GP. */ 111 /* Any CPU that has ever been online will */ 112 /* have its bit set. */ 113 unsigned long ffmask; /* Fully functional CPUs. */ 114 unsigned long grpmask; /* Mask to apply to parent qsmask. */ 115 /* Only one bit will be set in this mask. */ 116 int grplo; /* lowest-numbered CPU or group here. */ 117 int grphi; /* highest-numbered CPU or group here. */ 118 u8 grpnum; /* CPU/group number for next level up. */ 119 u8 level; /* root is at level 0. */ 120 bool wait_blkd_tasks;/* Necessary to wait for blocked tasks to */ 121 /* exit RCU read-side critical sections */ 122 /* before propagating offline up the */ 123 /* rcu_node tree? */ 124 struct rcu_node *parent; 125 struct list_head blkd_tasks; 126 /* Tasks blocked in RCU read-side critical */ 127 /* section. Tasks are placed at the head */ 128 /* of this list and age towards the tail. */ 129 struct list_head *gp_tasks; 130 /* Pointer to the first task blocking the */ 131 /* current grace period, or NULL if there */ 132 /* is no such task. */ 133 struct list_head *exp_tasks; 134 /* Pointer to the first task blocking the */ 135 /* current expedited grace period, or NULL */ 136 /* if there is no such task. If there */ 137 /* is no current expedited grace period, */ 138 /* then there can cannot be any such task. */ 139 struct list_head *boost_tasks; 140 /* Pointer to first task that needs to be */ 141 /* priority boosted, or NULL if no priority */ 142 /* boosting is needed for this rcu_node */ 143 /* structure. If there are no tasks */ 144 /* queued on this rcu_node structure that */ 145 /* are blocking the current grace period, */ 146 /* there can be no such task. */ 147 struct rt_mutex boost_mtx; 148 /* Used only for the priority-boosting */ 149 /* side effect, not as a lock. */ 150 unsigned long boost_time; 151 /* When to start boosting (jiffies). */ 152 struct task_struct *boost_kthread_task; 153 /* kthread that takes care of priority */ 154 /* boosting for this rcu_node structure. */ 155 unsigned int boost_kthread_status; 156 /* State of boost_kthread_task for tracing. */ 157 #ifdef CONFIG_RCU_NOCB_CPU 158 struct swait_queue_head nocb_gp_wq[2]; 159 /* Place for rcu_nocb_kthread() to wait GP. */ 160 #endif /* #ifdef CONFIG_RCU_NOCB_CPU */ 161 u8 need_future_gp[4]; /* Counts of upcoming GP requests. */ 162 raw_spinlock_t fqslock ____cacheline_internodealigned_in_smp; 163 164 spinlock_t exp_lock ____cacheline_internodealigned_in_smp; 165 unsigned long exp_seq_rq; 166 wait_queue_head_t exp_wq[4]; 167 struct rcu_exp_work rew; 168 bool exp_need_flush; /* Need to flush workitem? */ 169 } ____cacheline_internodealigned_in_smp; 170 171 /* Accessors for ->need_future_gp[] array. */ 172 #define need_future_gp_mask() \ 173 (ARRAY_SIZE(((struct rcu_node *)NULL)->need_future_gp) - 1) 174 #define need_future_gp_element(rnp, c) \ 175 ((rnp)->need_future_gp[(c) & need_future_gp_mask()]) 176 #define need_any_future_gp(rnp) \ 177 ({ \ 178 int __i; \ 179 bool __nonzero = false; \ 180 \ 181 for (__i = 0; __i < ARRAY_SIZE((rnp)->need_future_gp); __i++) \ 182 __nonzero = __nonzero || \ 183 READ_ONCE((rnp)->need_future_gp[__i]); \ 184 __nonzero; \ 185 }) 186 187 /* 188 * Bitmasks in an rcu_node cover the interval [grplo, grphi] of CPU IDs, and 189 * are indexed relative to this interval rather than the global CPU ID space. 190 * This generates the bit for a CPU in node-local masks. 191 */ 192 #define leaf_node_cpu_bit(rnp, cpu) (1UL << ((cpu) - (rnp)->grplo)) 193 194 /* 195 * Union to allow "aggregate OR" operation on the need for a quiescent 196 * state by the normal and expedited grace periods. 197 */ 198 union rcu_noqs { 199 struct { 200 u8 norm; 201 u8 exp; 202 } b; /* Bits. */ 203 u16 s; /* Set of bits, aggregate OR here. */ 204 }; 205 206 /* Per-CPU data for read-copy update. */ 207 struct rcu_data { 208 /* 1) quiescent-state and grace-period handling : */ 209 unsigned long completed; /* Track rsp->completed gp number */ 210 /* in order to detect GP end. */ 211 unsigned long gpnum; /* Highest gp number that this CPU */ 212 /* is aware of having started. */ 213 unsigned long rcu_qs_ctr_snap;/* Snapshot of rcu_qs_ctr to check */ 214 /* for rcu_all_qs() invocations. */ 215 union rcu_noqs cpu_no_qs; /* No QSes yet for this CPU. */ 216 bool core_needs_qs; /* Core waits for quiesc state. */ 217 bool beenonline; /* CPU online at least once. */ 218 bool gpwrap; /* Possible gpnum/completed wrap. */ 219 struct rcu_node *mynode; /* This CPU's leaf of hierarchy */ 220 unsigned long grpmask; /* Mask to apply to leaf qsmask. */ 221 unsigned long ticks_this_gp; /* The number of scheduling-clock */ 222 /* ticks this CPU has handled */ 223 /* during and after the last grace */ 224 /* period it is aware of. */ 225 226 /* 2) batch handling */ 227 struct rcu_segcblist cblist; /* Segmented callback list, with */ 228 /* different callbacks waiting for */ 229 /* different grace periods. */ 230 long qlen_last_fqs_check; 231 /* qlen at last check for QS forcing */ 232 unsigned long n_force_qs_snap; 233 /* did other CPU force QS recently? */ 234 long blimit; /* Upper limit on a processed batch */ 235 236 /* 3) dynticks interface. */ 237 struct rcu_dynticks *dynticks; /* Shared per-CPU dynticks state. */ 238 int dynticks_snap; /* Per-GP tracking for dynticks. */ 239 240 /* 4) reasons this CPU needed to be kicked by force_quiescent_state */ 241 unsigned long dynticks_fqs; /* Kicked due to dynticks idle. */ 242 unsigned long offline_fqs; /* Kicked due to being offline. */ 243 unsigned long cond_resched_completed; 244 /* Grace period that needs help */ 245 /* from cond_resched(). */ 246 247 /* 5) _rcu_barrier(), OOM callbacks, and expediting. */ 248 struct rcu_head barrier_head; 249 #ifdef CONFIG_RCU_FAST_NO_HZ 250 struct rcu_head oom_head; 251 #endif /* #ifdef CONFIG_RCU_FAST_NO_HZ */ 252 int exp_dynticks_snap; /* Double-check need for IPI. */ 253 254 /* 6) Callback offloading. */ 255 #ifdef CONFIG_RCU_NOCB_CPU 256 struct rcu_head *nocb_head; /* CBs waiting for kthread. */ 257 struct rcu_head **nocb_tail; 258 atomic_long_t nocb_q_count; /* # CBs waiting for nocb */ 259 atomic_long_t nocb_q_count_lazy; /* invocation (all stages). */ 260 struct rcu_head *nocb_follower_head; /* CBs ready to invoke. */ 261 struct rcu_head **nocb_follower_tail; 262 struct swait_queue_head nocb_wq; /* For nocb kthreads to sleep on. */ 263 struct task_struct *nocb_kthread; 264 raw_spinlock_t nocb_lock; /* Guard following pair of fields. */ 265 int nocb_defer_wakeup; /* Defer wakeup of nocb_kthread. */ 266 struct timer_list nocb_timer; /* Enforce finite deferral. */ 267 268 /* The following fields are used by the leader, hence own cacheline. */ 269 struct rcu_head *nocb_gp_head ____cacheline_internodealigned_in_smp; 270 /* CBs waiting for GP. */ 271 struct rcu_head **nocb_gp_tail; 272 bool nocb_leader_sleep; /* Is the nocb leader thread asleep? */ 273 struct rcu_data *nocb_next_follower; 274 /* Next follower in wakeup chain. */ 275 276 /* The following fields are used by the follower, hence new cachline. */ 277 struct rcu_data *nocb_leader ____cacheline_internodealigned_in_smp; 278 /* Leader CPU takes GP-end wakeups. */ 279 #endif /* #ifdef CONFIG_RCU_NOCB_CPU */ 280 281 /* 7) RCU CPU stall data. */ 282 unsigned int softirq_snap; /* Snapshot of softirq activity. */ 283 /* ->rcu_iw* fields protected by leaf rcu_node ->lock. */ 284 struct irq_work rcu_iw; /* Check for non-irq activity. */ 285 bool rcu_iw_pending; /* Is ->rcu_iw pending? */ 286 unsigned long rcu_iw_gpnum; /* ->gpnum associated with ->rcu_iw. */ 287 288 int cpu; 289 struct rcu_state *rsp; 290 }; 291 292 /* Values for nocb_defer_wakeup field in struct rcu_data. */ 293 #define RCU_NOCB_WAKE_NOT 0 294 #define RCU_NOCB_WAKE 1 295 #define RCU_NOCB_WAKE_FORCE 2 296 297 #define RCU_JIFFIES_TILL_FORCE_QS (1 + (HZ > 250) + (HZ > 500)) 298 /* For jiffies_till_first_fqs and */ 299 /* and jiffies_till_next_fqs. */ 300 301 #define RCU_JIFFIES_FQS_DIV 256 /* Very large systems need more */ 302 /* delay between bouts of */ 303 /* quiescent-state forcing. */ 304 305 #define RCU_STALL_RAT_DELAY 2 /* Allow other CPUs time to take */ 306 /* at least one scheduling clock */ 307 /* irq before ratting on them. */ 308 309 #define rcu_wait(cond) \ 310 do { \ 311 for (;;) { \ 312 set_current_state(TASK_INTERRUPTIBLE); \ 313 if (cond) \ 314 break; \ 315 schedule(); \ 316 } \ 317 __set_current_state(TASK_RUNNING); \ 318 } while (0) 319 320 /* 321 * RCU global state, including node hierarchy. This hierarchy is 322 * represented in "heap" form in a dense array. The root (first level) 323 * of the hierarchy is in ->node[0] (referenced by ->level[0]), the second 324 * level in ->node[1] through ->node[m] (->node[1] referenced by ->level[1]), 325 * and the third level in ->node[m+1] and following (->node[m+1] referenced 326 * by ->level[2]). The number of levels is determined by the number of 327 * CPUs and by CONFIG_RCU_FANOUT. Small systems will have a "hierarchy" 328 * consisting of a single rcu_node. 329 */ 330 struct rcu_state { 331 struct rcu_node node[NUM_RCU_NODES]; /* Hierarchy. */ 332 struct rcu_node *level[RCU_NUM_LVLS + 1]; 333 /* Hierarchy levels (+1 to */ 334 /* shut bogus gcc warning) */ 335 struct rcu_data __percpu *rda; /* pointer of percu rcu_data. */ 336 call_rcu_func_t call; /* call_rcu() flavor. */ 337 int ncpus; /* # CPUs seen so far. */ 338 339 /* The following fields are guarded by the root rcu_node's lock. */ 340 341 u8 boost ____cacheline_internodealigned_in_smp; 342 /* Subject to priority boost. */ 343 unsigned long gpnum; /* Current gp number. */ 344 unsigned long completed; /* # of last completed gp. */ 345 struct task_struct *gp_kthread; /* Task for grace periods. */ 346 struct swait_queue_head gp_wq; /* Where GP task waits. */ 347 short gp_flags; /* Commands for GP task. */ 348 short gp_state; /* GP kthread sleep state. */ 349 350 /* End of fields guarded by root rcu_node's lock. */ 351 352 struct mutex barrier_mutex; /* Guards barrier fields. */ 353 atomic_t barrier_cpu_count; /* # CPUs waiting on. */ 354 struct completion barrier_completion; /* Wake at barrier end. */ 355 unsigned long barrier_sequence; /* ++ at start and end of */ 356 /* _rcu_barrier(). */ 357 /* End of fields guarded by barrier_mutex. */ 358 359 struct mutex exp_mutex; /* Serialize expedited GP. */ 360 struct mutex exp_wake_mutex; /* Serialize wakeup. */ 361 unsigned long expedited_sequence; /* Take a ticket. */ 362 atomic_t expedited_need_qs; /* # CPUs left to check in. */ 363 struct swait_queue_head expedited_wq; /* Wait for check-ins. */ 364 int ncpus_snap; /* # CPUs seen last time. */ 365 366 unsigned long jiffies_force_qs; /* Time at which to invoke */ 367 /* force_quiescent_state(). */ 368 unsigned long jiffies_kick_kthreads; /* Time at which to kick */ 369 /* kthreads, if configured. */ 370 unsigned long n_force_qs; /* Number of calls to */ 371 /* force_quiescent_state(). */ 372 unsigned long gp_start; /* Time at which GP started, */ 373 /* but in jiffies. */ 374 unsigned long gp_activity; /* Time of last GP kthread */ 375 /* activity in jiffies. */ 376 unsigned long jiffies_stall; /* Time at which to check */ 377 /* for CPU stalls. */ 378 unsigned long jiffies_resched; /* Time at which to resched */ 379 /* a reluctant CPU. */ 380 unsigned long n_force_qs_gpstart; /* Snapshot of n_force_qs at */ 381 /* GP start. */ 382 unsigned long gp_max; /* Maximum GP duration in */ 383 /* jiffies. */ 384 const char *name; /* Name of structure. */ 385 char abbr; /* Abbreviated name. */ 386 struct list_head flavors; /* List of RCU flavors. */ 387 }; 388 389 /* Values for rcu_state structure's gp_flags field. */ 390 #define RCU_GP_FLAG_INIT 0x1 /* Need grace-period initialization. */ 391 #define RCU_GP_FLAG_FQS 0x2 /* Need grace-period quiescent-state forcing. */ 392 393 /* Values for rcu_state structure's gp_state field. */ 394 #define RCU_GP_IDLE 0 /* Initial state and no GP in progress. */ 395 #define RCU_GP_WAIT_GPS 1 /* Wait for grace-period start. */ 396 #define RCU_GP_DONE_GPS 2 /* Wait done for grace-period start. */ 397 #define RCU_GP_WAIT_FQS 3 /* Wait for force-quiescent-state time. */ 398 #define RCU_GP_DOING_FQS 4 /* Wait done for force-quiescent-state time. */ 399 #define RCU_GP_CLEANUP 5 /* Grace-period cleanup started. */ 400 #define RCU_GP_CLEANED 6 /* Grace-period cleanup complete. */ 401 402 #ifndef RCU_TREE_NONCORE 403 static const char * const gp_state_names[] = { 404 "RCU_GP_IDLE", 405 "RCU_GP_WAIT_GPS", 406 "RCU_GP_DONE_GPS", 407 "RCU_GP_WAIT_FQS", 408 "RCU_GP_DOING_FQS", 409 "RCU_GP_CLEANUP", 410 "RCU_GP_CLEANED", 411 }; 412 #endif /* #ifndef RCU_TREE_NONCORE */ 413 414 extern struct list_head rcu_struct_flavors; 415 416 /* Sequence through rcu_state structures for each RCU flavor. */ 417 #define for_each_rcu_flavor(rsp) \ 418 list_for_each_entry((rsp), &rcu_struct_flavors, flavors) 419 420 /* 421 * RCU implementation internal declarations: 422 */ 423 extern struct rcu_state rcu_sched_state; 424 425 extern struct rcu_state rcu_bh_state; 426 427 #ifdef CONFIG_PREEMPT_RCU 428 extern struct rcu_state rcu_preempt_state; 429 #endif /* #ifdef CONFIG_PREEMPT_RCU */ 430 431 int rcu_dynticks_snap(struct rcu_dynticks *rdtp); 432 433 #ifdef CONFIG_RCU_BOOST 434 DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_status); 435 DECLARE_PER_CPU(int, rcu_cpu_kthread_cpu); 436 DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_loops); 437 DECLARE_PER_CPU(char, rcu_cpu_has_work); 438 #endif /* #ifdef CONFIG_RCU_BOOST */ 439 440 #ifndef RCU_TREE_NONCORE 441 442 /* Forward declarations for rcutree_plugin.h */ 443 static void rcu_bootup_announce(void); 444 static void rcu_preempt_note_context_switch(bool preempt); 445 static int rcu_preempt_blocked_readers_cgp(struct rcu_node *rnp); 446 #ifdef CONFIG_HOTPLUG_CPU 447 static bool rcu_preempt_has_tasks(struct rcu_node *rnp); 448 #endif /* #ifdef CONFIG_HOTPLUG_CPU */ 449 static void rcu_print_detail_task_stall(struct rcu_state *rsp); 450 static int rcu_print_task_stall(struct rcu_node *rnp); 451 static int rcu_print_task_exp_stall(struct rcu_node *rnp); 452 static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp); 453 static void rcu_preempt_check_callbacks(void); 454 void call_rcu(struct rcu_head *head, rcu_callback_t func); 455 static void __init __rcu_init_preempt(void); 456 static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags); 457 static void rcu_preempt_boost_start_gp(struct rcu_node *rnp); 458 static void invoke_rcu_callbacks_kthread(void); 459 static bool rcu_is_callbacks_kthread(void); 460 #ifdef CONFIG_RCU_BOOST 461 static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp, 462 struct rcu_node *rnp); 463 #endif /* #ifdef CONFIG_RCU_BOOST */ 464 static void __init rcu_spawn_boost_kthreads(void); 465 static void rcu_prepare_kthreads(int cpu); 466 static void rcu_cleanup_after_idle(void); 467 static void rcu_prepare_for_idle(void); 468 static void rcu_idle_count_callbacks_posted(void); 469 static bool rcu_preempt_has_tasks(struct rcu_node *rnp); 470 static void print_cpu_stall_info_begin(void); 471 static void print_cpu_stall_info(struct rcu_state *rsp, int cpu); 472 static void print_cpu_stall_info_end(void); 473 static void zero_cpu_stall_ticks(struct rcu_data *rdp); 474 static void increment_cpu_stall_ticks(void); 475 static bool rcu_nocb_cpu_needs_barrier(struct rcu_state *rsp, int cpu); 476 static struct swait_queue_head *rcu_nocb_gp_get(struct rcu_node *rnp); 477 static void rcu_nocb_gp_cleanup(struct swait_queue_head *sq); 478 static void rcu_init_one_nocb(struct rcu_node *rnp); 479 static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp, 480 bool lazy, unsigned long flags); 481 static bool rcu_nocb_adopt_orphan_cbs(struct rcu_data *my_rdp, 482 struct rcu_data *rdp, 483 unsigned long flags); 484 static int rcu_nocb_need_deferred_wakeup(struct rcu_data *rdp); 485 static void do_nocb_deferred_wakeup(struct rcu_data *rdp); 486 static void rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp); 487 static void rcu_spawn_all_nocb_kthreads(int cpu); 488 static void __init rcu_spawn_nocb_kthreads(void); 489 #ifdef CONFIG_RCU_NOCB_CPU 490 static void __init rcu_organize_nocb_kthreads(struct rcu_state *rsp); 491 #endif /* #ifdef CONFIG_RCU_NOCB_CPU */ 492 static void __maybe_unused rcu_kick_nohz_cpu(int cpu); 493 static bool init_nocb_callback_list(struct rcu_data *rdp); 494 static void rcu_bind_gp_kthread(void); 495 static bool rcu_nohz_full_cpu(struct rcu_state *rsp); 496 static void rcu_dynticks_task_enter(void); 497 static void rcu_dynticks_task_exit(void); 498 499 #ifdef CONFIG_SRCU 500 void srcu_online_cpu(unsigned int cpu); 501 void srcu_offline_cpu(unsigned int cpu); 502 #else /* #ifdef CONFIG_SRCU */ 503 void srcu_online_cpu(unsigned int cpu) { } 504 void srcu_offline_cpu(unsigned int cpu) { } 505 #endif /* #else #ifdef CONFIG_SRCU */ 506 507 #endif /* #ifndef RCU_TREE_NONCORE */ 508