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9f77da9f PM |
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, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
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/threads.h> | |
28 | #include <linux/cpumask.h> | |
29 | #include <linux/seqlock.h> | |
30 | ||
31 | /* | |
32 | * Define shape of hierarchy based on NR_CPUS and CONFIG_RCU_FANOUT. | |
33 | * In theory, it should be possible to add more levels straightforwardly. | |
0209f649 PM |
34 | * In practice, this did work well going from three levels to four. |
35 | * Of course, your mileage may vary. | |
9f77da9f | 36 | */ |
cf244dc0 | 37 | #define MAX_RCU_LVLS 4 |
0209f649 PM |
38 | #if CONFIG_RCU_FANOUT > 16 |
39 | #define RCU_FANOUT_LEAF 16 | |
40 | #else /* #if CONFIG_RCU_FANOUT > 16 */ | |
41 | #define RCU_FANOUT_LEAF (CONFIG_RCU_FANOUT) | |
42 | #endif /* #else #if CONFIG_RCU_FANOUT > 16 */ | |
43 | #define RCU_FANOUT_1 (RCU_FANOUT_LEAF) | |
44 | #define RCU_FANOUT_2 (RCU_FANOUT_1 * CONFIG_RCU_FANOUT) | |
45 | #define RCU_FANOUT_3 (RCU_FANOUT_2 * CONFIG_RCU_FANOUT) | |
46 | #define RCU_FANOUT_4 (RCU_FANOUT_3 * CONFIG_RCU_FANOUT) | |
9f77da9f | 47 | |
0209f649 | 48 | #if NR_CPUS <= RCU_FANOUT_1 |
9f77da9f PM |
49 | # define NUM_RCU_LVLS 1 |
50 | # define NUM_RCU_LVL_0 1 | |
51 | # define NUM_RCU_LVL_1 (NR_CPUS) | |
52 | # define NUM_RCU_LVL_2 0 | |
53 | # define NUM_RCU_LVL_3 0 | |
cf244dc0 | 54 | # define NUM_RCU_LVL_4 0 |
0209f649 | 55 | #elif NR_CPUS <= RCU_FANOUT_2 |
9f77da9f PM |
56 | # define NUM_RCU_LVLS 2 |
57 | # define NUM_RCU_LVL_0 1 | |
0209f649 | 58 | # define NUM_RCU_LVL_1 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_1) |
9f77da9f PM |
59 | # define NUM_RCU_LVL_2 (NR_CPUS) |
60 | # define NUM_RCU_LVL_3 0 | |
cf244dc0 | 61 | # define NUM_RCU_LVL_4 0 |
0209f649 | 62 | #elif NR_CPUS <= RCU_FANOUT_3 |
9f77da9f PM |
63 | # define NUM_RCU_LVLS 3 |
64 | # define NUM_RCU_LVL_0 1 | |
0209f649 PM |
65 | # define NUM_RCU_LVL_1 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_2) |
66 | # define NUM_RCU_LVL_2 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_1) | |
67 | # define NUM_RCU_LVL_3 (NR_CPUS) | |
cf244dc0 | 68 | # define NUM_RCU_LVL_4 0 |
0209f649 | 69 | #elif NR_CPUS <= RCU_FANOUT_4 |
cf244dc0 PM |
70 | # define NUM_RCU_LVLS 4 |
71 | # define NUM_RCU_LVL_0 1 | |
0209f649 PM |
72 | # define NUM_RCU_LVL_1 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_3) |
73 | # define NUM_RCU_LVL_2 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_2) | |
74 | # define NUM_RCU_LVL_3 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_1) | |
75 | # define NUM_RCU_LVL_4 (NR_CPUS) | |
9f77da9f PM |
76 | #else |
77 | # error "CONFIG_RCU_FANOUT insufficient for NR_CPUS" | |
0209f649 | 78 | #endif /* #if (NR_CPUS) <= RCU_FANOUT_1 */ |
9f77da9f | 79 | |
cf244dc0 | 80 | #define RCU_SUM (NUM_RCU_LVL_0 + NUM_RCU_LVL_1 + NUM_RCU_LVL_2 + NUM_RCU_LVL_3 + NUM_RCU_LVL_4) |
9f77da9f PM |
81 | #define NUM_RCU_NODES (RCU_SUM - NR_CPUS) |
82 | ||
83 | /* | |
84 | * Dynticks per-CPU state. | |
85 | */ | |
86 | struct rcu_dynticks { | |
80d02085 PM |
87 | int dynticks_nesting; /* Track nesting level, sort of. */ |
88 | int dynticks; /* Even value for dynticks-idle, else odd. */ | |
89 | int dynticks_nmi; /* Even value for either dynticks-idle or */ | |
90 | /* not in nmi handler, else odd. So this */ | |
91 | /* remains even for nmi from irq handler. */ | |
9f77da9f PM |
92 | }; |
93 | ||
d71df90e PM |
94 | /* RCU's kthread states for tracing. */ |
95 | #define RCU_KTHREAD_STOPPED 0 | |
96 | #define RCU_KTHREAD_RUNNING 1 | |
97 | #define RCU_KTHREAD_WAITING 2 | |
15ba0ba8 PM |
98 | #define RCU_KTHREAD_OFFCPU 3 |
99 | #define RCU_KTHREAD_YIELDING 4 | |
100 | #define RCU_KTHREAD_MAX 4 | |
d71df90e | 101 | |
9f77da9f PM |
102 | /* |
103 | * Definition for node within the RCU grace-period-detection hierarchy. | |
104 | */ | |
105 | struct rcu_node { | |
1304afb2 | 106 | raw_spinlock_t lock; /* Root rcu_node's lock protects some */ |
1eba8f84 | 107 | /* rcu_state fields as well as following. */ |
20133cfc | 108 | unsigned long gpnum; /* Current grace period for this node. */ |
86848966 PM |
109 | /* This will either be equal to or one */ |
110 | /* behind the root rcu_node's gpnum. */ | |
20133cfc | 111 | unsigned long completed; /* Last GP completed for this node. */ |
d09b62df PM |
112 | /* This will either be equal to or one */ |
113 | /* behind the root rcu_node's gpnum. */ | |
9f77da9f PM |
114 | unsigned long qsmask; /* CPUs or groups that need to switch in */ |
115 | /* order for current grace period to proceed.*/ | |
1eba8f84 PM |
116 | /* In leaf rcu_node, each bit corresponds to */ |
117 | /* an rcu_data structure, otherwise, each */ | |
118 | /* bit corresponds to a child rcu_node */ | |
119 | /* structure. */ | |
12f5f524 | 120 | unsigned long expmask; /* Groups that have ->blkd_tasks */ |
d9a3da06 PM |
121 | /* elements that need to drain to allow the */ |
122 | /* current expedited grace period to */ | |
123 | /* complete (only for TREE_PREEMPT_RCU). */ | |
a26ac245 | 124 | unsigned long wakemask; /* CPUs whose kthread needs to be awakened. */ |
9f77da9f | 125 | unsigned long qsmaskinit; |
d9a3da06 | 126 | /* Per-GP initial value for qsmask & expmask. */ |
9f77da9f | 127 | unsigned long grpmask; /* Mask to apply to parent qsmask. */ |
1eba8f84 | 128 | /* Only one bit will be set in this mask. */ |
9f77da9f PM |
129 | int grplo; /* lowest-numbered CPU or group here. */ |
130 | int grphi; /* highest-numbered CPU or group here. */ | |
131 | u8 grpnum; /* CPU/group number for next level up. */ | |
132 | u8 level; /* root is at level 0. */ | |
133 | struct rcu_node *parent; | |
12f5f524 PM |
134 | struct list_head blkd_tasks; |
135 | /* Tasks blocked in RCU read-side critical */ | |
136 | /* section. Tasks are placed at the head */ | |
137 | /* of this list and age towards the tail. */ | |
138 | struct list_head *gp_tasks; | |
139 | /* Pointer to the first task blocking the */ | |
140 | /* current grace period, or NULL if there */ | |
141 | /* is no such task. */ | |
142 | struct list_head *exp_tasks; | |
143 | /* Pointer to the first task blocking the */ | |
144 | /* current expedited grace period, or NULL */ | |
145 | /* if there is no such task. If there */ | |
146 | /* is no current expedited grace period, */ | |
147 | /* then there can cannot be any such task. */ | |
27f4d280 PM |
148 | #ifdef CONFIG_RCU_BOOST |
149 | struct list_head *boost_tasks; | |
150 | /* Pointer to first task that needs to be */ | |
151 | /* priority boosted, or NULL if no priority */ | |
152 | /* boosting is needed for this rcu_node */ | |
153 | /* structure. If there are no tasks */ | |
154 | /* queued on this rcu_node structure that */ | |
155 | /* are blocking the current grace period, */ | |
156 | /* there can be no such task. */ | |
157 | unsigned long boost_time; | |
158 | /* When to start boosting (jiffies). */ | |
159 | struct task_struct *boost_kthread_task; | |
160 | /* kthread that takes care of priority */ | |
161 | /* boosting for this rcu_node structure. */ | |
162 | wait_queue_head_t boost_wq; | |
163 | /* Wait queue on which to park the boost */ | |
164 | /* kthread. */ | |
d71df90e PM |
165 | unsigned int boost_kthread_status; |
166 | /* State of boost_kthread_task for tracing. */ | |
0ea1f2eb PM |
167 | unsigned long n_tasks_boosted; |
168 | /* Total number of tasks boosted. */ | |
169 | unsigned long n_exp_boosts; | |
170 | /* Number of tasks boosted for expedited GP. */ | |
171 | unsigned long n_normal_boosts; | |
172 | /* Number of tasks boosted for normal GP. */ | |
173 | unsigned long n_balk_blkd_tasks; | |
174 | /* Refused to boost: no blocked tasks. */ | |
175 | unsigned long n_balk_exp_gp_tasks; | |
176 | /* Refused to boost: nothing blocking GP. */ | |
177 | unsigned long n_balk_boost_tasks; | |
178 | /* Refused to boost: already boosting. */ | |
179 | unsigned long n_balk_notblocked; | |
180 | /* Refused to boost: RCU RS CS still running. */ | |
181 | unsigned long n_balk_notyet; | |
182 | /* Refused to boost: not yet time. */ | |
183 | unsigned long n_balk_nos; | |
184 | /* Refused to boost: not sure why, though. */ | |
185 | /* This can happen due to race conditions. */ | |
27f4d280 | 186 | #endif /* #ifdef CONFIG_RCU_BOOST */ |
a26ac245 PM |
187 | struct task_struct *node_kthread_task; |
188 | /* kthread that takes care of this rcu_node */ | |
189 | /* structure, for example, awakening the */ | |
190 | /* per-CPU kthreads as needed. */ | |
191 | wait_queue_head_t node_wq; | |
192 | /* Wait queue on which to park the per-node */ | |
193 | /* kthread. */ | |
d71df90e PM |
194 | unsigned int node_kthread_status; |
195 | /* State of node_kthread_task for tracing. */ | |
9f77da9f PM |
196 | } ____cacheline_internodealigned_in_smp; |
197 | ||
a0b6c9a7 PM |
198 | /* |
199 | * Do a full breadth-first scan of the rcu_node structures for the | |
200 | * specified rcu_state structure. | |
201 | */ | |
202 | #define rcu_for_each_node_breadth_first(rsp, rnp) \ | |
203 | for ((rnp) = &(rsp)->node[0]; \ | |
204 | (rnp) < &(rsp)->node[NUM_RCU_NODES]; (rnp)++) | |
205 | ||
d9a3da06 PM |
206 | /* |
207 | * Do a breadth-first scan of the non-leaf rcu_node structures for the | |
208 | * specified rcu_state structure. Note that if there is a singleton | |
209 | * rcu_node tree with but one rcu_node structure, this loop is a no-op. | |
210 | */ | |
211 | #define rcu_for_each_nonleaf_node_breadth_first(rsp, rnp) \ | |
212 | for ((rnp) = &(rsp)->node[0]; \ | |
213 | (rnp) < (rsp)->level[NUM_RCU_LVLS - 1]; (rnp)++) | |
214 | ||
215 | /* | |
216 | * Scan the leaves of the rcu_node hierarchy for the specified rcu_state | |
217 | * structure. Note that if there is a singleton rcu_node tree with but | |
218 | * one rcu_node structure, this loop -will- visit the rcu_node structure. | |
219 | * It is still a leaf node, even if it is also the root node. | |
220 | */ | |
a0b6c9a7 PM |
221 | #define rcu_for_each_leaf_node(rsp, rnp) \ |
222 | for ((rnp) = (rsp)->level[NUM_RCU_LVLS - 1]; \ | |
223 | (rnp) < &(rsp)->node[NUM_RCU_NODES]; (rnp)++) | |
224 | ||
9f77da9f PM |
225 | /* Index values for nxttail array in struct rcu_data. */ |
226 | #define RCU_DONE_TAIL 0 /* Also RCU_WAIT head. */ | |
227 | #define RCU_WAIT_TAIL 1 /* Also RCU_NEXT_READY head. */ | |
228 | #define RCU_NEXT_READY_TAIL 2 /* Also RCU_NEXT head. */ | |
229 | #define RCU_NEXT_TAIL 3 | |
230 | #define RCU_NEXT_SIZE 4 | |
231 | ||
232 | /* Per-CPU data for read-copy update. */ | |
233 | struct rcu_data { | |
234 | /* 1) quiescent-state and grace-period handling : */ | |
20133cfc | 235 | unsigned long completed; /* Track rsp->completed gp number */ |
9f77da9f | 236 | /* in order to detect GP end. */ |
20133cfc | 237 | unsigned long gpnum; /* Highest gp number that this CPU */ |
9f77da9f | 238 | /* is aware of having started. */ |
20133cfc | 239 | unsigned long passed_quiesc_completed; |
9f77da9f PM |
240 | /* Value of completed at time of qs. */ |
241 | bool passed_quiesc; /* User-mode/idle loop etc. */ | |
242 | bool qs_pending; /* Core waits for quiesc state. */ | |
243 | bool beenonline; /* CPU online at least once. */ | |
6cc68793 | 244 | bool preemptible; /* Preemptible RCU? */ |
9f77da9f PM |
245 | struct rcu_node *mynode; /* This CPU's leaf of hierarchy */ |
246 | unsigned long grpmask; /* Mask to apply to leaf qsmask. */ | |
247 | ||
248 | /* 2) batch handling */ | |
249 | /* | |
250 | * If nxtlist is not NULL, it is partitioned as follows. | |
251 | * Any of the partitions might be empty, in which case the | |
252 | * pointer to that partition will be equal to the pointer for | |
253 | * the following partition. When the list is empty, all of | |
1eba8f84 PM |
254 | * the nxttail elements point to the ->nxtlist pointer itself, |
255 | * which in that case is NULL. | |
9f77da9f | 256 | * |
9f77da9f PM |
257 | * [nxtlist, *nxttail[RCU_DONE_TAIL]): |
258 | * Entries that batch # <= ->completed | |
259 | * The grace period for these entries has completed, and | |
260 | * the other grace-period-completed entries may be moved | |
261 | * here temporarily in rcu_process_callbacks(). | |
1eba8f84 PM |
262 | * [*nxttail[RCU_DONE_TAIL], *nxttail[RCU_WAIT_TAIL]): |
263 | * Entries that batch # <= ->completed - 1: waiting for current GP | |
264 | * [*nxttail[RCU_WAIT_TAIL], *nxttail[RCU_NEXT_READY_TAIL]): | |
265 | * Entries known to have arrived before current GP ended | |
266 | * [*nxttail[RCU_NEXT_READY_TAIL], *nxttail[RCU_NEXT_TAIL]): | |
267 | * Entries that might have arrived after current GP ended | |
268 | * Note that the value of *nxttail[RCU_NEXT_TAIL] will | |
269 | * always be NULL, as this is the end of the list. | |
9f77da9f PM |
270 | */ |
271 | struct rcu_head *nxtlist; | |
272 | struct rcu_head **nxttail[RCU_NEXT_SIZE]; | |
a71fca58 | 273 | long qlen; /* # of queued callbacks */ |
37c72e56 PM |
274 | long qlen_last_fqs_check; |
275 | /* qlen at last check for QS forcing */ | |
269dcc1c | 276 | unsigned long n_cbs_invoked; /* count of RCU cbs invoked. */ |
29494be7 LJ |
277 | unsigned long n_cbs_orphaned; /* RCU cbs orphaned by dying CPU */ |
278 | unsigned long n_cbs_adopted; /* RCU cbs adopted from dying CPU */ | |
37c72e56 PM |
279 | unsigned long n_force_qs_snap; |
280 | /* did other CPU force QS recently? */ | |
9f77da9f PM |
281 | long blimit; /* Upper limit on a processed batch */ |
282 | ||
283 | #ifdef CONFIG_NO_HZ | |
284 | /* 3) dynticks interface. */ | |
285 | struct rcu_dynticks *dynticks; /* Shared per-CPU dynticks state. */ | |
286 | int dynticks_snap; /* Per-GP tracking for dynticks. */ | |
80d02085 | 287 | int dynticks_nmi_snap; /* Per-GP tracking for dynticks_nmi. */ |
9f77da9f PM |
288 | #endif /* #ifdef CONFIG_NO_HZ */ |
289 | ||
290 | /* 4) reasons this CPU needed to be kicked by force_quiescent_state */ | |
291 | #ifdef CONFIG_NO_HZ | |
292 | unsigned long dynticks_fqs; /* Kicked due to dynticks idle. */ | |
293 | #endif /* #ifdef CONFIG_NO_HZ */ | |
294 | unsigned long offline_fqs; /* Kicked due to being offline. */ | |
295 | unsigned long resched_ipi; /* Sent a resched IPI. */ | |
296 | ||
297 | /* 5) __rcu_pending() statistics. */ | |
20133cfc PM |
298 | unsigned long n_rcu_pending; /* rcu_pending() calls since boot. */ |
299 | unsigned long n_rp_qs_pending; | |
d21670ac | 300 | unsigned long n_rp_report_qs; |
20133cfc PM |
301 | unsigned long n_rp_cb_ready; |
302 | unsigned long n_rp_cpu_needs_gp; | |
303 | unsigned long n_rp_gp_completed; | |
304 | unsigned long n_rp_gp_started; | |
305 | unsigned long n_rp_need_fqs; | |
306 | unsigned long n_rp_need_nothing; | |
9f77da9f PM |
307 | |
308 | int cpu; | |
309 | }; | |
310 | ||
311 | /* Values for signaled field in struct rcu_state. */ | |
83f5b01f PM |
312 | #define RCU_GP_IDLE 0 /* No grace period in progress. */ |
313 | #define RCU_GP_INIT 1 /* Grace period being initialized. */ | |
314 | #define RCU_SAVE_DYNTICK 2 /* Need to scan dyntick state. */ | |
ee47eb9f | 315 | #define RCU_FORCE_QS 3 /* Need to force quiescent state. */ |
9f77da9f PM |
316 | #ifdef CONFIG_NO_HZ |
317 | #define RCU_SIGNAL_INIT RCU_SAVE_DYNTICK | |
318 | #else /* #ifdef CONFIG_NO_HZ */ | |
ee47eb9f | 319 | #define RCU_SIGNAL_INIT RCU_FORCE_QS |
9f77da9f PM |
320 | #endif /* #else #ifdef CONFIG_NO_HZ */ |
321 | ||
322 | #define RCU_JIFFIES_TILL_FORCE_QS 3 /* for rsp->jiffies_force_qs */ | |
007b0924 PM |
323 | |
324 | #ifdef CONFIG_PROVE_RCU | |
325 | #define RCU_STALL_DELAY_DELTA (5 * HZ) | |
326 | #else | |
327 | #define RCU_STALL_DELAY_DELTA 0 | |
328 | #endif | |
329 | ||
b163760e PM |
330 | #define RCU_SECONDS_TILL_STALL_CHECK (CONFIG_RCU_CPU_STALL_TIMEOUT * HZ + \ |
331 | RCU_STALL_DELAY_DELTA) | |
007b0924 | 332 | /* for rsp->jiffies_stall */ |
b163760e | 333 | #define RCU_SECONDS_TILL_STALL_RECHECK (3 * RCU_SECONDS_TILL_STALL_CHECK + 30) |
007b0924 PM |
334 | /* for rsp->jiffies_stall */ |
335 | #define RCU_STALL_RAT_DELAY 2 /* Allow other CPUs time */ | |
336 | /* to take at least one */ | |
337 | /* scheduling clock irq */ | |
338 | /* before ratting on them. */ | |
9f77da9f | 339 | |
9f77da9f PM |
340 | |
341 | /* | |
342 | * RCU global state, including node hierarchy. This hierarchy is | |
343 | * represented in "heap" form in a dense array. The root (first level) | |
344 | * of the hierarchy is in ->node[0] (referenced by ->level[0]), the second | |
345 | * level in ->node[1] through ->node[m] (->node[1] referenced by ->level[1]), | |
346 | * and the third level in ->node[m+1] and following (->node[m+1] referenced | |
347 | * by ->level[2]). The number of levels is determined by the number of | |
348 | * CPUs and by CONFIG_RCU_FANOUT. Small systems will have a "hierarchy" | |
349 | * consisting of a single rcu_node. | |
350 | */ | |
351 | struct rcu_state { | |
352 | struct rcu_node node[NUM_RCU_NODES]; /* Hierarchy. */ | |
353 | struct rcu_node *level[NUM_RCU_LVLS]; /* Hierarchy levels. */ | |
354 | u32 levelcnt[MAX_RCU_LVLS + 1]; /* # nodes in each level. */ | |
355 | u8 levelspread[NUM_RCU_LVLS]; /* kids/node in each level. */ | |
394f99a9 | 356 | struct rcu_data __percpu *rda; /* pointer of percu rcu_data. */ |
9f77da9f PM |
357 | |
358 | /* The following fields are guarded by the root rcu_node's lock. */ | |
359 | ||
360 | u8 signaled ____cacheline_internodealigned_in_smp; | |
361 | /* Force QS state. */ | |
07079d53 PM |
362 | u8 fqs_active; /* force_quiescent_state() */ |
363 | /* is running. */ | |
46a1e34e PM |
364 | u8 fqs_need_gp; /* A CPU was prevented from */ |
365 | /* starting a new grace */ | |
366 | /* period because */ | |
367 | /* force_quiescent_state() */ | |
368 | /* was running. */ | |
20133cfc PM |
369 | unsigned long gpnum; /* Current gp number. */ |
370 | unsigned long completed; /* # of last completed gp. */ | |
1eba8f84 | 371 | |
d9a3da06 | 372 | /* End of fields guarded by root rcu_node's lock. */ |
1eba8f84 | 373 | |
1304afb2 | 374 | raw_spinlock_t onofflock; /* exclude on/offline and */ |
29494be7 | 375 | /* starting new GP. */ |
1304afb2 | 376 | raw_spinlock_t fqslock; /* Only one task forcing */ |
9f77da9f PM |
377 | /* quiescent states. */ |
378 | unsigned long jiffies_force_qs; /* Time at which to invoke */ | |
379 | /* force_quiescent_state(). */ | |
380 | unsigned long n_force_qs; /* Number of calls to */ | |
381 | /* force_quiescent_state(). */ | |
382 | unsigned long n_force_qs_lh; /* ~Number of calls leaving */ | |
383 | /* due to lock unavailable. */ | |
384 | unsigned long n_force_qs_ngp; /* Number of calls leaving */ | |
385 | /* due to no GP active. */ | |
9f77da9f PM |
386 | unsigned long gp_start; /* Time at which GP started, */ |
387 | /* but in jiffies. */ | |
388 | unsigned long jiffies_stall; /* Time at which to check */ | |
389 | /* for CPU stalls. */ | |
15ba0ba8 PM |
390 | unsigned long gp_max; /* Maximum GP duration in */ |
391 | /* jiffies. */ | |
4300aa64 | 392 | char *name; /* Name of structure. */ |
9f77da9f PM |
393 | }; |
394 | ||
d9a3da06 PM |
395 | /* Return values for rcu_preempt_offline_tasks(). */ |
396 | ||
397 | #define RCU_OFL_TASKS_NORM_GP 0x1 /* Tasks blocking normal */ | |
398 | /* GP were moved to root. */ | |
399 | #define RCU_OFL_TASKS_EXP_GP 0x2 /* Tasks blocking expedited */ | |
400 | /* GP were moved to root. */ | |
401 | ||
6258c4fb IM |
402 | /* |
403 | * RCU implementation internal declarations: | |
404 | */ | |
d6714c22 PM |
405 | extern struct rcu_state rcu_sched_state; |
406 | DECLARE_PER_CPU(struct rcu_data, rcu_sched_data); | |
6258c4fb IM |
407 | |
408 | extern struct rcu_state rcu_bh_state; | |
409 | DECLARE_PER_CPU(struct rcu_data, rcu_bh_data); | |
410 | ||
f41d911f PM |
411 | #ifdef CONFIG_TREE_PREEMPT_RCU |
412 | extern struct rcu_state rcu_preempt_state; | |
413 | DECLARE_PER_CPU(struct rcu_data, rcu_preempt_data); | |
414 | #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */ | |
415 | ||
017c4261 | 416 | #ifndef RCU_TREE_NONCORE |
9f77da9f | 417 | |
9b2619af | 418 | /* Forward declarations for rcutree_plugin.h */ |
dbe01350 | 419 | static void rcu_bootup_announce(void); |
9b2619af PM |
420 | long rcu_batches_completed(void); |
421 | static void rcu_preempt_note_context_switch(int cpu); | |
27f4d280 | 422 | static int rcu_preempt_blocked_readers_cgp(struct rcu_node *rnp); |
b668c9cf | 423 | #ifdef CONFIG_HOTPLUG_CPU |
d3f6bad3 PM |
424 | static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp, |
425 | unsigned long flags); | |
b668c9cf | 426 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
1ed509a2 | 427 | static void rcu_print_detail_task_stall(struct rcu_state *rsp); |
9b2619af | 428 | static void rcu_print_task_stall(struct rcu_node *rnp); |
53d84e00 | 429 | static void rcu_preempt_stall_reset(void); |
9b2619af PM |
430 | static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp); |
431 | #ifdef CONFIG_HOTPLUG_CPU | |
237c80c5 PM |
432 | static int rcu_preempt_offline_tasks(struct rcu_state *rsp, |
433 | struct rcu_node *rnp, | |
434 | struct rcu_data *rdp); | |
9b2619af PM |
435 | static void rcu_preempt_offline_cpu(int cpu); |
436 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
437 | static void rcu_preempt_check_callbacks(int cpu); | |
438 | static void rcu_preempt_process_callbacks(void); | |
439 | void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu)); | |
d9a3da06 PM |
440 | #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_TREE_PREEMPT_RCU) |
441 | static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp); | |
442 | #endif /* #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_TREE_PREEMPT_RCU) */ | |
9b2619af PM |
443 | static int rcu_preempt_pending(int cpu); |
444 | static int rcu_preempt_needs_cpu(int cpu); | |
445 | static void __cpuinit rcu_preempt_init_percpu_data(int cpu); | |
29494be7 | 446 | static void rcu_preempt_send_cbs_to_online(void); |
9b2619af | 447 | static void __init __rcu_init_preempt(void); |
a47cd880 | 448 | static void rcu_needs_cpu_flush(void); |
27f4d280 | 449 | static void __init rcu_init_boost_waitqueue(struct rcu_node *rnp); |
1217ed1b | 450 | static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags); |
27f4d280 PM |
451 | static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, |
452 | cpumask_var_t cm); | |
453 | static void rcu_preempt_boost_start_gp(struct rcu_node *rnp); | |
454 | static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp, | |
455 | struct rcu_node *rnp, | |
456 | int rnp_index); | |
9b2619af | 457 | |
017c4261 | 458 | #endif /* #ifndef RCU_TREE_NONCORE */ |