Root/
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, CONFIG_RCU_FANOUT, and |
33 | * CONFIG_RCU_FANOUT_LEAF. |
34 | * In theory, it should be possible to add more levels straightforwardly. |
35 | * In practice, this did work well going from three levels to four. |
36 | * Of course, your mileage may vary. |
37 | */ |
38 | #define MAX_RCU_LVLS 4 |
39 | #define RCU_FANOUT_1 (CONFIG_RCU_FANOUT_LEAF) |
40 | #define RCU_FANOUT_2 (RCU_FANOUT_1 * CONFIG_RCU_FANOUT) |
41 | #define RCU_FANOUT_3 (RCU_FANOUT_2 * CONFIG_RCU_FANOUT) |
42 | #define RCU_FANOUT_4 (RCU_FANOUT_3 * CONFIG_RCU_FANOUT) |
43 | |
44 | #if NR_CPUS <= RCU_FANOUT_1 |
45 | # define RCU_NUM_LVLS 1 |
46 | # define NUM_RCU_LVL_0 1 |
47 | # define NUM_RCU_LVL_1 (NR_CPUS) |
48 | # define NUM_RCU_LVL_2 0 |
49 | # define NUM_RCU_LVL_3 0 |
50 | # define NUM_RCU_LVL_4 0 |
51 | #elif NR_CPUS <= RCU_FANOUT_2 |
52 | # define RCU_NUM_LVLS 2 |
53 | # define NUM_RCU_LVL_0 1 |
54 | # define NUM_RCU_LVL_1 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_1) |
55 | # define NUM_RCU_LVL_2 (NR_CPUS) |
56 | # define NUM_RCU_LVL_3 0 |
57 | # define NUM_RCU_LVL_4 0 |
58 | #elif NR_CPUS <= RCU_FANOUT_3 |
59 | # define RCU_NUM_LVLS 3 |
60 | # define NUM_RCU_LVL_0 1 |
61 | # define NUM_RCU_LVL_1 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_2) |
62 | # define NUM_RCU_LVL_2 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_1) |
63 | # define NUM_RCU_LVL_3 (NR_CPUS) |
64 | # define NUM_RCU_LVL_4 0 |
65 | #elif NR_CPUS <= RCU_FANOUT_4 |
66 | # define RCU_NUM_LVLS 4 |
67 | # define NUM_RCU_LVL_0 1 |
68 | # define NUM_RCU_LVL_1 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_3) |
69 | # define NUM_RCU_LVL_2 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_2) |
70 | # define NUM_RCU_LVL_3 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_1) |
71 | # define NUM_RCU_LVL_4 (NR_CPUS) |
72 | #else |
73 | # error "CONFIG_RCU_FANOUT insufficient for NR_CPUS" |
74 | #endif /* #if (NR_CPUS) <= RCU_FANOUT_1 */ |
75 | |
76 | #define RCU_SUM (NUM_RCU_LVL_0 + NUM_RCU_LVL_1 + NUM_RCU_LVL_2 + NUM_RCU_LVL_3 + NUM_RCU_LVL_4) |
77 | #define NUM_RCU_NODES (RCU_SUM - NR_CPUS) |
78 | |
79 | extern int rcu_num_lvls; |
80 | extern int rcu_num_nodes; |
81 | |
82 | /* |
83 | * Dynticks per-CPU state. |
84 | */ |
85 | struct rcu_dynticks { |
86 | long long dynticks_nesting; /* Track irq/process nesting level. */ |
87 | /* Process level is worth LLONG_MAX/2. */ |
88 | int dynticks_nmi_nesting; /* Track NMI nesting level. */ |
89 | atomic_t dynticks; /* Even value for idle, else odd. */ |
90 | #ifdef CONFIG_RCU_FAST_NO_HZ |
91 | int dyntick_drain; /* Prepare-for-idle state variable. */ |
92 | unsigned long dyntick_holdoff; |
93 | /* No retries for the jiffy of failure. */ |
94 | struct timer_list idle_gp_timer; |
95 | /* Wake up CPU sleeping with callbacks. */ |
96 | unsigned long idle_gp_timer_expires; |
97 | /* When to wake up CPU (for repost). */ |
98 | bool idle_first_pass; /* First pass of attempt to go idle? */ |
99 | unsigned long nonlazy_posted; |
100 | /* # times non-lazy CBs posted to CPU. */ |
101 | unsigned long nonlazy_posted_snap; |
102 | /* idle-period nonlazy_posted snapshot. */ |
103 | int tick_nohz_enabled_snap; /* Previously seen value from sysfs. */ |
104 | #endif /* #ifdef CONFIG_RCU_FAST_NO_HZ */ |
105 | }; |
106 | |
107 | /* RCU's kthread states for tracing. */ |
108 | #define RCU_KTHREAD_STOPPED 0 |
109 | #define RCU_KTHREAD_RUNNING 1 |
110 | #define RCU_KTHREAD_WAITING 2 |
111 | #define RCU_KTHREAD_OFFCPU 3 |
112 | #define RCU_KTHREAD_YIELDING 4 |
113 | #define RCU_KTHREAD_MAX 4 |
114 | |
115 | /* |
116 | * Definition for node within the RCU grace-period-detection hierarchy. |
117 | */ |
118 | struct rcu_node { |
119 | raw_spinlock_t lock; /* Root rcu_node's lock protects some */ |
120 | /* rcu_state fields as well as following. */ |
121 | unsigned long gpnum; /* Current grace period for this node. */ |
122 | /* This will either be equal to or one */ |
123 | /* behind the root rcu_node's gpnum. */ |
124 | unsigned long completed; /* Last GP completed for this node. */ |
125 | /* This will either be equal to or one */ |
126 | /* behind the root rcu_node's gpnum. */ |
127 | unsigned long qsmask; /* CPUs or groups that need to switch in */ |
128 | /* order for current grace period to proceed.*/ |
129 | /* In leaf rcu_node, each bit corresponds to */ |
130 | /* an rcu_data structure, otherwise, each */ |
131 | /* bit corresponds to a child rcu_node */ |
132 | /* structure. */ |
133 | unsigned long expmask; /* Groups that have ->blkd_tasks */ |
134 | /* elements that need to drain to allow the */ |
135 | /* current expedited grace period to */ |
136 | /* complete (only for TREE_PREEMPT_RCU). */ |
137 | atomic_t wakemask; /* CPUs whose kthread needs to be awakened. */ |
138 | /* Since this has meaning only for leaf */ |
139 | /* rcu_node structures, 32 bits suffices. */ |
140 | unsigned long qsmaskinit; |
141 | /* Per-GP initial value for qsmask & expmask. */ |
142 | unsigned long grpmask; /* Mask to apply to parent qsmask. */ |
143 | /* Only one bit will be set in this mask. */ |
144 | int grplo; /* lowest-numbered CPU or group here. */ |
145 | int grphi; /* highest-numbered CPU or group here. */ |
146 | u8 grpnum; /* CPU/group number for next level up. */ |
147 | u8 level; /* root is at level 0. */ |
148 | struct rcu_node *parent; |
149 | struct list_head blkd_tasks; |
150 | /* Tasks blocked in RCU read-side critical */ |
151 | /* section. Tasks are placed at the head */ |
152 | /* of this list and age towards the tail. */ |
153 | struct list_head *gp_tasks; |
154 | /* Pointer to the first task blocking the */ |
155 | /* current grace period, or NULL if there */ |
156 | /* is no such task. */ |
157 | struct list_head *exp_tasks; |
158 | /* Pointer to the first task blocking the */ |
159 | /* current expedited grace period, or NULL */ |
160 | /* if there is no such task. If there */ |
161 | /* is no current expedited grace period, */ |
162 | /* then there can cannot be any such task. */ |
163 | #ifdef CONFIG_RCU_BOOST |
164 | struct list_head *boost_tasks; |
165 | /* Pointer to first task that needs to be */ |
166 | /* priority boosted, or NULL if no priority */ |
167 | /* boosting is needed for this rcu_node */ |
168 | /* structure. If there are no tasks */ |
169 | /* queued on this rcu_node structure that */ |
170 | /* are blocking the current grace period, */ |
171 | /* there can be no such task. */ |
172 | unsigned long boost_time; |
173 | /* When to start boosting (jiffies). */ |
174 | struct task_struct *boost_kthread_task; |
175 | /* kthread that takes care of priority */ |
176 | /* boosting for this rcu_node structure. */ |
177 | unsigned int boost_kthread_status; |
178 | /* State of boost_kthread_task for tracing. */ |
179 | unsigned long n_tasks_boosted; |
180 | /* Total number of tasks boosted. */ |
181 | unsigned long n_exp_boosts; |
182 | /* Number of tasks boosted for expedited GP. */ |
183 | unsigned long n_normal_boosts; |
184 | /* Number of tasks boosted for normal GP. */ |
185 | unsigned long n_balk_blkd_tasks; |
186 | /* Refused to boost: no blocked tasks. */ |
187 | unsigned long n_balk_exp_gp_tasks; |
188 | /* Refused to boost: nothing blocking GP. */ |
189 | unsigned long n_balk_boost_tasks; |
190 | /* Refused to boost: already boosting. */ |
191 | unsigned long n_balk_notblocked; |
192 | /* Refused to boost: RCU RS CS still running. */ |
193 | unsigned long n_balk_notyet; |
194 | /* Refused to boost: not yet time. */ |
195 | unsigned long n_balk_nos; |
196 | /* Refused to boost: not sure why, though. */ |
197 | /* This can happen due to race conditions. */ |
198 | #endif /* #ifdef CONFIG_RCU_BOOST */ |
199 | raw_spinlock_t fqslock ____cacheline_internodealigned_in_smp; |
200 | } ____cacheline_internodealigned_in_smp; |
201 | |
202 | /* |
203 | * Do a full breadth-first scan of the rcu_node structures for the |
204 | * specified rcu_state structure. |
205 | */ |
206 | #define rcu_for_each_node_breadth_first(rsp, rnp) \ |
207 | for ((rnp) = &(rsp)->node[0]; \ |
208 | (rnp) < &(rsp)->node[rcu_num_nodes]; (rnp)++) |
209 | |
210 | /* |
211 | * Do a breadth-first scan of the non-leaf rcu_node structures for the |
212 | * specified rcu_state structure. Note that if there is a singleton |
213 | * rcu_node tree with but one rcu_node structure, this loop is a no-op. |
214 | */ |
215 | #define rcu_for_each_nonleaf_node_breadth_first(rsp, rnp) \ |
216 | for ((rnp) = &(rsp)->node[0]; \ |
217 | (rnp) < (rsp)->level[rcu_num_lvls - 1]; (rnp)++) |
218 | |
219 | /* |
220 | * Scan the leaves of the rcu_node hierarchy for the specified rcu_state |
221 | * structure. Note that if there is a singleton rcu_node tree with but |
222 | * one rcu_node structure, this loop -will- visit the rcu_node structure. |
223 | * It is still a leaf node, even if it is also the root node. |
224 | */ |
225 | #define rcu_for_each_leaf_node(rsp, rnp) \ |
226 | for ((rnp) = (rsp)->level[rcu_num_lvls - 1]; \ |
227 | (rnp) < &(rsp)->node[rcu_num_nodes]; (rnp)++) |
228 | |
229 | /* Index values for nxttail array in struct rcu_data. */ |
230 | #define RCU_DONE_TAIL 0 /* Also RCU_WAIT head. */ |
231 | #define RCU_WAIT_TAIL 1 /* Also RCU_NEXT_READY head. */ |
232 | #define RCU_NEXT_READY_TAIL 2 /* Also RCU_NEXT head. */ |
233 | #define RCU_NEXT_TAIL 3 |
234 | #define RCU_NEXT_SIZE 4 |
235 | |
236 | /* Per-CPU data for read-copy update. */ |
237 | struct rcu_data { |
238 | /* 1) quiescent-state and grace-period handling : */ |
239 | unsigned long completed; /* Track rsp->completed gp number */ |
240 | /* in order to detect GP end. */ |
241 | unsigned long gpnum; /* Highest gp number that this CPU */ |
242 | /* is aware of having started. */ |
243 | bool passed_quiesce; /* User-mode/idle loop etc. */ |
244 | bool qs_pending; /* Core waits for quiesc state. */ |
245 | bool beenonline; /* CPU online at least once. */ |
246 | bool preemptible; /* Preemptible RCU? */ |
247 | struct rcu_node *mynode; /* This CPU's leaf of hierarchy */ |
248 | unsigned long grpmask; /* Mask to apply to leaf qsmask. */ |
249 | #ifdef CONFIG_RCU_CPU_STALL_INFO |
250 | unsigned long ticks_this_gp; /* The number of scheduling-clock */ |
251 | /* ticks this CPU has handled */ |
252 | /* during and after the last grace */ |
253 | /* period it is aware of. */ |
254 | #endif /* #ifdef CONFIG_RCU_CPU_STALL_INFO */ |
255 | |
256 | /* 2) batch handling */ |
257 | /* |
258 | * If nxtlist is not NULL, it is partitioned as follows. |
259 | * Any of the partitions might be empty, in which case the |
260 | * pointer to that partition will be equal to the pointer for |
261 | * the following partition. When the list is empty, all of |
262 | * the nxttail elements point to the ->nxtlist pointer itself, |
263 | * which in that case is NULL. |
264 | * |
265 | * [nxtlist, *nxttail[RCU_DONE_TAIL]): |
266 | * Entries that batch # <= ->completed |
267 | * The grace period for these entries has completed, and |
268 | * the other grace-period-completed entries may be moved |
269 | * here temporarily in rcu_process_callbacks(). |
270 | * [*nxttail[RCU_DONE_TAIL], *nxttail[RCU_WAIT_TAIL]): |
271 | * Entries that batch # <= ->completed - 1: waiting for current GP |
272 | * [*nxttail[RCU_WAIT_TAIL], *nxttail[RCU_NEXT_READY_TAIL]): |
273 | * Entries known to have arrived before current GP ended |
274 | * [*nxttail[RCU_NEXT_READY_TAIL], *nxttail[RCU_NEXT_TAIL]): |
275 | * Entries that might have arrived after current GP ended |
276 | * Note that the value of *nxttail[RCU_NEXT_TAIL] will |
277 | * always be NULL, as this is the end of the list. |
278 | */ |
279 | struct rcu_head *nxtlist; |
280 | struct rcu_head **nxttail[RCU_NEXT_SIZE]; |
281 | unsigned long nxtcompleted[RCU_NEXT_SIZE]; |
282 | /* grace periods for sublists. */ |
283 | long qlen_lazy; /* # of lazy queued callbacks */ |
284 | long qlen; /* # of queued callbacks, incl lazy */ |
285 | long qlen_last_fqs_check; |
286 | /* qlen at last check for QS forcing */ |
287 | unsigned long n_cbs_invoked; /* count of RCU cbs invoked. */ |
288 | unsigned long n_nocbs_invoked; /* count of no-CBs RCU cbs invoked. */ |
289 | unsigned long n_cbs_orphaned; /* RCU cbs orphaned by dying CPU */ |
290 | unsigned long n_cbs_adopted; /* RCU cbs adopted from dying CPU */ |
291 | unsigned long n_force_qs_snap; |
292 | /* did other CPU force QS recently? */ |
293 | long blimit; /* Upper limit on a processed batch */ |
294 | |
295 | /* 3) dynticks interface. */ |
296 | struct rcu_dynticks *dynticks; /* Shared per-CPU dynticks state. */ |
297 | int dynticks_snap; /* Per-GP tracking for dynticks. */ |
298 | |
299 | /* 4) reasons this CPU needed to be kicked by force_quiescent_state */ |
300 | unsigned long dynticks_fqs; /* Kicked due to dynticks idle. */ |
301 | unsigned long offline_fqs; /* Kicked due to being offline. */ |
302 | |
303 | /* 5) __rcu_pending() statistics. */ |
304 | unsigned long n_rcu_pending; /* rcu_pending() calls since boot. */ |
305 | unsigned long n_rp_qs_pending; |
306 | unsigned long n_rp_report_qs; |
307 | unsigned long n_rp_cb_ready; |
308 | unsigned long n_rp_cpu_needs_gp; |
309 | unsigned long n_rp_gp_completed; |
310 | unsigned long n_rp_gp_started; |
311 | unsigned long n_rp_need_nothing; |
312 | |
313 | /* 6) _rcu_barrier() and OOM callbacks. */ |
314 | struct rcu_head barrier_head; |
315 | #ifdef CONFIG_RCU_FAST_NO_HZ |
316 | struct rcu_head oom_head; |
317 | #endif /* #ifdef CONFIG_RCU_FAST_NO_HZ */ |
318 | |
319 | /* 7) Callback offloading. */ |
320 | #ifdef CONFIG_RCU_NOCB_CPU |
321 | struct rcu_head *nocb_head; /* CBs waiting for kthread. */ |
322 | struct rcu_head **nocb_tail; |
323 | atomic_long_t nocb_q_count; /* # CBs waiting for kthread */ |
324 | atomic_long_t nocb_q_count_lazy; /* (approximate). */ |
325 | int nocb_p_count; /* # CBs being invoked by kthread */ |
326 | int nocb_p_count_lazy; /* (approximate). */ |
327 | wait_queue_head_t nocb_wq; /* For nocb kthreads to sleep on. */ |
328 | struct task_struct *nocb_kthread; |
329 | #endif /* #ifdef CONFIG_RCU_NOCB_CPU */ |
330 | |
331 | int cpu; |
332 | struct rcu_state *rsp; |
333 | }; |
334 | |
335 | /* Values for fqs_state field in struct rcu_state. */ |
336 | #define RCU_GP_IDLE 0 /* No grace period in progress. */ |
337 | #define RCU_GP_INIT 1 /* Grace period being initialized. */ |
338 | #define RCU_SAVE_DYNTICK 2 /* Need to scan dyntick state. */ |
339 | #define RCU_FORCE_QS 3 /* Need to force quiescent state. */ |
340 | #define RCU_SIGNAL_INIT RCU_SAVE_DYNTICK |
341 | |
342 | #define RCU_JIFFIES_TILL_FORCE_QS 3 /* for rsp->jiffies_force_qs */ |
343 | |
344 | #define RCU_STALL_RAT_DELAY 2 /* Allow other CPUs time */ |
345 | /* to take at least one */ |
346 | /* scheduling clock irq */ |
347 | /* before ratting on them. */ |
348 | |
349 | #define rcu_wait(cond) \ |
350 | do { \ |
351 | for (;;) { \ |
352 | set_current_state(TASK_INTERRUPTIBLE); \ |
353 | if (cond) \ |
354 | break; \ |
355 | schedule(); \ |
356 | } \ |
357 | __set_current_state(TASK_RUNNING); \ |
358 | } while (0) |
359 | |
360 | /* |
361 | * RCU global state, including node hierarchy. This hierarchy is |
362 | * represented in "heap" form in a dense array. The root (first level) |
363 | * of the hierarchy is in ->node[0] (referenced by ->level[0]), the second |
364 | * level in ->node[1] through ->node[m] (->node[1] referenced by ->level[1]), |
365 | * and the third level in ->node[m+1] and following (->node[m+1] referenced |
366 | * by ->level[2]). The number of levels is determined by the number of |
367 | * CPUs and by CONFIG_RCU_FANOUT. Small systems will have a "hierarchy" |
368 | * consisting of a single rcu_node. |
369 | */ |
370 | struct rcu_state { |
371 | struct rcu_node node[NUM_RCU_NODES]; /* Hierarchy. */ |
372 | struct rcu_node *level[RCU_NUM_LVLS]; /* Hierarchy levels. */ |
373 | u32 levelcnt[MAX_RCU_LVLS + 1]; /* # nodes in each level. */ |
374 | u8 levelspread[RCU_NUM_LVLS]; /* kids/node in each level. */ |
375 | struct rcu_data __percpu *rda; /* pointer of percu rcu_data. */ |
376 | void (*call)(struct rcu_head *head, /* call_rcu() flavor. */ |
377 | void (*func)(struct rcu_head *head)); |
378 | #ifdef CONFIG_RCU_NOCB_CPU |
379 | void (*call_remote)(struct rcu_head *head, |
380 | void (*func)(struct rcu_head *head)); |
381 | /* call_rcu() flavor, but for */ |
382 | /* placing on remote CPU. */ |
383 | #endif /* #ifdef CONFIG_RCU_NOCB_CPU */ |
384 | |
385 | /* The following fields are guarded by the root rcu_node's lock. */ |
386 | |
387 | u8 fqs_state ____cacheline_internodealigned_in_smp; |
388 | /* Force QS state. */ |
389 | u8 boost; /* Subject to priority boost. */ |
390 | unsigned long gpnum; /* Current gp number. */ |
391 | unsigned long completed; /* # of last completed gp. */ |
392 | struct task_struct *gp_kthread; /* Task for grace periods. */ |
393 | wait_queue_head_t gp_wq; /* Where GP task waits. */ |
394 | int gp_flags; /* Commands for GP task. */ |
395 | |
396 | /* End of fields guarded by root rcu_node's lock. */ |
397 | |
398 | raw_spinlock_t orphan_lock ____cacheline_internodealigned_in_smp; |
399 | /* Protect following fields. */ |
400 | struct rcu_head *orphan_nxtlist; /* Orphaned callbacks that */ |
401 | /* need a grace period. */ |
402 | struct rcu_head **orphan_nxttail; /* Tail of above. */ |
403 | struct rcu_head *orphan_donelist; /* Orphaned callbacks that */ |
404 | /* are ready to invoke. */ |
405 | struct rcu_head **orphan_donetail; /* Tail of above. */ |
406 | long qlen_lazy; /* Number of lazy callbacks. */ |
407 | long qlen; /* Total number of callbacks. */ |
408 | /* End of fields guarded by orphan_lock. */ |
409 | |
410 | struct mutex onoff_mutex; /* Coordinate hotplug & GPs. */ |
411 | |
412 | struct mutex barrier_mutex; /* Guards barrier fields. */ |
413 | atomic_t barrier_cpu_count; /* # CPUs waiting on. */ |
414 | struct completion barrier_completion; /* Wake at barrier end. */ |
415 | unsigned long n_barrier_done; /* ++ at start and end of */ |
416 | /* _rcu_barrier(). */ |
417 | /* End of fields guarded by barrier_mutex. */ |
418 | |
419 | atomic_long_t expedited_start; /* Starting ticket. */ |
420 | atomic_long_t expedited_done; /* Done ticket. */ |
421 | atomic_long_t expedited_wrap; /* # near-wrap incidents. */ |
422 | atomic_long_t expedited_tryfail; /* # acquisition failures. */ |
423 | atomic_long_t expedited_workdone1; /* # done by others #1. */ |
424 | atomic_long_t expedited_workdone2; /* # done by others #2. */ |
425 | atomic_long_t expedited_normal; /* # fallbacks to normal. */ |
426 | atomic_long_t expedited_stoppedcpus; /* # successful stop_cpus. */ |
427 | atomic_long_t expedited_done_tries; /* # tries to update _done. */ |
428 | atomic_long_t expedited_done_lost; /* # times beaten to _done. */ |
429 | atomic_long_t expedited_done_exit; /* # times exited _done loop. */ |
430 | |
431 | unsigned long jiffies_force_qs; /* Time at which to invoke */ |
432 | /* force_quiescent_state(). */ |
433 | unsigned long n_force_qs; /* Number of calls to */ |
434 | /* force_quiescent_state(). */ |
435 | unsigned long n_force_qs_lh; /* ~Number of calls leaving */ |
436 | /* due to lock unavailable. */ |
437 | unsigned long n_force_qs_ngp; /* Number of calls leaving */ |
438 | /* due to no GP active. */ |
439 | unsigned long gp_start; /* Time at which GP started, */ |
440 | /* but in jiffies. */ |
441 | unsigned long jiffies_stall; /* Time at which to check */ |
442 | /* for CPU stalls. */ |
443 | unsigned long gp_max; /* Maximum GP duration in */ |
444 | /* jiffies. */ |
445 | char *name; /* Name of structure. */ |
446 | struct list_head flavors; /* List of RCU flavors. */ |
447 | }; |
448 | |
449 | /* Values for rcu_state structure's gp_flags field. */ |
450 | #define RCU_GP_FLAG_INIT 0x1 /* Need grace-period initialization. */ |
451 | #define RCU_GP_FLAG_FQS 0x2 /* Need grace-period quiescent-state forcing. */ |
452 | |
453 | extern struct list_head rcu_struct_flavors; |
454 | |
455 | /* Sequence through rcu_state structures for each RCU flavor. */ |
456 | #define for_each_rcu_flavor(rsp) \ |
457 | list_for_each_entry((rsp), &rcu_struct_flavors, flavors) |
458 | |
459 | /* Return values for rcu_preempt_offline_tasks(). */ |
460 | |
461 | #define RCU_OFL_TASKS_NORM_GP 0x1 /* Tasks blocking normal */ |
462 | /* GP were moved to root. */ |
463 | #define RCU_OFL_TASKS_EXP_GP 0x2 /* Tasks blocking expedited */ |
464 | /* GP were moved to root. */ |
465 | |
466 | /* |
467 | * RCU implementation internal declarations: |
468 | */ |
469 | extern struct rcu_state rcu_sched_state; |
470 | DECLARE_PER_CPU(struct rcu_data, rcu_sched_data); |
471 | |
472 | extern struct rcu_state rcu_bh_state; |
473 | DECLARE_PER_CPU(struct rcu_data, rcu_bh_data); |
474 | |
475 | #ifdef CONFIG_TREE_PREEMPT_RCU |
476 | extern struct rcu_state rcu_preempt_state; |
477 | DECLARE_PER_CPU(struct rcu_data, rcu_preempt_data); |
478 | #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */ |
479 | |
480 | #ifdef CONFIG_RCU_BOOST |
481 | DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_status); |
482 | DECLARE_PER_CPU(int, rcu_cpu_kthread_cpu); |
483 | DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_loops); |
484 | DECLARE_PER_CPU(char, rcu_cpu_has_work); |
485 | #endif /* #ifdef CONFIG_RCU_BOOST */ |
486 | |
487 | #ifndef RCU_TREE_NONCORE |
488 | |
489 | /* Forward declarations for rcutree_plugin.h */ |
490 | static void rcu_bootup_announce(void); |
491 | long rcu_batches_completed(void); |
492 | static void rcu_preempt_note_context_switch(int cpu); |
493 | static int rcu_preempt_blocked_readers_cgp(struct rcu_node *rnp); |
494 | #ifdef CONFIG_HOTPLUG_CPU |
495 | static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp, |
496 | unsigned long flags); |
497 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
498 | static void rcu_print_detail_task_stall(struct rcu_state *rsp); |
499 | static int rcu_print_task_stall(struct rcu_node *rnp); |
500 | static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp); |
501 | #ifdef CONFIG_HOTPLUG_CPU |
502 | static int rcu_preempt_offline_tasks(struct rcu_state *rsp, |
503 | struct rcu_node *rnp, |
504 | struct rcu_data *rdp); |
505 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
506 | static void rcu_preempt_check_callbacks(int cpu); |
507 | void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu)); |
508 | #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_TREE_PREEMPT_RCU) |
509 | static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp, |
510 | bool wake); |
511 | #endif /* #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_TREE_PREEMPT_RCU) */ |
512 | static void __init __rcu_init_preempt(void); |
513 | static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags); |
514 | static void rcu_preempt_boost_start_gp(struct rcu_node *rnp); |
515 | static void invoke_rcu_callbacks_kthread(void); |
516 | static bool rcu_is_callbacks_kthread(void); |
517 | #ifdef CONFIG_RCU_BOOST |
518 | static void rcu_preempt_do_callbacks(void); |
519 | static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp, |
520 | struct rcu_node *rnp); |
521 | #endif /* #ifdef CONFIG_RCU_BOOST */ |
522 | static void __cpuinit rcu_prepare_kthreads(int cpu); |
523 | static void rcu_prepare_for_idle_init(int cpu); |
524 | static void rcu_cleanup_after_idle(int cpu); |
525 | static void rcu_prepare_for_idle(int cpu); |
526 | static void rcu_idle_count_callbacks_posted(void); |
527 | static void print_cpu_stall_info_begin(void); |
528 | static void print_cpu_stall_info(struct rcu_state *rsp, int cpu); |
529 | static void print_cpu_stall_info_end(void); |
530 | static void zero_cpu_stall_ticks(struct rcu_data *rdp); |
531 | static void increment_cpu_stall_ticks(void); |
532 | static bool is_nocb_cpu(int cpu); |
533 | static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp, |
534 | bool lazy); |
535 | static bool rcu_nocb_adopt_orphan_cbs(struct rcu_state *rsp, |
536 | struct rcu_data *rdp); |
537 | static bool nocb_cpu_expendable(int cpu); |
538 | static void rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp); |
539 | static void rcu_spawn_nocb_kthreads(struct rcu_state *rsp); |
540 | static void init_nocb_callback_list(struct rcu_data *rdp); |
541 | static void __init rcu_init_nocb(void); |
542 | |
543 | #endif /* #ifndef RCU_TREE_NONCORE */ |
544 | |
545 | #ifdef CONFIG_RCU_TRACE |
546 | #ifdef CONFIG_RCU_NOCB_CPU |
547 | /* Sum up queue lengths for tracing. */ |
548 | static inline void rcu_nocb_q_lengths(struct rcu_data *rdp, long *ql, long *qll) |
549 | { |
550 | *ql = atomic_long_read(&rdp->nocb_q_count) + rdp->nocb_p_count; |
551 | *qll = atomic_long_read(&rdp->nocb_q_count_lazy) + rdp->nocb_p_count_lazy; |
552 | } |
553 | #else /* #ifdef CONFIG_RCU_NOCB_CPU */ |
554 | static inline void rcu_nocb_q_lengths(struct rcu_data *rdp, long *ql, long *qll) |
555 | { |
556 | *ql = 0; |
557 | *qll = 0; |
558 | } |
559 | #endif /* #else #ifdef CONFIG_RCU_NOCB_CPU */ |
560 | #endif /* #ifdef CONFIG_RCU_TRACE */ |
561 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9