rcutiny.h 4.1 KB

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  1. /*
  2. * Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition.
  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, you can access it online at
  16. * http://www.gnu.org/licenses/gpl-2.0.html.
  17. *
  18. * Copyright IBM Corporation, 2008
  19. *
  20. * Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
  21. *
  22. * For detailed explanation of Read-Copy Update mechanism see -
  23. * Documentation/RCU
  24. */
  25. #ifndef __LINUX_TINY_H
  26. #define __LINUX_TINY_H
  27. #include <linux/cache.h>
  28. static inline unsigned long get_state_synchronize_rcu(void)
  29. {
  30. return 0;
  31. }
  32. static inline void cond_synchronize_rcu(unsigned long oldstate)
  33. {
  34. might_sleep();
  35. }
  36. static inline void rcu_barrier_bh(void)
  37. {
  38. wait_rcu_gp(call_rcu_bh);
  39. }
  40. static inline void rcu_barrier_sched(void)
  41. {
  42. wait_rcu_gp(call_rcu_sched);
  43. }
  44. static inline void synchronize_rcu_expedited(void)
  45. {
  46. synchronize_sched(); /* Only one CPU, so pretty fast anyway!!! */
  47. }
  48. static inline void rcu_barrier(void)
  49. {
  50. rcu_barrier_sched(); /* Only one CPU, so only one list of callbacks! */
  51. }
  52. static inline void synchronize_rcu_bh(void)
  53. {
  54. synchronize_sched();
  55. }
  56. static inline void synchronize_rcu_bh_expedited(void)
  57. {
  58. synchronize_sched();
  59. }
  60. static inline void synchronize_sched_expedited(void)
  61. {
  62. synchronize_sched();
  63. }
  64. static inline void kfree_call_rcu(struct rcu_head *head,
  65. void (*func)(struct rcu_head *rcu))
  66. {
  67. call_rcu(head, func);
  68. }
  69. static inline void rcu_note_context_switch(void)
  70. {
  71. rcu_sched_qs();
  72. }
  73. /*
  74. * Take advantage of the fact that there is only one CPU, which
  75. * allows us to ignore virtualization-based context switches.
  76. */
  77. static inline void rcu_virt_note_context_switch(int cpu)
  78. {
  79. }
  80. /*
  81. * Return the number of grace periods started.
  82. */
  83. static inline unsigned long rcu_batches_started(void)
  84. {
  85. return 0;
  86. }
  87. /*
  88. * Return the number of bottom-half grace periods started.
  89. */
  90. static inline unsigned long rcu_batches_started_bh(void)
  91. {
  92. return 0;
  93. }
  94. /*
  95. * Return the number of sched grace periods started.
  96. */
  97. static inline unsigned long rcu_batches_started_sched(void)
  98. {
  99. return 0;
  100. }
  101. /*
  102. * Return the number of grace periods completed.
  103. */
  104. static inline unsigned long rcu_batches_completed(void)
  105. {
  106. return 0;
  107. }
  108. /*
  109. * Return the number of bottom-half grace periods completed.
  110. */
  111. static inline unsigned long rcu_batches_completed_bh(void)
  112. {
  113. return 0;
  114. }
  115. /*
  116. * Return the number of sched grace periods completed.
  117. */
  118. static inline unsigned long rcu_batches_completed_sched(void)
  119. {
  120. return 0;
  121. }
  122. static inline void rcu_force_quiescent_state(void)
  123. {
  124. }
  125. static inline void rcu_bh_force_quiescent_state(void)
  126. {
  127. }
  128. static inline void rcu_sched_force_quiescent_state(void)
  129. {
  130. }
  131. static inline void show_rcu_gp_kthreads(void)
  132. {
  133. }
  134. static inline void rcu_cpu_stall_reset(void)
  135. {
  136. }
  137. static inline void rcu_idle_enter(void)
  138. {
  139. }
  140. static inline void rcu_idle_exit(void)
  141. {
  142. }
  143. static inline void rcu_irq_enter(void)
  144. {
  145. }
  146. static inline void rcu_irq_exit(void)
  147. {
  148. }
  149. static inline void exit_rcu(void)
  150. {
  151. }
  152. #ifdef CONFIG_DEBUG_LOCK_ALLOC
  153. extern int rcu_scheduler_active __read_mostly;
  154. void rcu_scheduler_starting(void);
  155. #else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
  156. static inline void rcu_scheduler_starting(void)
  157. {
  158. }
  159. #endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */
  160. #if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE)
  161. static inline bool rcu_is_watching(void)
  162. {
  163. return __rcu_is_watching();
  164. }
  165. #else /* defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */
  166. static inline bool rcu_is_watching(void)
  167. {
  168. return true;
  169. }
  170. #endif /* #else defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */
  171. static inline void rcu_all_qs(void)
  172. {
  173. }
  174. #endif /* __LINUX_RCUTINY_H */