rcutiny.h 4.3 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 unsigned long get_state_synchronize_sched(void)
  37. {
  38. return 0;
  39. }
  40. static inline void cond_synchronize_sched(unsigned long oldstate)
  41. {
  42. might_sleep();
  43. }
  44. static inline void rcu_barrier_bh(void)
  45. {
  46. wait_rcu_gp(call_rcu_bh);
  47. }
  48. static inline void rcu_barrier_sched(void)
  49. {
  50. wait_rcu_gp(call_rcu_sched);
  51. }
  52. static inline void synchronize_rcu_expedited(void)
  53. {
  54. synchronize_sched(); /* Only one CPU, so pretty fast anyway!!! */
  55. }
  56. static inline void rcu_barrier(void)
  57. {
  58. rcu_barrier_sched(); /* Only one CPU, so only one list of callbacks! */
  59. }
  60. static inline void synchronize_rcu_bh(void)
  61. {
  62. synchronize_sched();
  63. }
  64. static inline void synchronize_rcu_bh_expedited(void)
  65. {
  66. synchronize_sched();
  67. }
  68. static inline void synchronize_sched_expedited(void)
  69. {
  70. synchronize_sched();
  71. }
  72. static inline void kfree_call_rcu(struct rcu_head *head,
  73. rcu_callback_t func)
  74. {
  75. call_rcu(head, func);
  76. }
  77. static inline void rcu_note_context_switch(void)
  78. {
  79. rcu_sched_qs();
  80. }
  81. /*
  82. * Take advantage of the fact that there is only one CPU, which
  83. * allows us to ignore virtualization-based context switches.
  84. */
  85. static inline void rcu_virt_note_context_switch(int cpu)
  86. {
  87. }
  88. /*
  89. * Return the number of grace periods started.
  90. */
  91. static inline unsigned long rcu_batches_started(void)
  92. {
  93. return 0;
  94. }
  95. /*
  96. * Return the number of bottom-half grace periods started.
  97. */
  98. static inline unsigned long rcu_batches_started_bh(void)
  99. {
  100. return 0;
  101. }
  102. /*
  103. * Return the number of sched grace periods started.
  104. */
  105. static inline unsigned long rcu_batches_started_sched(void)
  106. {
  107. return 0;
  108. }
  109. /*
  110. * Return the number of grace periods completed.
  111. */
  112. static inline unsigned long rcu_batches_completed(void)
  113. {
  114. return 0;
  115. }
  116. /*
  117. * Return the number of bottom-half grace periods completed.
  118. */
  119. static inline unsigned long rcu_batches_completed_bh(void)
  120. {
  121. return 0;
  122. }
  123. /*
  124. * Return the number of sched grace periods completed.
  125. */
  126. static inline unsigned long rcu_batches_completed_sched(void)
  127. {
  128. return 0;
  129. }
  130. static inline void rcu_force_quiescent_state(void)
  131. {
  132. }
  133. static inline void rcu_bh_force_quiescent_state(void)
  134. {
  135. }
  136. static inline void rcu_sched_force_quiescent_state(void)
  137. {
  138. }
  139. static inline void show_rcu_gp_kthreads(void)
  140. {
  141. }
  142. static inline void rcu_cpu_stall_reset(void)
  143. {
  144. }
  145. static inline void rcu_idle_enter(void)
  146. {
  147. }
  148. static inline void rcu_idle_exit(void)
  149. {
  150. }
  151. static inline void rcu_irq_enter(void)
  152. {
  153. }
  154. static inline void rcu_irq_exit(void)
  155. {
  156. }
  157. static inline void exit_rcu(void)
  158. {
  159. }
  160. #ifdef CONFIG_DEBUG_LOCK_ALLOC
  161. extern int rcu_scheduler_active __read_mostly;
  162. void rcu_scheduler_starting(void);
  163. #else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
  164. static inline void rcu_scheduler_starting(void)
  165. {
  166. }
  167. #endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */
  168. #if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE)
  169. static inline bool rcu_is_watching(void)
  170. {
  171. return __rcu_is_watching();
  172. }
  173. #else /* defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */
  174. static inline bool rcu_is_watching(void)
  175. {
  176. return true;
  177. }
  178. #endif /* #else defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */
  179. static inline void rcu_all_qs(void)
  180. {
  181. barrier(); /* Avoid RCU read-side critical sections leaking across. */
  182. }
  183. #endif /* __LINUX_RCUTINY_H */