preempt.h 1.4 KB

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  1. #ifndef __LINUX_PREEMPT_H
  2. #define __LINUX_PREEMPT_H
  3. /*
  4. * include/linux/preempt.h - macros for accessing and manipulating
  5. * preempt_count (used for kernel preemption, interrupt count, etc.)
  6. */
  7. #include <linux/thread_info.h>
  8. #include <linux/linkage.h>
  9. #ifdef CONFIG_DEBUG_PREEMPT
  10. extern void fastcall add_preempt_count(int val);
  11. extern void fastcall sub_preempt_count(int val);
  12. #else
  13. # define add_preempt_count(val) do { preempt_count() += (val); } while (0)
  14. # define sub_preempt_count(val) do { preempt_count() -= (val); } while (0)
  15. #endif
  16. #define inc_preempt_count() add_preempt_count(1)
  17. #define dec_preempt_count() sub_preempt_count(1)
  18. #define preempt_count() (current_thread_info()->preempt_count)
  19. #ifdef CONFIG_PREEMPT
  20. asmlinkage void preempt_schedule(void);
  21. #define preempt_disable() \
  22. do { \
  23. inc_preempt_count(); \
  24. barrier(); \
  25. } while (0)
  26. #define preempt_enable_no_resched() \
  27. do { \
  28. barrier(); \
  29. dec_preempt_count(); \
  30. } while (0)
  31. #define preempt_check_resched() \
  32. do { \
  33. if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) \
  34. preempt_schedule(); \
  35. } while (0)
  36. #define preempt_enable() \
  37. do { \
  38. preempt_enable_no_resched(); \
  39. barrier(); \
  40. preempt_check_resched(); \
  41. } while (0)
  42. #else
  43. #define preempt_disable() do { } while (0)
  44. #define preempt_enable_no_resched() do { } while (0)
  45. #define preempt_enable() do { } while (0)
  46. #define preempt_check_resched() do { } while (0)
  47. #endif
  48. #endif /* __LINUX_PREEMPT_H */