features.h 1.9 KB

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  1. /*
  2. * Only give sleepers 50% of their service deficit. This allows
  3. * them to run sooner, but does not allow tons of sleepers to
  4. * rip the spread apart.
  5. */
  6. SCHED_FEAT(GENTLE_FAIR_SLEEPERS, true)
  7. /*
  8. * Place new tasks ahead so that they do not starve already running
  9. * tasks
  10. */
  11. SCHED_FEAT(START_DEBIT, true)
  12. /*
  13. * Based on load and program behaviour, see if it makes sense to place
  14. * a newly woken task on the same cpu as the task that woke it --
  15. * improve cache locality. Typically used with SYNC wakeups as
  16. * generated by pipes and the like, see also SYNC_WAKEUPS.
  17. */
  18. SCHED_FEAT(AFFINE_WAKEUPS, true)
  19. /*
  20. * Prefer to schedule the task we woke last (assuming it failed
  21. * wakeup-preemption), since its likely going to consume data we
  22. * touched, increases cache locality.
  23. */
  24. SCHED_FEAT(NEXT_BUDDY, false)
  25. /*
  26. * Prefer to schedule the task that ran last (when we did
  27. * wake-preempt) as that likely will touch the same data, increases
  28. * cache locality.
  29. */
  30. SCHED_FEAT(LAST_BUDDY, true)
  31. /*
  32. * Consider buddies to be cache hot, decreases the likelyness of a
  33. * cache buddy being migrated away, increases cache locality.
  34. */
  35. SCHED_FEAT(CACHE_HOT_BUDDY, true)
  36. /*
  37. * Use arch dependent cpu power functions
  38. */
  39. SCHED_FEAT(ARCH_POWER, false)
  40. SCHED_FEAT(HRTICK, false)
  41. SCHED_FEAT(DOUBLE_TICK, false)
  42. SCHED_FEAT(LB_BIAS, true)
  43. /*
  44. * Spin-wait on mutex acquisition when the mutex owner is running on
  45. * another cpu -- assumes that when the owner is running, it will soon
  46. * release the lock. Decreases scheduling overhead.
  47. */
  48. SCHED_FEAT(OWNER_SPIN, true)
  49. /*
  50. * Decrement CPU power based on time not spent running tasks
  51. */
  52. SCHED_FEAT(NONTASK_POWER, true)
  53. /*
  54. * Queue remote wakeups on the target CPU and process them
  55. * using the scheduler IPI. Reduces rq->lock contention/bounces.
  56. */
  57. SCHED_FEAT(TTWU_QUEUE, true)
  58. SCHED_FEAT(FORCE_SD_OVERLAP, false)
  59. SCHED_FEAT(RT_RUNTIME_SHARE, true)
  60. SCHED_FEAT(LB_MIN, false)