features.h 2.0 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. * Prefer to schedule the task we woke last (assuming it failed
  14. * wakeup-preemption), since its likely going to consume data we
  15. * touched, increases cache locality.
  16. */
  17. SCHED_FEAT(NEXT_BUDDY, false)
  18. /*
  19. * Prefer to schedule the task that ran last (when we did
  20. * wake-preempt) as that likely will touch the same data, increases
  21. * cache locality.
  22. */
  23. SCHED_FEAT(LAST_BUDDY, true)
  24. /*
  25. * Consider buddies to be cache hot, decreases the likelyness of a
  26. * cache buddy being migrated away, increases cache locality.
  27. */
  28. SCHED_FEAT(CACHE_HOT_BUDDY, true)
  29. /*
  30. * Allow wakeup-time preemption of the current task:
  31. */
  32. SCHED_FEAT(WAKEUP_PREEMPTION, true)
  33. /*
  34. * Use arch dependent cpu power functions
  35. */
  36. SCHED_FEAT(ARCH_POWER, true)
  37. SCHED_FEAT(HRTICK, false)
  38. SCHED_FEAT(DOUBLE_TICK, false)
  39. SCHED_FEAT(LB_BIAS, true)
  40. /*
  41. * Spin-wait on mutex acquisition when the mutex owner is running on
  42. * another cpu -- assumes that when the owner is running, it will soon
  43. * release the lock. Decreases scheduling overhead.
  44. */
  45. SCHED_FEAT(OWNER_SPIN, true)
  46. /*
  47. * Decrement CPU power based on time not spent running tasks
  48. */
  49. SCHED_FEAT(NONTASK_POWER, true)
  50. /*
  51. * Queue remote wakeups on the target CPU and process them
  52. * using the scheduler IPI. Reduces rq->lock contention/bounces.
  53. */
  54. SCHED_FEAT(TTWU_QUEUE, true)
  55. SCHED_FEAT(FORCE_SD_OVERLAP, false)
  56. SCHED_FEAT(RT_RUNTIME_SHARE, true)
  57. SCHED_FEAT(LB_MIN, false)
  58. /*
  59. * Apply the automatic NUMA scheduling policy. Enabled automatically
  60. * at runtime if running on a NUMA machine. Can be controlled via
  61. * numa_balancing=. Allow PTE scanning to be forced on UMA machines
  62. * for debugging the core machinery.
  63. */
  64. #ifdef CONFIG_NUMA_BALANCING
  65. SCHED_FEAT(NUMA, false)
  66. SCHED_FEAT(NUMA_FORCE, false)
  67. #endif