| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 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 | /* |
| 9 | * Place new tasks ahead so that they do not starve already running |
| 10 | * tasks |
| 11 | */ |
| 12 | SCHED_FEAT(START_DEBIT, true) |
| 13 | |
| 14 | /* |
| 15 | * Based on load and program behaviour, see if it makes sense to place |
| 16 | * a newly woken task on the same cpu as the task that woke it -- |
| 17 | * improve cache locality. Typically used with SYNC wakeups as |
| 18 | * generated by pipes and the like, see also SYNC_WAKEUPS. |
| 19 | */ |
| 20 | SCHED_FEAT(AFFINE_WAKEUPS, true) |
| 21 | |
| 22 | /* |
| 23 | * Prefer to schedule the task we woke last (assuming it failed |
| 24 | * wakeup-preemption), since its likely going to consume data we |
| 25 | * touched, increases cache locality. |
| 26 | */ |
| 27 | SCHED_FEAT(NEXT_BUDDY, false) |
| 28 | |
| 29 | /* |
| 30 | * Prefer to schedule the task that ran last (when we did |
| 31 | * wake-preempt) as that likely will touch the same data, increases |
| 32 | * cache locality. |
| 33 | */ |
| 34 | SCHED_FEAT(LAST_BUDDY, true) |
| 35 | |
| 36 | /* |
| 37 | * Consider buddies to be cache hot, decreases the likelyness of a |
| 38 | * cache buddy being migrated away, increases cache locality. |
| 39 | */ |
| 40 | SCHED_FEAT(CACHE_HOT_BUDDY, true) |
| 41 | |
| 42 | /* |
| 43 | * Use arch dependent cpu power functions |
| 44 | */ |
| 45 | SCHED_FEAT(ARCH_POWER, false) |
| 46 | |
| 47 | SCHED_FEAT(HRTICK, false) |
| 48 | SCHED_FEAT(DOUBLE_TICK, false) |
| 49 | SCHED_FEAT(LB_BIAS, true) |
| 50 | |
| 51 | /* |
| 52 | * Spin-wait on mutex acquisition when the mutex owner is running on |
| 53 | * another cpu -- assumes that when the owner is running, it will soon |
| 54 | * release the lock. Decreases scheduling overhead. |
| 55 | */ |
| 56 | SCHED_FEAT(OWNER_SPIN, true) |
| 57 | |
| 58 | /* |
| 59 | * Decrement CPU power based on time not spent running tasks |
| 60 | */ |
| 61 | SCHED_FEAT(NONTASK_POWER, true) |
| 62 | |
| 63 | #ifndef CONFIG_PREEMPT_RT_FULL |
| 64 | /* |
| 65 | * Queue remote wakeups on the target CPU and process them |
| 66 | * using the scheduler IPI. Reduces rq->lock contention/bounces. |
| 67 | */ |
| 68 | SCHED_FEAT(TTWU_QUEUE, true) |
| 69 | #else |
| 70 | SCHED_FEAT(TTWU_QUEUE, false) |
| 71 | #endif |
| 72 | |
| 73 | SCHED_FEAT(FORCE_SD_OVERLAP, false) |
| 74 | SCHED_FEAT(RT_RUNTIME_SHARE, true) |
| 75 | SCHED_FEAT(LB_MIN, false) |