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 * Prefer to schedule the task we woke last (assuming it failed 16 * wakeup-preemption), since its likely going to consume data we 17 * touched, increases cache locality. 18 */ 19 SCHED_FEAT(NEXT_BUDDY, false) 20 21 /* 22 * Prefer to schedule the task that ran last (when we did 23 * wake-preempt) as that likely will touch the same data, increases 24 * cache locality. 25 */ 26 SCHED_FEAT(LAST_BUDDY, true) 27 28 /* 29 * Consider buddies to be cache hot, decreases the likelyness of a 30 * cache buddy being migrated away, increases cache locality. 31 */ 32 SCHED_FEAT(CACHE_HOT_BUDDY, true) 33 34 /* 35 * Allow wakeup-time preemption of the current task: 36 */ 37 SCHED_FEAT(WAKEUP_PREEMPTION, true) 38 39 SCHED_FEAT(HRTICK, false) 40 SCHED_FEAT(DOUBLE_TICK, false) 41 SCHED_FEAT(LB_BIAS, true) 42 43 /* 44 * Decrement CPU capacity based on time not spent running tasks 45 */ 46 SCHED_FEAT(NONTASK_CAPACITY, true) 47 48 /* 49 * Queue remote wakeups on the target CPU and process them 50 * using the scheduler IPI. Reduces rq->lock contention/bounces. 51 */ 52 SCHED_FEAT(TTWU_QUEUE, true) 53 54 SCHED_FEAT(FORCE_SD_OVERLAP, false) 55 SCHED_FEAT(RT_RUNTIME_SHARE, true) 56 SCHED_FEAT(LB_MIN, false) 57 58 SCHED_FEAT(ATTACH_AGE_LOAD, true) 59 60 /* 61 * Apply the automatic NUMA scheduling policy. Enabled automatically 62 * at runtime if running on a NUMA machine. Can be controlled via 63 * numa_balancing= 64 */ 65 #ifdef CONFIG_NUMA_BALANCING 66 SCHED_FEAT(NUMA, false) 67 68 /* 69 * NUMA_FAVOUR_HIGHER will favor moving tasks towards nodes where a 70 * higher number of hinting faults are recorded during active load 71 * balancing. 72 */ 73 SCHED_FEAT(NUMA_FAVOUR_HIGHER, true) 74 75 /* 76 * NUMA_RESIST_LOWER will resist moving tasks towards nodes where a 77 * lower number of hinting faults have been recorded. As this has 78 * the potential to prevent a task ever migrating to a new node 79 * due to CPU overload it is disabled by default. 80 */ 81 SCHED_FEAT(NUMA_RESIST_LOWER, false) 82 #endif 83 84 /* 85 * Energy aware scheduling. Use platform energy model to guide scheduling 86 * decisions optimizing for energy efficiency. 87 */ 88 SCHED_FEAT(ENERGY_AWARE, false) 89