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 /* 40 * Use arch dependent cpu power functions 41 */ 42 SCHED_FEAT(ARCH_POWER, true) 43 44 SCHED_FEAT(HRTICK, false) 45 SCHED_FEAT(DOUBLE_TICK, false) 46 SCHED_FEAT(LB_BIAS, true) 47 48 /* 49 * Spin-wait on mutex acquisition when the mutex owner is running on 50 * another cpu -- assumes that when the owner is running, it will soon 51 * release the lock. Decreases scheduling overhead. 52 */ 53 SCHED_FEAT(OWNER_SPIN, true) 54 55 /* 56 * Decrement CPU power based on time not spent running tasks 57 */ 58 SCHED_FEAT(NONTASK_POWER, true) 59 60 /* 61 * Queue remote wakeups on the target CPU and process them 62 * using the scheduler IPI. Reduces rq->lock contention/bounces. 63 */ 64 SCHED_FEAT(TTWU_QUEUE, true) 65 66 SCHED_FEAT(FORCE_SD_OVERLAP, false) 67 SCHED_FEAT(RT_RUNTIME_SHARE, true) 68 SCHED_FEAT(LB_MIN, false) 69 70 /* 71 * Apply the automatic NUMA scheduling policy. Enabled automatically 72 * at runtime if running on a NUMA machine. Can be controlled via 73 * numa_balancing=. Allow PTE scanning to be forced on UMA machines 74 * for debugging the core machinery. 75 */ 76 #ifdef CONFIG_NUMA_BALANCING 77 SCHED_FEAT(NUMA, false) 78 SCHED_FEAT(NUMA_FORCE, false) 79 #endif 80