1 /* SPDX-License-Identifier: GPL-2.0 */ 2 3 /* 4 * Only give sleepers 50% of their service deficit. This allows 5 * them to run sooner, but does not allow tons of sleepers to 6 * rip the spread apart. 7 */ 8 SCHED_FEAT(GENTLE_FAIR_SLEEPERS, true) 9 10 /* 11 * Using the avg_vruntime, do the right thing and preserve lag across 12 * sleep+wake cycles. EEVDF placement strategy #1, #2 if disabled. 13 */ 14 SCHED_FEAT(PLACE_LAG, true) 15 SCHED_FEAT(PLACE_DEADLINE_INITIAL, true) 16 SCHED_FEAT(RUN_TO_PARITY, true) 17 18 /* 19 * Prefer to schedule the task we woke last (assuming it failed 20 * wakeup-preemption), since its likely going to consume data we 21 * touched, increases cache locality. 22 */ 23 SCHED_FEAT(NEXT_BUDDY, false) 24 25 /* 26 * Consider buddies to be cache hot, decreases the likeliness of a 27 * cache buddy being migrated away, increases cache locality. 28 */ 29 SCHED_FEAT(CACHE_HOT_BUDDY, true) 30 31 /* 32 * Allow wakeup-time preemption of the current task: 33 */ 34 SCHED_FEAT(WAKEUP_PREEMPTION, true) 35 36 SCHED_FEAT(HRTICK, false) 37 SCHED_FEAT(HRTICK_DL, false) 38 SCHED_FEAT(DOUBLE_TICK, false) 39 40 /* 41 * Decrement CPU capacity based on time not spent running tasks 42 */ 43 SCHED_FEAT(NONTASK_CAPACITY, true) 44 45 #ifdef CONFIG_PREEMPT_RT 46 SCHED_FEAT(TTWU_QUEUE, false) 47 #else 48 49 /* 50 * Queue remote wakeups on the target CPU and process them 51 * using the scheduler IPI. Reduces rq->lock contention/bounces. 52 */ 53 SCHED_FEAT(TTWU_QUEUE, true) 54 #endif 55 56 /* 57 * When doing wakeups, attempt to limit superfluous scans of the LLC domain. 58 */ 59 SCHED_FEAT(SIS_PROP, false) 60 SCHED_FEAT(SIS_UTIL, true) 61 62 /* 63 * Issue a WARN when we do multiple update_rq_clock() calls 64 * in a single rq->lock section. Default disabled because the 65 * annotations are not complete. 66 */ 67 SCHED_FEAT(WARN_DOUBLE_CLOCK, false) 68 69 #ifdef HAVE_RT_PUSH_IPI 70 /* 71 * In order to avoid a thundering herd attack of CPUs that are 72 * lowering their priorities at the same time, and there being 73 * a single CPU that has an RT task that can migrate and is waiting 74 * to run, where the other CPUs will try to take that CPUs 75 * rq lock and possibly create a large contention, sending an 76 * IPI to that CPU and let that CPU push the RT task to where 77 * it should go may be a better scenario. 78 */ 79 SCHED_FEAT(RT_PUSH_IPI, true) 80 #endif 81 82 SCHED_FEAT(RT_RUNTIME_SHARE, false) 83 SCHED_FEAT(LB_MIN, false) 84 SCHED_FEAT(ATTACH_AGE_LOAD, true) 85 86 SCHED_FEAT(WA_IDLE, true) 87 SCHED_FEAT(WA_WEIGHT, true) 88 SCHED_FEAT(WA_BIAS, true) 89 90 /* 91 * UtilEstimation. Use estimated CPU utilization. 92 */ 93 SCHED_FEAT(UTIL_EST, true) 94 SCHED_FEAT(UTIL_EST_FASTUP, true) 95 96 SCHED_FEAT(LATENCY_WARN, false) 97 98 SCHED_FEAT(HZ_BW, true) 99