/* SPDX-License-Identifier: GPL-2.0 */ /* * Using the avg_vruntime, do the right thing and preserve lag across * sleep+wake cycles. EEVDF placement strategy #1, #2 if disabled. */ SCHED_FEAT(PLACE_LAG, true) /* * Give new tasks half a slice to ease into the competition. */ SCHED_FEAT(PLACE_DEADLINE_INITIAL, true) /* * Preserve relative virtual deadline on 'migration'. */ SCHED_FEAT(PLACE_REL_DEADLINE, true) /* * Inhibit (wakeup) preemption until the current task has either matched the * 0-lag point or until is has exhausted it's slice. */ SCHED_FEAT(RUN_TO_PARITY, true) /* * Allow wakeup of tasks with a shorter slice to cancel RUN_TO_PARITY for * current. */ SCHED_FEAT(PREEMPT_SHORT, true) /* * Prefer to schedule the task we woke last (assuming it failed * wakeup-preemption), since its likely going to consume data we * touched, increases cache locality. */ SCHED_FEAT(NEXT_BUDDY, false) /* * Consider buddies to be cache hot, decreases the likeliness of a * cache buddy being migrated away, increases cache locality. */ SCHED_FEAT(CACHE_HOT_BUDDY, true) /* * Delay dequeueing tasks until they get selected or woken. * * By delaying the dequeue for non-eligible tasks, they remain in the * competition and can burn off their negative lag. When they get selected * they'll have positive lag by definition. * * DELAY_ZERO clips the lag on dequeue (or wakeup) to 0. */ SCHED_FEAT(DELAY_DEQUEUE, true) SCHED_FEAT(DELAY_ZERO, true) /* * Allow wakeup-time preemption of the current task: */ SCHED_FEAT(WAKEUP_PREEMPTION, true) SCHED_FEAT(HRTICK, false) SCHED_FEAT(HRTICK_DL, false) /* * Decrement CPU capacity based on time not spent running tasks */ SCHED_FEAT(NONTASK_CAPACITY, true) #ifdef CONFIG_PREEMPT_RT SCHED_FEAT(TTWU_QUEUE, false) #else /* * Queue remote wakeups on the target CPU and process them * using the scheduler IPI. Reduces rq->lock contention/bounces. */ SCHED_FEAT(TTWU_QUEUE, true) #endif /* * When doing wakeups, attempt to limit superfluous scans of the LLC domain. */ SCHED_FEAT(SIS_UTIL, true) /* * Issue a WARN when we do multiple update_rq_clock() calls * in a single rq->lock section. Default disabled because the * annotations are not complete. */ SCHED_FEAT(WARN_DOUBLE_CLOCK, false) #ifdef HAVE_RT_PUSH_IPI /* * In order to avoid a thundering herd attack of CPUs that are * lowering their priorities at the same time, and there being * a single CPU that has an RT task that can migrate and is waiting * to run, where the other CPUs will try to take that CPUs * rq lock and possibly create a large contention, sending an * IPI to that CPU and let that CPU push the RT task to where * it should go may be a better scenario. */ SCHED_FEAT(RT_PUSH_IPI, true) #endif SCHED_FEAT(RT_RUNTIME_SHARE, false) SCHED_FEAT(LB_MIN, false) SCHED_FEAT(ATTACH_AGE_LOAD, true) SCHED_FEAT(WA_IDLE, true) SCHED_FEAT(WA_WEIGHT, true) SCHED_FEAT(WA_BIAS, true) /* * UtilEstimation. Use estimated CPU utilization. */ SCHED_FEAT(UTIL_EST, true) SCHED_FEAT(LATENCY_WARN, false)