/* * Only give sleepers 50% of their service deficit. This allows * them to run sooner, but does not allow tons of sleepers to * rip the spread apart. */ SCHED_FEAT(GENTLE_FAIR_SLEEPERS, 1) /* * Place new tasks ahead so that they do not starve already running * tasks */ SCHED_FEAT(START_DEBIT, 1) /* * Should wakeups try to preempt running tasks. */ SCHED_FEAT(WAKEUP_PREEMPT, 1) /* * Based on load and program behaviour, see if it makes sense to place * a newly woken task on the same cpu as the task that woke it -- * improve cache locality. Typically used with SYNC wakeups as * generated by pipes and the like, see also SYNC_WAKEUPS. */ SCHED_FEAT(AFFINE_WAKEUPS, 1) /* * 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, 0) /* * Prefer to schedule the task that ran last (when we did * wake-preempt) as that likely will touch the same data, increases * cache locality. */ SCHED_FEAT(LAST_BUDDY, 1) /* * Consider buddies to be cache hot, decreases the likelyness of a * cache buddy being migrated away, increases cache locality. */ SCHED_FEAT(CACHE_HOT_BUDDY, 1) /* * Use arch dependent cpu power functions */ SCHED_FEAT(ARCH_POWER, 0) SCHED_FEAT(HRTICK, 0) SCHED_FEAT(DOUBLE_TICK, 0) SCHED_FEAT(LB_BIAS, 1) /* * Spin-wait on mutex acquisition when the mutex owner is running on * another cpu -- assumes that when the owner is running, it will soon * release the lock. Decreases scheduling overhead. */ SCHED_FEAT(OWNER_SPIN, 1) /* * Decrement CPU power based on time not spent running tasks */ SCHED_FEAT(NONTASK_POWER, 1) /* * Queue remote wakeups on the target CPU and process them * using the scheduler IPI. Reduces rq->lock contention/bounces. */ SCHED_FEAT(TTWU_QUEUE, 1) SCHED_FEAT(FORCE_SD_OVERLAP, 0)