Contributors: 14
Author Tokens Token Proportion Commits Commit Proportion
Peter Zijlstra 158 65.29% 30 63.83%
Steven Rostedt 18 7.44% 2 4.26%
Thomas Gleixner 16 6.61% 1 2.13%
Juri Lelli 12 4.96% 1 2.13%
Ingo Molnar 11 4.55% 3 6.38%
Patrick Bellasi 7 2.89% 2 4.26%
Paul Turner 6 2.48% 1 2.13%
Chen Yu 4 1.65% 1 2.13%
Venkatesh Pallipadi 4 1.65% 1 2.13%
Nico Pitre 2 0.83% 1 2.13%
Mel Gorman 1 0.41% 1 2.13%
Huang Shijie 1 0.41% 1 2.13%
Daniel Bristot de Oliveira 1 0.41% 1 2.13%
Greg Kroah-Hartman 1 0.41% 1 2.13%
Total 242 47 


/* 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)

/*
 * Allow completely ignoring cfs_rq->next; which can be set from various
 * places:
 *   - NEXT_BUDDY (wakeup preemption)
 *   - yield_to_task()
 *   - cgroup dequeue / pick
 */
SCHED_FEAT(PICK_BUDDY, true)

/*
 * 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)

SCHED_FEAT(PARANOID_AVG, false)

/*
 * Allow wakeup-time preemption of the current task:
 */
SCHED_FEAT(WAKEUP_PREEMPTION, true)

#ifdef CONFIG_HRTIMER_REARM_DEFERRED
SCHED_FEAT(HRTICK, true)
SCHED_FEAT(HRTICK_DL, true)
#else
SCHED_FEAT(HRTICK, false)
SCHED_FEAT(HRTICK_DL, false)
#endif

/*
 * 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.
 *
 * This is best for PREEMPT_RT, but for non-RT it can cause issues
 * when preemption is disabled for long periods of time. Have
 * it only default enabled for PREEMPT_RT.
 */
# ifdef CONFIG_PREEMPT_RT
SCHED_FEAT(RT_PUSH_IPI, true)
# else
SCHED_FEAT(RT_PUSH_IPI, false)
# endif
#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)

/*
 * Do newidle balancing proportional to its success rate using randomization.
 */
SCHED_FEAT(NI_RANDOM, true)
SCHED_FEAT(NI_RATE, true)