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