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

source code of linux/kernel/sched/features.h