1/*
2 * Only give sleepers 50% of their service deficit. This allows
3 * them to run sooner, but does not allow tons of sleepers to
4 * rip the spread apart.
5 */
6SCHED_FEAT(GENTLE_FAIR_SLEEPERS, true)
7
8/*
9 * Place new tasks ahead so that they do not starve already running
10 * tasks
11 */
12SCHED_FEAT(START_DEBIT, true)
13
14/*
15 * Prefer to schedule the task we woke last (assuming it failed
16 * wakeup-preemption), since its likely going to consume data we
17 * touched, increases cache locality.
18 */
19SCHED_FEAT(NEXT_BUDDY, false)
20
21/*
22 * Prefer to schedule the task that ran last (when we did
23 * wake-preempt) as that likely will touch the same data, increases
24 * cache locality.
25 */
26SCHED_FEAT(LAST_BUDDY, true)
27
28/*
29 * Consider buddies to be cache hot, decreases the likelyness of a
30 * cache buddy being migrated away, increases cache locality.
31 */
32SCHED_FEAT(CACHE_HOT_BUDDY, true)
33
34/*
35 * Allow wakeup-time preemption of the current task:
36 */
37SCHED_FEAT(WAKEUP_PREEMPTION, true)
38
39/*
40 * Use arch dependent cpu capacity functions
41 */
42SCHED_FEAT(ARCH_CAPACITY, true)
43
44SCHED_FEAT(HRTICK, false)
45SCHED_FEAT(DOUBLE_TICK, false)
46SCHED_FEAT(LB_BIAS, true)
47
48/*
49 * Decrement CPU capacity based on time not spent running tasks
50 */
51SCHED_FEAT(NONTASK_CAPACITY, true)
52
53/*
54 * Queue remote wakeups on the target CPU and process them
55 * using the scheduler IPI. Reduces rq->lock contention/bounces.
56 */
57SCHED_FEAT(TTWU_QUEUE, true)
58
59#ifdef HAVE_RT_PUSH_IPI
60/*
61 * In order to avoid a thundering herd attack of CPUs that are
62 * lowering their priorities at the same time, and there being
63 * a single CPU that has an RT task that can migrate and is waiting
64 * to run, where the other CPUs will try to take that CPUs
65 * rq lock and possibly create a large contention, sending an
66 * IPI to that CPU and let that CPU push the RT task to where
67 * it should go may be a better scenario.
68 */
69SCHED_FEAT(RT_PUSH_IPI, true)
70#endif
71
72SCHED_FEAT(FORCE_SD_OVERLAP, false)
73SCHED_FEAT(RT_RUNTIME_SHARE, true)
74SCHED_FEAT(LB_MIN, false)
75
76/*
77 * Apply the automatic NUMA scheduling policy. Enabled automatically
78 * at runtime if running on a NUMA machine. Can be controlled via
79 * numa_balancing=
80 */
81#ifdef CONFIG_NUMA_BALANCING
82SCHED_FEAT(NUMA,	false)
83
84/*
85 * NUMA_FAVOUR_HIGHER will favor moving tasks towards nodes where a
86 * higher number of hinting faults are recorded during active load
87 * balancing.
88 */
89SCHED_FEAT(NUMA_FAVOUR_HIGHER, true)
90
91/*
92 * NUMA_RESIST_LOWER will resist moving tasks towards nodes where a
93 * lower number of hinting faults have been recorded. As this has
94 * the potential to prevent a task ever migrating to a new node
95 * due to CPU overload it is disabled by default.
96 */
97SCHED_FEAT(NUMA_RESIST_LOWER, false)
98#endif
99