Root/kernel/sched_features.h

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, 1)
7
8/*
9 * Place new tasks ahead so that they do not starve already running
10 * tasks
11 */
12SCHED_FEAT(START_DEBIT, 1)
13
14/*
15 * Should wakeups try to preempt running tasks.
16 */
17SCHED_FEAT(WAKEUP_PREEMPT, 1)
18
19/*
20 * Based on load and program behaviour, see if it makes sense to place
21 * a newly woken task on the same cpu as the task that woke it --
22 * improve cache locality. Typically used with SYNC wakeups as
23 * generated by pipes and the like, see also SYNC_WAKEUPS.
24 */
25SCHED_FEAT(AFFINE_WAKEUPS, 1)
26
27/*
28 * Prefer to schedule the task we woke last (assuming it failed
29 * wakeup-preemption), since its likely going to consume data we
30 * touched, increases cache locality.
31 */
32SCHED_FEAT(NEXT_BUDDY, 0)
33
34/*
35 * Prefer to schedule the task that ran last (when we did
36 * wake-preempt) as that likely will touch the same data, increases
37 * cache locality.
38 */
39SCHED_FEAT(LAST_BUDDY, 1)
40
41/*
42 * Consider buddies to be cache hot, decreases the likelyness of a
43 * cache buddy being migrated away, increases cache locality.
44 */
45SCHED_FEAT(CACHE_HOT_BUDDY, 1)
46
47/*
48 * Use arch dependent cpu power functions
49 */
50SCHED_FEAT(ARCH_POWER, 0)
51
52SCHED_FEAT(HRTICK, 0)
53SCHED_FEAT(DOUBLE_TICK, 0)
54SCHED_FEAT(LB_BIAS, 1)
55SCHED_FEAT(LB_SHARES_UPDATE, 1)
56SCHED_FEAT(ASYM_EFF_LOAD, 1)
57
58/*
59 * Spin-wait on mutex acquisition when the mutex owner is running on
60 * another cpu -- assumes that when the owner is running, it will soon
61 * release the lock. Decreases scheduling overhead.
62 */
63SCHED_FEAT(OWNER_SPIN, 1)
64

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