ARM: 6830/1: mach-ux500: force PrimeCell revisions
[linux-2.6/libata-dev.git] / kernel / sched_features.h
blobbe40f7371ee1ac2e2d91c6679bafbf798606e08e
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 */
6 SCHED_FEAT(GENTLE_FAIR_SLEEPERS, 1)
8 /*
9 * Place new tasks ahead so that they do not starve already running
10 * tasks
12 SCHED_FEAT(START_DEBIT, 1)
15 * Should wakeups try to preempt running tasks.
17 SCHED_FEAT(WAKEUP_PREEMPT, 1)
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.
25 SCHED_FEAT(AFFINE_WAKEUPS, 1)
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.
32 SCHED_FEAT(NEXT_BUDDY, 0)
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.
39 SCHED_FEAT(LAST_BUDDY, 1)
42 * Consider buddies to be cache hot, decreases the likelyness of a
43 * cache buddy being migrated away, increases cache locality.
45 SCHED_FEAT(CACHE_HOT_BUDDY, 1)
48 * Use arch dependent cpu power functions
50 SCHED_FEAT(ARCH_POWER, 0)
52 SCHED_FEAT(HRTICK, 0)
53 SCHED_FEAT(DOUBLE_TICK, 0)
54 SCHED_FEAT(LB_BIAS, 1)
57 * Spin-wait on mutex acquisition when the mutex owner is running on
58 * another cpu -- assumes that when the owner is running, it will soon
59 * release the lock. Decreases scheduling overhead.
61 SCHED_FEAT(OWNER_SPIN, 1)
64 * Decrement CPU power based on irq activity
66 SCHED_FEAT(NONIRQ_POWER, 1)
69 * Queue remote wakeups on the target CPU and process them
70 * using the scheduler IPI. Reduces rq->lock contention/bounces.
72 SCHED_FEAT(TTWU_QUEUE, 1)