Linux Kernel  3.7.1
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features.h
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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, true)
7 
8 /*
9  * Place new tasks ahead so that they do not starve already running
10  * tasks
11  */
12 SCHED_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  */
19 SCHED_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  */
26 SCHED_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  */
32 SCHED_FEAT(CACHE_HOT_BUDDY, true)
33 
34 /*
35  * Use arch dependent cpu power functions
36  */
37 SCHED_FEAT(ARCH_POWER, true)
38 
39 SCHED_FEAT(HRTICK, false)
40 SCHED_FEAT(DOUBLE_TICK, false)
41 SCHED_FEAT(LB_BIAS, true)
42 
43 /*
44  * Spin-wait on mutex acquisition when the mutex owner is running on
45  * another cpu -- assumes that when the owner is running, it will soon
46  * release the lock. Decreases scheduling overhead.
47  */
48 SCHED_FEAT(OWNER_SPIN, true)
49 
50 /*
51  * Decrement CPU power based on time not spent running tasks
52  */
53 SCHED_FEAT(NONTASK_POWER, true)
54 
55 /*
56  * Queue remote wakeups on the target CPU and process them
57  * using the scheduler IPI. Reduces rq->lock contention/bounces.
58  */
59 SCHED_FEAT(TTWU_QUEUE, true)
60 
61 SCHED_FEAT(FORCE_SD_OVERLAP, false)
62 SCHED_FEAT(RT_RUNTIME_SHARE, true)
63 SCHED_FEAT(LB_MIN, false)