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