| Peter Zijlstra | e26af0e | 2009-09-11 12:31:23 +0200 | [diff] [blame] | 1 | /* |
| Ingo Molnar | 51e0304 | 2009-09-16 08:54:45 +0200 | [diff] [blame] | 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) |
| Peter Zijlstra | e26af0e | 2009-09-11 12:31:23 +0200 | [diff] [blame] | 7 | |
| 8 | /* |
| Peter Zijlstra | e26af0e | 2009-09-11 12:31:23 +0200 | [diff] [blame] | 9 | * Place new tasks ahead so that they do not starve already running |
| 10 | * tasks |
| 11 | */ |
| Peter Zijlstra | f00b45c | 2008-04-19 19:45:00 +0200 | [diff] [blame] | 12 | SCHED_FEAT(START_DEBIT, 1) |
| Peter Zijlstra | e26af0e | 2009-09-11 12:31:23 +0200 | [diff] [blame] | 13 | |
| 14 | /* |
| 15 | * Should wakeups try to preempt running tasks. |
| 16 | */ |
| 17 | SCHED_FEAT(WAKEUP_PREEMPT, 1) |
| 18 | |
| 19 | /* |
| Peter Zijlstra | e26af0e | 2009-09-11 12:31:23 +0200 | [diff] [blame] | 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 | */ |
| 25 | SCHED_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 | */ |
| Mike Galbraith | 0ec9fab | 2009-09-15 15:07:03 +0200 | [diff] [blame] | 32 | SCHED_FEAT(NEXT_BUDDY, 0) |
| Peter Zijlstra | e26af0e | 2009-09-11 12:31:23 +0200 | [diff] [blame] | 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 | */ |
| 39 | SCHED_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 | */ |
| 45 | SCHED_FEAT(CACHE_HOT_BUDDY, 1) |
| 46 | |
| Peter Zijlstra | 8e6598a | 2009-09-03 13:20:03 +0200 | [diff] [blame] | 47 | /* |
| 48 | * Use arch dependent cpu power functions |
| 49 | */ |
| 50 | SCHED_FEAT(ARCH_POWER, 0) |
| 51 | |
| Ingo Molnar | 0c4b83d | 2008-10-20 14:27:43 +0200 | [diff] [blame] | 52 | SCHED_FEAT(HRTICK, 0) |
| Peter Zijlstra | f00b45c | 2008-04-19 19:45:00 +0200 | [diff] [blame] | 53 | SCHED_FEAT(DOUBLE_TICK, 0) |
| Peter Zijlstra | efc2dea | 2008-08-20 12:44:55 +0200 | [diff] [blame] | 54 | SCHED_FEAT(LB_BIAS, 1) |
| Peter Zijlstra | e26af0e | 2009-09-11 12:31:23 +0200 | [diff] [blame] | 55 | |
| 56 | /* |
| 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. |
| 60 | */ |
| Peter Zijlstra | 0d66bf6 | 2009-01-12 14:01:47 +0100 | [diff] [blame] | 61 | SCHED_FEAT(OWNER_SPIN, 1) |
| Venkatesh Pallipadi | aa48380 | 2010-10-04 17:03:22 -0700 | [diff] [blame] | 62 | |
| 63 | /* |
| Glauber Costa | 095c0aa | 2011-07-11 15:28:18 -0400 | [diff] [blame] | 64 | * Decrement CPU power based on time not spent running tasks |
| Venkatesh Pallipadi | aa48380 | 2010-10-04 17:03:22 -0700 | [diff] [blame] | 65 | */ |
| Glauber Costa | 095c0aa | 2011-07-11 15:28:18 -0400 | [diff] [blame] | 66 | SCHED_FEAT(NONTASK_POWER, 1) |
| Peter Zijlstra | 317f394 | 2011-04-05 17:23:58 +0200 | [diff] [blame] | 67 | |
| 68 | /* |
| 69 | * Queue remote wakeups on the target CPU and process them |
| 70 | * using the scheduler IPI. Reduces rq->lock contention/bounces. |
| 71 | */ |
| 72 | SCHED_FEAT(TTWU_QUEUE, 1) |
| Peter Zijlstra | e3589f6 | 2011-07-15 10:35:52 +0200 | [diff] [blame] | 73 | |
| 74 | SCHED_FEAT(FORCE_SD_OVERLAP, 0) |