| /* |
| * 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 |
| SCHED_FEAT(NUMA, false) |
| |
| /* |
| * NUMA_FAVOUR_HIGHER will favor moving tasks towards nodes where a |
| * higher number of hinting faults are recorded during active load |
| * balancing. |
| */ |
| SCHED_FEAT(NUMA_FAVOUR_HIGHER, true) |
| |
| /* |
| * NUMA_RESIST_LOWER will resist moving tasks towards nodes where a |
| * lower number of hinting faults have been recorded. As this has |
| * the potential to prevent a task ever migrating to a new node |
| * due to CPU overload it is disabled by default. |
| */ |
| SCHED_FEAT(NUMA_RESIST_LOWER, false) |
| #endif |