diff options
Diffstat (limited to 'kernel/sched/features.h')
-rw-r--r-- | kernel/sched/features.h | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/kernel/sched/features.h b/kernel/sched/features.h new file mode 100644 index 000000000..f1bf5e12d --- /dev/null +++ b/kernel/sched/features.h @@ -0,0 +1,95 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * 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) + +SCHED_FEAT(HRTICK, false) +SCHED_FEAT(DOUBLE_TICK, false) + +/* + * 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) + +/* + * When doing wakeups, attempt to limit superfluous scans of the LLC domain. + */ +SCHED_FEAT(SIS_AVG_CPU, false) +SCHED_FEAT(SIS_PROP, true) + +/* + * Issue a WARN when we do multiple update_rq_clock() calls + * in a single rq->lock section. Default disabled because the + * annotations are not complete. + */ +SCHED_FEAT(WARN_DOUBLE_CLOCK, false) + +#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(RT_RUNTIME_SHARE, false) +SCHED_FEAT(LB_MIN, false) +SCHED_FEAT(ATTACH_AGE_LOAD, true) + +SCHED_FEAT(WA_IDLE, true) +SCHED_FEAT(WA_WEIGHT, true) +SCHED_FEAT(WA_BIAS, true) + +/* + * UtilEstimation. Use estimated CPU utilization. + */ +SCHED_FEAT(UTIL_EST, true) +SCHED_FEAT(UTIL_EST_FASTUP, true) + +SCHED_FEAT(ALT_PERIOD, true) +SCHED_FEAT(BASE_SLICE, true) |