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-rw-r--r--kernel/sched/features.h65
1 files changed, 48 insertions, 17 deletions
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 68d369cba9e4..3c12d9f93331 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -1,16 +1,28 @@
/* 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.
+ * Using the avg_vruntime, do the right thing and preserve lag across
+ * sleep+wake cycles. EEVDF placement strategy #1, #2 if disabled.
*/
-SCHED_FEAT(GENTLE_FAIR_SLEEPERS, true)
-
+SCHED_FEAT(PLACE_LAG, true)
+/*
+ * Give new tasks half a slice to ease into the competition.
+ */
+SCHED_FEAT(PLACE_DEADLINE_INITIAL, true)
+/*
+ * Preserve relative virtual deadline on 'migration'.
+ */
+SCHED_FEAT(PLACE_REL_DEADLINE, true)
+/*
+ * Inhibit (wakeup) preemption until the current task has either matched the
+ * 0-lag point or until is has exhausted it's slice.
+ */
+SCHED_FEAT(RUN_TO_PARITY, true)
/*
- * Place new tasks ahead so that they do not starve already running
- * tasks
+ * Allow wakeup of tasks with a shorter slice to cancel RUN_TO_PARITY for
+ * current.
*/
-SCHED_FEAT(START_DEBIT, true)
+SCHED_FEAT(PREEMPT_SHORT, true)
/*
* Prefer to schedule the task we woke last (assuming it failed
@@ -20,42 +32,60 @@ SCHED_FEAT(START_DEBIT, true)
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.
+ * Allow completely ignoring cfs_rq->next; which can be set from various
+ * places:
+ * - NEXT_BUDDY (wakeup preemption)
+ * - yield_to_task()
+ * - cgroup dequeue / pick
*/
-SCHED_FEAT(LAST_BUDDY, true)
+SCHED_FEAT(PICK_BUDDY, true)
/*
- * Consider buddies to be cache hot, decreases the likelyness of a
+ * Consider buddies to be cache hot, decreases the likeliness of a
* cache buddy being migrated away, increases cache locality.
*/
SCHED_FEAT(CACHE_HOT_BUDDY, true)
/*
+ * Delay dequeueing tasks until they get selected or woken.
+ *
+ * By delaying the dequeue for non-eligible tasks, they remain in the
+ * competition and can burn off their negative lag. When they get selected
+ * they'll have positive lag by definition.
+ *
+ * DELAY_ZERO clips the lag on dequeue (or wakeup) to 0.
+ */
+SCHED_FEAT(DELAY_DEQUEUE, true)
+SCHED_FEAT(DELAY_ZERO, true)
+
+/*
* Allow wakeup-time preemption of the current task:
*/
SCHED_FEAT(WAKEUP_PREEMPTION, true)
SCHED_FEAT(HRTICK, false)
-SCHED_FEAT(DOUBLE_TICK, false)
+SCHED_FEAT(HRTICK_DL, false)
/*
* Decrement CPU capacity based on time not spent running tasks
*/
SCHED_FEAT(NONTASK_CAPACITY, true)
+#ifdef CONFIG_PREEMPT_RT
+SCHED_FEAT(TTWU_QUEUE, false)
+#else
+
/*
* Queue remote wakeups on the target CPU and process them
* using the scheduler IPI. Reduces rq->lock contention/bounces.
*/
SCHED_FEAT(TTWU_QUEUE, true)
+#endif
/*
* When doing wakeups, attempt to limit superfluous scans of the LLC domain.
*/
-SCHED_FEAT(SIS_AVG_CPU, false)
-SCHED_FEAT(SIS_PROP, true)
+SCHED_FEAT(SIS_UTIL, true)
/*
* Issue a WARN when we do multiple update_rq_clock() calls
@@ -89,4 +119,5 @@ SCHED_FEAT(WA_BIAS, true)
* UtilEstimation. Use estimated CPU utilization.
*/
SCHED_FEAT(UTIL_EST, true)
-SCHED_FEAT(UTIL_EST_FASTUP, true)
+
+SCHED_FEAT(LATENCY_WARN, false)