Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "The main changes in this cycle were:

   - Introduce "Energy Aware Scheduling" - by Quentin Perret.

     This is a coherent topology description of CPUs in cooperation with
     the PM subsystem, with the goal to schedule more energy-efficiently
     on asymetric SMP platform - such as waking up tasks to the more
     energy-efficient CPUs first, as long as the system isn't
     oversubscribed.

     For details of the design, see:

        https://lore.kernel.org/lkml/20180724122521.22109-1-quentin.perret@arm.com/

   - Misc cleanups and smaller enhancements"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  sched/fair: Select an energy-efficient CPU on task wake-up
  sched/fair: Introduce an energy estimation helper function
  sched/fair: Add over-utilization/tipping point indicator
  sched/fair: Clean-up update_sg_lb_stats parameters
  sched/toplogy: Introduce the 'sched_energy_present' static key
  sched/topology: Make Energy Aware Scheduling depend on schedutil
  sched/topology: Disable EAS on inappropriate platforms
  sched/topology: Add lowest CPU asymmetry sched_domain level pointer
  sched/topology: Reference the Energy Model of CPUs when available
  PM: Introduce an Energy Model management framework
  sched/cpufreq: Prepare schedutil for Energy Aware Scheduling
  sched/topology: Relocate arch_scale_cpu_capacity() to the internal header
  sched/core: Remove unnecessary unlikely() in push_*_task()
  sched/topology: Remove the ::smt_gain field from 'struct sched_domain'
  sched: Fix various typos in comments
  sched/core: Clean up the #ifdef block in add_nr_running()
  sched/fair: Make some variables static
  sched/core: Create task_has_idle_policy() helper
  sched/fair: Add lsub_positive() and use it consistently
  sched/fair: Mask UTIL_AVG_UNCHANGED usages
  ...

1 files changed, 12 insertions, 13 deletions

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 91e4202b0634..fb8b7b5d745d 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -727,7 +727,7 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se,
  * refill the runtime and set the deadline a period in the future,
  * because keeping the current (absolute) deadline of the task would
  * result in breaking guarantees promised to other tasks (refer to
- * Documentation/scheduler/sched-deadline.txt for more informations).
+ * Documentation/scheduler/sched-deadline.txt for more information).
  *
  * This function returns true if:
  *
@@ -1695,6 +1695,14 @@ static void start_hrtick_dl(struct rq *rq, struct task_struct *p)
 }
 #endif
 
+static inline void set_next_task(struct rq *rq, struct task_struct *p)
+{
+	p->se.exec_start = rq_clock_task(rq);
+
+	/* You can't push away the running task */
+	dequeue_pushable_dl_task(rq, p);
+}
+
 static struct sched_dl_entity *pick_next_dl_entity(struct rq *rq,
 						   struct dl_rq *dl_rq)
 {
@@ -1750,10 +1758,8 @@ pick_next_task_dl(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 	BUG_ON(!dl_se);
 
 	p = dl_task_of(dl_se);
-	p->se.exec_start = rq_clock_task(rq);
 
-	/* Running task will never be pushed. */
-       dequeue_pushable_dl_task(rq, p);
+	set_next_task(rq, p);
 
 	if (hrtick_enabled(rq))
 		start_hrtick_dl(rq, p);
@@ -1808,12 +1814,7 @@ static void task_fork_dl(struct task_struct *p)
 
 static void set_curr_task_dl(struct rq *rq)
 {
-	struct task_struct *p = rq->curr;
-
-	p->se.exec_start = rq_clock_task(rq);
-
-	/* You can't push away the running task */
-	dequeue_pushable_dl_task(rq, p);
+	set_next_task(rq, rq->curr);
 }
 
 #ifdef CONFIG_SMP
@@ -2041,10 +2042,8 @@ static int push_dl_task(struct rq *rq)
 		return 0;
 
 retry:
-	if (unlikely(next_task == rq->curr)) {
-		WARN_ON(1);
+	if (WARN_ON(next_task == rq->curr))
 		return 0;
-	}
 
 	/*
 	 * If next_task preempts rq->curr, and rq->curr