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 scheduler changes in this cycle were:

   - various sched/deadline fixes and enhancements

   - rescheduling latency fixes/cleanups

   - rework the rq->clock code to be more consistent and more robust.

   - minor micro-optimizations

   - ->avg.decay_count fixes

   - add a stack overflow check to might_sleep()

   - idle-poll handler fix, possibly resulting in power savings

   - misc smaller updates and fixes"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/Documentation: Remove unneeded word
  sched/wait: Introduce wait_on_bit_timeout()
  sched: Pull resched loop to __schedule() callers
  sched/deadline: Remove cpu_active_mask from cpudl_find()
  sched: Fix hrtick_start() on UP
  sched/deadline: Avoid pointless __setscheduler()
  sched/deadline: Fix stale yield state
  sched/deadline: Fix hrtick for a non-leftmost task
  sched/deadline: Modify cpudl::free_cpus to reflect rd->online
  sched/idle: Add missing checks to the exit condition of cpu_idle_poll()
  sched: Fix missing preemption opportunity
  sched/rt: Reduce rq lock contention by eliminating locking of non-feasible target
  sched/debug: Print rq->clock_task
  sched/core: Rework rq->clock update skips
  sched/core: Validate rq_clock*() serialization
  sched/core: Remove check of p->sched_class
  sched/fair: Fix sched_entity::avg::decay_count initialization
  sched/debug: Fix potential call to __ffs(0) in sched_show_task()
  sched/debug: Check for stack overflow in ___might_sleep()
  sched/fair: Fix the dealing with decay_count in __synchronize_entity_decay()

1 files changed, 3 insertions, 4 deletions

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index fe331fc391f5..7ce18f3c097a 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -676,7 +676,6 @@ void init_task_runnable_average(struct task_struct *p)
 {
 	u32 slice;
 
-	p->se.avg.decay_count = 0;
 	slice = sched_slice(task_cfs_rq(p), &p->se) >> 10;
 	p->se.avg.runnable_avg_sum = slice;
 	p->se.avg.runnable_avg_period = slice;
@@ -2574,11 +2573,11 @@ static inline u64 __synchronize_entity_decay(struct sched_entity *se)
 	u64 decays = atomic64_read(&cfs_rq->decay_counter);
 
 	decays -= se->avg.decay_count;
+	se->avg.decay_count = 0;
 	if (!decays)
 		return 0;
 
 	se->avg.load_avg_contrib = decay_load(se->avg.load_avg_contrib, decays);
-	se->avg.decay_count = 0;
 
 	return decays;
 }
@@ -5157,7 +5156,7 @@ static void yield_task_fair(struct rq *rq)
 		 * so we don't do microscopic update in schedule()
 		 * and double the fastpath cost.
 		 */
-		 rq->skip_clock_update = 1;
+		rq_clock_skip_update(rq, true);
 	}
 
 	set_skip_buddy(se);
@@ -5949,8 +5948,8 @@ static unsigned long scale_rt_capacity(int cpu)
 	 */
 	age_stamp = ACCESS_ONCE(rq->age_stamp);
 	avg = ACCESS_ONCE(rq->rt_avg);
+	delta = __rq_clock_broken(rq) - age_stamp;
 
-	delta = rq_clock(rq) - age_stamp;
 	if (unlikely(delta < 0))
 		delta = 0;