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-rw-r--r--kernel/sched.c16
-rw-r--r--kernel/sched_fair.c13
2 files changed, 15 insertions, 14 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index b387a8de26a..f06950c8a6c 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -668,6 +668,8 @@ const_debug unsigned int sysctl_sched_nr_migrate = 32;
*/
unsigned int sysctl_sched_rt_period = 1000000;
+static __read_mostly int scheduler_running;
+
/*
* part of the period that we allow rt tasks to run in us.
* default: 0.95s
@@ -689,14 +691,16 @@ unsigned long long cpu_clock(int cpu)
unsigned long flags;
struct rq *rq;
- local_irq_save(flags);
- rq = cpu_rq(cpu);
/*
* Only call sched_clock() if the scheduler has already been
* initialized (some code might call cpu_clock() very early):
*/
- if (rq->idle)
- update_rq_clock(rq);
+ if (unlikely(!scheduler_running))
+ return 0;
+
+ local_irq_save(flags);
+ rq = cpu_rq(cpu);
+ update_rq_clock(rq);
now = rq->clock;
local_irq_restore(flags);
@@ -3885,7 +3889,7 @@ pick_next_task(struct rq *rq, struct task_struct *prev)
asmlinkage void __sched schedule(void)
{
struct task_struct *prev, *next;
- long *switch_count;
+ unsigned long *switch_count;
struct rq *rq;
int cpu;
@@ -7284,6 +7288,8 @@ void __init sched_init(void)
* During early bootup we pretend to be a normal task:
*/
current->sched_class = &fair_sched_class;
+
+ scheduler_running = 1;
}
#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 6c091d6e159..c8e6492c592 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -202,17 +202,12 @@ static struct sched_entity *__pick_next_entity(struct cfs_rq *cfs_rq)
static inline struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
{
- struct rb_node **link = &cfs_rq->tasks_timeline.rb_node;
- struct sched_entity *se = NULL;
- struct rb_node *parent;
+ struct rb_node *last = rb_last(&cfs_rq->tasks_timeline);
- while (*link) {
- parent = *link;
- se = rb_entry(parent, struct sched_entity, run_node);
- link = &parent->rb_right;
- }
+ if (!last)
+ return NULL;
- return se;
+ return rb_entry(last, struct sched_entity, run_node);
}
/**************************************************************