1 files changed, 96 insertions, 2 deletions

diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 9a2a45c970e7..dc0f435a2779 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -558,8 +558,6 @@ struct rq {
 #ifdef CONFIG_NO_HZ_FULL
         unsigned long last_sched_tick;
 #endif
-        int skip_clock_update;
-
         /* capture load from *all* tasks on this cpu: */
         struct load_weight load;
         unsigned long nr_load_updates;
@@ -588,6 +586,7 @@ struct rq {
         unsigned long next_balance;
         struct mm_struct *prev_mm;
 
+        unsigned int clock_skip_update;
         u64 clock;
         u64 clock_task;
 
@@ -687,16 +686,35 @@ DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
 #define cpu_curr(cpu)           (cpu_rq(cpu)->curr)
 #define raw_rq()                raw_cpu_ptr(&runqueues)
 
+static inline u64 __rq_clock_broken(struct rq *rq)
+{
+        return ACCESS_ONCE(rq->clock);
+}
+
 static inline u64 rq_clock(struct rq *rq)
 {
+        lockdep_assert_held(&rq->lock);
         return rq->clock;
 }
 
 static inline u64 rq_clock_task(struct rq *rq)
 {
+        lockdep_assert_held(&rq->lock);
         return rq->clock_task;
 }
 
+#define RQCF_REQ_SKIP   0x01
+#define RQCF_ACT_SKIP   0x02
+
+static inline void rq_clock_skip_update(struct rq *rq, bool skip)
+{
+        lockdep_assert_held(&rq->lock);
+        if (skip)
+                rq->clock_skip_update |= RQCF_REQ_SKIP;
+        else
+                rq->clock_skip_update &= ~RQCF_REQ_SKIP;
+}
+
 #ifdef CONFIG_NUMA
 enum numa_topology_type {
         NUMA_DIRECT,
@@ -1362,6 +1380,82 @@ static inline void sched_avg_update(struct rq *rq) { }
 
 extern void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period);
 
+/*
+ * __task_rq_lock - lock the rq @p resides on.
+ */
+static inline struct rq *__task_rq_lock(struct task_struct *p)
+        __acquires(rq->lock)
+{
+        struct rq *rq;
+
+        lockdep_assert_held(&p->pi_lock);
+
+        for (;;) {
+                rq = task_rq(p);
+                raw_spin_lock(&rq->lock);
+                if (likely(rq == task_rq(p) && !task_on_rq_migrating(p)))
+                        return rq;
+                raw_spin_unlock(&rq->lock);
+
+                while (unlikely(task_on_rq_migrating(p)))
+                        cpu_relax();
+        }
+}
+
+/*
+ * task_rq_lock - lock p->pi_lock and lock the rq @p resides on.
+ */
+static inline struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags)
+        __acquires(p->pi_lock)
+        __acquires(rq->lock)
+{
+        struct rq *rq;
+
+        for (;;) {
+                raw_spin_lock_irqsave(&p->pi_lock, *flags);
+                rq = task_rq(p);
+                raw_spin_lock(&rq->lock);
+                /*
+                 *      move_queued_task()              task_rq_lock()
+                 *
+                 *      ACQUIRE (rq->lock)
+                 *      [S] ->on_rq = MIGRATING         [L] rq = task_rq()
+                 *      WMB (__set_task_cpu())          ACQUIRE (rq->lock);
+                 *      [S] ->cpu = new_cpu             [L] task_rq()
+                 *                                      [L] ->on_rq
+                 *      RELEASE (rq->lock)
+                 *
+                 * If we observe the old cpu in task_rq_lock, the acquire of
+                 * the old rq->lock will fully serialize against the stores.
+                 *
+                 * If we observe the new cpu in task_rq_lock, the acquire will
+                 * pair with the WMB to ensure we must then also see migrating.
+                 */
+                if (likely(rq == task_rq(p) && !task_on_rq_migrating(p)))
+                        return rq;
+                raw_spin_unlock(&rq->lock);
+                raw_spin_unlock_irqrestore(&p->pi_lock, *flags);
+
+                while (unlikely(task_on_rq_migrating(p)))
+                        cpu_relax();
+        }
+}
+
+static inline void __task_rq_unlock(struct rq *rq)
+        __releases(rq->lock)
+{
+        raw_spin_unlock(&rq->lock);
+}
+
+static inline void
+task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags)
+        __releases(rq->lock)
+        __releases(p->pi_lock)
+{
+        raw_spin_unlock(&rq->lock);
+        raw_spin_unlock_irqrestore(&p->pi_lock, *flags);
+}
+
 #ifdef CONFIG_SMP
 #ifdef CONFIG_PREEMPT