1 files changed, 57 insertions, 21 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 76c0e9691fc0..3c11ae0a948d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -309,6 +309,8 @@ static DEFINE_PER_CPU_SHARED_ALIGNED(struct rt_rq, init_rt_rq);
  */
 static DEFINE_SPINLOCK(task_group_lock);
 
+#ifdef CONFIG_FAIR_GROUP_SCHED
+
 #ifdef CONFIG_SMP
 static int root_task_group_empty(void)
 {
@@ -316,7 +318,6 @@ static int root_task_group_empty(void)
 }
 #endif
 
-#ifdef CONFIG_FAIR_GROUP_SCHED
 #ifdef CONFIG_USER_SCHED
 # define INIT_TASK_GROUP_LOAD   (2*NICE_0_LOAD)
 #else /* !CONFIG_USER_SCHED */
@@ -676,6 +677,7 @@ inline void update_rq_clock(struct rq *rq)
 
 /**
  * runqueue_is_locked
+ * @cpu: the processor in question.
  *
  * Returns true if the current cpu runqueue is locked.
  * This interface allows printk to be called with the runqueue lock
@@ -1563,11 +1565,7 @@ static unsigned long cpu_avg_load_per_task(int cpu)
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
 
-struct update_shares_data {
-        unsigned long rq_weight[NR_CPUS];
-};
-
-static DEFINE_PER_CPU(struct update_shares_data, update_shares_data);
+static __read_mostly unsigned long *update_shares_data;
 
 static void __set_se_shares(struct sched_entity *se, unsigned long shares);
 
@@ -1577,12 +1575,12 @@ static void __set_se_shares(struct sched_entity *se, unsigned long shares);
 static void update_group_shares_cpu(struct task_group *tg, int cpu,
                                     unsigned long sd_shares,
                                     unsigned long sd_rq_weight,
-                                    struct update_shares_data *usd)
+                                    unsigned long *usd_rq_weight)
 {
         unsigned long shares, rq_weight;
         int boost = 0;
 
-        rq_weight = usd->rq_weight[cpu];
+        rq_weight = usd_rq_weight[cpu];
         if (!rq_weight) {
                 boost = 1;
                 rq_weight = NICE_0_LOAD;
@@ -1617,7 +1615,7 @@ static void update_group_shares_cpu(struct task_group *tg, int cpu,
 static int tg_shares_up(struct task_group *tg, void *data)
 {
         unsigned long weight, rq_weight = 0, shares = 0;
-        struct update_shares_data *usd;
+        unsigned long *usd_rq_weight;
         struct sched_domain *sd = data;
         unsigned long flags;
         int i;
@@ -1626,11 +1624,11 @@ static int tg_shares_up(struct task_group *tg, void *data)
                 return 0;
 
         local_irq_save(flags);
-        usd = &__get_cpu_var(update_shares_data);
+        usd_rq_weight = per_cpu_ptr(update_shares_data, smp_processor_id());
 
         for_each_cpu(i, sched_domain_span(sd)) {
                 weight = tg->cfs_rq[i]->load.weight;
-                usd->rq_weight[i] = weight;
+                usd_rq_weight[i] = weight;
 
                 /*
                  * If there are currently no tasks on the cpu pretend there
@@ -1651,7 +1649,7 @@ static int tg_shares_up(struct task_group *tg, void *data)
                 shares = tg->shares;
 
         for_each_cpu(i, sched_domain_span(sd))
-                update_group_shares_cpu(tg, i, shares, rq_weight, usd);
+                update_group_shares_cpu(tg, i, shares, rq_weight, usd_rq_weight);
 
         local_irq_restore(flags);
 
@@ -1995,6 +1993,38 @@ static inline void check_class_changed(struct rq *rq, struct task_struct *p,
                 p->sched_class->prio_changed(rq, p, oldprio, running);
 }
 
+/**
+ * kthread_bind - bind a just-created kthread to a cpu.
+ * @p: thread created by kthread_create().
+ * @cpu: cpu (might not be online, must be possible) for @k to run on.
+ *
+ * Description: This function is equivalent to set_cpus_allowed(),
+ * except that @cpu doesn't need to be online, and the thread must be
+ * stopped (i.e., just returned from kthread_create()).
+ *
+ * Function lives here instead of kthread.c because it messes with
+ * scheduler internals which require locking.
+ */
+void kthread_bind(struct task_struct *p, unsigned int cpu)
+{
+        struct rq *rq = cpu_rq(cpu);
+        unsigned long flags;
+
+        /* Must have done schedule() in kthread() before we set_task_cpu */
+        if (!wait_task_inactive(p, TASK_UNINTERRUPTIBLE)) {
+                WARN_ON(1);
+                return;
+        }
+
+        spin_lock_irqsave(&rq->lock, flags);
+        set_task_cpu(p, cpu);
+        p->cpus_allowed = cpumask_of_cpu(cpu);
+        p->rt.nr_cpus_allowed = 1;
+        p->flags |= PF_THREAD_BOUND;
+        spin_unlock_irqrestore(&rq->lock, flags);
+}
+EXPORT_SYMBOL(kthread_bind);
+
 #ifdef CONFIG_SMP
 /*
  * Is this task likely cache-hot:
@@ -2007,7 +2037,7 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
         /*
          * Buddy candidates are cache hot:
          */
-        if (sched_feat(CACHE_HOT_BUDDY) &&
+        if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running &&
                         (&p->se == cfs_rq_of(&p->se)->next ||
                          &p->se == cfs_rq_of(&p->se)->last))
                 return 1;
@@ -2311,7 +2341,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
 {
         int cpu, orig_cpu, this_cpu, success = 0;
         unsigned long flags;
-        struct rq *rq;
+        struct rq *rq, *orig_rq;
 
         if (!sched_feat(SYNC_WAKEUPS))
                 wake_flags &= ~WF_SYNC;
@@ -2319,7 +2349,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
         this_cpu = get_cpu();
 
         smp_wmb();
-        rq = task_rq_lock(p, &flags);
+        rq = orig_rq = task_rq_lock(p, &flags);
         update_rq_clock(rq);
         if (!(p->state & state))
                 goto out;
@@ -2350,6 +2380,10 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
                 set_task_cpu(p, cpu);
 
         rq = task_rq_lock(p, &flags);
+
+        if (rq != orig_rq)
+                update_rq_clock(rq);
+
         WARN_ON(p->state != TASK_WAKING);
         cpu = task_cpu(p);
 
@@ -3656,6 +3690,7 @@ static void update_group_power(struct sched_domain *sd, int cpu)
 
 /**
  * update_sg_lb_stats - Update sched_group's statistics for load balancing.
+ * @sd: The sched_domain whose statistics are to be updated.
  * @group: sched_group whose statistics are to be updated.
  * @this_cpu: Cpu for which load balance is currently performed.
  * @idle: Idle status of this_cpu
@@ -6718,9 +6753,6 @@ EXPORT_SYMBOL(yield);
 /*
  * This task is about to go to sleep on IO. Increment rq->nr_iowait so
  * that process accounting knows that this is a task in IO wait state.
- *
- * But don't do that if it is a deliberate, throttling IO wait (this task
- * has set its backing_dev_info: the queue against which it should throttle)
  */
 void __sched io_schedule(void)
 {
@@ -9404,6 +9436,10 @@ void __init sched_init(void)
 #endif /* CONFIG_USER_SCHED */
 #endif /* CONFIG_GROUP_SCHED */
 
+#if defined CONFIG_FAIR_GROUP_SCHED && defined CONFIG_SMP
+        update_shares_data = __alloc_percpu(nr_cpu_ids * sizeof(unsigned long),
+                                            __alignof__(unsigned long));
+#endif
         for_each_possible_cpu(i) {
                 struct rq *rq;
 
@@ -9529,13 +9565,13 @@ void __init sched_init(void)
         current->sched_class = &fair_sched_class;
 
         /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */
-        alloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT);
+        zalloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT);
 #ifdef CONFIG_SMP
 #ifdef CONFIG_NO_HZ
-        alloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT);
+        zalloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT);
         alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT);
 #endif
-        alloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
+        zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
 #endif /* SMP */
 
         perf_event_init();