futex: Take mmap_sem for get_user_pages in fault_in_user_writeable

[firefly-linux-kernel-4.4.55.git] / kernel / sched.c

diff --git a/kernel/sched.c b/kernel/sched.c
index 3c11ae0a948d9337732ce9d0e37076d84c324ff6..d079a9f64a8ef25557b042c683e9f5f709fa814e 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -591,6 +591,8 @@ struct rq {
 
        u64 rt_avg;
        u64 age_stamp;
+       u64 idle_stamp;
+       u64 avg_idle;
 #endif
 
        /* calc_load related fields */
@@ -2440,6 +2442,17 @@ out_running:
 #ifdef CONFIG_SMP
        if (p->sched_class->task_wake_up)
                p->sched_class->task_wake_up(rq, p);
+
+       if (unlikely(rq->idle_stamp)) {
+               u64 delta = rq->clock - rq->idle_stamp;
+               u64 max = 2*sysctl_sched_migration_cost;
+
+               if (delta > max)
+                       rq->avg_idle = max;
+               else
+                       update_avg(&rq->avg_idle, delta);
+               rq->idle_stamp = 0;
+       }
 #endif
 out:
        task_rq_unlock(rq, &flags);
@@ -4126,7 +4139,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
        unsigned long flags;
        struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
 
-       cpumask_setall(cpus);
+       cpumask_copy(cpus, cpu_online_mask);
 
        /*
         * When power savings policy is enabled for the parent domain, idle
@@ -4289,7 +4302,7 @@ load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd)
        int all_pinned = 0;
        struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
 
-       cpumask_setall(cpus);
+       cpumask_copy(cpus, cpu_online_mask);
 
        /*
         * When power savings policy is enabled for the parent domain, idle
@@ -4429,6 +4442,11 @@ static void idle_balance(int this_cpu, struct rq *this_rq)
        int pulled_task = 0;
        unsigned long next_balance = jiffies + HZ;
 
+       this_rq->idle_stamp = this_rq->clock;
+
+       if (this_rq->avg_idle < sysctl_sched_migration_cost)
+               return;
+
        for_each_domain(this_cpu, sd) {
                unsigned long interval;
 
@@ -4443,8 +4461,10 @@ static void idle_balance(int this_cpu, struct rq *this_rq)
                interval = msecs_to_jiffies(sd->balance_interval);
                if (time_after(next_balance, sd->last_balance + interval))
                        next_balance = sd->last_balance + interval;
-               if (pulled_task)
+               if (pulled_task) {
+                       this_rq->idle_stamp = 0;
                        break;
+               }
        }
        if (pulled_task || time_after(jiffies, this_rq->next_balance)) {
                /*
@@ -9522,6 +9542,8 @@ void __init sched_init(void)
                rq->cpu = i;
                rq->online = 0;
                rq->migration_thread = NULL;
+               rq->idle_stamp = 0;
+               rq->avg_idle = 2*sysctl_sched_migration_cost;
                INIT_LIST_HEAD(&rq->migration_queue);
                rq_attach_root(rq, &def_root_domain);
 #endif