sched: silence PROVE_RCU in sched_fork()

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

diff --git a/kernel/sched.c b/kernel/sched.c
index d484081425037b5b59ce076c03f524ead13ec37b..a2d215d132f630ec8ed7dcf03af24b3c8524d966 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -544,6 +544,8 @@ struct rq {
        struct root_domain *rd;
        struct sched_domain *sd;
 
+       unsigned long cpu_power;
+
        unsigned char idle_at_tick;
        /* For active balancing */
        int post_schedule;
@@ -1499,24 +1501,9 @@ static unsigned long target_load(int cpu, int type)
        return max(rq->cpu_load[type-1], total);
 }
 
-static struct sched_group *group_of(int cpu)
-{
-       struct sched_domain *sd = rcu_dereference_sched(cpu_rq(cpu)->sd);
-
-       if (!sd)
-               return NULL;
-
-       return sd->groups;
-}
-
 static unsigned long power_of(int cpu)
 {
-       struct sched_group *group = group_of(cpu);
-
-       if (!group)
-               return SCHED_LOAD_SCALE;
-
-       return group->cpu_power;
+       return cpu_rq(cpu)->cpu_power;
 }
 
 static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);
@@ -1854,8 +1841,8 @@ static void dec_nr_running(struct rq *rq)
 static void set_load_weight(struct task_struct *p)
 {
        if (task_has_rt_policy(p)) {
-               p->se.load.weight = prio_to_weight[0] * 2;
-               p->se.load.inv_weight = prio_to_wmult[0] >> 1;
+               p->se.load.weight = 0;
+               p->se.load.inv_weight = WMULT_CONST;
                return;
        }
 
@@ -2507,7 +2494,16 @@ void sched_fork(struct task_struct *p, int clone_flags)
        if (p->sched_class->task_fork)
                p->sched_class->task_fork(p);
 
+       /*
+        * The child is not yet in the pid-hash so no cgroup attach races,
+        * and the cgroup is pinned to this child due to cgroup_fork()
+        * is ran before sched_fork().
+        *
+        * Silence PROVE_RCU.
+        */
+       rcu_read_lock();
        set_task_cpu(p, cpu);
+       rcu_read_unlock();
 
 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
        if (likely(sched_info_on()))
@@ -7605,6 +7601,7 @@ void __init sched_init(void)
 #ifdef CONFIG_SMP
                rq->sd = NULL;
                rq->rd = NULL;
+               rq->cpu_power = SCHED_LOAD_SCALE;
                rq->post_schedule = 0;
                rq->active_balance = 0;
                rq->next_balance = jiffies;