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 054a6012de99b7298d5f92c4b137be17a37335f3..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;
@@ -969,14 +971,6 @@ static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags)
        }
 }
 
-void task_rq_unlock_wait(struct task_struct *p)
-{
-       struct rq *rq = task_rq(p);
-
-       smp_mb(); /* spin-unlock-wait is not a full memory barrier */
-       raw_spin_unlock_wait(&rq->lock);
-}
-
 static void __task_rq_unlock(struct rq *rq)
        __releases(rq->lock)
 {
@@ -1507,24 +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);
@@ -1862,8 +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;
        }
 
@@ -2515,7 +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()))
@@ -4061,6 +4049,23 @@ int __sched wait_for_completion_killable(struct completion *x)
 }
 EXPORT_SYMBOL(wait_for_completion_killable);
 
+/**
+ * wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable))
+ * @x:  holds the state of this particular completion
+ * @timeout:  timeout value in jiffies
+ *
+ * This waits for either a completion of a specific task to be
+ * signaled or for a specified timeout to expire. It can be
+ * interrupted by a kill signal. The timeout is in jiffies.
+ */
+unsigned long __sched
+wait_for_completion_killable_timeout(struct completion *x,
+                                    unsigned long timeout)
+{
+       return wait_for_common(x, timeout, TASK_KILLABLE);
+}
+EXPORT_SYMBOL(wait_for_completion_killable_timeout);
+
 /**
  *     try_wait_for_completion - try to decrement a completion without blocking
  *     @x:     completion structure
@@ -7596,6 +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;