[PATCH] sched/fair: Cleanup task->numa_work initialization

[Thomas Gleixner]

- Resolve the ancient TODO by setting the numa_work function in
  init_numa_balancing() which is called on fork().

- Make task_numa_work() static as it's not used outside of the fair
  scheduler and lacks a prototype as well.

Signed-off-by: Thomas Gleixner <t...@linutronix.de>
---
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index bc9cfeaac8bd..f47869c0cdad 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1103,6 +1103,7 @@ static struct numa_group *deref_curr_numa_group(struct 
task_struct *p)
 
 static inline unsigned long group_faults_priv(struct numa_group *ng);
 static inline unsigned long group_faults_shared(struct numa_group *ng);
+static void task_numa_work(struct callback_head *work);
 
 static unsigned int task_nr_scan_windows(struct task_struct *p)
 {
@@ -1203,6 +1204,7 @@ void init_numa_balancing(unsigned long clone_flags, 
struct task_struct *p)
        p->node_stamp                   = 0;
        p->numa_scan_seq                = mm ? mm->numa_scan_seq : 0;
        p->numa_scan_period             = sysctl_numa_balancing_scan_delay;
+       p->numa_work.func               = task_numa_work;
        p->numa_work.next               = &p->numa_work;
        p->numa_faults                  = NULL;
        RCU_INIT_POINTER(p->numa_group, NULL);
@@ -2523,7 +2525,7 @@ static void reset_ptenuma_scan(struct task_struct *p)
  * The expensive part of numa migration is done from task_work context.
  * Triggered from task_tick_numa().
  */
-void task_numa_work(struct callback_head *work)
+static void task_numa_work(struct callback_head *work)
 {
        unsigned long migrate, next_scan, now = jiffies;
        struct task_struct *p = current;
@@ -2693,10 +2695,8 @@ static void task_tick_numa(struct rq *rq, struct 
task_struct *curr)
                        curr->numa_scan_period = task_scan_start(curr);
                curr->node_stamp += period;
 
-               if (!time_before(jiffies, curr->mm->numa_next_scan)) {
-                       init_task_work(work, task_numa_work); /* TODO: move 
this into sched_fork() */
+               if (!time_before(jiffies, curr->mm->numa_next_scan))
                        task_work_add(curr, work, true);
-               }
        }
 }