sched: remove sched_exit()

remove sched_exit(): the elaborate dance of us trying to recover
timeslices given to child tasks never really worked.

CFS does not need it either.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/exit.c

@@ -182,7 +182,6 @@ void release_task(struct task_struct * p)
 		zap_leader = (leader->exit_signal == -1);
 	}
 
-	sched_exit(p);
 	write_unlock_irq(&tasklist_lock);
 	proc_flush_task(p);
 	release_thread(p);

kernel/sched.c

@@ -1831,37 +1831,6 @@ void fastcall wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
 	task_rq_unlock(this_rq, &flags);
 }
 
-/*
- * Potentially available exiting-child timeslices are
- * retrieved here - this way the parent does not get
- * penalized for creating too many threads.
- *
- * (this cannot be used to 'generate' timeslices
- * artificially, because any timeslice recovered here
- * was given away by the parent in the first place.)
- */
-void fastcall sched_exit(struct task_struct *p)
-{
-	unsigned long flags;
-	struct rq *rq;
-
-	/*
-	 * If the child was a (relative-) CPU hog then decrease
-	 * the sleep_avg of the parent as well.
-	 */
-	rq = task_rq_lock(p->parent, &flags);
-	if (p->first_time_slice && task_cpu(p) == task_cpu(p->parent)) {
-		p->parent->time_slice += p->time_slice;
-		if (unlikely(p->parent->time_slice > task_timeslice(p)))
-			p->parent->time_slice = task_timeslice(p);
-	}
-	if (p->sleep_avg < p->parent->sleep_avg)
-		p->parent->sleep_avg = p->parent->sleep_avg /
-		(EXIT_WEIGHT + 1) * EXIT_WEIGHT + p->sleep_avg /
-		(EXIT_WEIGHT + 1);
-	task_rq_unlock(rq, &flags);
-}
-
 /**
  * prepare_task_switch - prepare to switch tasks
  * @rq: the runqueue preparing to switch