Commit f64f6114 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

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: default avatarIngo Molnar <mingo@elte.hu>
parent c65cc870

kernel/exit.c

+0 −1
Original line number Diff line number Diff line
@@ -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

+0 −31
Original line number Diff line number Diff line
@@ -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