python3 rq worker 数量是多少？

def worker(listen):
    with Connection(redis_conn):
        worker = Worker(map(Queue, listen))
        worker.work()

def run ():
    listen = ['high', 'scheduler']
    try:
        cpu_num = 2
        p = Pool(cpu_num)
        for i in range(cpu_num):
            p.apply_async(worker, args=(listen,))  # 开启 worker
        p.close()
        p.join()
    except Exception as e:
        print(e)

主机为 1CPU,4 核

运行程序后,加入队列的任务有点多(500 多个),在前台看了下处于正在处理的任务有 16 个，这是怎么计算出来的啊？生产环境中用 gunicorn 部署的,fastapi 框架,gunicorn workers 为 4,threads 为 5