[question] netif_rx() - why don't call raise_softirq()?

Hi,
I am newbie in the latest kernel development. Nowadays I am starting to work in
linux kernel. BTW, I find kernel code that I can't understand.
in bellow.

netif_rx() in 2.4.19
1238                         dev_hold(skb->dev);
1239                         __skb_queue_tail(&queue->input_pkt_queue,skb);
1240                         /* Runs from irqs or BH's, no need to wake BH */
1241                         cpu_raise_softirq(this_cpu, NET_RX_SOFTIRQ);
1242                         local_irq_restore(flags);

netif_rx() in 2.4.20
1254                         dev_hold(skb->dev);
1255                         __skb_queue_tail(&queue->input_pkt_queue,skb);
1256                         local_irq_restore(flags);

why 2.4.20's netif_rx() don't call raise_softirq()?  Is there never call net_rx_action()? 
maybe, IMHO, because NAPI. but I want to know exactly. I don't know reason why should 
you that. I could not find reason in google or netdev mailling list.

sorry for my stupid question. Any help is highly appriciated.
Thanks,
Lee