Commit ed734a97 authored Mar 21, 2009 by Eric Dumazet Committed by David S. Miller Mar 21, 2009

net: remove useless prefetch() call



There is no gain using prefetch() in dev_hard_start_xmit(), since
we already had to read ops->ndo_select_queue pointer in dev_pick_tx(),
and both pointers are probably located in the same cache line.

This prefetch call slows down fast path because of a stall in address
computation.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 8d2f9e81

net/core/dev.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -1670,7 +1670,6 @@ int dev_hard_start_xmit(struct sk_buff skb, struct net_device dev,
		const struct net_device_ops *ops = dev->netdev_ops;
		int rc;

		prefetch(&dev->netdev_ops->ndo_start_xmit);
		if (likely(!skb->next)) {
		if (!list_empty(&ptype_all))
		dev_queue_xmit_nit(skb, dev);