net: Optimize non-gso test checks

Avoid checking twice whether skb needs to be linearized, if one
skb_linearize was already done.

Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Krishna Kumar 2010-01-21 01:26:29 -08:00 committed by David S. Miller
parent 5f8cbc1322
commit 4b258461c0

View File

@ -1982,6 +1982,21 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
return rc;
}
/*
* Returns true if either:
* 1. skb has frag_list and the device doesn't support FRAGLIST, or
* 2. skb is fragmented and the device does not support SG, or if
* at least one of fragments is in highmem and device does not
* support DMA from it.
*/
static inline int skb_needs_linearize(struct sk_buff *skb,
struct net_device *dev)
{
return (skb_has_frags(skb) && !(dev->features & NETIF_F_FRAGLIST)) ||
(skb_shinfo(skb)->nr_frags && (!(dev->features & NETIF_F_SG) ||
illegal_highdma(dev, skb)));
}
/**
* dev_queue_xmit - transmit a buffer
* @skb: buffer to transmit
@ -2018,18 +2033,8 @@ int dev_queue_xmit(struct sk_buff *skb)
if (netif_needs_gso(dev, skb))
goto gso;
if (skb_has_frags(skb) &&
!(dev->features & NETIF_F_FRAGLIST) &&
__skb_linearize(skb))
goto out_kfree_skb;
/* Fragmented skb is linearized if device does not support SG,
* or if at least one of fragments is in highmem and device
* does not support DMA from it.
*/
if (skb_shinfo(skb)->nr_frags &&
(!(dev->features & NETIF_F_SG) || illegal_highdma(dev, skb)) &&
__skb_linearize(skb))
/* Convert a paged skb to linear, if required */
if (skb_needs_linearize(skb, dev) && __skb_linearize(skb))
goto out_kfree_skb;
/* If packet is not checksummed and device does not support