From 4b258461c0b31ded170a1a56b944b0fded1c887b Mon Sep 17 00:00:00 2001 From: Krishna Kumar Date: Thu, 21 Jan 2010 01:26:29 -0800 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/core/dev.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 5747b9edc1bb..4fad9db417b1 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -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