tcp: Slightly optimize tcp_sendmsg
Slightly optimize tcp_sendmsg since NETIF_F_SG is used many times iteratively in the loop. The only other modification is to change: } else if (i == MAX_SKB_FRAGS || (!i && !(sk->sk_route_caps & NETIF_F_SG))) { to: } else if (i == MAX_SKB_FRAGS || !sg) { The reason why this change is correct: this code (other than the MAX_SKB_FRAGS case) executes only due to the else part of: "if (skb_tailroom(skb) > 0) {" - i.e. there was no space in the skb to put the data inline. Hence SG is false is a sufficient condition, and there is no way a fragment can be added to the skb. Changelog: - Added the above explanation for the change Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com> Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
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