Commit bece1b97 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

tcp: tcp_tso_segment() small optimization 



We can move th->check computation out of the loop, as compiler
doesn't know each skb initially share same tcp headers after
skb_segment()

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent eb1d0640

net/ipv4/tcp.c

+5 −2
Original line number Diff line number Diff line
@@ -2886,6 +2886,7 @@ struct sk_buff *tcp_tso_segment(struct sk_buff *skb, 
	unsigned int oldlen;

	unsigned int mss;

	struct sk_buff *gso_skb = skb;

	__sum16 newcheck;



	if (!pskb_may_pull(skb, sizeof(*th)))

		goto out;
@@ -2936,11 +2937,13 @@ struct sk_buff *tcp_tso_segment(struct sk_buff *skb, 
	th = tcp_hdr(skb);

	seq = ntohl(th->seq);



	newcheck = ~csum_fold((__force __wsum)((__force u32)th->check +

					       (__force u32)delta));



	do {

		th->fin = th->psh = 0;

		th->check = newcheck;



		th->check = ~csum_fold((__force __wsum)((__force u32)th->check +

				       (__force u32)delta));

		if (skb->ip_summed != CHECKSUM_PARTIAL)

			th->check =

			     csum_fold(csum_partial(skb_transport_header(skb),