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: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 963bda1..dcb116d 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2886,6 +2886,7 @@
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 @@
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),