tcp: fill shinfo->gso_size at last moment
In commit cd7d8498c9a5 ("tcp: change tcp_skb_pcount() location") we stored
gso_segs in a temporary cache hot location.
This patch does the same for gso_size.
This allows to save 2 cache line misses in tcp xmit path for
the last packet that is considered but not sent because of
various conditions (cwnd, tso defer, receiver window, TSQ...)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 70a6fa8..684f095 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1316,12 +1316,12 @@
* code can come after this skb later on it's better to keep
* setting gso_size to something.
*/
- if (!skb_shinfo(prev)->gso_size)
- skb_shinfo(prev)->gso_size = mss;
+ if (!TCP_SKB_CB(prev)->tcp_gso_size)
+ TCP_SKB_CB(prev)->tcp_gso_size = mss;
/* CHECKME: To clear or not to clear? Mimics normal skb currently */
if (tcp_skb_pcount(skb) <= 1)
- skb_shinfo(skb)->gso_size = 0;
+ TCP_SKB_CB(skb)->tcp_gso_size = 0;
/* Difference in this won't matter, both ACKed by the same cumul. ACK */
TCP_SKB_CB(prev)->sacked |= (TCP_SKB_CB(skb)->sacked & TCPCB_EVER_RETRANS);
@@ -2248,7 +2248,7 @@
(oldcnt >= packets))
break;
- mss = skb_shinfo(skb)->gso_size;
+ mss = tcp_skb_mss(skb);
err = tcp_fragment(sk, skb, (packets - oldcnt) * mss,
mss, GFP_ATOMIC);
if (err < 0)
