[TCP]: Avoid clearing sacktag hint in trivial situations
There's no reason to clear the sacktag skb hint when small part
of the rexmit queue changes. Account changes (if any) instead when
fragmenting/collapsing. RTO/FRTO do not touch SACKED_ACKED bits so
no need to discard SACK tag hint at all.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 65b9f27..4c10d9c 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1671,7 +1671,7 @@
tp->high_seq = tp->frto_highmark;
TCP_ECN_queue_cwr(tp);
- tcp_clear_all_retrans_hints(tp);
+ tcp_clear_retrans_hints_partial(tp);
}
void tcp_clear_retrans(struct tcp_sock *tp)
@@ -1711,10 +1711,14 @@
tp->bytes_acked = 0;
tcp_clear_retrans(tp);
- /* Push undo marker, if it was plain RTO and nothing
- * was retransmitted. */
- if (!how)
+ if (!how) {
+ /* Push undo marker, if it was plain RTO and nothing
+ * was retransmitted. */
tp->undo_marker = tp->snd_una;
+ tcp_clear_retrans_hints_partial(tp);
+ } else {
+ tcp_clear_all_retrans_hints(tp);
+ }
tcp_for_write_queue(skb, sk) {
if (skb == tcp_send_head(sk))
@@ -1741,8 +1745,6 @@
TCP_ECN_queue_cwr(tp);
/* Abort FRTO algorithm if one is in progress */
tp->frto_counter = 0;
-
- tcp_clear_all_retrans_hints(tp);
}
static int tcp_check_sack_reneging(struct sock *sk)
