From b76892051cf1c04d95872838e70146f65e3b9d75 Mon Sep 17 00:00:00 2001 From: Ilpo Järvinen Date: Thu, 20 Sep 2007 11:37:19 -0700 Subject: [TCP]: Avoid clearing sacktag hint in trivial situations MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: David S. Miller --- net/ipv4/tcp_output.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'net/ipv4/tcp_output.c') diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index f46d24b8410f..cbb83acd830a 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -687,7 +687,7 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss BUG_ON(len > skb->len); - tcp_clear_all_retrans_hints(tp); + tcp_clear_retrans_hints_partial(tp); nsize = skb_headlen(skb) - len; if (nsize < 0) nsize = 0; @@ -1718,9 +1718,6 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int m BUG_ON(tcp_skb_pcount(skb) != 1 || tcp_skb_pcount(next_skb) != 1); - /* changing transmit queue under us so clear hints */ - tcp_clear_all_retrans_hints(tp); - /* Ok. We will be able to collapse the packet. */ tcp_unlink_write_queue(next_skb, sk); @@ -1759,6 +1756,13 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int m tcp_adjust_fackets_out(tp, skb, tcp_skb_pcount(next_skb)); tp->packets_out -= tcp_skb_pcount(next_skb); + + /* changed transmit queue under us so clear hints */ + tcp_clear_retrans_hints_partial(tp); + /* manually tune sacktag skb hint */ + if (tp->fastpath_skb_hint == next_skb) + tp->fastpath_skb_hint = skb; + sk_stream_free_skb(sk, next_skb); } } -- cgit v1.2.3-59-g8ed1b