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authorNeal Cardwell <ncardwell@google.com>2015-09-09 21:54:37 -0700
committerDavid S. Miller <davem@davemloft.net>2015-09-10 10:58:33 -0700
commit05c5a46d71f621df620fbabbd7758ee1b44575ad (patch)
tree748d299eb3c1e197b0f030daa52f5c87825ca7cd /net
parent32a844056fd43dda647e1c3c6b9983bdfa04d17d (diff)
downloadlinux-05c5a46d71f621df620fbabbd7758ee1b44575ad.tar.gz
tcp: generate CA_EVENT_TX_START on data frames
Issuing a CC TX_START event on control frames like pure ACK
is a waste of time, as a CC should not care.

Following patch needs this change, as we want CUBIC to properly track
idle time at a low cost, with a single TX_START being generated.

Yuchung might slightly refine the condition triggering TX_START
on a followup patch.

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Cc: Jana Iyengar <jri@google.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Sangtae Ha <sangtae.ha@gmail.com>
Cc: Lawrence Brakmo <lawrence@brakmo.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/tcp_output.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 1188e4fcf23b..f9a8a12b62ee 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -164,6 +164,9 @@ static void tcp_event_data_sent(struct tcp_sock *tp,
 	struct inet_connection_sock *icsk = inet_csk(sk);
 	const u32 now = tcp_time_stamp;
 
+	if (tcp_packets_in_flight(tp) == 0)
+		tcp_ca_event(sk, CA_EVENT_TX_START);
+
 	tp->lsndtime = now;
 
 	/* If it is a reply for ato after last received
@@ -940,9 +943,6 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
 							   &md5);
 	tcp_header_size = tcp_options_size + sizeof(struct tcphdr);
 
-	if (tcp_packets_in_flight(tp) == 0)
-		tcp_ca_event(sk, CA_EVENT_TX_START);
-
 	/* if no packet is in qdisc/device queue, then allow XPS to select
 	 * another queue. We can be called from tcp_tsq_handler()
 	 * which holds one reference to sk_wmem_alloc.