linux/net/ipv4
Eric Dumazet aae06bf5f9 tcp: ecn: dont delay ACKS after CE
While playing with CoDel and ECN marking, I discovered a
non optimal behavior of receiver of CE (Congestion Encountered)
segments.

In pathological cases, sender has reduced its cwnd to low values,
and receiver delays its ACK (by 40 ms).

While RFC 3168 6.1.3 (The TCP Receiver) doesn't explicitly recommend
to send immediate ACKS, we believe its better to not delay ACKS, because
a CE segment should give same signal than a dropped segment, and its
quite important to reduce RTT to give ECE/CWR signals as fast as
possible.

Note we already call tcp_enter_quickack_mode() from TCP_ECN_check_ce()
if we receive a retransmit, for the same reason.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-06 14:14:34 -07:00
..
netfilter ipv4: Adjust semantics of rt->rt_gateway. 2012-07-20 13:31:20 -07:00
af_inet.c net: tcp: GRO should be ECN friendly 2012-08-06 13:40:47 -07:00
ah4.c ipv4: Add redirect support to all protocol icmp error handlers. 2012-07-11 21:27:49 -07:00
arp.c ipv4: Fix input route performance regression. 2012-07-26 15:50:39 -07:00
cipso_ipv4.c cipso: don't follow a NULL pointer when setsockopt() is called 2012-07-18 09:01:12 -07:00
datagram.c
devinet.c ipv4: change inet_addr_hash() 2012-08-04 01:27:57 -07:00
esp4.c ipv4: Add redirect support to all protocol icmp error handlers. 2012-07-11 21:27:49 -07:00
fib_frontend.c ipv4: Properly purge netdev references on uncached routes. 2012-07-31 15:06:50 -07:00
fib_lookup.h
fib_rules.c ipv4: Don't store a rule pointer in fib_result. 2012-07-13 08:21:29 -07:00
fib_semantics.c ipv4: Cache routes in nexthop exception entries. 2012-07-31 15:02:02 -07:00
fib_trie.c ipv4: clean up put_child 2012-07-29 23:18:30 -07:00
gre.c net: ipv4: Standardize prefixes for message logging 2012-03-12 17:05:21 -07:00
icmp.c ipv4: Prepare for change of rt->rt_iif encoding. 2012-07-23 16:36:26 -07:00
igmp.c ipv4: fix checkpatch errors 2012-04-15 12:37:19 -04:00
inet_connection_sock.c ipv4: Kill FLOWI_FLAG_RT_NOCACHE and associated code. 2012-07-20 13:36:54 -07:00
inet_diag.c net: make sock diag per-namespace 2012-07-16 22:31:34 -07:00
inet_fragment.c inetpeer: add parameter net for inet_getpeer_v4,v6 2012-06-08 14:27:23 -07:00
inet_hashtables.c ipv4: fix checkpatch errors 2012-04-15 12:37:19 -04:00
inet_lro.c net: add skb frag size accessors 2011-10-19 03:10:46 -04:00
inet_timewait_sock.c net: ipv4 and ipv6: Convert printk(KERN_DEBUG to pr_debug 2012-05-16 01:01:03 -04:00
inetpeer.c ipv4: Maintain redirect and PMTU info in struct rtable again. 2012-07-10 22:40:14 -07:00
ip_forward.c snmp: fix OutOctets counter to include forwarded datagrams 2012-06-07 14:50:56 -07:00
ip_fragment.c ipv4: Fix input route performance regression. 2012-07-26 15:50:39 -07:00
ip_gre.c ipv4: Adjust semantics of rt->rt_gateway. 2012-07-20 13:31:20 -07:00
ip_input.c net: TCP early demux cleanup 2012-07-30 14:53:21 -07:00
ip_options.c ipv4: optimize fib_compute_spec_dst call in ip_options_echo 2012-07-19 08:30:49 -07:00
ip_output.c Merge branch 'kill_rtcache' 2012-07-22 17:04:15 -07:00
ip_sockglue.c ipv4: Prepare for change of rt->rt_iif encoding. 2012-07-23 16:36:26 -07:00
ip_vti.c net/ipv4/ip_vti.c: Fix __rcu warnings detected by sparse. 2012-07-23 13:00:54 -07:00
ipcomp.c ipv4: Add redirect support to all protocol icmp error handlers. 2012-07-11 21:27:49 -07:00
ipconfig.c net/ipv4/ipconfig: neaten __setup placement 2012-05-20 04:06:16 -04:00
ipip.c ipv4: Adjust semantics of rt->rt_gateway. 2012-07-20 13:31:20 -07:00
ipmr.c ipv4: Kill rt->rt_oif 2012-07-20 13:38:34 -07:00
Kconfig net/ipv4: VTI support new module for ip_vti. 2012-07-18 09:36:12 -07:00
Makefile memcg: rename config variables 2012-07-31 18:42:43 -07:00
netfilter.c net: Delete all remaining instances of ctl_path 2012-04-20 21:22:30 -04:00
ping.c ipv4: Add redirect support to all protocol icmp error handlers. 2012-07-11 21:27:49 -07:00
proc.c net-tcp: Fast Open client - sending SYN-data 2012-07-19 11:02:03 -07:00
protocol.c inet: Sanitize inet{,6} protocol demux. 2012-06-19 18:56:21 -07:00
raw.c ipv4: Add redirect support to all protocol icmp error handlers. 2012-07-11 21:27:49 -07:00
route.c ipv4: Introduce IN_DEV_NET_ROUTE_LOCALNET 2012-08-04 01:27:57 -07:00
syncookies.c net-tcp: Fast Open base 2012-07-19 10:55:36 -07:00
sysctl_net_ipv4.c Merge branch 'akpm' (Andrew's patch-bomb) 2012-07-31 19:25:39 -07:00
tcp_bic.c tcp: fix undo after RTO for BIC 2012-01-20 14:17:26 -05:00
tcp_cong.c tcp: Apply device TSO segment limit earlier 2012-08-02 00:19:17 -07:00
tcp_cubic.c tcp: fix undo after RTO for CUBIC 2012-01-20 14:17:26 -05:00
tcp_diag.c inet_diag: Rename inet_diag_req into inet_diag_req_v2 2012-01-11 12:56:06 -08:00
tcp_fastopen.c net-tcp: Fast Open base 2012-07-19 10:55:36 -07:00
tcp_highspeed.c
tcp_htcp.c
tcp_hybla.c tcp: bool conversions 2012-05-17 14:59:59 -04:00
tcp_illinois.c
tcp_input.c tcp: ecn: dont delay ACKS after CE 2012-08-06 14:14:34 -07:00
tcp_ipv4.c Merge branch 'akpm' (Andrew's patch-bomb) 2012-07-31 19:25:39 -07:00
tcp_lp.c
tcp_memcontrol.c memcg: decrement static keys at real destroy time 2012-05-29 16:22:28 -07:00
tcp_metrics.c tcp: avoid oops in tcp_metrics and reset tcpm_stamp 2012-07-23 00:57:12 -07:00
tcp_minisocks.c net: ipv4: fix RCU races on dst refcounts 2012-07-30 14:53:22 -07:00
tcp_output.c tcp: Apply device TSO segment limit earlier 2012-08-02 00:19:17 -07:00
tcp_probe.c net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
tcp_scalable.c
tcp_timer.c tcp: improve latencies of timer triggered events 2012-07-20 10:59:41 -07:00
tcp_vegas.c
tcp_vegas.h
tcp_veno.c
tcp_westwood.c
tcp_yeah.c
tcp.c tcp: Apply device TSO segment limit earlier 2012-08-02 00:19:17 -07:00
tunnel4.c net: Convert printks to pr_<level> 2012-03-11 23:42:51 -07:00
udp_diag.c net: make sock diag per-namespace 2012-07-16 22:31:34 -07:00
udp_impl.h ipv4: fix checkpatch errors 2012-04-15 12:37:19 -04:00
udp.c ipv4: Add redirect support to all protocol icmp error handlers. 2012-07-11 21:27:49 -07:00
udplite.c net: ipv4: Standardize prefixes for message logging 2012-03-12 17:05:21 -07:00
xfrm4_input.c ipv4: Fix input route performance regression. 2012-07-26 15:50:39 -07:00
xfrm4_mode_beet.c ipsec: be careful of non existing mac headers 2012-02-23 16:50:45 -05:00
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c net/ipv4: VTI support rx-path hook in xfrm4_mode_tunnel. 2012-07-18 09:36:12 -07:00
xfrm4_output.c xfrm4: Don't call icmp_send on local error 2011-07-01 17:33:19 -07:00
xfrm4_policy.c ipv4: Properly purge netdev references on uncached routes. 2012-07-31 15:06:50 -07:00
xfrm4_state.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
xfrm4_tunnel.c net: ipv4: Standardize prefixes for message logging 2012-03-12 17:05:21 -07:00