linux_dsm_epyc7002/net/ipv4
Yuchung Cheng e33099f96d tcp: implement RFC5682 F-RTO
This patch implements F-RTO (foward RTO recovery):

When the first retransmission after timeout is acknowledged, F-RTO
sends new data instead of old data. If the next ACK acknowledges
some never-retransmitted data, then the timeout was spurious and the
congestion state is reverted.  Otherwise if the next ACK selectively
acknowledges the new data, then the timeout was genuine and the
loss recovery continues. This idea applies to recurring timeouts
as well. While F-RTO sends different data during timeout recovery,
it does not (and should not) change the congestion control.

The implementaion follows the three steps of SACK enhanced algorithm
(section 3) in RFC5682. Step 1 is in tcp_enter_loss(). Step 2 and
3 are in tcp_process_loss().  The basic version is not supported
because SACK enhanced version also works for non-SACK connections.

The new implementation is functionally in parity with the old F-RTO
implementation except the one case where it increases undo events:
In addition to the RFC algorithm, a spurious timeout may be detected
without sending data in step 2, as long as the SACK confirms not
all the original data are dropped. When this happens, the sender
will undo the cwnd and perhaps enter fast recovery instead. This
additional check increases the F-RTO undo events by 5x compared
to the prior implementation on Google Web servers, since the sender
often does not have new data to send for HTTP.

Note F-RTO may detect spurious timeout before Eifel with timestamps
does so.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-21 11:47:51 -04:00
..
netfilter netfilter: remove unused "config IP_NF_QUEUE" 2013-03-20 00:11:43 +01:00
af_inet.c tunneling: Add generic Tunnel segmentation. 2013-03-09 16:09:17 -05:00
ah4.c net: Add skb_unclone() helper function. 2013-02-15 15:10:37 -05:00
arp.c net: proc: change proc_net_remove to remove_proc_entry 2013-02-18 14:53:08 -05:00
cipso_ipv4.c cipso: don't follow a NULL pointer when setsockopt() is called 2012-07-18 09:01:12 -07:00
datagram.c ipv4: Add a socket release callback for datagram sockets 2013-01-21 14:17:05 -05:00
devinet.c netconf: add the handler to dump entries 2013-03-06 15:40:53 -05:00
esp4.c xfrm4: Invalidate all ipv4 routes on IPsec pmtu events 2013-01-21 12:43:54 +01:00
fib_frontend.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
fib_lookup.h ipv4: Fix nexthop caching wrt. scoping. 2011-03-24 18:06:47 -07:00
fib_rules.c sections: fix section conflicts in net 2012-10-06 03:04:45 +09:00
fib_semantics.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
fib_trie.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
gre.c v4 GRE: Add TCP segmentation offload for GRE 2013-02-15 15:17:11 -05:00
icmp.c ipv4: fix error handling in icmp_protocol. 2013-02-22 15:10:18 -05:00
igmp.c net: proc: change proc_net_remove to remove_proc_entry 2013-02-18 14:53:08 -05:00
inet_connection_sock.c tcp: Remove TCPCT 2013-03-17 14:35:13 -04:00
inet_diag.c tcp: Tail loss probe (TLP) 2013-03-12 08:30:34 -04:00
inet_fragment.c inet: limit length of fragment queue hash table bucket lists 2013-03-19 10:28:36 -04:00
inet_hashtables.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
inet_lro.c ipv4: replace ip_fast_csum with csum_replace2 2013-03-15 09:12:25 -04:00
inet_timewait_sock.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
inetpeer.c Merge branch 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2012-10-02 09:54:49 -07:00
ip_forward.c ipv4: introduce rt_uses_gateway 2012-10-08 17:42:36 -04:00
ip_fragment.c inet: limit length of fragment queue hash table bucket lists 2013-03-19 10:28:36 -04:00
ip_gre.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-03-20 12:46:26 -04:00
ip_input.c ipv[4|6]: correct dropwatch false positive in local_deliver_finish 2013-03-01 15:56:29 -05:00
ip_options.c net/ipv4: Ensure that location of timestamp option is stored 2013-03-12 05:35:39 -04:00
ip_output.c net: Fix possible wrong checksum generation. 2013-02-13 13:30:10 -05:00
ip_sockglue.c net: prevent setting ttl=0 via IP_TTL 2013-01-08 17:57:10 -08:00
ip_vti.c net: Allow userns root to control ipv4 2012-11-18 20:32:45 -05:00
ipcomp.c ipcomp: Mark as netns_ok. 2013-02-04 15:46:15 -05:00
ipconfig.c ipconfig: Fix newline handling in log message. 2013-03-20 12:15:58 -04:00
ipip.c tunnel: use iptunnel_xmit() again 2013-03-10 03:05:44 -04:00
ipmr.c net: proc: change proc_net_remove to remove_proc_entry 2013-02-18 14:53:08 -05:00
Kconfig net/ipv4: remove depends on CONFIG_EXPERIMENTAL 2013-01-11 11:40:00 -08:00
Makefile memcg: rename config variables 2012-07-31 18:42:43 -07:00
netfilter.c netfilter: properly annotate ipv4_netfilter_{init,fini}() 2012-09-03 13:56:04 +02:00
ping.c ipv4: fix a bug in ping_err(). 2013-02-21 15:25:00 -05:00
proc.c tcp: TLP loss detection. 2013-03-12 08:30:34 -04:00
protocol.c ipv4: Disallow non-namespace aware protocols to register. 2013-02-05 14:42:23 -05:00
raw.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
route.c net: ipv4: fix waring -Wunused-variable 2013-02-19 13:18:13 -05:00
syncookies.c tcp: Remove TCPCT 2013-03-17 14:35:13 -04:00
sysctl_net_ipv4.c tcp: refactor F-RTO 2013-03-21 11:47:50 -04:00
tcp_bic.c tcp: fix undo after RTO for BIC 2012-01-20 14:17:26 -05:00
tcp_cong.c tcp: remove Appropriate Byte Count support 2013-02-05 14:51:16 -05:00
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 tcp: TCP Fast Open Server - header & support functions 2012-08-31 20:02:18 -04:00
tcp_highspeed.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_htcp.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_hybla.c tcp: bool conversions 2012-05-17 14:59:59 -04:00
tcp_illinois.c net: fix divide by zero in tcp algorithm illinois 2012-11-01 11:55:59 -04:00
tcp_input.c tcp: implement RFC5682 F-RTO 2013-03-21 11:47:51 -04:00
tcp_ipv4.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-03-20 12:46:26 -04:00
tcp_lp.c Fix common misspellings 2011-03-31 11:26:23 -03:00
tcp_memcontrol.c memcg: decrement static keys at real destroy time 2012-05-29 16:22:28 -07:00
tcp_metrics.c tcp: handle tcp_net_metrics_init() order-5 memory allocation failures 2012-11-16 13:36:27 -05:00
tcp_minisocks.c tcp: refactor F-RTO 2013-03-21 11:47:50 -04:00
tcp_output.c tcp: refactor F-RTO 2013-03-21 11:47:50 -04:00
tcp_probe.c net: proc: change proc_net_remove to remove_proc_entry 2013-02-18 14:53:08 -05:00
tcp_scalable.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_timer.c tcp: refactor F-RTO 2013-03-21 11:47:50 -04:00
tcp_vegas.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_vegas.h [TCP]: congestion control API pass RTT in microseconds 2007-07-31 02:27:57 -07:00
tcp_veno.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_westwood.c tcp: refactor F-RTO 2013-03-21 11:47:50 -04:00
tcp_yeah.c Fix common misspellings 2011-03-31 11:26:23 -03:00
tcp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-03-20 12:46:26 -04:00
tunnel4.c net: Convert printks to pr_<level> 2012-03-11 23:42:51 -07:00
udp_diag.c netlink: Rename pid to portid to avoid confusion 2012-09-10 15:30:41 -04:00
udp_impl.h ipv4: fix checkpatch errors 2012-04-15 12:37:19 -04:00
udp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-03-20 12:46:26 -04:00
udplite.c net: ipv4: Standardize prefixes for message logging 2012-03-12 17:05:21 -07:00
xfrm4_input.c net: Add skb_unclone() helper function. 2013-02-15 15:10:37 -05:00
xfrm4_mode_beet.c ipsec: be careful of non existing mac headers 2012-02-23 16:50:45 -05:00
xfrm4_mode_transport.c [IPSEC]: Use IPv6 calling convention as the convention for x->mode->output 2007-10-10 16:55:54 -07:00
xfrm4_mode_tunnel.c ip: fix warning in xfrm4_mode_tunnel_input 2013-02-18 12:42:48 -05:00
xfrm4_output.c xfrm4: Don't call icmp_send on local error 2011-07-01 17:33:19 -07:00
xfrm4_policy.c xfrm: make gc_thresh configurable in all namespaces 2013-02-06 11:36:29 +01:00
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