linux/net/tipc
Jon Maloy 16ad3f4022 tipc: introduce variable window congestion control
We introduce a simple variable window congestion control for links.
The algorithm is inspired by the Reno algorithm, covering both 'slow
start', 'congestion avoidance', and 'fast recovery' modes.

- We introduce hard lower and upper window limits per link, still
  different and configurable per bearer type.

- We introduce a 'slow start theshold' variable, initially set to
  the maximum window size.

- We let a link start at the minimum congestion window, i.e. in slow
  start mode, and then let is grow rapidly (+1 per rceived ACK) until
  it reaches the slow start threshold and enters congestion avoidance
  mode.

- In congestion avoidance mode we increment the congestion window for
  each window-size number of acked packets, up to a possible maximum
  equal to the configured maximum window.

- For each non-duplicate NACK received, we drop back to fast recovery
  mode, by setting the both the slow start threshold to and the
  congestion window to (current_congestion_window / 2).

- If the timeout handler finds that the transmit queue has not moved
  since the previous timeout, it drops the link back to slow start
  and forces a probe containing the last sent sequence number to the
  sent to the peer, so that this can discover the stale situation.

This change does in reality have effect only on unicast ethernet
transport, as we have seen that there is no room whatsoever for
increasing the window max size for the UDP bearer.
For now, we also choose to keep the limits for the broadcast link
unchanged and equal.

This algorithm seems to give a 50-100% throughput improvement for
messages larger than MTU.

Suggested-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-10 17:31:15 -08:00
..
Kconfig tipc: introduce TIPC encryption & authentication 2019-11-08 14:01:59 -08:00
Makefile tipc: introduce TIPC encryption & authentication 2019-11-08 14:01:59 -08:00
addr.c tipc: initialise addr_trail_end when setting node addresses 2019-08-11 21:40:04 -07:00
addr.h tipc: add 128-bit node identifier 2018-03-23 13:12:18 -04:00
bcast.c tipc: introduce variable window congestion control 2019-12-10 17:31:15 -08:00
bcast.h tipc: update replicast capability for broadcast send link 2019-11-22 09:29:50 -08:00
bearer.c tipc: introduce variable window congestion control 2019-12-10 17:31:15 -08:00
bearer.h tipc: introduce variable window congestion control 2019-12-10 17:31:15 -08:00
core.c tipc: fix ordering of tipc module init and exit routine 2019-12-06 12:01:09 -08:00
core.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-16 21:51:42 -08:00
crypto.c tipc: fix update of the uninitialized variable err 2019-11-11 22:04:03 -08:00
crypto.h tipc: introduce TIPC encryption & authentication 2019-11-08 14:01:59 -08:00
diag.c tipc: switch to rhashtable iterator 2018-08-29 18:04:54 -07:00
discover.c tipc: improve throughput between nodes in netns 2019-10-29 17:55:38 -07:00
discover.h tipc: some cleanups in the file discover.c 2018-03-23 13:12:17 -04:00
eth_media.c tipc: introduce variable window congestion control 2019-12-10 17:31:15 -08:00
group.c tipc: clean up skb list lock handling on send path 2019-08-18 14:01:07 -07:00
group.h tipc: extend sock diag for group communication 2018-06-30 21:05:42 +09:00
ib_media.c tipc: introduce variable window congestion control 2019-12-10 17:31:15 -08:00
link.c tipc: introduce variable window congestion control 2019-12-10 17:31:15 -08:00
link.h tipc: introduce variable window congestion control 2019-12-10 17:31:15 -08:00
monitor.c tipc: update mon's self addr when node addr generated 2019-11-12 19:45:45 -08:00
monitor.h tipc: update mon's self addr when node addr generated 2019-11-12 19:45:45 -08:00
msg.c tipc: introduce TIPC encryption & authentication 2019-11-08 14:01:59 -08:00
msg.h tipc: introduce TIPC encryption & authentication 2019-11-08 14:01:59 -08:00
name_distr.c tipc: improve throughput between nodes in netns 2019-10-29 17:55:38 -07:00
name_distr.h tipc: permit overlapping service ranges in name table 2018-03-31 22:19:52 -04:00
name_table.c tipc: support in-order name publication events 2019-11-22 09:29:50 -08:00
name_table.h tipc: support in-order name publication events 2019-11-22 09:29:50 -08:00
net.c tipc: update mon's self addr when node addr generated 2019-11-12 19:45:45 -08:00
net.h tipc: fix lockdep warning when reinitilaizing sockets 2018-11-17 22:01:31 -08:00
netlink.c tipc: add support for AEAD key setting via netlink 2019-11-08 14:01:59 -08:00
netlink.h net: tipc: allocate attrs locally instead of using genl_family_attrbuf in compat_dumpit() 2019-10-06 15:44:47 +02:00
netlink_compat.c tipc: fix link name length check 2019-11-26 10:03:12 -08:00
node.c tipc: introduce variable window congestion control 2019-12-10 17:31:15 -08:00
node.h tipc: add support for AEAD key setting via netlink 2019-11-08 14:01:59 -08:00
socket.c tipc: fix duplicate SYN messages under link congestion 2019-11-28 23:09:15 -08:00
socket.h tipc: add trace_events for tipc socket 2018-12-19 11:49:24 -08:00
subscr.c tipc: fix unbalanced reference counter 2018-04-12 21:46:10 -04:00
subscr.h tipc: fix modprobe tipc failed after switch order of device registration 2019-05-20 10:45:43 -07:00
sysctl.c tipc: introduce TIPC encryption & authentication 2019-11-08 14:01:59 -08:00
topsrv.c tipc: add loopback device tracking 2019-08-08 22:11:39 -07:00
topsrv.h tipc: rename tipc_server to tipc_topsrv 2018-02-16 15:26:34 -05:00
trace.c tipc: remove unneeded semicolon in trace.c 2019-01-17 22:04:43 -08:00
trace.h tipc: add trace_events for tipc bearer 2018-12-19 11:49:25 -08:00
udp_media.c tipc: introduce variable window congestion control 2019-12-10 17:31:15 -08:00
udp_media.h tipc: implement configuration of UDP media MTU 2018-04-20 11:04:05 -04:00