linux-toradex.git/net/ipv4/tcp_scalable.c, branch v3.14.50

tcp: properly handle stretch acks in slow start

2013-11-05T00:57:59+00:00

Slow start now increases cwnd by 1 if an ACK acknowledges some packets,
regardless the number of packets. Consequently slow start performance
is highly dependent on the degree of the stretch ACKs caused by
receiver or network ACK compression mechanisms (e.g., delayed-ACK,
GRO, etc).  But slow start algorithm is to send twice the amount of
packets of packets left so it should process a stretch ACK of degree
N as if N ACKs of degree 1, then exits when cwnd exceeds ssthresh. A
follow up patch will use the remainder of the N (if greater than 1)
to adjust cwnd in the congestion avoidance phase.

In addition this patch retires the experimental limited slow start
(LSS) feature. LSS has multiple drawbacks but questionable benefit. The
fractional cwnd increase in LSS requires a loop in slow start even
though it's rarely used. Configuring such an increase step via a global
sysctl on different BDPS seems hard. Finally and most importantly the
slow start overshoot concern is now better covered by the Hybrid slow
start (hystart) enabled by default.

Signed-off-by: Yuchung Cheng 
Signed-off-by: Neal Cardwell 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

tcp: mark tcp_congestion_ops read_mostly

2011-03-10T08:40:17+00:00

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

tcp: add helper for AI algorithm

2009-03-02T11:00:15+00:00

It seems that implementation in yeah was inconsistent to what
other did as it would increase cwnd one ack earlier than the
others do.

Size benefits:

  bictcp_cong_avoid |  -36
  tcp_cong_avoid_ai |  +52
  bictcp_cong_avoid |  -34
  tcp_scalable_cong_avoid |  -36
  tcp_veno_cong_avoid |  -12
  tcp_yeah_cong_avoid |  -38

= -104 bytes total

Signed-off-by: Ilpo Järvinen 
Signed-off-by: David S. Miller

tcp_scalable: Update malformed & dead url

2009-02-25T00:40:16+00:00

Signed-off-by: Joe Perches 
Signed-off-by: David S. Miller

[TCP]: Cong.ctrl modules: remove unused good_ack from cong_avoid

2008-01-28T22:55:41+00:00

Signed-off-by: Ilpo Järvinen 
Signed-off-by: Herbert Xu 
Signed-off-by: David S. Miller

[TCP]: remove unused argument to cong_avoid op

2007-07-18T08:46:58+00:00

None of the existing TCP congestion controls use the rtt value pased
in the ca_ops->cong_avoid interface.  Which is lucky because seq_rtt
could have been -1 when handling a duplicate ack.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

Remove obsolete #include

2006-06-30T17:25:36+00:00

Signed-off-by: Jörn Engel 
Signed-off-by: Adrian Bunk

[TCP]: add tcp_slow_start helper

2005-11-11T01:07:24+00:00

Move all the code that does linear TCP slowstart to one
inline function to ease later patch to add ABC support.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

[TCP]: fix congestion window update when using TSO deferal

2005-11-11T00:53:30+00:00

TCP peformance with TSO over networks with delay is awful.
On a 100Mbit link with 150ms delay, we get 4Mbits/sec with TSO and
50Mbits/sec without TSO.

The problem is with TSO, we intentionally do not keep the maximum
number of packets in flight to fill the window, we hold out to until 
we can send a MSS chunk. But, we also don't update the congestion window 
unless we have filled, as per RFC2861.

This patch replaces the check for the congestion window being full
with something smarter that accounts for TSO.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

[ICSK]: Move TCP congestion avoidance members to icsk

2005-08-29T22:56:18+00:00

This changeset basically moves tcp_sk()->{ca_ops,ca_state,etc} to inet_csk(),
minimal renaming/moving done in this changeset to ease review.

Most of it is just changes of struct tcp_sock * to struct sock * parameters.

With this we move to a state closer to two interesting goals:

1. Generalisation of net/ipv4/tcp_diag.c, becoming inet_diag.c, being used
   for any INET transport protocol that has struct inet_hashinfo and are
   derived from struct inet_connection_sock. Keeps the userspace API, that will
   just not display DCCP sockets, while newer versions of tools can support
   DCCP.

2. INET generic transport pluggable Congestion Avoidance infrastructure, using
   the current TCP CA infrastructure with DCCP.

Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller