| 688d1945bc89bd585ec67b5b83121f499e6290bb |
|
30-Aug-2014 |
stephen hemminger <stephen@networkplumber.org> |
tcp: whitespace fixes
Fix places where there is space before tab, long lines, and
awkward if(){, double spacing etc. Add blank line after declaration/initialization.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| 249015515fe3fc9818d86cb5c83bbc92505ad7dc |
|
03-May-2014 |
Eric Dumazet <edumazet@google.com> |
tcp: remove in_flight parameter from cong_avoid() methods
Commit e114a710aa505 ("tcp: fix cwnd limited checking to improve
congestion control") obsoleted in_flight parameter from
tcp_is_cwnd_limited() and its callers.
This patch does the removal as promised.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| 9f9843a751d0a2057f9f3d313886e7e5e6ebaac9 |
|
31-Oct-2013 |
Yuchung Cheng <ycheng@google.com> |
tcp: properly handle stretch acks in slow start
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 <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| fc16dcd8c2e1e9bc91ed765957e1f2bbf334253e |
|
18-Jan-2012 |
Neal Cardwell <ncardwell@google.com> |
tcp: fix undo after RTO for BIC
This patch fixes BIC so that cwnd reductions made during RTOs can be
undone (just as they already can be undone when using the default/Reno
behavior).
When undoing cwnd reductions, BIC-derived congestion control modules
were restoring the cwnd from last_max_cwnd. There were two problems
with using last_max_cwnd to restore a cwnd during undo:
(a) last_max_cwnd was set to 0 on state transitions into TCP_CA_Loss
(by calling the module's reset() functions), so cwnd reductions from
RTOs could not be undone.
(b) when fast_covergence is enabled (which it is by default)
last_max_cwnd does not actually hold the value of snd_cwnd before the
loss; instead, it holds a scaled-down version of snd_cwnd.
This patch makes the following changes:
(1) upon undo, revert snd_cwnd to ca->loss_cwnd, which is already, as
the existing comment notes, the "congestion window at last loss"
(2) stop forgetting ca->loss_cwnd on TCP_CA_Loss events
(3) use ca->last_max_cwnd to check if we're in slow start
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| a252bebe22155313ccdadc20b79f67a239dc9ecb |
|
10-Mar-2011 |
Stephen Hemminger <shemminger@vyatta.com> |
tcp: mark tcp_congestion_ops read_mostly
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| 758ce5c8d11d6fc57fe5f1dbc237aa8ff6386eac |
|
28-Feb-2009 |
Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> |
tcp: add helper for AI algorithm
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 <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| 0bc8c7bf9e7440500fe04f95d6cddc58ea023cd2 |
|
29-Feb-2008 |
Sangtae Ha <sha2@ncsu.edu> |
[TCP]: BIC web page link is corrected.
Signed-off-by: Sangtae Ha <sha2@ncsu.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| c3a05c6050a339c92e49fae0ba77dbba0d41fd99 |
|
01-Dec-2007 |
Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> |
[TCP]: Cong.ctrl modules: remove unused good_ack from cong_avoid
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| 35e8694198ba94b62df8aa35fa6e52a1cfb86df2 |
|
31-May-2007 |
Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> |
[TCP]: Remove num_acked>0 checks from cong.ctrl mods pkts_acked
There is no need for such check in pkts_acked because the
callback is not invoked unless at least one segment got fully
ACKed (i.e., the snd_una moved past skb's end_seq) by the
cumulative ACK's snd_una advancement.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| 30cfd0baf0a0c4329fff1ef4b622919297969ec8 |
|
26-Jul-2007 |
Stephen Hemminger <shemminger@linux-foundation.org> |
[TCP]: congestion control API pass RTT in microseconds
This patch changes the API for the callback that is done after an ACK is
received. It solves a couple of issues:
* Some congestion controls want higher resolution value of RTT
(controlled by TCP_CONG_RTT_SAMPLE flag). These don't really want a ktime, but
all compute a RTT in microseconds.
* Other congestion control could use RTT at jiffies resolution.
To keep API consistent the units should be the same for both cases, just the
resolution should change.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| 16751347a060a10c09b11593bb179fd5b0240c04 |
|
17-Jul-2007 |
Stephen Hemminger <shemminger@linux-foundation.org> |
[TCP]: remove unused argument to cong_avoid op
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 <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| 66e1e3b20cbbf99da63e6c1af0fc6d39c2ed099a |
|
13-Jun-2007 |
David S. Miller <davem@sunset.davemloft.net> |
[TCP]: Set initial_ssthresh default to zero in Cubic and BIC.
Because of the current default of 100, Cubic and BIC perform very
poorly compared to standard Reno.
In the worst case, this change makes Cubic and BIC as aggressive as
Reno. So this change should be very safe.
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| 164891aadf1721fca4dce473bb0e0998181537c6 |
|
24-Apr-2007 |
Stephen Hemminger <shemminger@linux-foundation.org> |
[TCP]: Congestion control API update.
Do some simple changes to make congestion control API faster/cleaner.
* use ktime_t rather than timeval
* merge rtt sampling into existing ack callback
this means one indirect call versus two per ack.
* use flags bits to store options/settings
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| 65e3d72654d9a33cdccd5c19777a5515ae9dd37d |
|
25-Aug-2006 |
Alexey Dobriyan <adobriyan@gmail.com> |
[TCP] tcp_bic: use BUILD_BUG_ON
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| 6ab3d5624e172c553004ecc862bfeac16d9d68b7 |
|
30-Jun-2006 |
Jörn Engel <joern@wohnheim.fh-wedel.de> |
Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
|
| 72dc5b9225c53310c010b68a70ea97c8c8e24bdf |
|
06-Jun-2006 |
Stephen Hemminger <shemminger@osdl.org> |
[TCP]: Minimum congestion window consolidation.
Many of the TCP congestion methods all just use ssthresh
as the minimum congestion window on decrease. Rather than
duplicating the code, just have that be the default if that
handle in the ops structure is not set.
Minor behaviour change to TCP compound. It probably wants
to use this (ssthresh) as lower bound, rather than ssthresh/2
because the latter causes undershoot on loss.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| 05d054503a9c4652212b8730150608787547ecc3 |
|
14-Dec-2005 |
Stephen Hemminger <shemminger@osdl.org> |
[TCP] BIC: spelling and whitespace
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| 018da8f44c066d5fc390011b8c953135f973b3a9 |
|
14-Dec-2005 |
Stephen Hemminger <shemminger@osdl.org> |
[TCP] BIC: remove low utilization code.
The latest BICTCP patch at:
http://www.csc.ncsu.edu:8080/faculty/rhee/export/bitcp/index_files/Page546.htm
disables the low_utilization feature of BICTCP because it doesn't work
in some cases. This patch removes it.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| 7faffa1c7fb9b8e8917e3225d4e2638270c0a48b |
|
11-Nov-2005 |
Stephen Hemminger <shemminger@osdl.org> |
[TCP]: add tcp_slow_start helper
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 <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| f4805eded7d38c4e42bf473dc5eb2f34853beb06 |
|
11-Nov-2005 |
Stephen Hemminger <shemminger@osdl.org> |
[TCP]: fix congestion window update when using TSO deferal
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 <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| 450b5b18983cc15f4d27bd3f62901e02281e818b |
|
02-Nov-2005 |
Stephen Hemminger <shemminger@osdl.org> |
[TCP]: BIC max increment too large
The max growth of BIC TCP is too large. Original code was based on
BIC 1.0 and the default there was 32. Later code (2.6.13) included
compensation for delayed acks, and should have reduced the default
value to 16; since normally TCP gets one ack for every two packets sent.
The current value of 32 makes BIC too aggressive and unfair to other
flows.
Submitted-by: Injong Rhee <rhee@eos.ncsu.edu>
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Acked-by: Ian McDonald <imcdnzl@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
|
| 42a39450f830c57432fd4e5644fa81f41ce7156d |
|
05-Oct-2005 |
Stephen Hemminger <shemminger@osdl.org> |
[TCP]: BIC coding bug in Linux 2.6.13
Missing parenthesis in causes BIC to be slow in increasing congestion
window.
Spotted by Injong Rhee.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| 6687e988d9aeaccad6774e6a8304f681f3ec0a03 |
|
10-Aug-2005 |
Arnaldo Carvalho de Melo <acme@mandriva.com> |
[ICSK]: Move TCP congestion avoidance members to icsk
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 <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| 83803034f4233d810c4adc52008921da060c55d1 |
|
23-Jun-2005 |
Stephen Hemminger <shemminger@osdl.org> |
[TCP]: Add TCP BIC congestion control module.
TCP BIC congestion control reworked to use the new congestion control
infrastructure. This version is more up to date than the BIC
code in 2.6.12; it incorporates enhancements from BICTCP 1.1,
to handle low latency links.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|