src-test2/sys/modules/cc, branch release/11.3.0

MFC r314651,r318439,r318440:

2017-05-30T04:11:12Z

r314651: sys/modules: normalize .CURDIR-relative paths to SRCTOP This simplifies make output/logic Tested with: `cd sys/modules; make ALL_MODULES=` on amd64 r318439: Normalize .PATH on SRCTOP This will help Jenkins dedupe 9 warnings between the static build and the module build of ipsec(4). Missed in SRCTOP conversion in r314651. MFC with: r314651 r318440: Normalize SYSDIR on SRCTOP instead of .CURDIR This is being done to simplify pathing for CFLAGS and source files.

DCTCP (Data Center TCP) implementation.

2015-01-12T08:33:04Z

DCTCP congestion control algorithm aims to maximise throughput and minimise latency in data center networks by utilising the proportion of Explicit Congestion Notification (ECN) marked packets received from capable hardware as a congestion signal. Highlights: Implemented as a mod_cc(4) module. ECN (Explicit congestion notification) processing is done differently from RFC3168. Takes one-sided DCTCP into consideration where only one of the sides is using DCTCP and other is using standard ECN. IETF draft: http://tools.ietf.org/html/draft-bensley-tcpm-dctcp-00 Thesis report by Midori Kato: https://eggert.org/students/kato-thesis.pdf Submitted by: Midori Kato and Lars Eggert with help and modifications from hiren Differential Revision: https://reviews.freebsd.org/D604 Reviewed by: gnn

Remove unnecessary inclusions of bsd.own.mk.

2014-08-04T22:34:12Z

Import an implementation of the CAIA Delay-Gradient (CDG) congestion control

2013-07-02T08:44:56Z

algorithm, which is based on the 2011 v0.1 patch release and described in the paper "Revisiting TCP Congestion Control using Delay Gradients" by David Hayes and Grenville Armitage. It is implemented as a kernel module compatible with the modular congestion control framework. CDG is a hybrid congestion control algorithm which reacts to both packet loss and inferred queuing delay. It attempts to operate as a delay-based algorithm where possible, but utilises heuristics to detect loss-based TCP cross traffic and will compete effectively as required. CDG is therefore incrementally deployable and suitable for use on shared networks. In collaboration with: David Hayes and Grenville Armitage MFC after: 4 days Sponsored by: Cisco University Research Program and FreeBSD Foundation

Import an implementation of the CAIA-Hamilton-Delay (CHD) congestion control

2011-02-01T07:05:14Z

algorithm described in the paper "Improved coexistence and loss tolerance for delay based TCP congestion control" by Hayes and Armitage. It is implemented as a kernel module compatible with the recently committed modular congestion control framework. CHD enhances the approach taken by the Hamilton-Delay (HD) algorithm to provide tolerance to non-congestion related packet loss and improvements to coexistence with loss-based congestion control algorithms. A key idea in improving coexistence with loss-based congestion control algorithms is the use of a shadow window, which attempts to track how NewReno's congestion window (cwnd) would evolve. At the next packet loss congestion event, CHD uses the shadow window to correct cwnd in a way that reduces the amount of unfairness CHD experiences when competing with loss-based algorithms. In collaboration with: David Hayes and Grenville Armitage Sponsored by: FreeBSD Foundation Reviewed by: bz and others along the way MFC after: 3 months

Import a clean-room implementation of the Hamilton-Delay (HD) congestion control

2011-02-01T06:42:46Z

algorithm based on the paper "A strategy for fair coexistence of loss and delay-based congestion control algorithms" by Budzisz, Stanojevic, Shorten and Baker. It is implemented as a kernel module compatible with the recently committed modular congestion control framework. HD uses a probabilistic approach to reacting to delay-based congestion. The probability of reducing cwnd is zero when the queuing delay is very small, increasing to a maximum at a set threshold, then back down to zero again when the queuing delay is high. Normal operation keeps the queuing delay below the set threshold. However, since loss-based congestion control algorithms push the queuing delay high when probing for bandwidth, having the probability of reducing cwnd drop back to zero for high delays allows HD to compete with loss-based algorithms. In collaboration with: David Hayes and Grenville Armitage Sponsored by: FreeBSD Foundation Reviewed by: bz and others along the way MFC after: 3 months

Import a clean-room implementation of the VEGAS congestion control algorithm

2011-02-01T06:17:00Z

based on the paper "TCP Vegas: end to end congestion avoidance on a global internet" by Brakmo and Peterson. It is implemented as a kernel module compatible with the recently committed modular congestion control framework. VEGAS uses network delay as a congestion indicator and unlike regular loss-based algorithms, attempts to keep the network operating with stable queuing delays and no congestion losses. By keeping network buffers used along the path within a set range, queuing delays are kept low while maintaining high throughput. In collaboration with: David Hayes and Grenville Armitage Sponsored by: FreeBSD Foundation Reviewed by: bz and others along the way MFC after: 3 months

Import a clean-room implementation of the experimental H-TCP congestion control

2010-12-02T06:40:21Z

algorithm based on the Internet-Draft "draft-leith-tcp-htcp-06.txt". It is implemented as a kernel module compatible with the recently committed modular congestion control framework. H-TCP was designed to provide increased throughput in fast and long-distance networks. It attempts to maintain fairness when competing with legacy NewReno TCP in lower speed scenarios where NewReno is able to operate adequately. The paper "H-TCP: A framework for congestion control in high-speed and long-distance networks" provides additional detail. In collaboration with: David Hayes and Grenville Armitage Sponsored by: FreeBSD Foundation Reviewed by: rpaulo (older patch from a few weeks ago) MFC after: 3 months

Import a clean-room implementation of the experimental CUBIC congestion control

2010-12-02T06:05:44Z

algorithm based on the Internet-Draft "draft-rhee-tcpm-cubic-02.txt". It is implemented as a kernel module compatible with the recently committed modular congestion control framework. CUBIC was designed for provide increased throughput in fast and long-distance networks. It attempts to maintain fairness when competing with legacy NewReno TCP in lower speed scenarios where NewReno is able to operate adequately. The paper "CUBIC: A New TCP-Friendly High-Speed TCP Variant" provides additional detail. In collaboration with: David Hayes and Grenville Armitage Sponsored by: FreeBSD Foundation Reviewed by: rpaulo (older patch from a few weeks ago) MFC after: 3 months

Add build infrastructure for the forthcoming CC algorithm modules.

2010-12-02T03:10:35Z

Sponsored by: FreeBSD Foundation Submitted by: David Hayes MFC after: 3 months