CHANNEL CLASSES: A NEW CONCEPT FOR DEADLOCK AVOIDANCE IN WORMHOLE NETWORKS

1992 ◽  
Vol 02 (04) ◽  
pp. 347-354 ◽  
Author(s):  
JOSÉ DUATO

In previous papers, we have developed the theoretical background for the design of deadlock-free adaptive routing algorithms for store-and-forward and wormhole networks. Some definitions and theorems have been proposed, developing conditions to verify that an adaptive algorithm is deadlock-free, even when there are cyclic dependencies between channels. Also, two design methodologies have been proposed. In this paper, we propose a partial order between channels as well as an equivalence relation. This relation splits the set of channels into equivalence classes. Then, we extend our previous theory by considering equivalence classes (channel classes) instead of channels. This extension drastically simplifies the verification of deadlock freedom for adaptive routing algorithms with cyclic dependencies between channels. Finally, we present an example.

1993 ◽  
Vol 03 (04) ◽  
pp. 321-333 ◽  
Author(s):  
JOSÉ DUATO

Multicast communication refers to the delivery of the same message from one source node to an arbitrary number of destination nodes. Two multicast wormhole routing methods have been presented in [13] for multicomputers with 2D-mesh and hypercube topologies. Also, a theory for the design of deadlock-free adaptive routing algorithms for wormhole networks has been proposed in [7, 8]. This theory supplies the sufficient conditions for an adaptive routing algorithm to be deadlock-free, even when there are cyclic dependencies between channels. This paper analyses the additional channel dependencies produced by multicast routing algorithms on wormhole networks. Then, the theory proposed in [7, 8] is extended by considering them. As an example, the multicast routing algorithms presented in [13] are extended, taking advantage of the alternative paths offered by the network.


2013 ◽  
Vol 05 (01) ◽  
pp. 34-49 ◽  
Author(s):  
Yasuyuki Miura ◽  
Masahiro Kaneko ◽  
M. M. Hafizur Rahman ◽  
Shigeyoshi Watanabe

2021 ◽  
Vol 20 (3) ◽  
pp. 1-6
Author(s):  
Mohammed Shaba Saliu ◽  
Muyideen Omuya Momoh ◽  
Pascal Uchenna Chinedu ◽  
Wilson Nwankwo ◽  
Aliu Daniel

Network-on-Chip (NoC) has been proposed as a viable solution to the communication challenges on System-on-Chips (SoCs). As the communication paradigm of SoC, NoCs performance depends mainly on the type of routing algorithm chosen. In this paper different categories of routing algorithms were compared. These include XY routing, OE turn model adaptive routing, DyAD routing and Age-Aware adaptive routing.  By varying the load at different Packet Injection Rate (PIR) under random traffic pattern, comparison was conducted using a 4 × 4 mesh topology. The Noxim simulator, a cycle accurate systemC based simulator was employed. The packets were modeled as a Poisson distribution; first-in-first-out (FIFO) input buffer channel with a depth of five (5) flits and a flit size of 32 bits; and a packet size of 3 flits respectively. The simulation time was 10,000 cycles. The findings showed that the XY routing algorithm performed better when the PIR is low.  In a similar vein, the DyAD routing and Age-aware algorithms performed better when the load i.e. PIR is high.


2005 ◽  
Vol 15 (01n02) ◽  
pp. 153-168 ◽  
Author(s):  
A. KHONSARI ◽  
H. SARBAZI-AZAD ◽  
M. OULD-KHAOUA

Recent studies have revealed that deadlocks are generally infrequent in the network. Thus the hardware resources, e.g. virtual channels, dedicated for deadlock avoidance are not utilised most of the time. This consideration has motivated the development of novel adaptive routing algorithms with deadlock recovery. This paper describes a new analytical model to predict message latency in hypercubes with a true fully adaptive routing algorithm with progressive deadlock recovery. One of the main features of the proposed model is the use of results from queueing systems with impatient customers to capture the effects of the timeout mechanism used in this routing algorithm for deadlock detection. The validity of the model is demonstrated by comparing analytical results with those obtained through simulation experiments.


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