Guaranteed in-order packet delivery using Exclusive Dynamic Virtual Channel Allocation

In-order packet delivery, a critical abstraction for many higher-level protocols, can severely limit the performance potential in low-latency networks (common, for example, in network-on-chip designs with many cores). While basic variants of dimension-order routing guarantee in-order delivery, impro...

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Main Authors: Devadas, Srinivas, Cho, Myong Hyon, Shim, Keun Sup, Lis, Mieszko
Other Authors: Srini Devadas
Published: 2009
Online Access:http://hdl.handle.net/1721.1/46353
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author Devadas, Srinivas
Cho, Myong Hyon
Shim, Keun Sup
Lis, Mieszko
author2 Srini Devadas
author_facet Srini Devadas
Devadas, Srinivas
Cho, Myong Hyon
Shim, Keun Sup
Lis, Mieszko
author_sort Devadas, Srinivas
collection MIT
description In-order packet delivery, a critical abstraction for many higher-level protocols, can severely limit the performance potential in low-latency networks (common, for example, in network-on-chip designs with many cores). While basic variants of dimension-order routing guarantee in-order delivery, improving performance by adding multiple dynamically allocated virtual channels or using other routing schemes compromises this guarantee. Although this can be addressed by reordering out-of-order packets at the destination core, such schemes incur significant overheads, and, in the worst case, raise the specter of deadlock or require expensive retransmission. We present Exclusive Dynamic VCA, an oblivious virtual channel allocation scheme which combines the performance advantages of dynamic virtual allocation with in-network, deadlock-free in-order delivery. At the same time, our scheme reduces head-of-line blocking, often significantly improving throughput compared to equivalent baseline (out-of-order) dimension-order routing when multiple virtual channels are used, and so may be desirable even when in-order delivery is not required. Implementation requires only minor, inexpensive changes to traditional oblivious dimension-order router architectures, more than offset by the removal of packet reorder buffers and logic.
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spelling mit-1721.1/463532019-04-12T07:36:57Z Guaranteed in-order packet delivery using Exclusive Dynamic Virtual Channel Allocation Devadas, Srinivas Cho, Myong Hyon Shim, Keun Sup Lis, Mieszko Srini Devadas Computation Structures In-order packet delivery, a critical abstraction for many higher-level protocols, can severely limit the performance potential in low-latency networks (common, for example, in network-on-chip designs with many cores). While basic variants of dimension-order routing guarantee in-order delivery, improving performance by adding multiple dynamically allocated virtual channels or using other routing schemes compromises this guarantee. Although this can be addressed by reordering out-of-order packets at the destination core, such schemes incur significant overheads, and, in the worst case, raise the specter of deadlock or require expensive retransmission. We present Exclusive Dynamic VCA, an oblivious virtual channel allocation scheme which combines the performance advantages of dynamic virtual allocation with in-network, deadlock-free in-order delivery. At the same time, our scheme reduces head-of-line blocking, often significantly improving throughput compared to equivalent baseline (out-of-order) dimension-order routing when multiple virtual channels are used, and so may be desirable even when in-order delivery is not required. Implementation requires only minor, inexpensive changes to traditional oblivious dimension-order router architectures, more than offset by the removal of packet reorder buffers and logic. 2009-08-18T22:30:03Z 2009-08-18T22:30:03Z 2009-08-18 http://hdl.handle.net/1721.1/46353 MIT-CSAIL-TR-2009-036 10 p. application/pdf application/postscript
spellingShingle Devadas, Srinivas
Cho, Myong Hyon
Shim, Keun Sup
Lis, Mieszko
Guaranteed in-order packet delivery using Exclusive Dynamic Virtual Channel Allocation
title Guaranteed in-order packet delivery using Exclusive Dynamic Virtual Channel Allocation
title_full Guaranteed in-order packet delivery using Exclusive Dynamic Virtual Channel Allocation
title_fullStr Guaranteed in-order packet delivery using Exclusive Dynamic Virtual Channel Allocation
title_full_unstemmed Guaranteed in-order packet delivery using Exclusive Dynamic Virtual Channel Allocation
title_short Guaranteed in-order packet delivery using Exclusive Dynamic Virtual Channel Allocation
title_sort guaranteed in order packet delivery using exclusive dynamic virtual channel allocation
url http://hdl.handle.net/1721.1/46353
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