DocumentCode :
3782098
Title :
Using network interface support to avoid asynchronous protocol processing in shared virtual memory systems
Author :
A. Bilas; Cheng Liao;J.P. Singh
Author_Institution :
Dept. of Electr. & Comput. Eng., Toronto Univ., Ont., Canada
fYear :
1999
Firstpage :
282
Lastpage :
293
Abstract :
The performance of page-based software shared virtual memory (SVM) is still far from that achieved on hardware-coherent distributed shared memory (DSM) systems. The interrupt cost for asynchronous protocol processing has been found to be a key source of performance loss and complexity. This paper shows that by providing simple and general support for asynchronous message handling in a commodity network interface (NI), and by altering SVM protocols appropriately, protocol activity can be decoupled from asynchronous message handling and the need for interrupts or polling can be eliminated. The NI mechanisms needed are generic, not SVM-dependent. They also require neither visibility into the node memory system nor code instrumentation to identify memory operations. We prototype the mechanisms and such a synchronous home-based LRC protocol, called GeNIMA (GEneral-purpose Network Interface support in a shared Memory Abstraction), on a cluster of SMPs with a programmable NI, though the mechanisms are simple and do not require programmability. We find that the performance improvements are substantial, bringing performance on a small-scale SMP cluster much closer to that of hardware-coherent shared memory for many applications, and we show the value of each of the mechanisms in different applications. Application performance improves by about 37% on average for reasonably well performing applications, even on our relatively slow programmable NI, and more for others. We discuss the key remaining bottlenecks at the protocol level and use a firmware performance monitor in the NI to understand the interactions with and the implications for the communication layer.
Keywords :
"Network interfaces","Protocols","Support vector machines","Software performance","Costs","Performance loss","Instruments","Prototypes","Microprogramming","Monitoring"
Publisher :
ieee
Conference_Titel :
Computer Architecture, 1999. Proceedings of the 26th International Symposium on
ISSN :
1063-6897
Print_ISBN :
0-7695-0170-2
Type :
conf
DOI :
10.1109/ISCA.1999.765958
Filename :
765958
Link To Document :
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