Active Messages: a Mechanism for Integrated Communication and Computation

Thorsten von Eicken, David E. Culler, Seth Copen Goldstein and Klaus Erik Schauser

EECS Department
University of California, Berkeley
Technical Report No. UCB/CSD-92-675
March 1992

http://www2.eecs.berkeley.edu/Pubs/TechRpts/1992/CSD-92-675.pdf

The design challenge for large-scale multiprocessors is (1) to minimize communication overhead, (2) allow communication to overlap computation, and (3) coordinate the two without sacrificing processor cost/performance. We show that existing message passing multiprocessors have unnecessarily high communication costs. Research prototypes of message driven machines demonstrate low communication overhead, but poor processor cost/performance. We introduce a simple communication mechanism, Active Messages, show that it is intrinsic to both architectures, allows cost effective use of the hardware, and offers tremendous flexibility. Implementations on nCUBE/2 and CM-5 are described and evaluated using a split-phase shared-memory extension to C, Split-C. We further show that active messages are sufficient to implement the dynamically scheduled languages for which message driven machines were designed. With this mechanism, latency tolerance becomes a programming/compiling concern. Hardware support for active messages is desirable and we outline a range of enhancements to mainstream processors.


BibTeX citation:

@techreport{von Eicken:CSD-92-675,
    Author = {von Eicken, Thorsten and Culler, David E. and Goldstein, Seth Copen and Schauser, Klaus Erik},
    Title = {Active Messages: a Mechanism for Integrated Communication and Computation},
    Institution = {EECS Department, University of California, Berkeley},
    Year = {1992},
    Month = {Mar},
    URL = {http://www2.eecs.berkeley.edu/Pubs/TechRpts/1992/5569.html},
    Number = {UCB/CSD-92-675},
    Abstract = {The design challenge for large-scale multiprocessors is (1) to minimize communication overhead, (2) allow communication to overlap computation, and (3) coordinate the two without sacrificing processor cost/performance. We show that existing message passing multiprocessors have unnecessarily high communication costs. Research prototypes of message driven machines demonstrate low communication overhead, but poor processor cost/performance. We introduce a simple communication mechanism, Active Messages, show that it is intrinsic to both architectures, allows cost effective use of the hardware, and offers tremendous flexibility. Implementations on nCUBE/2 and CM-5 are described and evaluated using a split-phase shared-memory extension to C, Split-C. We further show that active messages are sufficient to implement the dynamically scheduled languages for which message driven machines were designed. With this mechanism, latency tolerance becomes a programming/compiling concern. Hardware support for active messages is desirable and we outline a range of enhancements to mainstream processors.}
}

EndNote citation:

%0 Report
%A von Eicken, Thorsten
%A Culler, David E.
%A Goldstein, Seth Copen
%A Schauser, Klaus Erik
%T Active Messages: a Mechanism for Integrated Communication and Computation
%I EECS Department, University of California, Berkeley
%D 1992
%@ UCB/CSD-92-675
%U http://www2.eecs.berkeley.edu/Pubs/TechRpts/1992/5569.html
%F von Eicken:CSD-92-675