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2013 IEEE 19th International Symposium on High Performance Computer Architecture (HPCA) (2001)
Nuevo Leone, Mexico
Jan. 20, 2001 to Jan. 24, 2001
ISBN: 0-7695-1019-1
pp: 0085
Andreas Moshovos , University of Toronto
Gokhan Memik , Northwestern University
Alok Choudhary , Northwestern University
Babak Falsafi , Carnegie Mellon University
ABSTRACT
Abstract: We propose methods for reducing the energy consumed by snoop requests in snoopy bus-based symmetric multiprocessor (SMP)systems. Observing that a large fraction of snoops do not find copies in many of the other caches, we introduce JETTY, a small, cache-like structure. A JETTY is introduced in-between the bus and the L2 backside of each processor. There it filters the vast majority of snoops that would not find a locally cached copy. Energy is reduced as accesses to the much more energy demanding L2 tag arrays are decreased. No changes in the existing coherence protocol are required and no performance loss is experienced. We evaluate our method on a 4-way SMP server using a set of shared-memory applications. We demonstrate that a very small JETTY filters 74%(average)of all snoop-induced tag accesses that would miss. This results in an average energy reduction of 29% (range:12%to 40%) measured as a fraction of the energy required by all L2 accesses (both tag and data arrays).
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CITATION
Andreas Moshovos, Gokhan Memik, Alok Choudhary, Babak Falsafi, "JETTY:Filtering Snoops for Reduced Energy Consumption in SMP Servers", 2013 IEEE 19th International Symposium on High Performance Computer Architecture (HPCA), vol. 00, no. , pp. 0085, 2001, doi:10.1109/HPCA.2001.903254
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