Definition
A Cache-Only Memory Architecture (COMA) is a type of cache-coherent nonuniform memory access (CC-NUMA) architecture. Unlike in a conventional CC-NUMA architecture, in a COMA, every shared-memory module in the machine is a cache, where each memory line has a tag with the line’s address and state. As a processor references a line, it transparently brings it to both its private cache(s) and its nearby portion of the NUMA shared memory (Local Memory) – possibly displacing a valid line from its local memory. Effectively, each shared-memory module acts as a huge cache memory, giving the name COMA to the architecture. Since the COMA hardware automatically replicates the data and migrates it to the memory module of the node that is currently accessing it, COMA increases the chances of data being available locally. This reduces the possibility of frequent long-latency memory accesses. Effectively, COMA dynamically adapts the shared data...
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Torrellas, J. (2011). Cache-Only Memory Architecture (COMA). In: Padua, D. (eds) Encyclopedia of Parallel Computing. Springer, Boston, MA. https://doi.org/10.1007/978-0-387-09766-4_166
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