Chapter 3 - Data processing systems

Abstract

A data processing system includes one or more processors 4, 5, 6, 7 operable to initiate atomic memory requests for execution threads and plural data caches 8, 9, 10, 1 1 that are used to store data needed to perform an atomic memory operation when an atomic memory operation is to be performed. When atomic operations are to be performed against a data cache, the results of atomic operations that are to access the same memory location are accumulated in a temporary cache line in the data cache pending the arrival in the cache of the "true" cache line from memory. The accumulated results of the atomic operations stored in the temporary cache line are then combined with the cache line from memory when the cache line arrives in the cache. Individual atomic values can also be reconstructed once the cache line arrives at the cache.