NVIDIA Corporation
TECHNIQUES FOR ORDERING ATOMIC OPERATIONS

Abstract:

In various embodiments, an ordered atomic operation enables a parallel processing subsystem to executes an atomic operation associated with a memory location in a specified order relative to other ordered atomic operations associated with the memory location. A level 2 (L2) cache slice includes an atomic processing circuit and a content-addressable memory (CAM). The CAM stores an ordered atomic operation specifying at least a memory address, an atomic operation, and an ordering number. In operation, the atomic processing circuit performs a look-up operation on the CAM, where the look-up operation specifies the memory address. After the atomic processing circuit determines that the ordering number is equal to a current ordering number associated with the memory address, the atomic processing circuit executes the atomic operation and returns the result to a processor executing an algorithm. Advantageously, the ordered atomic operation enables the algorithm to achieve a deterministic result while optimizing latency.