SELECTIVE FAULT STALLING FOR A GPU MEMORY PIPELINE IN A UNIFIED VIRTUAL MEMORY SYSTEM

摘要

One embodiment of the present invention is a parallel processing unit (PPU) that includes one or more streaming multiprocessors (SMs) and implements a selective fault-stalling pipeline. Upon detecting a memory access fault associated with an operation executing on a particular SM, a replay unit in the selective fault-stalling pipeline considers the operation as a faulting operation. Subsequently, instead of notifying the SM of the memory access fault, the replay unit recirculates the operation—reinserting the operation into the selective fault-stalling pipeline. Recirculating faulting operations in such a fashion enables the SM to execute other operation while the replay unit stalls the faulting request until the associated access fault is resolved. Advantageously, the overall performance of the PPU is improved compared to conventional PPUs that, upon detecting a memory access fault, cancel the associated operation and subsequent operations.