Advanced Micro Devices, Inc.
TECHNIQUES FOR IMPROVED LATENCY OF THREAD SYNCHRONIZATION MECHANISMS

Abstract:

A memory fence or other similar operation is executed with reduced latency. An early fence operation is executed and acts as a hint to the processor executing the thread that executes the fence. This hint causes the processor to begin performing sub-operations for the fence earlier than if no such hint were executed. Examples of sub-operations for the fence include operations to make data written to by writes prior to the fence operation available to other threads. A resolving fence, which occurs after the early fence, performs the remaining sub-operations for the fence. By triggering some or all of the sub-operations for a memory fence that will occur in the future, the early fence operation reduces the amount of latency associated with that memory fence operation.