International Business Machines Corporation
Low latency management of processor core wait state

Abstract:

A data processing system includes multiple processing units all having access to a shared memory. A processing unit includes a lower level cache memory and a processor core coupled to the lower level cache memory. The processor core includes an execution unit for executing instructions in a plurality of simultaneous hardware threads, an upper level cache memory, and a plurality of wait flags each associated with a respective one of the plurality of simultaneous hardware threads. The processor core is configured to set a wait flag among the plurality of wait flags to indicate the associated hardware thread is in a wait state in which the hardware thread suspends instruction execution and to exit the wait state based on the wait flag being reset.