1. A system, comprising: a processor chip that includes a plurality of thread contexts for concurrent thread execution and also includes a resource that is shared by two or more of the thread contexts; and system software to program redirection of a hardware event to only one of the thread contexts that shares the resource; wherein the system software is further to program the redirection responsive to a communication that one of the plurality of thread contexts has been added by an operating system to a subset of the plurality of thread contexts.