THREAD CONTEXT PRESERVATION IN A MULTITHREADING COMPUTER SYSTEM

摘要

According to one aspect, a computer system includes a configuration with a core configurable between a single thread (ST) mode and a multithreading (MT) mode. The ST mode addresses a primary thread, and the MT mode addresses the primary thread and one or more secondary threads. The computer system also includes a multithreading facility configured to control utilization of the configuration to perform a method. Based on determining, by the core in the MT mode, that MT is to be disabled, the MT mode switches to the ST mode, where the primary thread of the MT mode is maintained as the primary thread of the ST mode. A thread context of the one or more secondary threads is made inaccessible to programs. Based on the switching, any one of clearing the program accessible register values or retaining the program accessible register values is performed.

主权项

1. A computer system, comprising:
a configuration comprising a core configurable between a single thread (ST) mode and a multithreading (MT) mode, the ST mode addressing a primary thread and the MT mode addressing the primary thread and one or more secondary threads on shared resources of the core; and a multithreading facility configured to control utilization of the configuration to perform a method comprising:
based on determining, by the core in the MT mode, that MT is to be disabled, switching from the MT mode to the ST mode, wherein the primary thread of the MT mode is maintained as the primary thread of the ST mode, wherein a thread context comprising program accessible register values and program counter values of the one or more secondary threads is made inaccessible to programs; andbased on the switching, performing any one of clearing the program accessible register values or retaining the program accessible register values.