Apple Inc.
Closed loop performance controller work interval instance propagation

Abstract:

Systems and methods are disclosed for scheduling threads on an asymmetric multiprocessing system having multiple core types. Each core type can run at a plurality of selectable voltage and frequency scaling (DVFS) states. Threads from a plurality of processes can be grouped into thread groups. Execution metrics are accumulated for threads of a thread group and fed into a plurality of tunable controllers. A closed loop performance control (CLPC) system determines a control effort for the thread group and maps the control effort to a recommended core type and DVFS state. A closed loop thermal and power management system can limit the control effort determined by the CLPC for a thread group, and limit the power, core type, and DVFS states for the system. Metrics for workloads offloaded to co-processors can be tracked and integrated into metrics for the offloading thread group.