Dynamic estimation of task level parallelism with operating system

The amount of task level parallelism (TLP) in runtime workload is useful information to determine the efficient usage of multiprocessors. This paper presents mechanisms to dynamically estimate the amount of TLP in runtime workloads. Modifications are added to the operating system (OS) to collect information about processor utilization, task activities, from which TLP can be calculated. By effectively utilizing the time stamp counter (TSC) hardware, the task activities can be monitored at fine time resolution, resulting in capability of estimation of TLP at fine granularity. We implement the mechanisms on a recent version of Linux OS. Evaluation results indicate that the mechanisms can estimate TLP accurately for various kinds of workloads with small overheads.