Introduction to Clusters

The CPU topology displays the hierarchical structure of CPUs on the hardware, including clusters, cores, and threads. Such information is presented to the kernel by using the Advanced Configuration and Power Interface (ACPI) or a device tree (DT) to facilitate task scheduling tuning.

A cluster is a hardware unit. In an ARM processor, a cluster usually consists of multiple homogeneous cores. The cores in the same cluster share the same L3 cache tag. By adding the option for cluster task scheduling tuning of the operating system (OS) kernel, cross-cluster thread scheduling can be prevented and L3 cache tag resources can be reused, improving the CPU scheduling efficiency and memory bandwidth utilization of multi-thread applications. It also leverages hardware resources more efficiently, increases the system throughput, and speeds up responses to requests.