CPU0

CPU0 refers to the first central processing unit (CPU) in a multi-processor system. In systems with only one CPU, it is often referred to as CPU0 by default in operating system kernels and hardware monitoring tools. This designation is primarily used for internal referencing and task scheduling. When a system boots, the initial code execution is handled by a specific processor, which is then conventionally identified as CPU0. Subsequent processors are then assigned indices like CPU1, CPU2, and so on.

The operating system kernel utilizes CPU0 as a primary point of control. It's often where the scheduler initiates its operations and where critical system processes might be initially anchored. While modern operating systems are designed to distribute workloads across all available CPUs for optimal performance, CPU0 retains its foundational role in the system's startup sequence and core management. In troubleshooting scenarios, identifying activities or resource utilization on CPU0 can be a starting point for diagnosing performance issues, especially if that processor appears to be a bottleneck. The concept of CPU0 is therefore fundamental to understanding how operating systems manage and interact with the hardware components of a computer.