The CPU scheduler is a critical component of any operating system, including Linux, as it determines how processes are allocated and executed on the CPU. The CPU scheduler plays a vital role in optimizing the utilization of the CPU, ensuring fair allocation of resources, and improving overall system performance. In the Linux environment, the CPU scheduler is highly configurable and offers various scheduling policies to meet different requirements.

Examples:

1. Scheduling Policies in Linux:

   • The Linux kernel provides several scheduling policies, including the Completely Fair Scheduler (CFS), Real-Time (RT) scheduler, and Deadline scheduler.
   • To view the current scheduling policy of a process, use the 'chrt' command with the '-p' option: chrt -p <pid>.
   • To change the scheduling policy of a process, use the 'chrt' command with the '-r' option for real-time scheduling or '-d' option for deadline scheduling: chrt -r <priority> <pid> or chrt -d <deadline> <pid>.

2. Process Priorities in Linux:

   • Linux assigns priorities to processes based on their scheduling policy.
   • The 'nice' command allows adjusting the priority of a process. Higher values indicate lower priority, and vice versa. For example, to set a lower priority for a process, use: nice -n <value> <command>.
   • The 'renice' command allows changing the priority of a running process. For example, to increase the priority of a process with PID 1234, use: renice -n <value> -p 1234.

3. CPU Affinity in Linux:

   • CPU affinity determines which CPU cores a process can execute on.
   • The 'taskset' command allows setting CPU affinity for a process. For example, to bind a process with PID 1234 to CPU cores 0 and 1, use: taskset -c 0,1 -p 1234.
   • To check the CPU affinity of a process, use the 'taskset' command with the '-p' option: taskset -p 1234.