Scheduling policy plays a crucial role in determining how the Linux kernel schedules processes and allocates resources. It is important for system administrators and developers to understand the different scheduling policies available in Linux and how to set them according to their specific requirements.

In Linux, the default scheduling policy is called the Completely Fair Scheduler (CFS). CFS provides fair CPU time allocation to processes and ensures that each process gets an equal share of the CPU. However, there are other scheduling policies available that can be used to prioritize certain processes or optimize system performance.

To set the scheduling policy in Linux, the "chrt" command is used. This command allows you to change the scheduling policy of a process or launch a new process with a specific scheduling policy.

Here are some examples of how to set scheduling policy using the "chrt" command:

1. Set a process to the Real-Time scheduling policy:

   chrt -r <priority> <command>

   The Real-Time (RT) scheduling policy provides the highest priority to a process, allowing it to preempt all other processes in the system. The priority value ranges from 1 to 99, where a lower value indicates a higher priority. Replace <priority> with the desired priority value and <command> with the command or program you want to run.

2. Set a process to the Round Robin scheduling policy:

   chrt -r -p <priority> <command>

   The Round Robin (RR) scheduling policy is a preemptive policy that allows processes to run for a fixed time slice before being preempted and moved to the end of the queue. This policy is suitable for processes that require equal CPU time and responsiveness. Replace <priority> with the desired priority value and <command> with the command or program you want to run.

3. Set a process to the Idle scheduling policy:

   chrt -i <command>

   The Idle scheduling policy assigns the lowest priority to a process, allowing it to run only when the CPU is idle. This policy is useful for background tasks or processes that should not interfere with the performance of other critical processes.