Overview of Process Schedulers

Process schedulers are components of the operating system responsible for moving processes between different states. These schedulers manage the state transitions discussed in process state diagrams and are essential for effective process management in multiprogramming systems.

Long-term Scheduler

Primary Function

The long-term scheduler brings processes from disk to RAM, effectively moving processes to the ready state once they are loaded into memory.

Key Responsibilities

Controls Degree of Multiprogramming:

• Determines how many processes are present in RAM at any given time
• Manages the overall system load and resource allocation

Process Mix Management:

The long-term scheduler should ideally bring a good mix of I/O bound and CPU-bound processes into memory:

• I/O Bound Process: Spends most of its time performing input/output operations
• CPU Bound Process: Spends most of its time using the CPU for computations

Why Process Mix Matters

Problem with Only I/O Bound Processes:

• CPU may remain idle most of the time
• Poor CPU utilization as processes wait for I/O operations

Problem with Only CPU Bound Processes:

• CPU becomes unavailable for other processes
• System becomes unresponsive to new process requests