Which I/O scheduler creates queues for each process, providing read requests priority over write requests?

The I/O scheduler that creates queues for each process and prioritizes read requests over write requests is known as the Completely Fair Queuing (CFQ) scheduler. CFQ operates by allocating a fair amount of I/O bandwidth to each process and uses this fair allocation to manage I/O operations efficiently. It does so by maintaining separate queues for each process, allowing it to give precedence to read requests as they typically require faster access to data, enhancing overall system performance.

This approach helps in reducing latency for read operations, which is often crucial for applications that need quick access to data, while still ensuring that write operations are handled fairly over time. The mechanism enables more efficient handling of both read and write requests, making CFQ suitable for a variety of workloads in Linux systems.

The other options do not implement this specific mechanism. For instance, while the noop scheduler simply merges requests to optimize for throughput without providing comprehensive prioritization, and the deadline scheduler attempts to minimize latency for both reads and writes but does not prioritize reads distinctly over writes, bfq (Budget Fair Queueing) differs by focusing on fairness based on the budgeted resources for each process, but doesn't centrally prioritize read requests in the same manner as CFQ.