The I/O scheduler is an important component in the Linux kernel, which is responsible for determining the processing order of disk I/O requests. One of the scheduling algorithms is Noop (also known as No-op or no-op scheduler), which is a simple FIFO (first in, first out) scheduling algorithm. In this article, we will explore how the Noop scheduler works and provide a sample code to demonstrate how to use the Noop I/O scheduler in Linux.
The main goal of the Noop scheduler is to provide low latency and high throughput I/O operations. It achieves this by queuing I/O requests in the order of arrival, without considering any other factors such as request size, location, etc. This makes the Noop scheduler perform well in many situations, especially for systems with good I/O load balancing.
Configuring the Noop scheduler in Linux is very simple. We can specify the scheduler used by modifying the /sys/block//queue/scheduler file. In this file we can see a list with various scheduler names. To set a device's scheduler to Noop, we simply write its name to a file. Below is a sample code that demonstrates how to use a shell script to configure the Noop scheduler:
#!/bin/bash
DEVICE="/dev/sda" # 替换为你的设备路径
# 检查设备是否存在
if [