What tools and approaches are used to analyze CPU usage in Linux via the command line during load diagnosis?

Tools commonly used for analyzing CPU usage in Linux via the command line include:

• top — shows current CPU load, processes with the highest resource consumption, and allows dynamic system monitoring.
• htop — an improved version of top with a user-friendly interface and interactive process management.
• mpstat (from the sysstat package) — displays statistics on CPU or core load over a specified interval.
• pidstat — shows CPU statistics for specific processes.
• vmstat — provides overall system information, including CPU, memory, and input/output usage.
• sar — collects and displays historical CPU load data.

Example of using the top command:

top

For more detailed analysis, you can use mpstat:

mpstat -P ALL 1 5

This command shows the load of all CPU cores with a 1-second interval, repeated 5 times.

Approaches to diagnostics:

• Identify processes consuming the most CPU.
• Check for excessive context switching.
• Assess whether the load is related to system or user processes.
• Use historical data to identify peaks and patterns.