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Using the top Command in the ChromeOS Linux Environment

The top command in Linux provides a real-time, dynamic overview of system resource usage, including CPU and memory consumption, running processes, and system load. It is an essential tool for monitoring system performance in the ChromeOS Linux (Crostini) environment.

Basic Usage

Running top

To start top, simply run:

top

This displays a real-time list of system processes, sorted by CPU usage by default.

Exiting top

To exit top, press:

q

Understanding the Output

A typical top display consists of:

  • System Uptime & Load Averages: Shows how long the system has been running and the load averages over 1, 5, and 15 minutes.
  • Task Summary: Displays the number of total, running, sleeping, stopped, and zombie processes.
  • CPU Usage: Shows CPU utilization by system, user, and idle time.
  • Memory Usage: Displays the total, used, and free memory (RAM and swap).
  • Process List: Displays active processes sorted by CPU usage.

While top is running, you can use the following keys to interact with it:

  • h – Show help menu
  • k – Kill a process by entering its PID
  • r – Renice a process (change priority)
  • M – Sort by memory usage
  • P – Sort by CPU usage
  • q – Quit top

Filtering and Sorting

Displaying Only Processes for a Specific User

To view processes owned by a specific user, use:

top -u username

Changing the Refresh Interval

To change the update interval (default: 3 seconds), use:

top -d 1

Sorting by Memory Usage

To sort by memory usage instead of CPU, press:

M

Practical Use Cases

  • Monitoring CPU-intensive processes: 
    top
  • Identifying memory-hungry applications: 
    top -o %MEM
  • Killing unresponsive processes: 
    top (press `k` and enter the PID)

Conclusion

The top command is an essential tool for monitoring system health and managing processes in the ChromeOS Linux environment. With real-time insights into CPU and memory usage, top helps users identify performance bottlenecks and optimize resource utilization.