How to calculate cpu load using linux top command?

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by brock , in category: General Help , 9 months ago

How to calculate cpu load using linux top command?

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2 answers

by damian_mills , 9 months ago

@brock 

To calculate CPU load using the top command in Linux, you can follow these steps:

  1. Open the terminal on your Linux machine.
  2. Run the top command by typing top and hitting Enter.
  3. In the top command interface, you will see various information related to the system, including CPU usage.
  4. Look for the line that shows the CPU usage, usually located at the top-right corner of the screen.
  5. The CPU usage is divided into percentages for each core or processor thread. For example, if you have a quad-core CPU, you will see four lines, each showing the usage for a different core.
  6. The percentages represent the load on each core. A higher percentage means more load on the CPU core.
  7. Additionally, you can check the overall CPU usage at the top of the top interface. Look for the line that shows the overall CPU usage in percentages. It is usually displayed as "%Cpu(s)" or "%Cpu". This line gives you the overall CPU load across all cores.
  8. The CPU load is typically displayed in real-time, continuously updating as the load changes.


Note: The top command can provide more detailed information on CPU usage, memory usage, running processes, and other system metrics. Press q to exit the top command interface.


Keep in mind that there are alternative commands available (such as htop) that provide more user-friendly displays of CPU load and system information.

by raphaelle , 3 months ago

@brock 

To calculate the CPU load using the top command, you typically look at the "%Cpu(s)" line displayed at the top of the top interface. This line breaks down the CPU usage into various categories such as user, system, nice, idle, and others.


To interpret the CPU load from the "%Cpu(s)" line:

  • %us: The percentage of CPU time spent on user processes.
  • %sy: The percentage of CPU time spent on kernel processes.
  • %ni: The percentage of CPU time spent on processes with a positive nice value.
  • %id: The percentage of CPU time spent idle.
  • %wa: The percentage of CPU time spent waiting for I/O operations to complete.
  • %hi: The percentage of CPU time spent servicing hardware interrupts.
  • %si: The percentage of CPU time spent servicing software interrupts.
  • %st: The percentage of CPU time stolen from a virtual machine.


To calculate the CPU load based on these values, you can sum the relevant percentages based on your specific requirements. For example, to calculate the total CPU load, you might sum %us, %sy, %ni, and possibly %wa. Alternatively, you can focus on specific aspects like user CPU usage or system CPU usage by looking at the corresponding percentages.


Just keep in mind that the calculation involves interpreting these values based on what aspects of CPU load you want to consider. The top command provides a comprehensive view of CPU usage in real-time, aiding you in understanding the load distribution across different processes running on your system.