In the last article, we introduced the basic syntax, command options, and some usage examples of the linux top command.
In this article we introduce how to use the top command to monitor cpu usage in linux/unix systems.
Use top command to monitor system CPU usage
In the following example, we use the linux top command to monitor the system CPU usage. We can type top in the terminal and press Enter to see the current CPU usage.
➜ ~ top
Using the linux top monitoring command, we can view the running status of the system in real time, including CPU usage.
The third line of the screenshot shows the current CPU usage in different states.
CPU status field description：
us, user : time running un-niced user processes
sy, system : time running kernel processes
ni, nice : time running niced user processes
id, idle : time spent in the kernel idle handler
wa, IO-wait : time waiting for I/O completion
hi : time spent servicing hardware interrupts
si : time spent servicing software interrupts
st : time stolen from this vm by the hypervisor
In the lower list of screenshots, we can view the CPU usage of each command in real time.
Use the top command to monitor the usage of multiple cores of the system CPU
In the above example, we use the top command to monitor the current system operation in real time. In the following example, we will view the multi-core CPU in real time, and the real-time usage of each core.
To view the CPU multi-core usage, we only need to enter the number “1” when using the top command for real-time monitoring.
➜ ~ top
#Enter the number "1"
Use the linux top command sort by cpu usage
In the following example, we will use the linux top monitoring command to sort by CPU usage.