A user space program is any process that doesn't belong to the kernel. The CPU line will look something like this: %Cpu(s): 24.8 us, 0.5 sy, 0.0 ni, 73.6 id, 0.4 wa, 0.0 hi, 0.2 si, 0.0 stĢ4.8 us - This tells us that the processor is spending 24.8% of its time running user space processes. This list can be sorted by PID, CPU usage, memory usage, and so on. Beneath these stats is a live list of the current running processes. The first few lines give a summary of the system resources including a breakdown of the number of tasks, the CPU statistics, and the current memory usage. The output from top is divided into two sections. To start the top command you just type top at the command line: The most common is probably using the top command. There are several different ways to see the various CPU statistics. See our blog post Restricting process CPU usage using nice, cpulimit, and cgroups for more information on nice. By default processes on Linux are started with a niceness of 0. The niceness level ranges from -20 (most favorable scheduling) to 19 (least favorable). Niceness is a way to tweak the priority level of a process so that it runs less frequently.

For example, user space programs can be categorized as those running under their initial priority level or those running with a nice priority. These three meta states can be further subdivided. Running the kernel, servicing interrupts or managing resources.

Running a user space program, like a command shell, an email server, or a compiler.

Idle, which means it has nothing to do.

There are 3 general states your CPU can be in: You see the CPU metrics:īut what do all of those 2-letter abbreviations mean? The 3 CPU states Your Linux server is running slow, so you follow standard procedure and run top. Updated version of an article first published on February 24th, 2015.

Centos check cpu usage