CPUΒΆ

The CPU stats are shown as a percentage or value and for the configured refresh time. The total CPU usage is displayed on the first line.

../_images/cpu.png

If enough horizontal space is available, extended CPU information are displayed.

../_images/cpu-wide.png

CPU stats description:

  • user: percent time spent in user space

> User CPU time is time spent on the processor running your program’s code (or code in libraries) * system: percent time spent in kernel space > System CPU time is the time spent running code in the operating system kernel * idle: percent of CPU used by any program > Every program or task that runs on a computer system occupies a certain amount of processing time on the CPU. If the CPU has completed all tasks it is idle. * nice: percent time occupied by user level processes with a positive nice value > The time the CPU has spent running users’ processes that have been “niced” * irq: percent time spent servicing/handling hardware/software interrupts > Time servicing interrupts (hardware + software) * iowait: percent time spent in wait (on disk) > Time spent by the CPU waiting for a IO operations to complete * steal: percent time in involuntary wait by virtual CPU > Steal time is the percentage of time a virtual CPU waits for a real CPU while the hypervisor is servicing another virtual processor * ctx_sw: number of context switches (voluntary + involuntary) per second > A context switch is a procedure that a computer’s CPU (central processing unit) follows to change from one task (or process) to another while ensuring that the tasks do not conflict * inter: number of interrupts per second * sw_inter: number of software interrupts per second. Always set to 0 on Windows and SunOS. * syscal: number of system calls per second. Do not displayed on Linux (always 0).

To switch to per-CPU stats, just hit the 1 key:

../_images/per-cpu.png

By default, steal CPU time alerts aren’t logged. If you want that, just add to the configuration file:

[cpu]
steal_log=True

Legend:

CPU (user/system) Status
<50% OK
>50% CAREFUL
>70% WARNING
>90% CRITICAL

Note

Limit values can be overwritten in the configuration file under the [cpu] and/or [percpu] sections.