What do top %cpu abbreviations mean?

Ray N. Franklin picture Ray N. Franklin · Sep 23, 2014 · Viewed 27.1k times · Source

Does anyone know what the 2-letter abbreviations mean in the %CPU line in the header above the top table of processes? Here's a sample output from running top.

top - 15:10:34 up 8 days,  5:11,  1 user,  load average: 0.10, 3.80, 26.82
Tasks:   1 total,   0 running,   1 sleeping,   0 stopped,   0 zombie
%Cpu(s):  0.3 us,  0.7 sy,  0.0 ni, 98.0 id,  1.1 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem:   2051456 total,   623544 used,  1427912 free,     1292 buffers
KiB Swap:  3203068 total,   147188 used,  3055880 free,    38352 cached

Here are my guesses and the ones I don't know.

us = user
sy = system
ni = ?
id = idle?
wa = ?
hi = ?
si = ?
st = ?

Answer

DavidPostill picture DavidPostill · Sep 23, 2014

In "top" what are us, sy, ni, id, wa, hi, si and st (for CPU usage)?

  • us - user cpu time (or) % CPU time spent in user space
  • sy - system cpu time (or) % CPU time spent in kernel space
  • ni - user nice cpu time (or) % CPU time spent on low priority processes
  • id - idle cpu time (or) % CPU time spent idle
  • wa - io wait cpu time (or) % CPU time spent in wait (on disk)
  • hi - hardware irq (or) % CPU time spent servicing/handling hardware interrupts
  • si - software irq (or) % CPU time spent servicing/handling software interrupts
  • st - steal time % CPU time in involuntary wait by virtual cpu while hypervisor is servicing another processor (or) % CPU time stolen from a virtual machine

Source: In Linux "top" command what are us, sy, ni, id, wa, hi, si and st (for CPU usage)?