itop - look at top interrupt activity

When I want to see interrupt activity on a Linux box I normally use the following rune:

watch -n 1 cat /proc/interrupts

..which simply dumps out the interrupt information every second.  Another way is to use itop, which has the benefit that it outputs the interrupt rate which is lacking from my rune above.

To install, use:

sudo apt-get install itop

and to run, use:

itop

The output is refreshed every second, and outputs something like the following:

INT                NAME          RATE             MAX
  0 [PIC-edge      time]   154 Ints/s     (max:   154)
 14 [PIC-edge      ata_]    16 Ints/s     (max:    16)
 18 [PIC-fasteoi   ehci]     4 Ints/s     (max:     4)
 22 [PIC-fasteoi   ohci]     2 Ints/s     (max:     2)
 29 [MSI-edge      i915]    38 Ints/s     (max:    38)
 30 [MSI-edge      iwl3]     6 Ints/s     (max:     6)

Unfortunately itop does truncate the interrupt names, but I'm not so worried about this - I generally want to see very quickly if a machine is suffering from interrupt saturation or is missing interrupts, which I can get from itop easily.

To see all interrupts, run itop with:

itop -a

And to run for a number of iterations, run with the -n flag, e.g.

itop -n 10