Dynamic behaviour of CPU usage in System Information widget of pfsense

ppfsenseavan

In System Information widget of pfsense 'CPU usage' gets updated automatically every 10 seconds. My question is where is the code that's modifying 'CPU usage' every 10 seconds.

What I have done so far:

Code that displays CPU usage is:

CPU usage

![left bar](./themes/<?= $g['theme']; ?>/images/misc/bar_left.gif)![red bar](./themes/<?= $g['theme']; ?>/images/misc/bar_blue.gif)![gray bar](./themes/<?= $g['theme']; ?>/images/misc/bar_gray.gif)![right bar](./themes/<?= $g['theme']; ?>/images/misc/bar_right.gif)

(Updating in 10 seconds)

When 'id=cpumeter' is removed, '(Updating in 10 seconds)' is displayed forever. If 'id=cpumeter' is not removed then '(Updating in 10 seconds)' is displayed for 10 seconds and then replaced by 2% or 3% (depending upon the cpu usage). The precentage gets modified every 10 seconds.

So I tried searching the code that is updating CPU usage every 10 seconds but couldn't find it. I think java script is updating CPU usage but not sure. How can I find the code that is updating the CPU usage every 10 seconds?