Title: ps: improved/fixed calculation of CPU utilization (linux)
Level: 2
Component: checks
Version: 1.2.5i3
Date: 1401100287
Class: feature

Previously, the CPU utilization value was taken from the output <tt>pcpu</tt> from
the ps command. This value didn't reflect the exact utilization since the last check
because its definition is <br>
<pre>
CPU usage is currently expressed as the percentage of time spent running
during the entire lifetime of a process.  This is not ideal, and it does not
conform to the standards that ps otherwise conforms to.  CPU usage is
unlikely to add up to exactly 100%.
</pre>

The evaluation of the <tt>pcpu</tt> field has been removed and got replaced
by the field <tt>cputime</tt>, which reflects the number of cpu seconds since program start.
With the <tt>cputime</tt> we are able to determine the correct value.

To utilize this new calculation method, you need to update the check_mk_agent on the target host.
The ps check itself is able to handle both formats, <tt>pcpu</tt> and <tt>cputime</tt>.

<br>
Note: This bug only applied to hosts using the linux check_mk_agent

