To start with, high cpu utilization does not necessarily mean that there is a problem. It just means that there is a lot of work that PAM is being asked to do. You just have to check whether the workload is expected and if the CPU utilization returns to normal when the task is done.
The most common way that CPU utilization become artificially high is if the LDAP Update interval is set too low. You will see lots of LDAP update messages in the Session log if this is the case. The default setting is 1440 minutes, or once a day. You can make it lower, but take a look at how long your updates take before changing the value. Make sure that the updates are not running continuously. Similarly, importing and exporting of csv files will also put a big workload on PAM. It just depends on how may entries are being processed.
The next most common impact to PAM's performance is recording post-processing. If you see high CPU utilization you should check if there are a lot of recordings being processed. If so, wait until the processing completes and check if the CPU usage has dropped.
Next comes programmatic activity. Are you loading a lot of entries into PAM using the APIs? Once again, wait until the processing completes and check the CPU utilization.
Regarding of these workloads, the true measure of whether or not there is a problem is how well PAM is responding during these periods of high CPU utilization. Are your users complaining about poor response? If so, open a ticket so we may look into the issue more deeply. It may be necessary to turn on some additional logging, and get the system logs if that is the case.