Someone is telling me that Splunk doesn't grab Perfmon data properly...they are getting %Processor Time from both the Process and Processor counters. They say that if they grab the data from Process for each process and add them up, they don't get the same value as the value from the Processor counter (even taking the number of CPUs/Cores/Hyperthreading into account). They say they asked Splunk for updates and got some updates and they still don't work.
It's true, perfmon has a lot of limitations when it comes to monitoring processes. Did some research and some of the limitations are :
Perfmon doesn't collect null values for CPU usage.
For multi-core Perfmon max CPU is 100% if the option useWinApiProcStats is not set. This option is best practice is case of multi-core systems as it uses theGetProcessTime function to build multi core CPU and Processor KPIs.