I got the DFM alert saying that my CPU is too busy. "sysstat" output showed the CPU utilization between 90% to 96%. below is the "sysstat -M" output; as you can see the WAFL-Ex(Kahu) percentage crossed 100%. I heard that any domain that reaches 100% is a bottleneck, is that true? Can anyone tell what exactly this domain does? and is it the culprit in this case? if yes what is the solution?
Since 8.1, processes have been well multi-threaded, so running over 100% just means its using more than one core
On our 6210 system (DOT8.1.2, 8 cores) for example, Wafl_EX hovers over 200% most the time - We used to get regular DFM alerts about high CPU, and a normal sysstat showed cpu pegged at 99%, but that counter is not a good indicator in the more modern multi-cpu systems.
(in later versions of DFM5 the high cpu alarm is actually disabled by default because of this)
As said above, the "avg" counter on sysstat -m output is a better indicator as thats the average of all the cores. Unfortunately DFM does not "understand" this counter.