On 3.10 kernel (R80.40) UMFW is enabled by default.
I can confirm similar behavior on some firewalls. What surprises me is that the basic process is already producing about 10%-20% CPU load (without firewall traffic).
In UMFW the fw instances are threads of the fwk0_dev_0 so by default the top shows all the threads cpu utilization under the main thread. Top has the option to present the utilization per thread as well.
A small calculation sample for the utilization of process fwk0_dev_0:
fwk0_dev_0 = ∑ fwk0_x + ∑ fwk0_dev_x + fwk0_kissd + fwk0_hp
Thread from process fwk0_dev_0:
- fwk0_X -> fw instance thread that takes care for the packet processing
- fwk0_dev_X -> the thread that takes care for communication between fw instances and other CP daemons
- fwk0_kissd -> legacy Kernel Infrastructure (obsolete)
- fwk0_hp -> (high priority) cluster thread
More read here:
R80.x - Performance Tuning Tip – User Mode Firewall vs. Kernel Mode Firewall
➜ CCSM Elite, CCME, CCTE