vpnagentd occasionally causes high CPU and IO load, that could be seen in top(1) and iotop(8). The load does not disappear by itself, vpnagentd must be restarted.
Attempts for resolution
I have tried to investigate the cause of the high load with strace and I figured out, that /etc/resolv.conf is somehow involved in the situation. An inotify watch is set on the file, then it is written, and jumping back to the inotify_add_watch system call.
I have also tried to eliminate the load without restarting the vpnagend, because that breaks my workflow. I have changed the /etc/resolv.conf to break the infinite loop in vpnagentd with the following attempts and results:
write a space character at the end of /etc/resolv.conf, sleep 1s and repeat until the load disappears. That might help sporadically.
rename the /etc/resolv.conf file then move it back to the original name. That helps, but after a while the /etc/resolv.conf file changes back to the dhcpcd generated one, so no VPN related name servers are registered.
strace(1) logs are attached.
linux kernel version: 4.19.97-gentoo
NetworkManager is not installed in the system
network autoconfiguration is done with DHCP protocol, dhcpcd client v7.2.3