@robocide
Did you try the solutions mentioned in this thread?
I played around with unbound's ip ratelimit settings.
With a limit of 20-25 requests per second, the log showed requests from 127.0.0.1 (openwrt itself) got throttled, doing reverse dns lookups.
For example:
unbound: [31868:0] notice: ip_ratelimit exceeded 127.0.0.1 20 12.0.0.10.in-addr.arpa. IN PTR
unbound: [31868:0] notice: ip_ratelimit exceeded 127.0.0.1 20 12.0.0.10.in-addr.arpa. IN PTR
unbound: [31868:0] notice: ip_ratelimit exceeded 127.0.0.1 20 12.0.0.10.in-addr.arpa. IN PTR
I don't know if this is intended behavior to do 20-25+ reverse dns lookups for the same hosts.
So every time the status page is refreshed these reverse dns lookups do happen.
And I guess if one has a lot of hosts and/or dnsmasq with a large adblock list in place things are slowing down?