Page allocation fault on CubieTruck acting as IPv6 router

I've set up a HE.net IPv6 tunnel on my CubieTruck, which announces itself in the network as a router for IPv6 network traffic. However, when I transfer data from other computers via the CubieTruck, bandwidth is very bad. rsyslogd causes a very high load on the CubieTruck and transfer rates are only up to several hundred KB/s. However, when I test downloading files from the CubieTruck itself, load doesn't increase and I can use my full line speed of 4 MB/s.

As rsyslogd is the logging daemon, I looked into the syslog and found hundreds of page allocation failures like the one I attached to this post. What's wrong and how can I fix this?