Back in August there was a report of these errors popping up in dmesg, and as far as I can tell it’s still unresolved even in the latest kernel.
System RAM resource [mem 0xc8000000-0xcfffffff] cannot be added xen_balloon: reserve_additional_memory: add_memory() failed: -17
On this example its running 3.10.20-11.el6.CentOS.alt.x86_64
To replicate this just disable Dom0 memory ballooning in /etc/xen/xend-config.sxp and these errors will over time completely fill up dmesg.
This is because the amount of memory within these two sys files is different:
We can manually edit to work around the problem and stop the error but its not ideal, I would help with making a patch but don’t really know where to start!