[CentOS-virt] xen_balloon: reserve_additional_memory: add_memory() Errors

Sun Jan 5 17:33:50 UTC 2014
Stefano Stabellini <stefano.stabellini at eu.citrix.com>

On Fri, 3 Jan 2014, Chris Elliott wrote:
> Hi All
> 
> 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.

When you disable dom0 memory ballooning, do you also reboot passing
dom0_mem=something to the Xen command line (for example dom0_mem=4G)?
If you do so, do you still see those errors?


  
> This is because the amount of memory within these two sys files is different:
> 
>  
> 
> /sys/devices/system/xen_memory/xen_memory0/info/current_kb
> 
> /sys/devices/system/xen_memory/xen_memory0/target_kb
> 
>  
> 
> 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!