Openvpn tap uses 99% cpu time

[Bruce M. Simpson]

Emile Coetzee wrote:
> Okay I finally have a ktrace of the offending process. You can view it here:
> http://www.clarotech.co.za/dump/openvpn2.txt
>   
Thanks for this. If this is the correct trace, of the correct process, 
then it looks like OpenVPN is hanging immediately on opening the tap device.

In a quick look at the code, nothing jumps out at me which is out of the 
ordinary about the locking during clone and open. It would have been 
useful to have the ps output to correlate with in case the process was 
spinning trying to acquire a spin lock, which would show up in the WCHAN 
field.

One thing that does jump out at me is the use of the persist-tun 
keyword. Can you try removing the use of this keyword? It is something 
I've never had to use with OpenVPN.

To the best of my knowledge there have been no other reports of this 
problem on FreeBSD. I'm sorry there is just very little hard information 
to go on here at the moment.