Memory leaks with GRE Tunnels

["Deepinder Singh" <dsingh@somanetworks.com>]

Hi ,

I have been doing some testing using GRE tunnels in Linux ( which btw 
work great ). I found that creating and deleting a tunnel results in a 
memory leak.

To test it out I wrote a small script that basically loops around 
creating and then deleting 8000 tunnel interfaces at a time. On the 
eighth iteration  the system hangs a whole with no error messages. There 
  was still enoungh virtual memory around even with the leaks so I 
figured something else is wrong. It turns out that the interface numbers 
( as seen in ' ip link ls' )  do not seem to be reused when an interface 
is deleted and as such the system hangs when the number reaches 64K.

I suspect the two issues are realted but am more of a cisco guy and know 
kernel internals. The total mem leak for the 64 K tunnels is about 200 megs.

Please cc me if you reply to this post as I am not on the list.

thanks,
Deepinder Singh
Sr. Network Eng.
Soma Networks