Memory leaks with GRE Tunnels

Deepinder Singh
2002-01-31T18:33:50Z

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