Re: Memory leaks with GRE Tunnels

Deepinder Singh
2002-01-31T19:41:23Z

Sorry for the oversight - I am running 2.4.16

It probably is realted. Normally a physical interface really never needs
to be deleted so maybe no one is thinking of reusing the freed up
numbers and just grabbing the next unused one ( far less management
issues ) .

-Deepinder

George Bonser wrote:

> I wonder if this also causes a different problem ... when using CIPE
> (which is a tunnel of a different sort) if I stop a tunnel, I can not
> restart it with the same cipe device number. I get a message that the
> device is in use. I have to unload and reload the CIPE module to be
> able to use the device numbers configured in the config file. If I
> increment the device each time (e.g. cipcb0, then cipcb1, cipcb2) I
> restart the tunnel, it works. I wonder if it is something in the way
> Linux handles tunnel interfaces in the generic sense and not just
> limited to GRE.
>
> By the way, this behavior is on 2.2 kernels, I have no CIPE units
> running 2.4 and you did not mention which kernel version you are
> using.
>
>
>
>>-----Original Message-----
>>From: linux-kernel-owner@vger.kernel.org
>>[mailto:linux-kernel-owner@vger.kernel.org]On Behalf Of
>>Deepinder Singh
>>Sent: Thursday, January 31, 2002 10:33 AM
>>To: linux-kernel@vger.kernel.org
>>Subject: Memory leaks with GRE Tunnels
>>
>>
>>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
>>
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