Benjamin LaHaise [off-list ref] writes:

On Mon, Aug 09, 2010 at 12:59:14PM -0700, Eric W. Biederman wrote:

quoted

The network device deletion batching code has gone in, which is
a big help, as have some dev_put deletions, so we hit that 250ms
delay less often.  

I'll see how much that helps.  Odds are I'm going to have to move the 
device deletion into a separate thread.  That should give me a natural 
boundary to queue up deletions at, which should fix the tunnel-flap and 
partial tunnel-flap cases I'm worried about.  At some point I have to 
figure out how to get my API needs met by the in-kernel L2TP code, but 
that's a worry for another day.

In case it is useful, if you delete a network namespace in general
all of the network device deletions can be batched.  

Eric