From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Thu, 11 Sep 2008 21:45:02 +1000

On Thu, Sep 11, 2008 at 04:42:55AM -0700, David Miller wrote:

quoted

And we don't have the qdisc lock here, taking it is undesirable,
and if we do take it we have to transfer that lock down into
__qdisc_run() which means adjusting all the other __qdisc_run()
callers.

Last I checked qdisc_run did run under the root lock...

That certainly changes things :)

Ok, so implementing ->peek() is the first step in dealing
with this.