From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH take 2] pkt_sched: Fix qdisc_watchdog() vs.
 dev_deactivate() race
Date: Thu, 11 Sep 2008 04:47:17 -0700 (PDT)
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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:
> > 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.