Re: [RFC][PATCH 2/9] deadlock prevention core

Peter Zijlstra
2006-08-09T16:19:54Z

On Wed, 2006-08-09 at 18:18 +0200, Thomas Graf wrote:
> * Peter Zijlstra <a.p.zijlstra@chello.nl> 2006-08-09 16:07
> > I think Daniel was thinking of adding struct net_device *
> > sk_buff::alloc_dev,
> > I know I was after reading the first few mails. However if adding a
> > field
> > there is strict no-no....
> >
> > /me takes a look at struct sk_buff
> >
> > Hmm, what does sk_buff::input_dev do? That seems to store the initial
> > device?
>
> No, skb->input_dev is used when redirecting packets around in the
> stack and may change. Even if it would keep its value the reference
> to the netdevice is not valid anymore when you free the skb as the
> skb was queued and the refcnt acquired in __netifx_rx_schedule()
> has been released again thus making it possible for the netdevice
> to disappear.

Bah, tricky stuff that.

disregards this part from -v2 then :-(