Re: [PATCH] Deadlock in af_packet/packet_rcv

[Tommy Christensen <tommy.christensen@xxxxxxxxx>]

Olaf Kirch wrote:
> On Tue, Nov 30, 2004 at 12:31:50PM +0100, Tommy Christensen wrote:
>
> > I still don't agree with the conclusion, though. The spin_lock_bh()
> > is changed to a local_bh_disable() and an optional spin_lock().
> > That should not lead to what you are seeing!
>
>
> Well, the code in 2.6.9 has
>
> #define HARD_TX_LOCK(dev, cpu) {                        \
>         if ((dev->features & NETIF_F_LLTX) == 0) {      \
>                 spin_lock(&dev->xmit_lock);             \
>                 dev->xmit_lock_owner = cpu;             \
>         }                                               \
> }
>
> i.e. there's no local_bh_disable at all - adding the local_bh_disable
> was the whole point of my patch. Or did you refer to a different spinlock?

The local_bh_disable() is called earlier in dev_queue_xmit(), and
is held across the whole HARD_TX_LOCK/dev_queue_xmit_nit/
hard_start_xmit/HARD_TX_UNLOCK sequence.

-Tommy