Re: [patch 10/10] forcedeth: work around NULL skb dereference crash

Ingo Molnar
2007-04-03T06:26:50Z

* Ayaz Abdulla <AAbdulla@nvidia.com> wrote:

> I had responded eariler to the thread asking you to try out the patch
> found in bug 8058:
> http://bugzilla.kernel.org/show_bug.cgi?id=8058
>
> I believe that is the caush of the NULL skb dereference issue.

there's a different type of regression now: under high load i dont get a
crash, i get a hung interface instead. No error packets or other weird
interface state - just a hung interface. The condition happens after a
stream of:

eth1: too many iterations (6) in nv_nic_irq.
eth1: too many iterations (6) in nv_nic_irq.
eth1: too many iterations (6) in nv_nic_irq.
eth1: too many iterations (6) in nv_nic_irq.
eth1: too many iterations (6) in nv_nic_irq.

If i increase max_interrupt_work from 5 to 50 to paper over this
condition then the hangs go away. So i suspect there might still be a
queue-wakeup problem in one of these paths - or that a filled up tx ring
somehow gets stuck. (and i've got commits 3ba4d093fe8a26f and
fcc5f2665c81e08, so all the latest stuff that is upstream at the moment)

Ingo