Subject: Re: [PATCH] gianfar: Fix crashes on RX path (Was Re: [Bugme-new] [Bug 19692] New: linux-2.6.36-rc5 crash with gianfar ethernet at full line rate traffic)

From: Jarek Poplawski <[email-masked]>
Date: Fri, 22 Oct 2010 08:52:48 +0000

On Fri, Oct 22, 2010 at 06:52:31AM +0000, Jarek Poplawski wrote:
> On Fri, Oct 22, 2010 at 08:11:57AM +0200, Eric Dumazet wrote:
...
> > Gianfar claims to be multiqueue, but only one cpu can run gfar_poll()
> > and call gfar_clean_tx_ring() / gfar_clean_rx_ring()
> > 
> > If not, there would be more bugs than only rx_recycle thing
> 
> I didn't find what prevents running gfar_poll on many cpus and don't
> claim there is no more bugs around.

On the other hand, I don't see your point in the code below either.
These're only per gfargrp queues - not per device, aren't they?

Jarek P.

> 
> > 
> > vi +2822 drivers/net/gianfar.c
> > 
> >                 for_each_set_bit(i, &gfargrp->rx_bit_map, priv->num_rx_queues) {
> >                         if (test_bit(i, &serviced_queues))
> >                                 continue;
> >                         rx_queue = priv->rx_queue[i];
> >                         tx_queue = priv->tx_queue[rx_queue->qindex];
> > 
> >                         tx_cleaned += gfar_clean_tx_ring(tx_queue);
> >                         rx_cleaned_per_queue = gfar_clean_rx_ring(rx_queue,
> >                                                         budget_per_queue);
> >                         rx_cleaned += rx_cleaned_per_queue;
> >                         if(rx_cleaned_per_queue < budget_per_queue) {
> >                                 left_over_budget = left_over_budget +
> >                                         (budget_per_queue - rx_cleaned_per_queue);
> >                                 set_bit(i, &serviced_queues);
> >                                 num_queues--;
> >                         }
> >                 }
> > 
> >