[PATCH] ibm_newemac: Fixes memory leak in ibm_newemac ethernet driver

[SathyaNarayanan]

On Wed, Jul 2, 2008 at 11:16 AM, Benjamin Herrenschmidt <
benh at kernel.crashing.org> wrote:

>
> >
> > Actually the meachanism of stopping the queue and starting it is
> > already there.  But even then due to some sync issue between the poll
> > routine and xmit, we were resulted in using the slots of skb which was
> > not actually got freed before.
> > I agree this could a bug , Since its not is not clear why buffers are
> > not getting transferred timely?. But to handle this we should have a
> > work around otherwise system may go out of memory. If we go for
> > stopping the queue in these scenario also ( Where a unfreed skbs slot
> > has been assigned  to another ), Then kernel may call tx timeout, And
> > reset the driver. In that case handelling this special case here could
> > lead us better performance as compared to stopping the queue
> > Let me know your comments.
>
> Well, if we have a bug, we need to fix it. ie, understand how it is that
> the existing mechanism to stop the queue doesn't work, and prevent xmit
> from overwriting a non-clear transmit slot (possibly displaying an error
> to help us track down the bug).
>
> I'll have to dig a bit, I'll see if I can find some time tomorrow.


The reason could be sync issue between poll and xmit. I would like to have
one clarification , Why in the present design no locks has been implemented
to protect the queue from simulatenous access ??

>
>
> Cheers,
> Ben.
>
>
>
>
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