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

From: Benjamin Herrenschmidt <[email-masked]>
Date: Wed, 02 Jul 2008 15:46:00 +1000

> 
> 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.

Cheers,
Ben.