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Re: serious netpoll bug w/NAPI

To: Matt Mackall <mpm@xxxxxxxxxxx>
Subject: Re: serious netpoll bug w/NAPI
From: "David S. Miller" <davem@xxxxxxxxxxxxx>
Date: Wed, 16 Feb 2005 15:54:07 -0800
Cc: jmoyer@xxxxxxxxxx, netdev@xxxxxxxxxxx
In-reply-to: <20050216234406.GA3120@xxxxxxxxx>
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On Wed, 16 Feb 2005 15:44:06 -0800
Matt Mackall <mpm@xxxxxxxxxxx> wrote:

> Ok. We've got a few cases:
> 
> 1) recursion on cpu1

If you hit this case, and therefore can't re-enter into ->poll(),
you must drop the packet or so something else if netif_queue_stopped()
since netpoll has no means by which to cause the TX queue to make
forward progress.

Do you at least agree with this?

Perhaps you can create a "pending netpoll() packet" queue so that
you don't have to drop the SKB in this case.  Make the queue get
processed via softint processing.  I think this will work.

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