Re: [Qemu-devel] [PATCH v2] fix unbounded NetQueue

[Stefan Hajnoczi]

On Tue, Feb 05, 2013 at 06:29:09PM +0100, Luigi Rizzo wrote:
> In the current implementation of qemu, running without a network
> backend will cause the queue to grow unbounded when the guest is
> transmitting traffic.
> 
> This patch fixes the problem by implementing bounded size NetQueue,
> used with an arbitrary limit of 10000 packets, and dropping packets
> when the queue is full _and_ the sender does not pass a callback.
> 
> The second condition makes sure that we never drop packets that
> contains a callback (which would be tricky, because the producer
> expects the callback to be run when all previous packets have been
> consumed; so we cannot run it when the packet is dropped).
> 
> If documentation is correct, producers that submit a callback should
> stop sending when their packet is queued, so there is no real risk
> that the queue exceeds the max size by large values.
> 
> Signed-off-by: Luigi Rizzo <address@hidden>

Thanks, applied to the net-next tree:
https://github.com/stefanha/qemu/commits/net-next

This patch will be part of the first net pull request for QEMU 1.5.

Stefan