Re: gso: Attempt to handle mega-GRO packets

Herbert Xu
2013-11-07T01:47:35Z

On Wed, Nov 06, 2013 at 05:03:28PM -0800, Eric Dumazet wrote:
>
> > But once the system has been running for a while, I see nothing
> > in the virtio_net code that tries to prevent fragmentation. Once
> > fragmentation sets in, you'll be back in the terrible situation
> > that we were in prior to the coalesce patch.
>
> There is no fragmentation, since we allocate 32Kb pages.

Say the system is fragmented sufficiently that you'll end up with
0-order pages. In that case you'll only ever be able to coalesce
two packets.

Real systems that run for more than a day do end up with seriously
fragmented memory.

Cheers,
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
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