[PATCH 0/12] virtio_net perf patches

[Mark McLoughlin <markmc@redhat.com>]

Hi Avi,
        Here's the set of patches that I think make sense to apply.

        I've left out Anthony's zero-copy patch since I wasn't seeing
a measurable difference with it, it's quite invasive and isn't safe
with the "drop the global mutex during tapfd read()" patch.

        I left that mutex patch 'til last since you may still be
nervous about concurrency issues and also the posix-timers kernel race
that it triggers.

        Another change since the first round of patches is that it
took a bit of ugly hackery to handle the case where IFF_VNET_HDR
is supported and we're using e.g. e1000. Since it's difficult to
only enable IFF_VNET_HDR when we're using virtio_net_hdr, I went with
this approach.

        Lastly, I need to add a "vnet_hdr=on" param to "-net tap" so
that we can know if the supplied tap fd has IFF_VNET_HDR enabled.
There's no interface to query that on the fd right now, and even if
I did cook up a patch it probably wouldn't make 2.6.27.

Cheers,
Mark.