Messages in this thread | | | Date | Wed, 23 Dec 2009 09:03:56 -0600 | From | Anthony Liguori <> | Subject | Re: [GIT PULL] AlacrityVM guest drivers for 2.6.33 |
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On 12/23/2009 06:14 AM, Andi Kleen wrote: >> http://www.redhat.com/f/pdf/summit/cwright_11_open_source_virt.pdf >> >> See slide 32. This is without vhost-net. > > Thanks. Do you also have latency numbers?
They'll be along the lines of the vbus numbers.
But I caution people from relying too much on just netperf TCP_RR and TCP_STREAM numbers. There's a lot of heuristics in play in getting this sort of numbers. They really aren't good ways to compare different drivers.
A better thing to do is look more deeply at the architectures and consider things like the amount of copying imposed, the cost of processing an exit, and the mechanisms for batching packet transmissions.
The real argument that vbus needs to make IMHO is not "look how much better my netperf TCP_STREAM results are" but "we can eliminate N copies from the transmit path and virtio-net cannot" or "we require N exits to handle a submission and virtio-net requires N+M".
It's too easy to tweak for benchmarks.
Regards,
Anthony Liguori
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