Messages in this thread | | | Date | Tue, 22 Dec 2009 10:27:33 -0600 | From | Anthony Liguori <> | Subject | Re: [GIT PULL] AlacrityVM guest drivers for 2.6.33 |
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On 12/22/2009 10:21 AM, Andi Kleen wrote: >> So far, the only actual technical advantage I've seen is that vbus avoids >> EOI exits. >> > The technical advantage is that it's significantly faster today. >
There are two separate pieces of code in question. There are front-end drivers and there are back-end drivers.
Right now, there are only front-end drivers in the kernel today. The combination of vbus front-end drivers and *kernel* back-end drivers are faster than the *combination* of virtio front-end drivers and *userspace* back-end drivers.
vhost-net is our kernel back-end driver. No one has yet established that the combination of virtio front-end driver and kernel back-end driver is really significantly slower than vbus.
> Maybe your proposed alternative is as fast, or maybe it's not. Who knows? > > >> We think we understand why vbus does better than the current userspace >> virtio backend. That's why we're building vhost-net. It's not done yet, >> but our expectation is that it will do just as well if not better. >> > That's the vapourware vs working code disconnect I mentioned. One side has hard > numbers&working code and the other has expectations. I usually find it sad when the > vapourware holds up the working code. >
We're not talking about vaporware. vhost-net exists.
Regards,
Anthony Liguori
> -Andi >
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