[LSF/MM/BPF ATTEND][LSF/MM/BPF Topic] Non-block IO

[Bart Van Assche]

On 2/10/23 10:00, Kanchan Joshi wrote:
> 3. DMA cost: is high in presence of IOMMU. Keith posted the work[1],
> with block IO path, last year. I imagine plumbing to get a bit simpler
> with passthrough-only support. But what are the other things that must
> be sorted out to have progress on moving DMA cost out of the fast path?

Are performance numbers available?

Isn't IOMMU cost something that has already been solved? From 
https://www.usenix.org/system/files/conference/atc15/atc15-paper-peleg.pdf: 
"Evaluation of our designs under Linux shows that (1)
they achieve 88.5%–100% of the performance obtained
without an IOMMU".

Thanks,

Bart.