Re: [LSF/MM/BPF TOPIC] dmabuf backed read/write

Anuj Gupta/Anuj Gupta
2026-02-04T06:07:48Z

On 2/3/2026 11:37 PM, Keith Busch wrote:
> Thanks for submitting the topic. The performance wins look great, but
> I'm a little surpised passthrough didn't show any difference. We're
> still skipping a bit of transformations with the dmabuf compared to not
> having it, so maybe it's just a matter of crafting the right benchmark
> to show the benefit.
>

Those numbers were from a drive that saturates at ~5M IOPS,
sopassthrough didn’t have much headroom. I did a quick run with two such
drives and saw a small improvement (~2–3%): ~5.97 MIOPS -> ~6.13 MIOPS,
but I’ll try tweaking the kernel config a bit to see if there’s more
headroom.

+1 on the topic - I'm interested in attending the discussion and
reviewing/testing v3 when it lands.

Thanks,
Anuj