Re: [PATCH v1 00/15] io_uring zero copy rx

Pedro Tammela
2024-10-09T18:21:59Z

On 09/10/2024 13:55, Mina Almasry wrote:
> [...]
>
> If not, I would like to see a comparison between TCP RX zerocopy and
> this new io-uring zerocopy. For Google for example we use the TCP RX
> zerocopy, I would like to see perf numbers possibly motivating us to
> move to this new thing.
>
> [1] https://lwn.net/Articles/752046/
>

Hi!

From my own testing, the TCP RX Zerocopy is quite heavy on the page
unmapping side. Since the io_uring implementation is expected to be
lighter (see patch 11), I would expect a simple comparison to show
better numbers for io_uring.

To be fair to the existing implementation, it would then be needed to be
paired with some 'real' computation, but that varies a lot. As we
presented in netdevconf this year, HW-GRO eventually was the best option
for us (no app changes, etc...) but still a case by case decision.