Re: [PATCH net-next v19 00/13] Device Memory TCP

On Tue, 13 Aug 2024 21:13:02 +0000 Mina Almasry wrote:

v18 got a thorough review (thanks!), and this iteration addresses the feedback.

Major changes:

• Prevent deactivating mp bound queues.
• Prevent installing xdp on mp bound netdevs, or installing mps on xdp installed netdevs.
• Fix corner cases in netlink API vis-a-vis missing attributes.
• Iron out the unreadable netmem driver support story. To be honest, the conversation with Jakub & Pavel got a bit confusing for me. I've implemented an approach in this set that makes sense to me, and AFAICT, addresses the requirements. It may be good as-is, or it may be a conversation starter/continuer. To be honest IMO there are many ways to skin this cat and I don't see an extremely strong reason to go for one approach over another. Here is one approach you may like.
• Don't reset niov dma_addr on allocation & free.
• Add some tests to the selftest that catches some of the issues around missing netlink attributes or deactivating mp-bound queues.

Something is going awry in two existing test:

https://netdev.bots.linux.dev/contest.html?branch=net-next-2024-08-14--15-00...

Example:

https://netdev-3.bots.linux.dev/vmksft-net-drv/results/727462/2-queues-py/st...

I'll take a closer look at the code in the evening, but gotta discard if from pw already..