Re: [PATCH net-next v2 08/15] net: page_pool: add nlspec for basic access to page pools
From: Jakub Kicinski <kuba@kernel.org>
Date: 2023-11-21 20:37:23
On Tue, 21 Nov 2023 13:24:07 -0500 Willem de Bruijn wrote:
Do you want to introduce a separate ID for page pools? That brings some issues regarding network namespace isolation. As a user API, it is also possible (and intuitive?) to refer to a page_pool by (namespacified) ifindex plus netdev_rx_queue index, or napi_id.
That does not work for "destroyed" pools. In general, there is no natural key for a page pool I can think of.
In fairness, napi_id is also global, not per netns. By iterating over "for_each_netdev(net, ..", dump already limits output to pools in the same netns and get only reports pools that match the netns. So it's only a minor matter of visible numbering, and perhaps superfluous new id.
The IDs are not stable. Any reconfiguration of a device will create a new page pool and therefore assign a new ID. So applications can't hold onto the ID long term. That said the only use case for exposing the ID right now is to implement do/GET (since there is no other unique key). And manual debug with drgn, but that doesn't require uAPI. So if you prefer strongly I can drop the ID from the uAPI and do/GET support.