Re: [PATCH net-next v10 4/5] net: devmem: document NETDEV_A_DMABUF_AUTORELEASE netlink attribute

Jakub Kicinski
2026-01-21T00:36:52Z

On Thu, 15 Jan 2026 21:02:15 -0800 Bobby Eshleman wrote:
> +- Once a system-wide autorelease mode is selected (via the first binding),
> + all subsequent bindings must use the same mode. Attempts to create bindings
> + with a different mode will be rejected with -EBUSY.

Why?

> +- Applications using manual release mode (autorelease=0) must ensure all tokens
> + are returned via SO_DEVMEM_DONTNEED before socket close to avoid resource
> + leaks during the lifetime of the dmabuf binding. Tokens not released before
> + close() will only be freed when all RX queues are unbound AND all sockets
> + that called recvmsg() are closed.

Could you add a short example on how? by calling shutdown()?