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

From: Jakub Kicinski <[email-masked]>
Date: Tue, 20 Jan 2026 16:36:50 -0800

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()?