Re: [PATCH net-next v10 4/5] net: devmem: document NETDEV_A_DMABUF_AUTORELEASE netlink attribute
From: Jakub Kicinski <kuba@kernel.org>
Date: 2026-01-21 00:36:52
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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()?