Re: [rcf/patch] netpoll: Make it RT friendly

From: Mike Galbraith
Date: Wed Dec 15 2021 - 14:54:57 EST


On Wed, 2021-12-15 at 17:06 +0100, Sebastian Andrzej Siewior wrote:
>
> What is the context for netpoll_send_skb()? Why do we need to disable BH
> + RCU on RT?

Because rcu_dereference_bh() says it better be, but..

> If interrupts are never disabled, doesn't this break the assumption made
> in netpoll_tx_running()?
>
> queue_process() is also busted.

..that makes it kinda moot, and wasn't unexpected. It works, or at
least netconsole does, and lockdep was fine with it, but I figured it
unlikely to fly. In fact, I had already taken the silence as a "Surely
you jest" or such.

-Mike