Re: [PATCH net] netpoll: run NAPI poll in softirq context to avoid rq->lock self-deadlock

[Sebastian Andrzej Siewior]

On 2026-06-16 08:11:28 [-0700], Jakub Kicinski wrote:
> > 
> > Adding sched and printk folks for opinions while eyeballing
> > WARN_ON_DEFERRED().
> 
> Thanks a lot for looking into this! To be clear - the printk_deferred /
> WARN_DEFERRED would be just for stable? Or there's still some
> sensitivity even with nbcon?

We already have printk_deferred(). WARN_DEFERRED() would be new. I
*think* this is not limited netpoll/ netconsole but all console drivers
not using CON_NBCON if the printk (via WARN) occurs with the rq held.
I don't remember all the details but printk_deferred() was introduced to
circumvent this until printk is fixed.

Once we get rid of those legacy drivers and NBCON is the default we can
get rid of printk_deferred() :)

Sebastian