Re: [PATCH 0/2] Fix BUG: Invalid wait context in hrtimer_interrupt()

[Sergey Senozhatsky]

On (21/01/23 23:37), Qais Yousef wrote:
> 
> I hit a pr_warn() inside hrtimer_interrupt() which lead to a BUG: Invalid wait
> context splat.
> 
> The problem wasn't reproducible but I think the cause is obvious, printk can't
> be called from interrupt context.
> 
> AFAICU printk_deferred() is safe from NMI, so I assumed it is safe to be called
> from hrtimer_interrupt() too. Adding a pr_warn_once() inside
> hrtimer_interrupt() in a location where it is always hit produces the BUG
> splat. Replacing it with pr_warn_deferred_once() generates the printk warning
> without any splat.

Could you please post the lockdep splat?
Why is it invalid? Is this... -rt kernel, perhaps?

	-ss