Subject: Re: [PATCH net-next 1/3] net: provide macros for commonly copied lockless queue stop/wake code

From: Jakub Kicinski <[email-masked]>
Date: Thu, 6 Apr 2023 07:46:48 -0700

On Thu, 6 Apr 2023 07:17:09 -0700 Paul E. McKenney wrote:
> > > Mightn't preemption or interrupts cause further issues?  Or are preemption
> > > and/or interrupts disabled across the relevant sections of code?  
> > 
> > The code in question is supposed to run in softirq context.  So
> > both interrupts and preemption should be disabled.  
> 
> Agreed, preemption will be enabled in softirq, but interrupts can still
> happen, correct?

Starting the queue only happens from softirq (I hope) and stopping 
can happen from any context. So we're risking false-starts again.
I think this puts to bed any hope of making this code safe against
false-starts with just barriers :(