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Date:   Thu, 6 Apr 2023 07:46:48 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     "Paul E. McKenney" <paulmck@kernel.org>
Cc:     Herbert Xu <herbert@gondor.apana.org.au>,
        Alexander Duyck <alexander.duyck@gmail.com>,
        Heiner Kallweit <hkallweit1@gmail.com>, davem@davemloft.net,
        netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com
Subject: Re: [PATCH net-next 1/3] net: provide macros for commonly copied
 lockless queue stop/wake code
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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 :(