netdev - Re: [patchlet] r8169: fix napi_schedule_irqoff() called with irqs enabled warning

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Date:   Fri, 16 Oct 2020 17:26:11 +0300
From:   Vladimir Oltean <olteanv@...il.com>
To:     Heiner Kallweit <hkallweit1@...il.com>
Cc:     Mike Galbraith <efault@....de>, netdev <netdev@...r.kernel.org>,
        Realtek linux nic maintainers <nic_swsd@...ltek.com>
Subject: Re: [patchlet] r8169: fix napi_schedule_irqoff() called with irqs
 enabled warning

On Fri, Oct 16, 2020 at 01:34:55PM +0200, Heiner Kallweit wrote:
> I'm aware of the topic, but missing the benefits of the irqoff version
> unconditionally doesn't seem to be the best option.

What are the benefits of the irqoff version? As far as I see it, the
only use case for that function is when the caller has _explicitly_
disabled interrupts.

The plain napi_schedule call will check if irqs are disabled. If they
are, it won't do anything further in that area. There is no performance
impact except for a check.

> Needed is a function that dynamically picks the right version.

So you want to replace a check with another check, am I right? How will
that improve anything performance-wise?