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

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Message-ID: <42ff951039f3c92def8490d3842e3f7eaf6900ff.camel@gmx.de>
Date:   Fri, 16 Oct 2020 19:11:22 +0200
From:   Mike Galbraith <efault@....de>
To:     Vladimir Oltean <olteanv@...il.com>,
        Heiner Kallweit <hkallweit1@...il.com>
Cc:     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, 2020-10-16 at 17:26 +0300, Vladimir Oltean wrote:
> 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.

Yeah, it's a straight up correctness issue as it sits.  There is a
dinky bit of overhead added to the general case when using the correct
function though, at least on x86.  I personally don't see why we should
care deeply enough to want to add more code to avoid it given there are
about a zillions places where we do the same for the same reason, but
that's a maintainer call.

	-Mike