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Date: Mon, 14 Oct 2024 17:26:02 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Lorenz Brun <lorenz@monogon.tech>
Cc: "David S. Miller" <davem@davemloft.net>, Eric Dumazet
 <edumazet@google.com>, Paolo Abeni <pabeni@redhat.com>,
 netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH RESEND] net: add config option for tunnel fallback devs
Message-ID: <20241014172602.7c55a4d4@kernel.org>
In-Reply-To: <20241009110421.41187-1-lorenz@monogon.tech>
References: <20241009110421.41187-1-lorenz@monogon.tech>
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On Wed,  9 Oct 2024 13:04:19 +0200 Lorenz Brun wrote:
> This adds a Kconfig option to set the default behavior regarding tunnel
> fallback devices.
> For setups where the initial namespace should also not have these, the
> only preexisting option is to use a kernel command line option which
> needs to be passed to every kernel invocation, which can be inconvenient
> in certain setups.
> If a kernel is built for a specific environment this knob allows
> disabling the compatibility behavior outright, without requiring any
> additional actions.

I don't hate the idea, but could you comment a bit more on practical
usability of such a change? Whatever software depends on the new
behavior will likely not work with distro kernels, right?

Did you consider kernel boot param?