From: Alyssa Ross <hi@alyssa.is>
To: Fernando Fernandez Mancera <fmancera@suse.de>,
"David S. Miller" <davem@davemloft.net>,
David Ahern <dsahern@kernel.org>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Simon Horman <horms@kernel.org>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
"Ricardo B . Marlière" <rbm@suse.com>,
"Krzysztof Kozlowski" <krzk@kernel.org>
Subject: Re: [PATCH v2] ipv6: default IPV6_SIT to m
Date: Mon, 04 May 2026 16:30:51 +0200 [thread overview]
Message-ID: <878q9zdz6s.fsf@alyssa.is> (raw)
In-Reply-To: <5f676587-fcdd-4704-9523-07a7fd98455a@suse.de>
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Fernando Fernandez Mancera <fmancera@suse.de> writes:
> On 5/3/26 9:25 PM, Alyssa Ross wrote:
>> This basically defaulted to m until recently, since IPV6 defaulted to
>> m. Since IPV6 was changed to a boolean with a default of y, IPV6_SIT
>> started defaulting to built-in as well. This results in a surprise
>> sit0 device by default for defconfig (and defconfig-derived config)
>> users at boot. For me, this broke an (admittedly non-robust) script.
>> Preserve the behaviour of most configs by avoiding building this
>> module, that's probably overall seldom used compared to IPv6 as a
>> whole, into the kernel.
>>
>> Fixes: 309b905deee59 ("ipv6: convert CONFIG_IPV6 to built-in only and clean up Kconfigs")
>> Signed-off-by: Alyssa Ross <hi@alyssa.is>
>
> Hi, I am not sure about this. IPV6_SIT was already defaulting to 'y' for
> most distributions (except for ARM). Sure, if you had CONFIG_IPV6=m then
> CONFIG_IPV6_SIT was defaulting to 'm'.
>
> Hm. Maybe we can aim this for net-next tree instead of net? I just don't
> think this is a fix but a change in behavior. FWIW, it makes sense to me
> to have this as a module by default.
>
> Let's see what do others think.
Yes, it appears you're right. I had only tested on ARM. In that case,
perhaps it make sense to instead set this to m in the arm64 defconfig, to
preserve the previous situation, but I can also see the value in
reducing platform discongruity by letting it change to y on arm64 too.
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next prev parent reply other threads:[~2026-05-04 14:30 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-03 19:25 [PATCH v2] ipv6: default IPV6_SIT to m Alyssa Ross
2026-05-04 10:30 ` Fernando Fernandez Mancera
2026-05-04 14:30 ` Alyssa Ross [this message]
2026-05-04 15:01 ` Fernando Fernandez Mancera
2026-05-05 0:09 ` Jakub Kicinski
2026-05-05 20:16 ` Fernando Fernandez Mancera
2026-05-05 20:17 ` Fernando Fernandez Mancera
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