From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.yourmailgateway.de (relay.yourmailgateway.de [194.59.206.189]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 73D0839A4D6 for ; Wed, 3 Jun 2026 07:18:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=194.59.206.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780471104; cv=none; b=IiykWsvRLChcHgmAJO4y2mlO6iKgMo0YvNVCeIeq6bWP4DHKDg9ypgRylKZV/n3PJkWuj/DodpifKOPEtNwzH9dl1QPTiqYpNdz3wEySpFJi9i4HSPMILTYKbn0iW3dDy7HkPyI9wfCilUSxVMQMgSFgOIRlWecBWA3SsC13tOY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780471104; c=relaxed/simple; bh=6AZli0waDkqPPv4RYfw4UTCBZr6umj22h0dhXR1Jr4Y=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=M4P4LYaFwPgMKFmUBCD9FCeCy7OuNfPYklExcWFewMEDGWBYXormECXzBdAZDK4kPT7S06qz0IrqvQnEKK8fI3BiZNrZ1DRUqI6OdGs1rpiFhAuRld1RdIvr//6H5kzmoNccwUkw7TxF7NvVP6EyWvhSkblmMyHZYMVNPuTaUkw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=leemhuis.info; spf=pass smtp.mailfrom=leemhuis.info; dkim=pass (2048-bit key) header.d=leemhuis.info header.i=@leemhuis.info header.b=PZo8u9ES; arc=none smtp.client-ip=194.59.206.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=leemhuis.info Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=leemhuis.info Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=leemhuis.info header.i=@leemhuis.info header.b="PZo8u9ES" Received: from relay02-mors.netcup.net (localhost [127.0.0.1]) by relay02-mors.netcup.net (Postfix) with ESMTPS id 4gVfDK1zM1z44TC; Wed, 3 Jun 2026 09:17:53 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=leemhuis.info; s=key2; t=1780471073; bh=6AZli0waDkqPPv4RYfw4UTCBZr6umj22h0dhXR1Jr4Y=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=PZo8u9ES/eDEnOLUv4zPK5PT0RYgcx0DzP3CNid17so5QbcNr4mNP3zXV7GzevQph jVeen7yRdabS2ngfW2VxsarG4/o4Uqu+NFfdRrUz685pLJLrlDhsZHajvG1pT9ONwL F14AMkiodK4oLDhlXLdPdowPukLu3HYDYzTvFUEvTfMyrERizr8mBWVR5igbwVKzMi tiQeFAqy82C7jKLXGFEiMG8aR2mvOAVJNuCm4xCPSpBeC3CzG+FHBjCqtYU5qG01yG fWCEwji0RQk7SGUGK+46P7BXUzjROEIkYn+O3G+FTw4sqpFvLQyNtSwiaFhJCSC40g 1+Zwi6fLifhbg== Received: from policy02-mors.netcup.net (unknown [46.38.225.35]) by relay02-mors.netcup.net (Postfix) with ESMTPS id 4gVfDK1FmZz7x8R; Wed, 3 Jun 2026 09:17:53 +0200 (CEST) Received: from mxe9fb.netcup.net (unknown [10.243.12.53]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by policy02-mors.netcup.net (Postfix) with ESMTPS id 4gVfDF24yqz8sb8; Wed, 3 Jun 2026 09:17:49 +0200 (CEST) Received: from [IPV6:2a02:8108:8984:1d00:a0cf:1912:4be:477f] (unknown [IPv6:2a02:8108:8984:1d00:a0cf:1912:4be:477f]) by mxe9fb.netcup.net (Postfix) with ESMTPSA id E18645F96B; Wed, 3 Jun 2026 09:17:47 +0200 (CEST) Authentication-Results: mxe9fb; spf=pass (sender IP is 2a02:8108:8984:1d00:a0cf:1912:4be:477f) smtp.mailfrom=regressions@leemhuis.info smtp.helo=[IPV6:2a02:8108:8984:1d00:a0cf:1912:4be:477f] Received-SPF: pass (mxe9fb: connection is authenticated) Message-ID: Date: Wed, 3 Jun 2026 09:17:46 +0200 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net v2] Revert "ipv6: preserve insertion order for same-scope addresses" To: =?UTF-8?B?w43DsWlnbyBIdWd1ZXQ=?= , Matthieu Baerts Cc: Stefano Brivio , Fernando Fernandez Mancera , netdev@vger.kernel.org, yuhuang@redhat.com, justin.iurman@gmail.com, horms@kernel.org, pabeni@redhat.com, kuba@kernel.org, edumazet@google.com, davem@davemloft.net, idosch@nvidia.com, dsahern@kernel.org, Chris Adams , David Gibson , Beniamino Galvani , Andrew Lunn , regressions@lists.linux.dev References: <20260529112357.5079-1-fmancera@suse.de> <20260529134045.56330243@elisabeth> <5079261a-79e5-421b-bf6a-a511acaaeca4@kernel.org> <20260601153525.546746a8@elisabeth> <8e9cbf0a-caff-4575-afb7-fe852df8a51a@kernel.org> From: Thorsten Leemhuis Content-Language: de-DE, en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-PPP-Message-ID: <178047106860.2884229.11167975002197488257@mxe9fb.netcup.net> X-NC-CID: oXfrpjjwOSKR5sEbKrJBTtL/u+qg0NyG0cVHx0QSERX9DU+6VGE= On 6/3/26 08:53, Íñigo Huguet wrote: > Stating that the order is "random" implies that someone will change > the default insertion order in the future, as the documentation says > that it's not UAPI. So they'll cause the UAPI breakage that we are > trying to avoid now. Moreover, if we consider the default order > "random" and state that userspace programs must not rely on it, why > can't we change it now? Because the UAPI is only indirectly important, as it's "something that used to work doesn't anymore" is what matters; you in fact can break the UAPI all you want, as long as everything continues to work. Or to quote Linus from: https://www.kernel.org/doc/html/latest/process/handling-regressions.html#on-what-qualifies-as-userspace-interface-abi-api-documented-interfaces-etc "I just wanted to point out that the argument about whether it's an ABI change or not is irrelevant. If it turns out that some program - not a test script, but something with relevance to conscious user expectations ~ depended on the old broken behavior, then it needs to be done some other way."" Yes, he talks about ABIs here, but it's the same for APIs. Ciao, Thorsten