From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f45.google.com (mail-wr1-f45.google.com [209.85.221.45]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BC5D9438FFA for ; Thu, 30 Apr 2026 15:44:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.45 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777563900; cv=none; b=ht5SwvyuJ9b5zctYZHSy+a9vPyejbAEPzbQqaMW3BHs+2HwBFjpH9qPdaP2uK9SnYiBKTI/QlWBWiaVNhqmlALlnwtS+B3dTXFE5rTpEELughCDfT5PBjbuBcOPNgIEQp2JvH5K+ur5sNY/1aSXoRz1pS9YbVtrDPVo9rhA1Yno= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777563900; c=relaxed/simple; bh=RUE0wRnDSulogZaSv/Phdq6tG4EVlY/e2/sK/FRA2lg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=K+5ko7KOjT7X2k7b7BmMnAefHsnqfUVVTNVvJRCqh9A8Mh5x/VWhZU/B4I4e9HJ2CG1ID5OHBls68IGNNG5oKNge3Gzs50EcQu9Nl0y4OTm/0a/v4EBp86TjS+0Tc+BmXuN797u1Wrd7sFEk5KzdwiQLcbXvVqCbRf/IE1u59v4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=6wind.com; spf=pass smtp.mailfrom=6wind.com; dkim=pass (2048-bit key) header.d=6wind.com header.i=@6wind.com header.b=kIVovgty; arc=none smtp.client-ip=209.85.221.45 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=6wind.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=6wind.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=6wind.com header.i=@6wind.com header.b="kIVovgty" Received: by mail-wr1-f45.google.com with SMTP id ffacd0b85a97d-43d7828221bso53082f8f.3 for ; Thu, 30 Apr 2026 08:44:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=6wind.com; s=google; t=1777563895; x=1778168695; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:organization:content-language :from:references:cc:to:subject:reply-to:user-agent:mime-version:date :message-id:from:to:cc:subject:date:message-id:reply-to; bh=nVdkXGvjipVBSYbCT/dFGYanP9qbDtxjNRTDheTpI08=; b=kIVovgty868XFtEfPeoHV5DB5ZZXqPyEvjft08k376aiPD3ETBi0iiahiRcDAmGjQE 07nsaK+WoWWxpfYJgOUZ2BPC+VlYMk3DLAyrfqeVAqFVWbAKcFadIEDqNTjq8iAO3kl7 6Wb/uKRGSvGzwnTigQRGQ69RO3oeJavhGaTN/wSrW0ic7t8Dd+W+cqVM28+KDqtOTMez Qj1r39hVVgI1wqPz3Gc4a8Ldq8zkUcsx+6fcfg2nZSC0vTWli3r2tD3amDLZ/pUVEczp /qD/5BLRwNAV/dYiec+0oWCNVfnXmGSMQ7V6tM1yIF7mjvBfFWnbJI3MzZ5/AjC4Mp2G duuw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777563895; x=1778168695; h=content-transfer-encoding:in-reply-to:organization:content-language :from:references:cc:to:subject:reply-to:user-agent:mime-version:date :message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=nVdkXGvjipVBSYbCT/dFGYanP9qbDtxjNRTDheTpI08=; b=lm3yQNQf9+Qmfi6a4RDX+2PW5IluJ9mwnc3d+HL+dquKIMumaN85yn2o+DELuIqzwc msEK5d+TXId5lIOXqZwTtwd1JHZQGdt4qNFfX3AA+ijgOD2tDBU9go8SOGOYwpN3Auet XfYkDtTmoOOBbB5dJrgnl/kkTpWitjQGIua5/CZVGvGUFmz0+OxH/Xack6GrtJzJKJ7S EQDModbPd9cetXpxDQs3FQEoLd4IlwIp9aSdg6oIWbS3D3ogC6VWsxbek/wX3jjVlcUc 6wzZ5xcJ04VxRHgBK7096P2d/2/87EwicbnluYN0+5NdIcAgCDj+yv8t/gWkqWxIFz0L ZEVA== X-Forwarded-Encrypted: i=1; AFNElJ+xwTDT1uT9j1aVcVVpvWJJeKXPVhdc66m9kJ4RavCVmFglc+vaIAElDTVFV8cS0XJz5cXuWDc=@vger.kernel.org X-Gm-Message-State: AOJu0YzXoLed3x13D3xqXRco65B7EK9CNWkDz/1kH8/oCXZxLOWfTznU 5oZuTGOFED7jFQbXa+FhAfwEzpVzzALP9XVgO3AodPIP9UnpSEURK8q34bcqY+wE+Bc= X-Gm-Gg: AeBDieuKv7FF9GHFzIvyxFCVS8r2VvO24OxLTzeWcND0QnNoeGwXaeg205IrUkTkx0H V5tAYeJNd33SRgu0k1K710nUOsmSp5iGaATZs2rvcd78ys4rICoc+wOfBfpFrzz6YB8o1qWUsw1 Qa4xjLTfkALYIjmabWbcSjjHS0y+vRMBhlrRt3xv5wkJ1sCGOS6q4iTWbPzJyjDrl/g/P9rsRt6 zw1Fi7wR+WOyBp9mSNCxDF0w9UmXdmhFQ+ilPxL9ml66ApmUFqvTXAIbJ1XkHVAR60wGQJKTWht Y0YtA/yDuWvXBRdHwDxjk2erfCqYARV4sjakgqvBMUY6hsjjqYE5EVZT+tHS/nJWsmXxMXEyplg 7TMVCpja8DzEZdCyTSR+bzqvzuZXcYPdnBJxw+grrpu0br2CXn54VYGNxksYRTF+mTavWap/o8i FaRgzvJcneslRq5AbVch0TQAXtsIUrb1GIzQdK2OS6BfJIhWqVzGEvdawWbrjo9z89RhKisFZRl iCFfG48VzAlNFc= X-Received: by 2002:a05:6000:2995:20b0:43d:1d3a:b60a with SMTP id ffacd0b85a97d-449403aa04bmr1985624f8f.7.1777563894613; Thu, 30 Apr 2026 08:44:54 -0700 (PDT) Received: from ?IPV6:2a01:e0a:b41:c160:6a1d:efff:fe52:1959? ([2a01:e0a:b41:c160:6a1d:efff:fe52:1959]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-449c576d0a2sm3615047f8f.31.2026.04.30.08.44.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 30 Apr 2026 08:44:54 -0700 (PDT) Message-ID: <3f8d63a3-e39e-48f9-a0d0-517be7c05498@6wind.com> Date: Thu, 30 Apr 2026 17:44:53 +0200 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Reply-To: nicolas.dichtel@6wind.com Subject: Re: [RFC PATCH net-next 0/3] netns: optionally inherit IPv4 TCP sysctls from old net To: nmreadelf , davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, corbet@lwn.net, dsahern@kernel.org Cc: horms@kernel.org, chia-yu.chang@nokia-bell-labs.com, idosch@nvidia.com, ij@kernel.org, brauner@kernel.org, jack@suse.cz, kuniyu@google.com, jlayton@kernel.org, netdev@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, lance.yang@linux.dev, leon.hwang@linux.dev References: From: Nicolas Dichtel Content-Language: en-US Organization: 6WIND In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Le 30/04/2026 à 03:30, nmreadelf a écrit : > a new network namespace starts with built-in TCP defaults. > In container-heavy setups, operators often tune TCP sysctls in init_net and then > need to re-apply the same values for each new netns. > > This series adds an opt-in mechanism to initialize per-netns IPv4 TCP sysctl > settings from init_net at netns creation time. > > Behavior: > > Default is unchanged. > When net.ipv4.netns_inherit_tcp_sysctls=1, new netns inherit > TCP sysctl from old_net. There is the same kind of sysctl for net.{ipv4,ipv6}.conf.{all,default}.*: net.core.devconf_inherit_init_net. https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/admin-guide/sysctl/net.rst#n401 I'm not sure if it's acceptable to use this existing entry to control the TCP sysctl. At least, putting the new one in the same place + using the same template for the name + the same values would be nice. Something like net.core.tcp_inherit_init_net. Regards, Nicolas