From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=74.125.82.50 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794329364; b=2xiEIX9g4dFKcCWxF9yuA6GM9lBdVZZyztcZ+S/yXrMpbHHkovma2ZKvqeyJFcS9N5mX rb0lTkjYowpmSKATMeBMExs9+k0D7jQ0WwJ+Wp/V3a5nGJ1jOZPe0C+a0atEbSevfLrYq LOCEx0Sa6oOfbDSVhB57j5BqQ/Js3Iu1bFbxLzUBrF0LkMmsWJbr1Mqn2l70HJnneKZz7 fkC358DxV1beLNybGAeh9Lrm3hzACpgK19mctXl7Pu45GYGs6gvHUwREQrwWPH1EvAJmp 2I4B0uZaabBIclFKOb2fpDFesgjykMjlzr/D/M3P//UuJZkg7lovS438v4i0/deNYQQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794329364; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Gm-Gg:X-Received:Received: Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc: Content-Transfer-Encoding:Message-Id:References:To:X-Mailer; bh=nPtrbd2Pn3rK1sw5Bc8c1fg7SY1qBfAR8Azz15uZZXI=; b=Uj5OcajhQTWa0FSfrrwHH+o96MpGPO4gSXj1KEB3EhmSSc//I+0vtgealONyf4aIIi7w et/LOP9q/CQew1Tq3kJv6J0XRjtx1llbW1EqqJBk/kByHAPMNw818MTGIxZbJXB2vet5R JYyZeXG8AtMwLtL1LqrVzr7RLAV9jJwCv2krCgBG3xZYHxnUg3v+Sg6RXFuzDM8Z6Ps6T hSYH7rxdjgPdKFjDgAqgINKkcbJoR78c810fV3aQBMIA4u/7tf2rfdskhZMkfNxsHAa7c bklmqAJGNEe9zDltCPGPQp6Dya6RI7YhPAiuA/iAeyB4e1MGVd18dfcmPP0HR9DjBYw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=POE2dKJi; arc=none smtp.remote-ip=74.125.82.50 Received: from mail-dl1-f50.google.com (mail-dl1-f50.google.com [74.125.82.50]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C72DB606A326 for ; Tue, 10 Nov 2026 16:49:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org C72DB606A326 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=POE2dKJi Received: by mail-dl1-f50.google.com with SMTP id a92af1059eb24-18818daa3e7so659548c88.0 for ; Tue, 10 Nov 2026 08:49:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20260707; t=1794329363; x=1794934163; darn=vger.kernel.org; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:content-type:from:to:cc :subject:date:message-id:reply-to:content-type; bh=nPtrbd2Pn3rK1sw5Bc8c1fg7SY1qBfAR8Azz15uZZXI=; b=POE2dKJio14LyaDVkR+BmbhlmJfL3c+ppSMEYXAn68Zh1qMJQkRRgYrFpfcjoPIdxe LKNTJZ+qLl5KycuQa/KBAa0V7qCYDceZ72rU4/d7aIOqMEqb76zw8F2kBmFjv/dkSrts 8KeVMjltoTlxis9vnEKSzF/mz0U2xBpQzv/CUbpoABR8TmmaIhAtN95GBKAYj0bQ5y4K WTflcwHcbLFOlptFw+pVwlZcd51SidZ/s0KEYDXY1vnyaH6k3oFribB2jbDeLWBn3Dei 8tpKh9Mhgze0pDpKuFNQ/iUQl12ffQjfbg9Z47WfuKSCBcxZHxrCfv+ORkavKx8ydT5n yrSQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1794329363; x=1794934163; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:content-type:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=nPtrbd2Pn3rK1sw5Bc8c1fg7SY1qBfAR8Azz15uZZXI=; b=U8zRVqg+kIE1cYGpwxerb+/qgIBXKLP1gZGd6toou7dNkXPsUDTKa6386ZdOPJBwJ1 AmjXJPufTVSyos9qBzzuHO3X8KROXCMhJ/AdUu48DMpbeW6EYGdknEzlAdHoqtloIUGR HhWnwsNOYqv45VxLEs7xl1sFd2fVgAKaAwecYwBpy4AuLNSKvk0pYTfmTFaPSvfH5t8B H3KqDflxAbSbzCFWzDFsaTXbDgKMDsdUmd0hFSnjvmKKZcS3T80gRujXRrjzIdpEQHtC V5dbNi8X+67wybUkEjZjRPFFMOKIisiUTtKJMUU05/YUIdbbdAwjCEsSXysa1ghKxcs8 Bc5g== X-Forwarded-Encrypted: i=1; AL+hErFLBE1it871Y26CXfMd/YUaDWpEYcSkYy5710LGLTO+58ImDmiQ9azF4DwB5LspeWDAbeAs2SH4vIJqrjs=@vger.kernel.org X-Gm-Message-State: APuU4Z96hoUJnLD24+n9M2OIXUYxjWJ4+pnVFFsHw68+ew2lI+5h8eiQ TwYt5jtNhDVYb/5gjwpbDSkF85Ez+XuQw5/lD4uv+JnWwbmRnnV48j/U X-Gm-Gg: AYBFou3cb+E2F5BPBkU5giwB9lWHrg8uqt1hVov0dfTQRdq40fFLYaFJwfxonGA2xpt Ux4jSSlKR+aQIQs2xK1tMSJh7RgBPVAf6dEc2XHZzZptGt8IJmJ5GJ22ihKiObYnh6IhDoKZg1f NX+lpu3BGv/sRPDyd8TYtVjoqajHZOdE0g8QAevIVSqcMup3wb3c2qLWr9OC4V/s2BFV+W7L1TP kIHRDL/FITWK7AsyqeFAnpSO6BMMzFcTb8Cq7nVtY/Ozrd1MuyZUFigzTUhcqWWnrLrPTVbcyio LGUXm5Ik1TmTuG5uRi7v4rflZEV2oMmg7crhFNqfwGrFPb82l9eplm82fdCr5Vuas1+T3yB5da9 Mk3Dn+3SzfQx1JIk31yoQxVN/UD1yD1wOYhugScVyyzUFqq2HNwrFyj/wz+TNJ4aOvzXmuzMIWf 3ARGt0fcuBylry1FCkhjcn7KwhwVJu/m5WRu+a0iHYHW6B81sU+3XcsoiauO/YDXzaoPoC0zf5M JlX48myrltOz74XZLfnw1hZLh6hy0quvb1jR44PnZ2TMClJk48mdA9Y86RWiSCNGbfJUYOmQxJO cFPVuSWbZxsC5DvS1E1Tn8lKFkXXCgbifM9hty+eD9aWgVH2fYZwDoyVGGf9z9o/O3o= X-Received: by 2002:a05:7022:1586:b0:14e:d0ba:75af with SMTP id a92af1059eb24-1b3bee94f73mr67874c88.6.1794329362760; Tue, 10 Nov 2026 08:49:22 -0800 (PST) Received: from smtpclient.apple (v133-18-180-162.vir.kagoya.net. [133.18.180.162]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-1b3b5ba8426sm7208003c88.23.2026.11.10.08.49.18 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 10 Nov 2026 08:49:22 -0800 (PST) Content-Type: text/plain; charset=us-ascii X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3901.100.1.1.12\)) Subject: Re: [PATCH net-next v3 3/4] selftests/net: packetdrill: add TCP black hole detection test From: Esko Mobius In-Reply-To: Date: Wed, 11 Nov 2026 00:49:06 +0800 Cc: davem@davemloft.net, edumazet@kernel.org, pabeni@redhat.com, shuah@kernel.org, kuniyu@google.com, horms@kernel.org, kuba@kernel.org, netdev@vger.kernel.org, panweiping3@gmail.com, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <18B3E417-AC3D-4A70-88BD-4ADA9003ACAF@gmail.com> References: <20261110-mtu-probing-series-v3-0-dedfab25d641@gmail.com> <20261110-mtu-probing-series-v3-3-dedfab25d641@gmail.com> To: Neal Cardwell X-Mailer: Apple Mail (2.3901.100.1.1.12) > So I'd suggest renaming this case to be something like > tcp_mtu_probing_blackhole_no_tlp_retries1_is_1.pkt. > > Then I'd suggest creating a test like this, but with only the = following setting: > > `./defaults.sh > sysctl -q net.ipv4.tcp_mtu_probing=3D1` Thanks, Neal. That makes sense. I renamed this case and added a test that only sets tcp_mtu_probing=3D1 on top of defaults.sh. With the default settings, the TLP and the first three RTO retransmissions keep the full size. The fourth RTO falls back to tcp_base_mss, about 4.8 seconds after the original transmission. The new test passes in all three IP modes on x86_64 KVM. v4 has both tests. Thanks, Yongjian=