From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-x433.google.com (mail-wr1-x433.google.com [IPv6:2a00:1450:4864:20::433]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 832C93B2A4 for ; Fri, 6 Jul 2018 09:17:55 -0400 (EDT) Received: by mail-wr1-x433.google.com with SMTP id t6-v6so4180504wrn.7 for ; Fri, 06 Jul 2018 06:17:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=heistp.net; s=google; h=from:mime-version:subject:message-id:date:to; bh=3/reazCDHaobkRR/RNa5qRWxRnp9qJlbn+KTXpbky8g=; b=Mv5XE70GjOhss6GHt7Sxd83GNX0kzmfMvFf2AhCn+mscI8G/trXF4m4v6D0SLUSmZb ZERc9zLtxS6QF1GTJcyj9lMpjQAO2zgYA1xIGaXeW4xfSSRkuBOuOdJxCjtlX+imD/OZ TbXowbRyHo0B2yBZ/xbAfl2yEBl7ZA/L/595RXF7N5mW4bwo6WgzUf/LkdtE/cLocgli D7s3N69lIJBrtGoJ32bC4qXXgOG/TQX2E9sVCYljmEumQ2wVjhKLXme+QmNLiAqxdi91 +pHi1V5bR3d6/dESZdYYiEIg/pGiaVF2oLIcmVbT+oR6AY+pNRDijBG3Zfe6KaXD8F3I ORNg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:mime-version:subject:message-id:date:to; bh=3/reazCDHaobkRR/RNa5qRWxRnp9qJlbn+KTXpbky8g=; b=BrM2I5RzsY1BLEqOncrvvuxyZ2zijFBWuh1kNbyI37VPBAW4iPIwc22TM3FkTTS/DU jwWTOtOvRq0mt672kP02q5s2nLV3NjIQFqOjerTGJJQSp0qZZFovpTHFO3rQHK0v/faF xDyW5YUA7gndgJLK0LGFwaGYuRFI4sYZRPF+39ksR9ntP54PjHpaX80Ghqg1qQOTgJny ulzq+cf6C1RxoYpJl7c9VNBF34IqfNOGVmQJrg+xx1Dq/PaN1YEUCJn4fOKCNuhMY8Lw zxyw9hz0KIzGq52QVEV/1J4iGX8FcyDwW57Zj6GbFyrDhW6fWVQGerr5niqLVspGDGkf 70gg== X-Gm-Message-State: APt69E0lIR/ucZydRBFoB/ZW/Y6cTbkzHMbG3Ycb9XNCoQzLh12HwQq3 WenIHw/vuUDpvLaJ82A1Rr9997lY1bI= X-Google-Smtp-Source: AAOMgpdv3RqwsbJiVQOzG0VZel8yMxEhpiNVCSzX4b0j7epBiLCOkh55cU52pZn5CegYRjTxCFvs0A== X-Received: by 2002:adf:b86b:: with SMTP id u40-v6mr7355848wrf.162.1530883074224; Fri, 06 Jul 2018 06:17:54 -0700 (PDT) Received: from tron.luk.heistp.net (h-1169.lbcfree.net. [185.193.85.130]) by smtp.gmail.com with ESMTPSA id c7-v6sm15611073wre.73.2018.07.06.06.17.53 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 06 Jul 2018 06:17:53 -0700 (PDT) From: Pete Heist Content-Type: multipart/mixed; boundary="Apple-Mail=_36198547-BCA7-4FAA-BE4E-6E000CAF1B4F" Mime-Version: 1.0 (Mac OS X Mail 11.4 \(3445.8.2\)) Message-Id: <761C7004-247B-42B4-B56C-2527816826C7@heistp.net> Date: Fri, 6 Jul 2018 15:17:52 +0200 To: cake@lists.bufferbloat.net X-Mailer: Apple Mail (2.3445.8.2) Subject: [Cake] lockup with cake and veth X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 06 Jul 2018 13:17:55 -0000 --Apple-Mail=_36198547-BCA7-4FAA-BE4E-6E000CAF1B4F Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 I don=E2=80=99t know if we want to call this an issue, but... I=E2=80=99m seeing a lockup with cake (and also sfq, but not either = pfifo or fq_codel), when run over veth devices. Two network namespaces = are created, one for client and one for server, each with one veth = device. Netem is added as the root qdisc with a delay of 1ms, and a leaf = qdisc may be added. Lockups occur on my box when the leaf qdisc is = either cake or sfq, and I'm running flent=E2=80=99s tcp_ndown test with = >=3D 4 download streams. Note that I happen to be running on a = quad-core. - If no leaf qdisc is added below netem, no lockup occurs. - If either pfifo or fq_codel is added below netem, no lockup occurs. - If either cake or sfq is the leaf, the lockup occurs. The symptoms (lockup with >=3D 4 streams on a quad-core box), and the = fact that it occurs with both cake and sfq, make me think that it may = simply have to do with the code not being re-entrant, which may be the = case for veth, and this is just by design? maybe something that we = should consider fixing but wouldn=E2=80=99t be a show-stopper? But that = should be confirmed. I=E2=80=99ll keep investigating, but am sharing the scripts I=E2=80=99m = running meanwhile in case anyone else wants to look. See README.txt in = the attached... Pete --Apple-Mail=_36198547-BCA7-4FAA-BE4E-6E000CAF1B4F Content-Disposition: attachment; filename=veth_cake.tgz Content-Type: application/octet-stream; x-unix-mode=0644; name="veth_cake.tgz" Content-Transfer-Encoding: base64 H4sIACtrP1sAA+1YX0/bSBDP6+2nmJqqAh1O7MRJaE5URyFXIQHlgN49XE/Rxl43Fs7aeO1Avv3N rv/ETgy5B0qF6lGLk9nZ2dkZz29msmDxbGLTW9ZpfTcykIb9vnyaw75RfubUMns9czgY9K1er2WY ve6g24L+9zNpRYmIaQTQEktBnbnHH5Pbtv5KaVHEP2Y0coJ73hazZz5jW/x7ppXF3zIsE/lm3+oO WmA8sx219JPHf+dNZ+rxzpSKGSE7XgicxVwAe2A2cPfOBmT5Hr8Fh/n4fwE2vjBGjaTYkBSF5CMK aqQLtZJt+16VIaIFYfYsAO2CzpkIqc3UAouZ09bIj/bla6RV/mMAkvD5k7+1Nf+7vf5gDf+t4WDY 5P9LUCX/j89OJxfjm/H55Ojq0/WhhqlFl2DOhaaWzsZHf0z+PDm9Pj7U5CujkZ11duh6blDDF+5d Dde9m9gBHlKzpBFyffXXY9bIpRpr1tm5Nev81Jp1bsma9SW0ZgeRzosh4MCiKIgIpgvoTPLlpyTE R7RgUYpPOgNNl5RxYZfngCVBbG/0lWsraKOOo6Ath0T1XcIhxMuQgUxRCBlqkUoy/Mxl5eEFfGb6 Ml0lfEYOlHek0klYL4bnR8oI02ib3Tb+6XStOpAuNsU23DmesNWulTlREMQwo9zxGZgjuYnN4W01 rsRz4R/Q3lZdrsGbQ9A0+Pc3iGeMk1/+95khjRiP5XFrKonrbfGKHzzpklKssTLhIatYf+VptFN+ OdrIqYl2VtkqEbRLEaxUPmUHciq22vURzMQ2ItjNI2jXRFBu2vCm/UQEqziRR7Cawlsi+MSZpQhW VW5GcN0rdREsuaTpEDZoVf+jhE9cHz3/7D1Aqf6rWW/tafR6VlH/u31L1n8DHy9b/+Wb/pTctvVX SpX6vwl9+DWra8JnLAQTMdAP7FvEwBkNQ4ay9x6WJzk4+gF1JiKOGJ0L+HAIFrhBBHO2L4vmfAl3 CXV0O4hYTYKqFw90HwELdD1mItYRBhBFYyx768oPzQFiRzjhcmFVpEh46/l+yeQf7dvXQKv8vxof nZyP2/HDs7/mMscHlvVY/68+F/2/mv+tYb+Z/1+ELj7fjAm5SrCtxZRZxjOPfwMqVOFvYw8+vvly ScgpRy9hbnkhi9wexAFgtZB1PeWATNh2IZUmMzYNMhfT9dWGdDHdQK6Pr04vb64JyYfPkSzjQrZY uPU+iG6Bryb9TtouCNidY9RgypTSKUOYYUqj2COyiimblDL8JgqjUYCUi1y2vDKIlH4CG2W/K4ga Qwi5vPr88Wx8Tsjf2NoAQwREmJJZBIh4OF2Ap/o85khXUvAZddFOP7jPOqhdwRhUmxvpr7W5BjwO uWP29kEECIceGgFxRF3XQ4SOg1CgYhmzkArBHPTpKYQRi+Ml2AEXnojxdv4S5IEYXJHBNlAMEER4 ZjAHqRScJJJqqiEiysFL0Mp+0/bhXl5bivJkPsWrB24B0pBXAC8rAgr8SQH+aOGRK1Fdbq+WElko sGOmHHiAS/wbSoXSKDeSVs5Y3nfj65TNVaqM7IPXZu0RaJt1RW0vKoQmvTOjC7Q7kEOQusTKJ1kc ZUELkjiPW9qiYlzVpROBGkkmmU+MclXNmni5G6kQ/6m3YU6FvCp6j0tDAj4iMrF+j9hy1JGfOgX+ 7kCixjudkjOPJw+AMmC137cNfaDTuTOwYMeE6/NLOGFTD30k1w4OdPNXh03fJybsdg3zQDf6ujHc g4eDwQR3fLr40lHaHq2F1f4vz5znxZht/Z857Ob4j3LDpv97Qar+/qsAtYyXdcOwWtUF6Ca8+9DB ua3DE0T9d0WLWDd/pZvsUrf2o2/eUEMNNdRQQw011FBDDTX0c9F/bauoWQAoAAA= --Apple-Mail=_36198547-BCA7-4FAA-BE4E-6E000CAF1B4F--