From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf1-x130.google.com (mail-lf1-x130.google.com [IPv6:2a00:1450:4864:20::130]) (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 3CA2D3CB37; Mon, 10 Apr 2023 22:41:11 -0400 (EDT) Received: by mail-lf1-x130.google.com with SMTP id r27so8669478lfe.0; Mon, 10 Apr 2023 19:41:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1681180870; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=TBnncm4NFHFUmxA8RTmMv5lXBM+JKuprKxg0rIC4/wU=; b=EiBsFxPIeBdKxmhprblP/u3WlsaLNiWVoSkMprNX++7yrvAc0qzu0Ou0sjZx8Cd85o flcMPutg0Xi/KoJ8GLss/Cnc3ShALmrMCOtl8F+1telfM+EuUyqCy6gVGiDpadOt4Ob6 RJnjCIeUGNVxGC1qS2kRs9dPwfV9QQtWPOolzDZbLqc7NcR5fzaG5NVZRZHCixAMuk7m D0G9+LHnhAOawK33henmKvwEeTCuaFiHF/4lX0pSJK9NrJui55TFXw3888BwBn4AaJGO 3kJcGkGABR846ZRH7gqF+Xp/jfS7i559fXlXvoHfHG8R2mtmE3z+frR6KajG3MEmmEM9 XCbQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681180870; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=TBnncm4NFHFUmxA8RTmMv5lXBM+JKuprKxg0rIC4/wU=; b=EkZwxevk+XtzShWQuLORZFjZEJvO0htmhKzfNZHvKad1r2kKnurCy//LVjT5JDlx01 JzmX77AXtF3T4rsByrilytlHxQuOwumJUFaCMK+KiWoT6Eu59BS1jjVDsYMUK2VS+W+p Utq0XBmtQ5UohJVOmQZ2Rf4lblyzhEnE2FyYM8aASZI3y+nj3f/iE8tcXJ1vgZEiqga7 6qd9PaSrmcZJHcXAWozu7UqjhYoVdQ9oZRAqkpMkc4xd4WgwQUELdZb8BtqqLk4lp0np +di4j6V3kmQ6CZdSEA4fSSSA/SMdYAT4iU5QkFHedqyBhFJbpLFbMcvn4T1a6qtFKrdb 0r9A== X-Gm-Message-State: AAQBX9eb3Nnn85JGC9dpsVT8ENruOv8E21pN3GQeKJWV0w+kNcmpNHA3 FYoxh7SNFSq+n0210ubjigA= X-Google-Smtp-Source: AKy350aUn3wrc5xx+HuwsijFa6GCiMl2BYTuPKnpx3/xrDe91O9jqAvIQQV2uQHTTz3aeQvnweHkhw== X-Received: by 2002:ac2:59ca:0:b0:4ec:8c1e:c816 with SMTP id x10-20020ac259ca000000b004ec8c1ec816mr1090204lfn.34.1681180869649; Mon, 10 Apr 2023 19:41:09 -0700 (PDT) Received: from smtpclient.apple (37-219-190-117.nat.bb.dnainternet.fi. [37.219.190.117]) by smtp.gmail.com with ESMTPSA id n25-20020a195519000000b004eb51cfb147sm2331197lfe.115.2023.04.10.19.41.08 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 10 Apr 2023 19:41:09 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.100.0.2.22\)) From: Jonathan Morton In-Reply-To: Date: Tue, 11 Apr 2023 05:41:07 +0300 Cc: bloat , codel@lists.bufferbloat.net Content-Transfer-Encoding: quoted-printable Message-Id: <541FD0C8-4BAF-47D1-93F8-7C5A879ADF23@gmail.com> References: To: Dave Taht X-Mailer: Apple Mail (2.3654.100.0.2.22) Subject: Re: [Bloat] =?utf-8?q?=5BCodel=5D_ACM_queue_article_on_facebook=C2=B4?= =?utf-8?q?s_=22Adaptive_LIFO=22_and_codel?= X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 Apr 2023 02:41:11 -0000 > On 11 Apr, 2023, at 5:12 am, Dave Taht wrote: >=20 > I have no idea what an "adaptive LIFO" is, but the acm queue paper > here just takes the defaults from codel... >=20 > https://twitter.com/teivah/status/1645362443986640896 They're applying it to a server request queue, not a network packet = queue. I can see the logic of it in that context, but I would also note = that LIFO breaks one of Codel's core assumptions, which is that the = maximum delay of the queue it's controlling can be inferred from the = delay experienced by the most recently dequeued item. Maybe it still happens to work by accident, or maybe they've implemented = some specific workaround, but that paper is a very high-level overview = (of more than one technology, to boot) without much technical detail. = If I didn't already know a great deal about Codel from the coal face, I = wouldn't even know to consider such a failure mode, let alone be able to = infer what they could do to mitigate it. - Jonathan Morton=