From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf1-x12f.google.com (mail-lf1-x12f.google.com [IPv6:2a00:1450:4864:20::12f]) (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 AB8AB3CB37 for ; Thu, 7 Oct 2021 06:29:50 -0400 (EDT) Received: by mail-lf1-x12f.google.com with SMTP id x27so22898929lfa.9 for ; Thu, 07 Oct 2021 03:29:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=CMUgtaaTTZO4hddgOX3V9/mGRWONgodf4UTXdgnaxhw=; b=pX0pH/nJIjarYx16BnI5XfHC8t24suYnMSfdd2uPg8OmJPiyycw8SzsFe0D2omNp32 ui/9yh31AWN35v7zFGzmPOXv7uULelYO2zirM0xMtO8C8C2Ase01jE2fM02oNIDth0mP qg7/od7dKlXWutR3faTLTxb0heAEd4B+dekBVU/UPcCRssm7V33mx8B+rGxgWjjzLEka 7tWPq+lwmUcSVrW1gz+jYxCl5Ns1SOkcLrQc3JTPmQbf0QLGjkVktawuQuxHB/9uUUNn swzSYQhgxNvp0w4KKCgmJoasd8jvUDRtnxNw6TxIQXLbE3Rz45qWgQHKowuE2dl0khDJ k43Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=CMUgtaaTTZO4hddgOX3V9/mGRWONgodf4UTXdgnaxhw=; b=2uSoEipAjdCsE89AA+yzvqNzO/F0FFYLFbZtpfE1RWKj5SXxCJgrsD2npk6pc1Ate3 4Z6TIr0ntzmBsWD47PgTglLZyoxpvIb9LM3u2DwFB1NUbOINqTkBR4rJYU44S7vvBc6V vE3EsIOgVzaL0HRiGGNEWwrPScalqZGooakV7FfFiITvQ5LAj4eN50bwBu+W7us0bNse gxpciZrYfrWrzo1Rn9dHH6hKDrBz1TiTLbO7EWP/fKC/OrH1czcy0ENpEAXO6qB3zsQF KWZECflYdDG1vZYgI1fPuK90pTWeFggIzYYc39bdwZHACwtX4MmUF7d146XANxMVrvHv atLw== X-Gm-Message-State: AOAM53095HL+p8EYk57SVPrvY059Z2rZrIvyfmxnkAsEjvQ1PMA6MKWn Z4KSfa8JwK50uQXrqpj6YGw= X-Google-Smtp-Source: ABdhPJyzBuxYVxM6aDbpDy0gZu2w9Xhh/mCWTXY8qD+Nz8X+W/mZK7IxWszRdyi02g0E1w1rf6UsPQ== X-Received: by 2002:a05:6512:1520:: with SMTP id bq32mr3412748lfb.232.1633602589278; Thu, 07 Oct 2021 03:29:49 -0700 (PDT) Received: from smtpclient.apple (176-93-88-52.bb.dnainternet.fi. [176.93.88.52]) by smtp.gmail.com with ESMTPSA id b23sm303076lfi.12.2021.10.07.03.29.48 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 07 Oct 2021 03:29:48 -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: Thu, 7 Oct 2021 13:29:47 +0300 Cc: Dave Taht , Rpm Content-Transfer-Encoding: quoted-printable Message-Id: References: To: Christoph Paasch X-Mailer: Apple Mail (2.3654.100.0.2.22) Subject: Re: [Rpm] Alternate definitions of "working condition" - unnecessary? X-BeenThere: rpm@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: revolutions per minute - a new metric for measuring responsiveness List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 07 Oct 2021 10:29:50 -0000 > On 7 Oct, 2021, at 3:11 am, Christoph Paasch = wrote: >=20 >>> On 7 Oct, 2021, at 12:22 am, Dave Taht via Rpm = wrote: >>> There are additional cases where, perhaps, the fq component works, = and the aqm doesn't. >>=20 >> Such as Apple's version of FQ-Codel? The source code is public, so = we might as well talk about it. >=20 > Let's not just talk about it, but actually read it ;-) >=20 >> There are two deviations I know about in the AQM portion of that. = First is that they do the marking and/or dropping at the tail of the = queue, not the head. Second is that the marking/dropping frequency is = fixed, instead of increasing during a continuous period of congestion as = real Codel does. >=20 > We don't drop/mark locally generated traffic (which is the use-case we = care abhout). > We signal flow-control straight back to the TCP-stack at which point = the queue > is entirely drained before TCP starts transmitting again. >=20 > So, drop-frequency really doesn't matter because there is no drop. Hmm, that would be more reasonable behaviour for a machine that never = has to forward anything - but that is not at all obvious from the source = code I found. I think I'll need to run tests to see what actually = happens in practice. - Jonathan Morton=