From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-x22a.google.com (mail-qt0-x22a.google.com [IPv6:2607:f8b0:400d:c0d::22a]) (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 5C0033B29E for ; Tue, 24 Jul 2018 23:34:41 -0400 (EDT) Received: by mail-qt0-x22a.google.com with SMTP id m13-v6so6368386qth.1 for ; Tue, 24 Jul 2018 20:34:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to :content-transfer-encoding; bh=bYaDI2HP6FL6cs4tRRoX9KYOXIeQYlsq+5ZJNK7wuEI=; b=qCdIJft+rG/Dd9bknyMcMD+44elh17iuswvjpEBNc/vJt9LGx1kuaa2NwTexbEz+fH 7L1VCDbGn5CrtvHys1Gk5hnXqUcTfrwojWiuMKiQn1ogPRwIgm3aFgHv935cGeWWJpHS uWwDj0t7M41deKLfWVuR5anqq2FDScw+r7z89V67U+ifDJhP/DLqZ4oXbg7kEANV4r4e 1ofHMklMnJRjfCnKUy3MbeQ/t/dYvQyBKaPpwBmomLtohua8JGv/ZupCUfr0ZDVi6Hrm EfIsYn19681x20rydvTZUXW2jKBVL9+/U8ABhdvbscNvvWaxHpDNVMeomrVPtzBZXqS5 Ovyg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to :content-transfer-encoding; bh=bYaDI2HP6FL6cs4tRRoX9KYOXIeQYlsq+5ZJNK7wuEI=; b=mBzE1I5EF1JnCHNaZmR23WF9QwFmaM4BYmaFBe39D1i54vsEZnvmMdB1XFEkmH1yJM dWO/bIaVPRkJ7sajI3lSW2eQB6Ot8d9A6Jsrm+DrvnsXwSwWkq3nlUpEAgkfrjG8ay58 KzFA1LaFkuE7ibho8n7FtuvlczbbgeplkP4D7ixeSKMrXtKG8o2NKbXDrthHu/J4Sl+/ LhcqOIMm3vN0bref9XmsU7DsGxX/llXx1YE6feFKTdprQctOhgp4WZBs0oVl5mNTBpKs GXYaDEeKt9YAvNn3wFud3wEW0ZokmrNVlVaA/V+OarOG0d0BYkk3baXveIcOlmFNPLh5 JqRA== X-Gm-Message-State: AOUpUlEy6iWJWEgD2pUqA86eMhKTrMCOm6FscVKxnuYHxW+Zo3wjAOjf qtTdSZ7rSwB0uXr0o+zy+7eZuawXfx+umBlYZlxc0E8t X-Google-Smtp-Source: AAOMgpfo0h4HcussZb6Y5A27lKeiUNBgphO2g/pKu7oJOtbL0cis35ITNEXEpqkwEdEPf1NWVmVmuiEt0UUR1TkKeRg= X-Received: by 2002:a0c:bfd8:: with SMTP id u24-v6mr17686684qvj.158.1532489680625; Tue, 24 Jul 2018 20:34:40 -0700 (PDT) MIME-Version: 1.0 From: Dave Taht Date: Tue, 24 Jul 2018 20:34:28 -0700 Message-ID: To: Cake List Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: [Cake] making split_gso_threshold configurable 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: Wed, 25 Jul 2018 03:34:41 -0000 I really wanted cake to always optimize for low latency. I wanted it to "just work" at line rate on dsl, on 100mbit, even 10mbit ethernet, to work against pause frames, etc, without configuration. I wanted to defeat drivers like the mvneta that can do 64k of software GRO automagically. Along the way to mainlining it, cake's behavior got changed, to scale well to 50Gbit by allowing GSO above a 1gbit shaped rate, and *always allowing GSO at line rate*. if (q->rate_bps && q->rate_bps <=3D CAKE_SPLIT_GSO_THRESHOLD) q->rate_flags |=3D CAKE_FLAG_SPLIT_GSO; else q->rate_flags &=3D ~CAKE_FLAG_SPLIT_GSO; I don't care about 50gbit. I'm delighted, even astonished, it does 50Gbit. I want it to do 1mbit with 13ms interpacket latency when hit by an IW10 burst from somewhere else, not 130, with hardware pause frames in use on the dsl modem or elsewhere. so, I'd like to A) default to always split shaped or unshaped. And B) expose the split threshold to be configured via userspace. This latter option would give a tunable for those struggling a bit for cpu to play with, also. anyone disagree? --=20 Dave T=C3=A4ht CEO, TekLibre, LLC http://www.teklibre.com Tel: 1-669-226-2619