From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 77A9BC433EF for ; Wed, 20 Oct 2021 21:16:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 546D461215 for ; Wed, 20 Oct 2021 21:16:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230052AbhJTVSy (ORCPT ); Wed, 20 Oct 2021 17:18:54 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:47827 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229695AbhJTVSx (ORCPT ); Wed, 20 Oct 2021 17:18:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1634764598; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xE+bQZv+QDyBlcOTtnVbPzWniWbiHKRhHJ641Q/JjN8=; b=e60PJBxgxSthS0j0m8Hq2KLgT/D1G+t8suwhIPeNNhp2NWhGiQyFO09cxYnZu5wNeE+znP 8Z1Zsu1w+MPK3thDU/iaGZZsuDg09va5BMh4WxrIoNlyG3DB5lK65p7T1lotwx/tsvjR6R bqvvGGcRulRQvQpmpD/67vN7jq0ZoPc= Received: from mail-ed1-f69.google.com (mail-ed1-f69.google.com [209.85.208.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-6-riOhDgyeMTSdSiQUCGxnmQ-1; Wed, 20 Oct 2021 17:16:37 -0400 X-MC-Unique: riOhDgyeMTSdSiQUCGxnmQ-1 Received: by mail-ed1-f69.google.com with SMTP id c25-20020a056402143900b003dc19782ea8so18782155edx.3 for ; Wed, 20 Oct 2021 14:16:36 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version:content-transfer-encoding; bh=xE+bQZv+QDyBlcOTtnVbPzWniWbiHKRhHJ641Q/JjN8=; b=2z7bzg7goOWR3HLGM/TPKA5tCI4H4pfbAfIEUMXslFYwR7jbJUh1FhUySPy0Mht+7W o3ONC3XMaacNB3GjMVJ2eg2zazRgCZGvmqrd12pOvseDuoRce235xzLd6NgvL5kj2ZSC YYRW/GBHUd2WSvd2iofRHOJP4hgVxbfuUtVneDld57fsbdfw1vO4LkL4ZMI8hTry9CYa E/8YyjR9taPFIXs98DEgGFnoZLM+ziW4kmEO1j9q0Khnx5F1QHKmowiDhgCQx8KK7YQV IrYdqSbRK5gpdGoOc6AotXtjNsdUN99yfpwQYfW6BGUMe+9l/8ZlgWqHTM4hYdfFw7kA 9dGg== X-Gm-Message-State: AOAM5315pWeHMHJzUIdGIHuojAkrlcD60JACNVp/bLNaV22huuwVxSzd 2pvZAzF3DMyFLmAmXhQuXlwvx81nQywq/G9jwubuU3XPyJlyX3/bHLcg9R++OK2oVhgs+wxaFJ5 9gNIPwssTLzJ3R+Tl X-Received: by 2002:a05:6402:4248:: with SMTP id g8mr1874640edb.126.1634764594761; Wed, 20 Oct 2021 14:16:34 -0700 (PDT) X-Google-Smtp-Source: ABdhPJx9YtiUPlYXfU87ZpmRqFX4VYX4cSk0ORf0w8UIjHOkyofacPPibnEYVEg1MPDbuaIxxXLvcg== X-Received: by 2002:a05:6402:4248:: with SMTP id g8mr1874545edb.126.1634764593765; Wed, 20 Oct 2021 14:16:33 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([2a0c:4d80:42:443::2]) by smtp.gmail.com with ESMTPSA id b26sm1557401ejl.82.2021.10.20.14.16.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 20 Oct 2021 14:16:33 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 72CF1180262; Wed, 20 Oct 2021 23:16:32 +0200 (CEST) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Eric Dumazet , davem@davemloft.net, kuba@kernel.org Cc: netdev@vger.kernel.org, edumazet@google.com Subject: Re: [PATCH net-next v2] fq_codel: generalise ce_threshold marking for subset of traffic In-Reply-To: <9cec30c9-ede1-82aa-9eca-ca76bcb206d5@gmail.com> References: <20211019174709.69081-1-toke@redhat.com> <9cec30c9-ede1-82aa-9eca-ca76bcb206d5@gmail.com> X-Clacks-Overhead: GNU Terry Pratchett Date: Wed, 20 Oct 2021 23:16:32 +0200 Message-ID: <87ilxre6rz.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Eric Dumazet writes: > On 10/19/21 10:47 AM, Toke H=C3=B8iland-J=C3=B8rgensen wrote: >> The commit in the Fixes tag expanded the ce_threshold feature of FQ-CoDel >> so it can be applied to a subset of the traffic, using the ECT(1) bit of >> the ECN field as the classifier. However, hard-coding ECT(1) as the only >> classifier for this feature seems limiting, so let's expand it to be more >> general. >>=20 >> To this end, change the parameter from a ce_threshold_ect1 boolean, to a >> one-byte selector/mask pair (ce_threshold_{selector,mask}) which is appl= ied >> to the whole diffserv/ECN field in the IP header. This makes it possible= to >> classify packets by any value in either the ECN field or the diffserv >> field. In particular, setting a selector of INET_ECN_ECT_1 and a mask of >> INET_ECN_MASK corresponds to the functionality before this patch, and a >> mask of ~INET_ECN_MASK allows using the selector as a straight-forward >> match against a diffserv code point: >>=20 >> # apply ce_threshold to ECT(1) traffic >> tc qdisc replace dev eth0 root fq_codel ce_threshold 1ms ce_threshold_s= elector 0x1/0x3 >>=20 >> # apply ce_threshold to ECN-capable traffic marked as diffserv AF22 >> tc qdisc replace dev eth0 root fq_codel ce_threshold 1ms ce_threshold_s= elector 0x50/0xfc >>=20 >> Regardless of the selector chosen, the normal rules for ECN-marking of >> packets still apply, i.e., the flow must still declare itself ECN-capable >> by setting one of the bits in the ECN field to get marked at all. >>=20 >> v2: >> - Add tc usage examples to patch description >>=20 >> Fixes: e72aeb9ee0e3 ("fq_codel: implement L4S style ce_threshold_ect1 ma= rking") >> Signed-off-by: Toke H=C3=B8iland-J=C3=B8rgensen >> --- > > Reviewed-by: Eric Dumazet Thanks! > BTW, the Fixes: tag seems not really needed, your patch is a > followup/generalization. Yeah, I included it because I don't know of any other way to express "this is a follow-up commit to this other one, and the two should be kept together" - for e.g., backports. And I figured that since this changes the UAPI from your initial patch, this was important to express in case someone does backport that. Is there another way to express this that I'm not aware of? -Toke