From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: mail.toke.dk; dkim=pass header.d=toke.dk; arc=none (Message is not ARC signed); dmarc=pass (Used From Domain Record) header.from=toke.dk policy.dmarc=reject From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=toke.dk; s=20161023; t=1764408095; bh=TcHF9XI+kpMbFyGDJlrjny70cbMfdgOug3ms9WKBPl4=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=B8illfKGqRmxTe+Hw/pryELSotuukBz7eIrdjZ14eGSw49arwh8yrw5fGQTwF6CjL HRrHmziB7DQqVW29bk4WSXKkCwRqioiiJQrOV1+jShpdMXsIT9HOAw9+9GqjysDnRt IVi8hybtYRmeIHA4ZbQBQxQAnRwN8/MkjX9dqA1iWr2nioV/d24DVfHgm8Yb+su5jV Pwy7DE16Sxi5oZ/JJ6/OA+Fy/XtY2gVNBgkTVzhNTCseSkYoKWpe+KiTUf42m246dR WXftBuGoKDN4+Wdn8tJZcbjLhro/ES1sy77ybXSa7YvSJQ6phJJ6Fh5L+Zt6fTIXGp JRsNS2REtfP9Q== To: Willem de Bruijn , Jamal Hadi Salim , Cong Wang , Jiri Pirko , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman Cc: Jonas =?utf-8?Q?K=C3=B6ppeler?= , cake@lists.bufferbloat.net, netdev@vger.kernel.org In-Reply-To: References: <20251127-mq-cake-sub-qdisc-v2-0-24d9ead047b9@redhat.com> <20251127-mq-cake-sub-qdisc-v2-2-24d9ead047b9@redhat.com> Date: Sat, 29 Nov 2025 10:21:34 +0100 X-Clacks-Overhead: GNU Terry Pratchett Message-ID: <87a505b3dt.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Message-ID-Hash: MJR3OG3MFZE6BSHOJV44S2BHVKTJ7TX3 X-Message-ID-Hash: MJR3OG3MFZE6BSHOJV44S2BHVKTJ7TX3 X-MailFrom: toke@toke.dk X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list Subject: [Cake] Re: [PATCH net-next v2 2/4] net/sched: sch_cake: Add cake_mq qdisc for using cake on mq devices List-Id: Cake - FQ_codel the next generation Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Willem de Bruijn writes: > Toke H=C3=B8iland-J=C3=B8rgensen wrote: >> Add a cake_mq qdisc which installs cake instances on each hardware >> queue on a multi-queue device. >>=20 >> This is just a copy of sch_mq that installs cake instead of the default >> qdisc on each queue. Subsequent commits will add sharing of the config >> between cake instances, as well as a multi-queue aware shaper algorithm. >>=20 >> Reviewed-by: Jamal Hadi Salim >> Signed-off-by: Toke H=C3=B8iland-J=C3=B8rgensen >> --- >> net/sched/sch_cake.c | 214 ++++++++++++++++++++++++++++++++++++++++++++= ++++++- >> 1 file changed, 213 insertions(+), 1 deletion(-) > > Is this code duplication unavoidable? > > Could the same be achieved by either > > extending the original sch_mq to have a variant that calls the > custom cake_mq_change. > > Or avoid hanging the shared state off of parent mq entirely. Have the > cake instances share it directly. E.g., where all but the instance on > netdev_get_tx_queue(dev, 0) are opened in a special "shared" mode (a > bit like SO_REUSEPORT sockets) and lookup the state from that > instance. We actually started out with something like that, but ended up with the current variant for primarily UAPI reasons: Having the mq variant be a separate named qdisc is simple and easy to understand ('cake' gets you single-queue, 'cake_mq' gets you multi-queue). I think having that variant live with the cake code makes sense. I suppose we could reuse a couple of the mq callbacks by exporting them and calling them from the cake code and avoid some duplication that way. I can follow up with a patch to consolidate those if you think it is worth it to do so? -Toke