From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 667FA39D6D5; Tue, 18 Aug 2026 14:45:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787064310; cv=none; b=cHmtU88rrlcC37Y4I1/+HFdwPa6eqKutal8NtUYLJK5Qo1Mo5jNRHPW7L4gta3jcYPI0hWrhQbUrxHdM6548u0IGOCy7H51tCmGDQVQTEam5tFWrm6+9uPMc+2HeqDNDe+0N2HXHNsFKZcxFdghTai9yQexSLvbNWK2TjYRiBvI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787064310; c=relaxed/simple; bh=pCLPljKlb3SjZPtd+3dUvUC2a9ehGYxjNjYf2noMkVI=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=YBa761LxEUUChkvdnwRj2rlSoadm/Rl5xEoteXwIPcWq6XKtpiFv7GGjtTaQOSmj3v8e8/fpJU007vugjLW2Pbrdk9Hy+JNTueWgqkjBKUcK48tBj23U21sZyO/Zmwrm7fXRGf8UUJCV2CtdcwHGdSnNfFDnXzD22ho29S41CfA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ejw6JTtE; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ejw6JTtE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B81981F000E9; Tue, 18 Aug 2026 14:45:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787064309; bh=c7d9ILLdl2uuQua9nlVx5VA+VFdRGqZMMziyq+6TtNM=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=ejw6JTtEj2RXE01+LkkolUTifB1hteyc9s+hqHtIDbkQifeKWvV7fMoFX78BdI+QB lZTYTHoCbO3NABFCslgxjl9HEJQEVyXFnvZbsxHrJz7C823kDW/YO8uPIENsVtNFKk xb+hJ8ejFaHQ9VPwtKwsmzudIvLpqENibzkLNudrsT9Vx+x99mn1XSrum/cbpcOEQ9 Ldj+PlsE2WjK06yXGw8rL8oqrKV+D3pivv/JlYEwZ85ChzIG+Yr8dwf3rUQ/E7Z4gr EHGWhTs+v506XJvG4upnJVGY/SMHDygCKC63BBxmk62Wx13K2ix4LEz7t+BMtoPx8v Ntefd27PzzAVg== Date: Tue, 18 Aug 2026 07:45:08 -0700 From: Jakub Kicinski To: Cedric Jehasse Cc: Cedric Jehasse via B4 Relay , cedric.jehasse@luminex.be, Andrew Lunn , Vladimir Oltean , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , Russell King , Jamal Hadi Salim , Jiri Pirko , Vinicius Costa Gomes , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Luke Howard , Marek =?UTF-8?B?QmVow7pu?= Subject: Re: [PATCH net-next v8 2/3] net: dsa: mv88e6xxx: use the hw tx queues Message-ID: <20260818074508.26e626b4@kernel.org> In-Reply-To: References: <20260811-net-next-mv88e6xxx-cbs-v8-0-10d0baab2905@luminex.be> <20260811-net-next-mv88e6xxx-cbs-v8-2-10d0baab2905@luminex.be> <20260817105024.65be6d55@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 18 Aug 2026 10:59:35 +0200 Cedric Jehasse wrote: > > Pretending that a DSA device has multiple Tx queues _from the stack_ > > makes no sense. You should be offloading PRIO as the root qdisc, > > like mlxsw does. Then the rate limiters should be attached as children > > of PRIO. > > This patch follows what the implementation i found in other dsa drivers. > mlxsw seems to be the only driver handling TC_SETUP_QDISC_PRIO. > Wouldn't that mean setting up cbs for a mv88e6xxx switch would use different > tc commands than setting it up for another dsa switch (prio vs mqprio)? > Is your comment specific to this driver, or for dsa drivers in general? Maybe Vladimir can comment why he picked mqprio. He probably explained it to me and I forgot. My mental model is that mqprio offload is for the host ("NIC", IOW host traffic egress). But if you're configuring a switch where most of the traffic is internally forwarded within the ASIC. We should have a way to report stats and offload status. There's no need to pretend we have multiple host queues and waste memory.