From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 DD39A142659; Wed, 12 Mar 2025 15:10:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741792243; cv=none; b=P3wu5m8ViVakCmc5MyG+H1VQh1CVuz8ZuaIACast9Ioa10WayYYiexYH0AVTdRyGAlaBB51wasegvAaUExLAz3hSBc0hnoaRrgNkMrWg5a3ZGug8rlXi8XlqBiJePAjE9AtQXmRPEAa0afgI3uhV61n+72TDM/fXb9rJ8DnYpoY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741792243; c=relaxed/simple; bh=feyOgx8IA2ysiNd2yFBWWhwxIJoait0rEV2rixVlKQ8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=bJmrRfTnvE0YBFurq1iCMUreQC/VL/jlB/qOKMZ/LrSnfKYGgSGaeYRlTr9aLXCY4BhNrmux6fCG2yjtL1jPJsPDf4sX7FrGygWy6UTx+i4H+R/h/PLPG8WKAD9whGYgt6I+ztUs/UmrpIbCWuL4CFOfMgLdNQNaqY+j2rLMKF0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cYJ/bcnz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cYJ/bcnz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2A89C4CEDD; Wed, 12 Mar 2025 15:10:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741792242; bh=feyOgx8IA2ysiNd2yFBWWhwxIJoait0rEV2rixVlKQ8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=cYJ/bcnzu87KHde0Gkwx+VRElazIxRdAUPV6Twztq8Ov3Mm6aNYxPHSeO7U+lCXjd ZOOwE+MayuIMQGTyEvU8A839PQXSfGha2CAyWUkWF9cfrvEf+eGNYp7sTQ7TGoad3K bVJUxe3TVYDTw3nec/Ooi5YKfSchH+lLf4SvAMd3fq2nQaKuDtqPll5MOjrM1yG9cH XKsNNGRW2Ys1ma+D6fJ1kooDE8nqNImpqDjDwrODU3nbIrK24BDLEERQn6tL0PUiG+ k3Fp7nDX8qg3gbnBHUbl0l4J9I8c7Q96+6udbYf2oMQFJIEsrMZzJZM4BxPhAzCRlH UG1v65rJUY2EA== Date: Wed, 12 Mar 2025 17:10:37 +0200 From: Leon Romanovsky To: Nikolay Aleksandrov Cc: netdev@vger.kernel.org, shrijeet@enfabrica.net, alex.badea@keysight.com, eric.davis@broadcom.com, rip.sohan@amd.com, dsahern@kernel.org, bmt@zurich.ibm.com, roland@enfabrica.net, winston.liu@keysight.com, dan.mihailescu@keysight.com, kheib@redhat.com, parth.v.parikh@keysight.com, davem@redhat.com, ian.ziemba@hpe.com, andrew.tauferner@cornelisnetworks.com, welch@hpe.com, rakhahari.bhunia@keysight.com, kingshuk.mandal@keysight.com, linux-rdma@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com, Jason Gunthorpe Subject: Re: [RFC PATCH 00/13] Ultra Ethernet driver introduction Message-ID: <20250312151037.GE1322339@unreal> References: <20250306230203.1550314-1-nikolay@enfabrica.net> <20250308184650.GV1955273@unreal> <2f06a40d-2f14-439a-9c95-0231dce5772d@enfabrica.net> <20250312112921.GA1322339@unreal> <86af1a4b-e988-4402-aed2-60609c319dc1@enfabrica.net> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <86af1a4b-e988-4402-aed2-60609c319dc1@enfabrica.net> On Wed, Mar 12, 2025 at 04:20:08PM +0200, Nikolay Aleksandrov wrote: > On 3/12/25 1:29 PM, Leon Romanovsky wrote: > > On Wed, Mar 12, 2025 at 11:40:05AM +0200, Nikolay Aleksandrov wrote: > >> On 3/8/25 8:46 PM, Leon Romanovsky wrote: > >>> On Fri, Mar 07, 2025 at 01:01:50AM +0200, Nikolay Aleksandrov wrote: > [snip] > >> Also we have the ephemeral PDC connections>> that come and go as > needed. There more such objects coming with more > >> state, configuration and lifecycle management. That is why we added a > >> separate netlink family to cleanly manage them without trying to fit > >> a square peg in a round hole so to speak. > > > > Yeah, I saw that you are planning to use netlink to manage objects, > > which is very questionable. It is slow, unreliable, requires sockets, > > needs more parsing logic e.t.c > > > > To avoid all this overhead, RDMA uses netlink-like ioctl calls, which > > fits better for object configurations. > > > > Thanks > > We'd definitely like to keep using netlink for control path object > management. Also please note we're talking about genetlink family. It is > fast and reliable enough for us, very easily extensible, > has a nice precise object definition with policies to enforce various > limitations, has extensive tooling (e.g. ynl), communication can be > monitored in realtime for debugging (e.g. nlmon), has a nice human > readable error reporting, gives the ability to easily dump large object > groups with filters applied, YAML family definitions and so on. > Having sockets or parsing are not issues. Of course it is issue as netlink relies on Netlink sockets, which means that you constantly move your configuration data instead of doing standard to whole linux kernel pattern of allocating configuration structs in user-space and just providing pointer to that through ioctl call. However, this discussion is premature and as an intro it is worth to read this cover letter for how object management is done in RDMA subsystem. https://lore.kernel.org/linux-rdma/1501765627-104860-1-git-send-email-matanb@mellanox.com/ Thanks > > Cheers, > Nik > >