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 1B6FB7F9; Sun, 16 Feb 2025 09:26:51 +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=1739698012; cv=none; b=uUDcsbBFLsKrvX5lBHZLXxZWXuTJeKMCaRqowT+gqvjdkwend2u8XrkYk4EiGuqaV2cFx6ZLX4nGgbEtYDg6iLt1pGS78AA/Z1EYHITtJa6IDP+fwluLhK2ciGDP85J1NFaL9ayxsVjvoio8jamacxDjaQ4k7YFqj6JznWlUIqw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739698012; c=relaxed/simple; bh=qOKEtCKMyux97ZLVC7VY7mjdb0VsP0z9R+6QKp1pThE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=brVG8h+Cuv51znlnXofFgG4YRshrmmUkR61X+fNQlGx34PDLF+/cvMHuAr5Msnw8gfnCWa2rDdRWMlrP2ttVkL8JJVHzKxolmPf0j9KwzeVrAncTd+rZP+MTPb9/AL83s5ndS/UBo4vnI/bsXv9GT99FgiG2bEOHTDYX2bDm2h0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WC8dIz7e; 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="WC8dIz7e" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9C1E5C4CEDD; Sun, 16 Feb 2025 09:26:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739698011; bh=qOKEtCKMyux97ZLVC7VY7mjdb0VsP0z9R+6QKp1pThE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WC8dIz7ex2oAFNaCXgB5ktq8MYAn6ChCVhuclMZvs01XUI9hX/63BW8OA9Rlx4I8M tDUJjmBuN4hWQi5v/ndfIpUmy7HA2FjduJy2OTmhil/t2Kj7QNsGa199PFREqPy4TR ezxIjwovP5p7qL1bUkMMRT67mXC1fskCEpG8vFhaZJuHJ03HxJR4Gh0FkFlN+54aVO gaI95//S3F4PvElYDvX4ftz5ZinoDjiOT4UMD2GyBwd56T/Fn6qFGcOGoleUF2MDpp 8QVV2CYL6pY8cydNsYULwDh9EMwji5szZlBzrOogtrugAu+YqSy7P/cPDumWIV1zPT QrYoIUzT57WFA== Date: Sun, 16 Feb 2025 09:26:46 +0000 From: Simon Horman To: Jakub Kicinski Cc: Amit Cohen , Alexei Starovoitov , Petr Machata , "David S. Miller" , Eric Dumazet , Paolo Abeni , Andrew Lunn , Network Development , Ido Schimmel , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , bpf , mlxsw Subject: Re: [PATCH net-next 00/12] mlxsw: Preparations for XDP support Message-ID: <20250216092646.GY1615191@kernel.org> References: <20250205090958.278ffaff@kernel.org> <20250215140252.GP1615191@kernel.org> <20250215081043.063e995a@kernel.org> 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: <20250215081043.063e995a@kernel.org> On Sat, Feb 15, 2025 at 08:10:43AM -0800, Jakub Kicinski wrote: > On Sat, 15 Feb 2025 14:02:52 +0000 Simon Horman wrote: > > > TBH I also feel a little ambivalent about adding advanced software > > > features to mlxsw. You have a dummy device off which you hang the NAPIs, > > > the page pools, and now the RXQ objects. That already works poorly with > > > our APIs. How are you going to handle the XDP side? Program per port, > > > I hope? But the basic fact remains that only fallback traffic goes thru > > > the XDP program which is not the normal Linux model, routing is after > > > XDP. > > > > > > On one hand it'd be great if upstream switch drivers could benefit from > > > the advanced features. On the other the HW is clearly not capable of > > > delivering in line with how NICs work, so we're signing up for a stream > > > of corner cases, bugs and incompatibility. Dunno. > > > > FWIIW, I do think that as this driver is actively maintained by the vendor, > > and this is a grey zone, it is reasonable to allow the vendor to decide if > > they want the burden of this complexity to gain some performance. > > Yes, I left this series in PW for an extra couple of days expecting > a discussion but I suppose my email was taken as a final judgment. Yes, I was trying to spur that discussion. > The object separation can be faked more accurately, and analyzed > (in the cover letter) to give us more confidence that the divergence > won't create problems. > > The "actively maintained" part is true and very much appreciated, but > it's both something that may easily change, and is hard to objectively > adjudicate. Reporting results to the upstream CI would be much more > objective and hopefully easier to maintain, were the folks supporting > mlxsw to "join a startup", or otherwise disengage. A good point. Things can change. And that may leave upstream maintainers caring the can.