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 A1C2E5B681; Sun, 11 Feb 2024 16:59:20 +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=1707670761; cv=none; b=ttsIPKvh2wq9Z6hAyjBAKEBRIPrzpnYN87dU6Zgy+LTcczXO5A06886Mjppfj1JQHUCnOSGqF4EbDiC7PgAwIm34/i5D+rJpnHW1mMm2aFFv/XtoIbxGqv+w7lgoK9sAZXQEQg9hGDLGi3z2eZcj7MQZ1hWjffVjiEPGml5WXTQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707670761; c=relaxed/simple; bh=tWajLxkLpjlSl0BwK5EiC3LNBNa+4WaPAw7y0wd1l8w=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Xa+HKTxgMz1yQfSotdalOfebt+O/+FJDl6vksJR2OcAidzd2UfPT09OlC0xMgmSH8DALpGN22r9W+5RDL1xIP8OYqc5eutGvmrlorm5vLZGuv2Y/TK8xo+oMbjumBsDZPxJ0wpFj1FVep6G+CezishEAR3kwezMoLKk9QJ/M3ok= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Z5DwrBVs; 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="Z5DwrBVs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BBF56C433C7; Sun, 11 Feb 2024 16:59:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707670760; bh=tWajLxkLpjlSl0BwK5EiC3LNBNa+4WaPAw7y0wd1l8w=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Z5DwrBVs3ODUEJKweEzi7KzXcsU35NBQLN0UghwPoCdrHsExChYroeRjHKewaDXH1 CB2uai1YKRocCvrTWl1v2jCLqUWxV4jyBrw6FIiZzo0t7/Zpmw5fUvRIePArMxNDY7 8LSOHgk6AuJUpZ7xjZwwPYFfhFCEhk6s0Pk9r43lEZiOGLTzX7MrSJzp9HCAPN1XtK 3Ig3uuWlVtjMxj5fAf8OBmfVkCpol/61qWFW89q99xzvRTkWmvtH+jjbwEvA8REOoP hAOwGvlENifvnrn3qv8wSI7m5i1hItU3jPyWWHMe8M83foYcSfrsaPUdgmm/IWynJq dkFQrVGF1TlaQ== Message-ID: <2880b448-2431-44be-94ba-32eb46526c66@kernel.org> Date: Sun, 11 Feb 2024 09:59:18 -0700 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH V4 0/5] mlx5 ConnectX control misc driver To: Jason Gunthorpe Cc: Jakub Kicinski , Saeed Mahameed , Arnd Bergmann , Greg Kroah-Hartman , Leon Romanovsky , Jiri Pirko , Leonid Bloch , Itay Avraham , Saeed Mahameed , Aron Silverton , Christoph Hellwig , andrew.gospodarek@broadcom.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org References: <20240207072435.14182-1-saeed@kernel.org> <20240207070342.21ad3e51@kernel.org> <20240208181555.22d35b61@kernel.org> <2bdc5510-801a-4601-87a3-56eb941d661a@kernel.org> <20240210010129.GA1010957@nvidia.com> Content-Language: en-US From: David Ahern In-Reply-To: <20240210010129.GA1010957@nvidia.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/9/24 6:01 PM, Jason Gunthorpe wrote: > On Fri, Feb 09, 2024 at 03:42:16PM -0700, David Ahern wrote: >> On 2/8/24 7:15 PM, Jakub Kicinski wrote: >>>>> Ah yes, the high frequency counters. Something that is definitely >>>>> impossible to implement in a generic way. You were literally in the >>>>> room at netconf when David Ahern described his proposal for this. >> >> The key point of that proposal is host memory mapped to userspace where >> H/W counters land (either via direct DMA by a H/W push or a >> kthread/timer pulling in updates). That is similar to what is proposed here. > > The counter experiment that inspired Saeed to write about it here was > done using mlx5ctl interfaces and some other POC stuff on an RDMA > network monitoring RDMA workloads, inspecting RDMA objects. > > So if your proposal also considers how to select RDMA object counters, > control the detailed sampling hardware with RDMA stuff, and works > on a netdev-free InfiniBand network, then it might be interesting. Response at netconf in September was mixed. As I recall Jakub for example was shaking his head at 'yet another stats proposal', but since he has referenced it a couple of times now maybe it is worth moving beyond slides to a POC. The uapi discussed was netlink (genl) based; driver hooks were not discussed. Perhaps I can get a working POC for both stacks by netdevconf in July.