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 CB83E1714CF; Thu, 15 Aug 2024 16:08:58 +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=1723738138; cv=none; b=mxr3Xr7S7VnPLtrPh7COx/Kn4GlCd5giPPOEJE70ZBP4SkCB4cMBC8Al4ubH9gVkL6+L5jczYkOgarKzyjmcxdsedCallrJ4dWxDiHJzszELO9hmvMDA40kAhugA6XEVpqQ/miZXsE/AuatiSLuf3+CkevIXuNRlXq9lfzb48gA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723738138; c=relaxed/simple; bh=Pwhcosg/2481mlBnXLoezww6CFiK4+irt0TdYQPusVY=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=J9bBHN8Cjz0SrpLgMr5Qs4Ntnicw0SAXLTKF6104VHlo7jmBIp3SxhzVvM8YC1LR+M6VDcqd+cAE8GVLG1KiTXUif4I31GNqs5B7u9uNBQm6PN+JRLHoi9N3lbOhHa06Q1a2Q0bqOvK9nEXfy7bwKG0STL9EPoYd6Geo1VhTnJ0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tWeGID1d; 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="tWeGID1d" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C323CC32786; Thu, 15 Aug 2024 16:08:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1723738138; bh=Pwhcosg/2481mlBnXLoezww6CFiK4+irt0TdYQPusVY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=tWeGID1dqVq0A4zE/XNllRjdBT2rj0QtMLBrKwIqtyv/SH0wW05FKVpXZ8tHcytNj cFlcmLItIXJXGiRIXbniBYnsJGo1lsT5TEGe3nD6tMNX/SUAgNlz5OyuukwWk+0/1D QsrhMrtGSDdtieIN/iFTEiIvpqYrg3h5h2/GZg7qfCWJQhFnvfM1yZqBv0P3Ksd0JC aONCoBHm7hvxUanrGZR5zuJ8CZWJy+L67QCluLcDnNPeX+yNOaG+VBG7e6EKtE6y7Q h5RoRbjPCKbe7T8SJ2W67gmq+Hq65QAyWQ8ck2qoO2v7UDlYBxZXBpHPROpfj+AC9g pmcMZLEuMcJjw== Date: Thu, 15 Aug 2024 09:08:56 -0700 From: Jakub Kicinski To: Erni Sri Satya Vennela Cc: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, linux-hyperv@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, ernis@microsoft.com Subject: Re: [PATCH v2] net: netvsc: Update default VMBus channels Message-ID: <20240815090856.7f8ec005@kernel.org> In-Reply-To: <1723654753-27893-1-git-send-email-ernis@linux.microsoft.com> References: <1723654753-27893-1-git-send-email-ernis@linux.microsoft.com> 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-Transfer-Encoding: 7bit On Wed, 14 Aug 2024 09:59:13 -0700 Erni Sri Satya Vennela wrote: > Change VMBus channels macro (VRSS_CHANNEL_DEFAULT) in > Linux netvsc from 8 to 16 to align with Azure Windows VM > and improve networking throughput. > > For VMs having less than 16 vCPUS, the channels depend > on number of vCPUs. Between 16 to 32 vCPUs, the channels > default to VRSS_CHANNEL_DEFAULT. For greater than 32 vCPUs, > set the channels to number of physical cores / 2 as a way > to optimize CPU resource utilization and scale for high-end > processors with many cores. > Maximum number of channels are by default set to 64. > > Based on this change the subchannel creation would change as follows: > > ------------------------------------------------------------- > |No. of vCPU |dev_info->num_chn |subchannel created | > ------------------------------------------------------------- > | 0-16 | 16 | vCPU | > | >16 & <=32 | 16 | 16 | > | >32 & <=128 | vCPU/2 | vCPU/2 | > | >128 | vCPU/2 | 64 | > ------------------------------------------------------------- > > Performance tests showed significant improvement in throughput: > - 0.54% for 16 vCPUs > - 0.83% for 32 vCPUs > - 1.76% for 48 vCPUs > - 10.35% for 64 vCPUs > - 13.47% for 96 vCPUs Is there anything that needs clarifying in my feedback on v1? https://lore.kernel.org/all/20240807201857.445f9f95@kernel.org/ Ignoring maintainer feedback is known to result in angry outbursts.