From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH 00/12] introduce fail-safe PMD Date: Fri, 3 Mar 2017 09:27:21 -0800 Message-ID: <20170303092721.7033b660@xeon-e3> References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: dev@dpdk.org, Thomas Monjalon , Adrien Mazarguil , Jingjing Wu To: Gaetan Rivet Return-path: Received: from mail-pg0-f48.google.com (mail-pg0-f48.google.com [74.125.83.48]) by dpdk.org (Postfix) with ESMTP id 6411B2952 for ; Fri, 3 Mar 2017 18:27:29 +0100 (CET) Received: by mail-pg0-f48.google.com with SMTP id b129so46004441pgc.2 for ; Fri, 03 Mar 2017 09:27:29 -0800 (PST) In-Reply-To: List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Fri, 3 Mar 2017 16:40:22 +0100 Gaetan Rivet wrote: > This PMD intercepts and manages Ethernet device removal events issued by > slave PMDs and re-initializes them transparently when brought back so that > existing applications do not need to be modified to benefit from true > hot-plugging support. > > The stacked PMD approach shares many similarities with the bonding PMD but > with a different purpose. While bonding provides the ability to group > several links into a single logical device for enhanced throughput and > supports fail-over at link level, this one manages the sudden disappearance > of the underlying device; it guarantees applications face a valid device in > working order at all times. > > Each fail-safe instance is configured to run atop one or several > devices, with one defined as the preferred device. Hot-plug events are > handled on all of them, and Tx is always directed to the preferred device > if present or to the next available failover device (Rx is always performed > on all devices for simplicity). > > Moreover, the configured slaves (preferred or failover) do not need to be > present at initialization time and may appear later. > > Slaves configuration is continuously synchronized with that of the virtual > device, which exposes their common set of capabilities to the application. > Failure to apply the current configuration state to a slave for any reason > simply reschedules its initialization. > This looks interesting for SR-IOV VF support on Hyper-V. It would be good if the driver worked in interrupt mode as well.