From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Dichtel Subject: switchdev offload & ecmp Date: Mon, 15 May 2017 16:25:43 +0200 Message-ID: <84b9801f-0c2a-cd55-61a4-411261943024@6wind.com> Reply-To: nicolas.dichtel@6wind.com Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: Nikolay Aleksandrov , Roopa Prabhu , netdev To: Jiri Pirko , Ido Schimmel Return-path: Received: from mail-wm0-f45.google.com ([74.125.82.45]:37118 "EHLO mail-wm0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933222AbdEOOZq (ORCPT ); Mon, 15 May 2017 10:25:46 -0400 Received: by mail-wm0-f45.google.com with SMTP id d127so78450548wmf.0 for ; Mon, 15 May 2017 07:25:45 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: Hi Jiri and Ido, I'm trying to understand how ecmp offloading works. It seems that rocker doesn't support it: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/ethernet/rocker/rocker_ofdpa.c#n2409. But I saw that the support was added in spectrum: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?h=684a95c064fc. Is there a consistency between the ecmp algorithm of the kernel and the one from spectrum? I suspect that there can be scenarii where some packets of a flow are forwarded by the driver and some other are forwarded by the kernel. For example, an ecmp route with two nexthops: a connected route and a gw? In that case, the periodic nexthops update (https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c#n987) won't help. How do you ensure that all packets of the flow are always forwarded through the same nexthop? Regards, Nicolas