From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net] mlxsw: spectrum_buffers: Set up a dedicated pool for BUM traffic Date: Wed, 05 Sep 2018 07:56:19 -0700 (PDT) Message-ID: <20180905.075619.663023561756737629.davem@davemloft.net> References: Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, jiri@mellanox.com, idosch@mellanox.com To: petrm@mellanox.com Return-path: Received: from shards.monkeyblade.net ([23.128.96.9]:46266 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726366AbeIET0y (ORCPT ); Wed, 5 Sep 2018 15:26:54 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: From: Petr Machata Date: Wed, 05 Sep 2018 12:16:00 +0200 > MC-aware mode was recently enabled by mlxsw on Spectrum switches in > commit 7b8195306694 ("mlxsw: spectrum: Configure MC-aware mode on mlxsw > ports"). Unfortunately, testing has shown that the fix is incomplete and > in the presented form actually makes the problem even worse, because any > amount of MC traffic causes UC disruption. > > The reason for this is that currently, mlxsw configures the MC-specific > TCs (8..15) to map to pool 0. It also configures a maximum buffer size > of 0, but for MC traffic that maximum is disregarded and not part of the > quota. Therefore MC traffic is always admitted to the egress buffer. > > Fix the configuration by directing the MC TCs into pool 15, which is > dedicated to MC traffic and recognized as such by the silicon. > > Fixes: 7b8195306694 ("mlxsw: spectrum: Configure MC-aware mode on mlxsw ports") > Signed-off-by: Petr Machata > Acked-by: Jiri Pirko Applied, thank you.