From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean-Michel Hautbois Subject: Re: UDP ordering when using multiple rx queue Date: Wed, 11 Jul 2012 13:13:21 +0200 Message-ID: References: <1342004939.27284.28.camel@lb-tlvb-meravs.il.broadcom.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: netdev To: Merav Sicron Return-path: Received: from mail-wg0-f44.google.com ([74.125.82.44]:34946 "EHLO mail-wg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751642Ab2GKLNm (ORCPT ); Wed, 11 Jul 2012 07:13:42 -0400 Received: by wgbdr13 with SMTP id dr13so928332wgb.1 for ; Wed, 11 Jul 2012 04:13:41 -0700 (PDT) In-Reply-To: <1342004939.27284.28.camel@lb-tlvb-meravs.il.broadcom.com> Sender: netdev-owner@vger.kernel.org List-ID: 2012/7/11 Merav Sicron : > On Wed, 2012-07-11 at 00:53 -0700, Jean-Michel Hautbois wrote: > >> Several tests lead to a simple conclusion : when the NIC has only one >> RX queue, everything is ok (like be2net for instance), but when it has >> more than one RX queue, then I can have "lost packets". >> This is the case for bnx2x or mlx4 for instance. > >From what you describe I assume that you use different source IP / > destination IP in each packet - is this something that you can control? > Because with the same IP addresses the traffic will be steered to the > same queue. OK, sorry for not having explained that : the packets are multicast with a port for each stream. Sending one stream multicast on a bnx2x based NIC can lead to several queues used (two, for what I can see) and then, to the problem reported. >> Here are my questions : >> - Is it possible to force a driver to use only one rx queue, even if >> it can use more without reloading the driver (and this is feasible >> only when a parameter exists for that !) ? > You can reduce the number of queues using "ethtool -L ethX combined 1". > Note however that it will cause automatic driver unload/load. OK, thanks for this tip :). JM