From mboxrd@z Thu Jan 1 00:00:00 1970 From: Or Gerlitz Subject: Re: RDMAoE / lossless Ethernet (ewg: SC'09 BOF - Meeting notes) Date: Wed, 23 Dec 2009 10:09:44 +0200 Message-ID: <4B31D048.5040001@voltaire.com> References: <2ED289D4E09FBD4D92D911E869B97FDD01AF10F2@mtlexch01.mtl.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <2ED289D4E09FBD4D92D911E869B97FDD01AF10F2-ia22CT07NJfiMCgWhms8HQC/G2K4zDHf@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Liran Liss , Yevgeny Petrilin Cc: Or Gerlitz , Richard Frank , Sean Hefty , Roland Dreier , Linux RDMA list , Paul Grun List-Id: linux-rdma@vger.kernel.org Liran Liss wrote: > >> all the rdmaoe materials saying the lossless traffic class is a > must, are you saying that this works well also >> without it? then > why from architect point of view you have posed this requirement? > > lossless traffic can be achieved today using global pause, for > example. PFC is still important; we will submit initial patches that > support it next wee Liran, I would say that OTOH global pause isn't the way to go and OTHO IB RC functions quite bad when many packets are lost. As such RDMAoE without PFC and mapping priorities into TCs (the Ethernet VLs) isn't really for production, for any non trivial environment involving more then one hop. Also, this email is from one month ago, any news on the patches? Yevgeny, I took a look, and there are patches to support pfc for the mlx4_en driver, but they were never submitted upstream, which means that even if rdmaoe goes upstream, mainline users will not be able even to really test it. Also, the pfc in these patches configuration seems to be done with sysfs and not through the Netlink APIs defined in include/net/dcbnl.c, did you had any specific reason not to integrate with the mainline method of pfc/tc configuration? Or. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html