From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shawn Bohrer Subject: Re: Linux 3.2-rc1 vs. OFED 1.5.4-rc4: Packets are looped back Date: Thu, 17 Nov 2011 17:33:09 +0000 (UTC) Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org Christoph Lameter writes: > > We have an app here that runs fine with OFED. But if I try to use the > kernel IB subsystem in 3.2 it complains about packets being looped back to > the application. > > That seems to be controlled by IB_DEVICE_BLOCK_MULTICAST_LOOPBACK and > IB_QP_CREATE_BLOCK_MULTICAST_LOOPBACK. > > Why does it not work in the kernel IB stack? The only place the 3.2 kernel sets IB_QP_CREATE_BLOCK_MULTICAST_LOOPBACK is in ipoib_transport_dev_init() so unless you are doing IPoIB you will get loopback traffic. The reason you do not get loopback traffic with OFED is because OFED has the following patch that adds the block_loopback module parameter to mlx4_core and defaults to blocking-enabled. http://git.openfabrics.org/git?p=ofed_1_5/linux-2.6.git;a=blob;f=kernel_patches/fixes/mlx4_0290_mcast_loopback.patch;h=786a3926529befac2c2d1fa6d8c36bada79d61a7;hb=HEAD -- 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