From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve Wise Subject: Re: [PATCH v2] RDMA/CMA: fix iWARP adapter TCP port space usage Date: Wed, 23 Jun 2010 14:42:43 -0500 Message-ID: <4C2263B3.9010608@opengridcomputing.com> References: <4C225078.6050001@opengridcomputing.com> <4C225697.6060702@opengridcomputing.com> <20100623192909.GT4630@obsidianresearch.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20100623192909.GT4630-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jason Gunthorpe Cc: Roland Dreier , Bernard Metzler , "Tung, Chien Tin" , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Peter P Waskiewicz Jr List-Id: linux-rdma@vger.kernel.org Jason Gunthorpe wrote: > On Wed, Jun 23, 2010 at 01:46:47PM -0500, Steve Wise wrote: > > >> Yes. Perusing the drivers/scsi/cxgb3i code I see the iscsi ipaddr is >> actually stored in the port_info struct which is hung of the netdev_priv >> of the cxgb3 device. It is set by cxgb3i_host_set_param() which is part >> of the iscsi transport interface. >> > > I wonder how does neighbor discovery, routing, etc work with iscsi? > > For cxgb3i: ND is handled by initiating ND via exported kernel services (neigh_event_send()) and registering for NETEVENT_NEIGH_UPDATE net events to get updated neigh entries. The host routing table is consulted via ip_route_output_flow() to map a destination ip address to a local netdev, and then if that device is T3, it will do the iscsi offload. >> I just think the customer looses when we add iwarp-specific tools, >> ipaddrs, subnets, etc etc. And what about software iwarp? Will it use >> the host stack tools and not these new tools? So then we end up with 2 >> sets of tools for iwarp devices. :( >> > > Well, maybe you can get netdev to agree on some way to create an > interface that has all the IP services, but no TCP protocol binding? > Then the configuration could be largely the same. If you could share > that with the iscsi world then maybe it isn't so bad? > Maybe. I fear this will meet the same resistance from the netdev folks. Steve. -- 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