From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: [PATCH 2/3] infiniband-diags: libibnetdisc Allow a DR Path partial fabric query starting at a CA Date: Wed, 20 Jul 2011 17:34:51 -0600 Message-ID: <20110720233451.GL18090@obsidianresearch.com> References: <20110720161655.1ed38052.weiny2@llnl.gov> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20110720161655.1ed38052.weiny2-i2BcT+NCU+M@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ira Weiny Cc: "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Hal Rosenstock List-Id: linux-rdma@vger.kernel.org On Wed, Jul 20, 2011 at 04:16:55PM -0700, Ira Weiny wrote: > > The old algorithm would attempt to extend a DR path through the CA and fail. > The new algorithm retracts the path properly. > > This does not work when combined routing is used with the CA as a starting > point. :-( The ibtool version of this switches the starting LID with the connected switch in this case.. Having that general functionality means you can easially write a traceroute routine with this common code. Note, doing tricks like this with the DR path screws up the localPortNum value, so if you ever read Port/NodeInfo using a path that has been manipulated like this it needs a fixup step. Also, there is a bug, you can't DLID route to the local HCA and then use that as a source of a DR path, even though intuitively that should work. Jason -- 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