[ofa-general] [RFC][PATCH] ibnetdiscover: remove report of max hops discovered.

[Ira Weiny]

The number reported as "max hops" from ibnetdiscover can change depending on
the algorithm used to discover the fabric.  As Hal says in the message below
using this number is therefore dangerous.

If no one is currently using this number I propose the patch below which
removes the "max hops discovered" from the output.

Ira

On Tue, 5 May 2009 14:25:32 -0400
Hal Rosenstock <hal.rosenstock at gmail.com> wrote:

> Hi Al,
> 
> On Tue, May 5, 2009 at 1:08 PM, Al Chu <chu11 at llnl.gov> wrote:

[snip]

> >
> > Ira says that the output of the hops is actually "max hops used to get
> > from my port to another port during my search of the network".  So the
> > number could change if (hypotehtical example) depth-first-search were
> > used instead of BFS.
> 
> Sure; it can depend on how the search is done but isn't it the max
> from the initiated node (which could be different depending on the
> algo used) ? Using that number seems dangerous for that very reason. I
> always thought that number was "nice" to have but nothing more. It
> predated my work on ibnetdiscover.
> 
> -- Hal
> 


From: Ira Weiny <weiny2 at llnl.gov>
Date: Wed, 6 May 2009 17:56:23 -0700
Subject: [PATCH] ibnetdiscover: remove report of max hops discovered.


Signed-off-by: Ira Weiny <weiny2 at llnl.gov>
---
 infiniband-diags/src/ibnetdiscover.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/infiniband-diags/src/ibnetdiscover.c b/infiniband-diags/src/ibnetdiscover.c
index 1799618..89e4f0f 100644
--- a/infiniband-diags/src/ibnetdiscover.c
+++ b/infiniband-diags/src/ibnetdiscover.c
@@ -448,7 +448,6 @@ dump_topology(int group, ibnd_fabric_t *fabric)
 	struct iter_user_data iter_user_data;
 
 	fprintf(f, "#\n# Topology file: generated on %s#\n", ctime(&t));
-	fprintf(f, "# Max of %d hops discovered\n", fabric->maxhops_discovered);
 	fprintf(f, "# Initiated from node %016" PRIx64 " port %016" PRIx64 "\n",
 		fabric->from_node->guid,
 		mad_get_field64(fabric->from_node->info, 0, IB_NODE_PORT_GUID_F));
-- 
1.5.4.5