[ofa-general] [PATCH OpenSM 0/3] Fat Tree - Routing between non-CN nodes

[Nicolas Morey Chaisemartin]

Hi,

We are current working on a Ftree topology where IO nodes are connected on spine switches.
Using the cn_guid_file and root_guid_file works great.
It is possible to route the whole tree as a fat tree. All the CNs are connected to the other CN and IO nodes.
However, we are missing some connectivity between IO nodes. This is the expected behavior as the route between those IO nodes would have
to go down to go back up on another spine switch.

However, we need at least a bit of connectivity between those nodes. There won't be any real traffic but just some "ping" for HA purposes.

Therefore, I have implemented two new options to openSM: io_guid_file and max_reverse_hops.
The io_guid_file provides a list of all the IO guid (it may differs from the list of non-CN nodes)
The max_reverse_hops gives the number of time IO nodes (described by io_guid_file) are allowed to use a switch backward.

According to my tests this has absolutely no effects on regular routing and manages to connect the io nodes together, if max_reverse_hops is big enough.

This is a first draft for this feature. I'd be happy to have some feedback about how to upgrade it and make it as clean as possible, wether it is integrated in the mainstream or not.

Regards

Nicolas Morey- Chaisemartin



---------

Nicolas Morey-Chaisemartin (3):
   Added io_guid_file options and variables in the different structures
     and functions.
   Added max_reverse_hops option for I/O nodes
   Added possible reverse hops for Ftree algorithm.

  opensm/include/opensm/osm_subnet.h |    6 +
  opensm/opensm/main.c               |   26 +++++-
  opensm/opensm/osm_subnet.c         |   18 ++++
  opensm/opensm/osm_ucast_ftree.c    |  183 +++++++++++++++++++++++++++++++-----
  4 files changed, 207 insertions(+), 26 deletions(-)