On Wed, Feb 23, 2011 at 9:24 PM, Michael Heinz <[email protected]> wrote:
> The common practice in IB fabrics is to set the description of an HCA to be
> the hostname of the machine plus a description (i.e., "myhost hca-1", "myhost
> hca-2", etc..)
>
> This has a limitation, however.  The first is that if the machine's hostname
> is set via DHCP, the HCA description may be set before the hostname is, 
> leading
> to an incorrect description. This can also occur if the machine's hostname
> changes for some other reason after boot.
>
> This can cause difficulties and confusion when trying to maintain a large
> fabric - if all your nodes are described as "localhost HCA-1" it can be very
> difficult to figure out which node is suffering from symbol errors.
>
> This patch addresses the problem by providing a function to build the node
> description. If the provided source string for the description contains a '%h'
> it will be replaced at read time with the hostname of the node. If the 
> provided
> source string contains a '%d' it will be replaced at read time with the name 
> of
> the HCA.  For example, the first Mellanox HCA on a node called "homer" would
> have the default description:
>
> homer: mthca0 MT25208 InfiniHostEx Mellanox Technologies
>
> While the default description for the second QLogic HCA on node-a13 would be:
>
> node-a2: qib0 QLogic kernel.org driver
>
> This ensures that even after a fabric has been completely initialized, if a
> node's hostname changes, that change will be reflected in the next sweep of 
> the
> SM,

assuming the SM sweep reads the NodeDescription, right ?

-- Hal

> but also maintains compatibility with existing code since the behavior is
> unchanged if the description string does not contain a '%' character.
>
> Changes from Version 1:
>
> Replaced the original substitution of the hostname for '@' with an
> implementation of the '%h' and '%d' fields, and changed the default node
> description for Mellanox and QLogic HCA types to default to
> "%h: %d <description>" where '<description>' is the old default message.
>
> ---
>
> Michael Heinz (2):
>      Function for improved node descriptions
>      Add support for ib_build_node_desc() to the HCAs.
>
>
>  drivers/infiniband/core/mad.c                |   33 
> ++++++++++++++++++++++++++
>  drivers/infiniband/hw/ipath/ipath_mad.c      |    2 +-
>  drivers/infiniband/hw/ipath/ipath_verbs.c    |    4 ++-
>  drivers/infiniband/hw/mlx4/mad.c             |    2 +-
>  drivers/infiniband/hw/mlx4/main.c            |    3 ++
>  drivers/infiniband/hw/mthca/mthca_mad.c      |    2 +-
>  drivers/infiniband/hw/mthca/mthca_provider.c |    3 ++
>  drivers/infiniband/hw/qib/qib_mad.c          |    2 +-
>  drivers/infiniband/hw/qib/qib_verbs.c        |    2 +-
>  include/rdma/ib_mad.h                        |    9 +++++++
>  10 files changed, 53 insertions(+), 9 deletions(-)
>
> --
> Signed-off-by: Michael Heinz <[email protected]>
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