[PATCH net/for-next V2 0/1] change IPoIB neighbour handling

changes from V1:
  
- applied feeback from Dave on hash usage and identation

- applied feedback from Christoph, use values fom the exported arp_tbl
  for the hash table size and the frequency of garbage collection

changes from V0:

- following feedback from Mike and Dave, changed the ipoib_neigh hash table 
  to allow for lock-free read side, the model follows the RCU based implementation 
  in net/core/neighbour.c

- since RCU hash table uses unidirectional collision list, now ipoib_neigh_free 
  needs to do a linked search in order to find the deleted neighbour predecessor 
  in order to link it to the neighbour successor.

- different implementation of hash lookup in ipoib_neigh_get (read-side) 
  vs ipoib_neigh_alloc and ipoib_neigh_free (write-side)

- path_free and ipoib_mcast_free now make use of the ipoib_del_neighs_by_gid helper 
  function in order to delete neighbours related to that path or mcast. This new helper 
  scans the hash table and deletes neighbours with the given GID. It had to be done 
  this way of as  of the unidrectional nature of the linking which by itself 
  arises from the lock free requirement made here...

- a completion mechanism was added to prevent freeing the IPoIB netdevice priv 
  data structure before the RCU based code freed all the neighbours.

Again, the patch was made over net-next as of few IPoIB changes that 
took place there and the parallel submission of the eIPoIB driver. 

Or.

Cc: Shlomo Pongratz <redacted>

Shlomo Pongratz (1):
  IB/ipoib: break linkage to neighbouring system

 drivers/infiniband/ulp/ipoib/ipoib.h           |   54 ++-
 drivers/infiniband/ulp/ipoib/ipoib_cm.c        |   16 +-
 drivers/infiniband/ulp/ipoib/ipoib_main.c      |  641 +++++++++++++++++------
 drivers/infiniband/ulp/ipoib/ipoib_multicast.c |   57 +--
 4 files changed, 533 insertions(+), 235 deletions(-)