[ofa-general] [PATCH 0/4] opensm: more routing optimizations

[Sasha Khapyorsky]

Mostly it implements the "switch only" optimization idea and affects
the min hops matrices building phase (for both up/down and default
builders).

The main trick is to keep the min hop tables _ONLY_ for switches base
LIDs and don't bother with CAs, routers LIDs and any secondary LIDs in
case when LMC > 0 - this saves a lot of memory and cpu cycles needed
for calculation and storing the huge whole fabric matrices.

For CA and router ports we will refer its neighbor switch's min hop
vectors. And for LMC > 0 case we will use base LID's min hop vectors
for any secondary LIDs (for CAs and routers it will neighbor switch's
base LID).

Preliminary testing shows 3-4x speedup in the min-hop generation phase
and yet another 2x for up/down.

Sasha