This mpool will have no btl module owner there was no btl created for
the HCA with no ports, but it will still be tracked in the mpool
framework (i.e., it's available).
If MPI_ALLOC_MEM is called by the app, one of two things will happen:
1. if there's an HCA on the host with some active ports, the openib
btl component will still be in the process space, and therefore
the "mpool with no btl" (MWNB) module will still be able to call
the reg/dereg functions, and all will be fine. However, if
MPI_FREE_MEM is never invoked to free the memory, bad things will
happen during MPI_FINALIZE. The pml is finalized, which finalizes
all the btls. The btls finalize all their mpools and all is fine.
But later we close down the mpool framework which then finalizes
any left over mpool modules, such as MWNB. However, the openib
BTL module functions that the MWNB was registered with are no
longer in the process space, and it segv's while trying deregister
the memory.
2. if there are *no* HCA's on the host with active ports, then the
openib btl will have been unloaded, and when the MWNM tries to
register the memory, the functions it tries to call (in the openib
btl) are no longer there, and we segv.
This commit was SVN r15735.
0fb8cf65a8