[Mpi3-ft] MPI RMA FT Notes

[Jim Dinan]

Hello,

Here are my notes on open issues to investigate in FT for MPI RMA:

  * Separate/Unified memory models -- Is there any difference in which 
data is corrupted by a failure between these two models?

  * MPI_Win_allocate() allocates the window buffer.  Do failures have 
any impact on how this buffer is managed?  Can it be exposed in another 
window after a failure occurs?

  * MPI_Win_allocate_shared() similar to win_allocate().

  * What are the semantics of MPI_Win_free() on a revoked window?  It is 
normally synchronizing (to quiesce passive target communication).  Is it 
a local operation when the window has been revoked?

  * Because of the difficulty in managing a distributed lock, it has 
been proposed that all synchronizations that occur after a failure on a 
window should fail.  Investigate if this semantic is too restrictive.

  ~Jim.