NOTE: mmap is still the default.
Some highlights:
o Silent component failover.
o The sysv component will only be queried for selection if it is placed before
the mmap component (for example, -mca mpi_common_sm sysv,posix,mmap). In the
default case, sysv will never be queried/selected.
o Per some on-list discussion, now unlinking mmaped file in both mmap and posix
components (see: "System V Shared Memory for Open MPI: Request for Community
Input and Testing" thread).
o Assuming local process homogeneity with respect to all utilized shared
memory facilities. That is, if one local process deems a particular shared
memory facility acceptable, then ALL local processes should be able to
utilize that facility. As it stands, this is an important point because one
process dictates to all other local processes which common sm component will
be selected based on its own, local run-time test.
o Addressed some of George's code reuse concerns.
This commit was SVN r23633.
Configure Option:
--enable-sysv
MCA Parameter:
mpi_common_sm
mpi_common_sm accepts a comma delimited list of: [sysv],mmap (order
dependent). The first component that is successfully selected is used. For
example, -mca mpi_common_sm sysv,mmap will first try sysv. If sysv is not
successfully selected, then mmap will be used. mmap will be used if
mpi_common_sm is not provided.
Notes:
Please make certain that your system's shmmax limit, or equivalent, is larger
than mpool_sm_min_size. Otherwise, shmget may fail.
This commit was SVN r23260.
