* If (legal) non-uniform data type signatures are used in ibcast
then the chosen algorithm may fail on the request, and worst case
it could produce wrong answers.
* Add an MCA parameter that, by default, protects the user from this
scenario. If the user really wants to use it then they have to
'opt-in' by setting the following parameter to false:
- `-mca coll_libnbc_ibcast_skip_dt_decision f`
* Once the following Issues are resolved then this parameter can
be removed.
- https://github.com/open-mpi/ompi/issues/2256
- https://github.com/open-mpi/ompi/issues/1763
Signed-off-by: Joshua Hursey <jhursey@us.ibm.com>
This commit rewrites parts of libnbc to fix issues identified by
coverity and myself. The changes are as follows:
- libnbc function would return invalid error codes (internal to
libnbc) to the mpi layer. These codes names are of the form
NBC_. They do not match up with the error codes expected by the mpi
layer. I purged the use of all these error codes with the exception
of NBC_OK and NBC_CONTINUE in progress. These codes are used to
identify when a request handle is complete.
- Handles and schedules were leaked by all collective routines on
error. A new routine was added to return a collective handle
(NBC_Return_handle).
- Temporary buffers containting in/out neighbors for neighborhood
collectives were always leaked.
- Neigborhood collectives contained code to handle MPI_IN_PLACE which
is never a valid input for the send or receive buffer. Stipped this
code out.
- Files were inconsistently named. Most are nbc_isomething.c but one
was named coll_libnbc_ireduce_scatter_block.c.
- Made the NBC_Schedule "structure" and object so it can be
retained/released. This may enable the use of schedule caching at a
later time. More testing will be needed to ensure the caching code
works. If it doesn't the code should be stripped out completely.
- Added code to simply common case of scheduling send/recv +
barrier.
- Code cleanup for readability.
The code now passes the clang static analyzer.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
I know it does not make much sense but one can play around with the
performance. Numbers are available at http://www.unixer.de/research/nbcoll/perf/.
This is the first step towards collv2. Next step includes the addition
of non-blocking functions to the MPI-Layer and the collv1 interface.
It implements all MPI-1 collective algorithms in a non-blocking manner.
However, the collv1 interface does not allow non-blocking collectives so
that all collectives are used blocking by the ompi-glue layer.
I wanted to add LibNBC as a separate subdirectory, but I could not
convince the buildsystem (and had not the time). So the component looks
pretty messy. It would be great if somebody could explain me how to move
all nbc*{c,h}, and {hb,dict}*{c,h} to a seperate subdirectory.
It's .ompi_ignored because I did not test it exhaustively yet.
This commit was SVN r11401.
