This commit adds support for performing one-sided operations over
supported hardware (currently Infiniband and Cray Gemini/Aries). This
component is still undergoing active development.
Current features:
- Use network atomic operations (fadd, cswap) for implementing
locking and PSCW synchronization.
- Aggregate small contiguous puts.
- Reduced memory footprint by storing window data (pointer, keys,
etc) at the lowest rank on each node. The data is fetched as each
process needs to communicate with a new peer. This is a trade-off
between the performance of the first operation on a peer and the
memory utilization of a window.
TODO:
- Add support for the accumulate_ops info key. If it is known that
the same op or same op/no op is used it may be possible to use
hardware atomics for fetch-and-op and compare-and-swap.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
The ompi_osc_signal_outgoing was moved from ompi_osc_rdma_frag_start to frag_send
which gave correct results for the bug reproducer but hangs with simple OSC
tests. Moved the ompi_osc_signal_outgoing back and it now passes all tests.
Closes#256
osc/rdma uses counters to determine if all messages have been received
before exiting synchronization calls. The problem is that the active
target counter is always increasing (never zeroed). If over 2^31-1
messages are sent this causes the counter to overflow (in itself this
isn't an error). This causes test/wait to return before the communication
is complete. There is an additional error in the use of the fragment
flush function. If PSCW synchronization is in use this function CAN NOT
be called unless a post message has arrived.
Relevant mailing list thread: http://www.open-mpi.org/community/lists/devel/2014/10/16016.php
This commit fixes both issues. Tested against MTT and issue reproducer.
Closes#224.
The post and start window calls are supposed to be matching. The code
did not check to see that an incoming post matched with the start call.
This commit fixes the bug by placing the post on a pending list that
will be checked by the next call to start.
cmr=v1.8.2:reviewer=dgoodell
This commit was SVN r32017.
This commit adds large datatype description support to the osc/rdma
component. Support is provided by an additional send/recv of the datatype
description if the description does not fit in an eager buffer. The
code is designed to require minimal new code and not for speed. We
consider this code path to be a slow path.
Refs trac:1905
cmr=v1.8:reviewer=jsquyres
This commit was SVN r31197.
The following Trac tickets were found above:
Ticket 1905 --> https://svn.open-mpi.org/trac/ompi/ticket/1905
Dave Goodell correctly pointed out that it is unusual to return MPI
error classes from internal ompi functions. Correct this in the RMA
case by adding an internal error code to match MPI_ERR_RMA_SYNC.
This does change OMPI_ERR_MAX. I don't think this will cause any
problems with ABI.
cmr=v1.7.5:reviewer=jsquyres
This commit was SVN r31012.
