gcc complains about ret possibly being used uninitialized. That will
never happen but we should still quiet the warning. This commit sets
ret to a valid value.
Fixes#5513
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
The osc/rdma module did not wait for all pending atomics to complete
before tearing down. This could lead to weird issues as the target
location may no longer be registered or allocated.
This commit also fixes an offset calculation issue in
ompi_osc_get_data_blocking ().
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
This commit is a large update to the osc/rdma component. Included in
this commit:
- Add support for using hardware atomics for fetch-and-op and single
count accumulate when using the accumulate lock. This will improve
the performance of these operations even when not setting the
single intrinsic info key.
- Rework how large accumulates are done. They now block on the get
operation to fix some bugs discovered by an IBM one-sided test. I
may roll back some of the changes if the underlying bug in the
original design is discovered. There appear to be no real
difference (on the hardware this was tested with) in performance so
its probably a non-issue. References #2530.
- Add support for an additional lock-all algorithm: on-demand. The
on-demand algorithm will attempt to acquire the peer lock when
starting an RMA operation. The lock algorithm default has not
changed. The algorithm can be selected by setting the
osc_rdma_locking_mode MCA variable. The valid values are two_level
and on_demand.
- Make use of the btl_flush function if available. This can improve
performance with some btls.
- When using btl_flush do not keep track of the number of put
operations. This reduces the number of atomic operations in the
critical path.
- Make the window buffers more friendly to multi-threaded
applications. This was done by dropping support for multiple
buffers per MPI window. I intend to re-add that support once the
underlying performance bug under the old buffering scheme is
fixed.
- Fix a bug in request completion in the accumulate, get, and put
paths. This also helps with #2530.
- General code cleanup and fixes.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
This commit eliminates the old opal_atomic_bool_cmpset functions. They
have been replaced by the opal_atomic_compare_exchange_strong
functions.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
This commit changes the locking code to allow the lock release to be
non-blocking. This helps with releasing the accumulate lock which may
occur in a BTL callback.
Fixes#3616
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
Under heavy load the locking code could fail if the underlying btl
module started to return OPAL_ERR_OUT_OF_RESOURCE on atomic
operations. This commit updates the code to gracefully handle btl
errors.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
This commit adds code to handle large unaligned gets. There are two
possible code paths for these transactions:
1) The remote region and local region have the same alignment. In
this case the get will be broken down into at most three get
transactions: 1 transaction to get the unaligned start of the region
(buffered), 1 transaction to get the aligned portion of the region,
and 1 transaction to get the end of the region.
2) The remote and local regions do not have the same alignment. This
should be an uncommon case and is not optimized. In this case a
buffer is allocated and registered locally to hold the aligned data
from the remote region. There may be cases where this fails (low
memory, can't register memory). Those conditions are unlikely and
will be handled later.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
A previous commit updated the one-sided code to register the state
region only once. This created an issue when using the scratch lock
with fetching atomics. In this case on any rank that isn't local rank
0 the module->state_handle is NULL. This commit fixes the issue by
removing the scratch lock and using a fragment pointer instead.
Fixesopen-mpi/ompi#1290
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
This commit fixes several bugs in the osc/rdma component:
- Complete aggregated requests immediately. Completion of RMA
requests indicates local completion anyway. This fixes a hang in
the c_reqops test.
- Correctly mark Rget_accumulate requests.
- Set the local base flag correctly on the local peer.
- Clear or set the no locks flag on the window if the value is
changed by MPI_Win_set_info.
- Actually update the target when using MPI_OP_REPLACE.
Fixesopen-mpi/ompi#1010
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
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>
