This commit adds a new optional function to the BTL module:
btl_flush. This function takes an optional BTL endpoint. When called
this function completes all outstanding RDMA and atomic operations
started prior to the call to btl_flush.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
This commit uses the new flag "enumerator" to support comma-delimited
lists of flags for both the btl and btl atomic flags. After this
commit is is valid to specify something like -mca btl_foo_flags
self,put,get,in-place. All non-deprecated flags are supported by the
enumerator.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
This commit adds an interface for btl's to export support for 64-bit atomic
operations on integers. BTL's that can support atomic operations should
implement these functions and set the appropriate btl_flags and btl_atomic_flags.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
The old BTL interface provided support for RDMA through the use of
the btl_prepare_src and btl_prepare_dst functions. These functions were
expected to prepare as much of the user buffer as possible for the RDMA
operation and return a descriptor. The descriptor contained segment
information on the prepared region. The btl user could then pass the
RDMA segment information to a remote peer. Once the peer received that
information it then packed it into a similar descriptor on the other
side that could then be passed into a single btl_put or btl_get
operation.
Changes:
- Added functions to register and deregister memory regions with the
btl. If no registration is needed a btl should set these function
pointers to NULL. These function take over for btl_prepare_src/dst
and btl_free for RDMA operations. The caller should specify the
maximum permissions needed on the memory.
- Changed the function signatures for both btl_put and btl_get. In
place of a prepared descriptor the caller should provide the source
and destination addresses and registration handles as well as a
new callback function. The callback will be provided with the local
address and registration handle, callback context, callback data, and
status. See mca_btl_base_rdma_completion_fn_t in btl.h.
- Added a new btl constraint: MCA_BTL_REG_HANDLE_MAX_SIZE. This
value specifies the maximum size of any btl's registration handle.
- Removed the btl_prepare_dst function. This reflects the fact that
RDMA operations no longer depend on "prepared" descriptors.
- Removed the btl_seg_size member. There is no need to btl's to
subclass the mca_btl_base_segment_t class anymore.
- Expose the btl's put/get limitations with new struct members:
btl_put_limit, btl_put_alignment, btl_get_limit, btl_get_alignment.
- Remove the mca_mpool_base_registration_t argument from the btl_prepare_src
function. The argument was intended to support RDMA operations and is no
longer necessary.
- Remove des_remote/des_remote_count from the mca_btl_base_descriptor_t
structure. This structure member was originally used to specify the remote
segment for RDMA operations. Since the new btl interface no longer uses
desriptors for RDMA this member no longer has a purpose. In addition
to removing these members the local segment structure fields have been
renamed to from des_local/des_local_count to des_segments/des_segment_count.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
The old BTL interface provided support for RDMA through the use of
the btl_prepare_src and btl_prepare_dst functions. These functions were
expected to prepare as much of the user buffer as possible for the RDMA
operation and return a descriptor. The descriptor contained segment
information on the prepared region. The btl user could then pass the
RDMA segment information to a remote peer. Once the peer received that
information it then packed it into a similar descriptor on the other
side that could then be passed into a single btl_put or btl_get
operation.
Changes:
- Removed the btl_prepare_dst function. This reflects the fact that
RDMA operations no longer depend on "prepared" descriptors.
- Removed the btl_seg_size member. There is no need to btl's to
subclass the mca_btl_base_segment_t class anymore.
...
Add more
WHAT: Open our low-level communication infrastructure by moving all necessary components (btl/rcache/allocator/mpool) down in OPAL
All the components required for inter-process communications are currently deeply integrated in the OMPI layer. Several groups/institutions have express interest in having a more generic communication infrastructure, without all the OMPI layer dependencies. This communication layer should be made available at a different software level, available to all layers in the Open MPI software stack. As an example, our ORTE layer could replace the current OOB and instead use the BTL directly, gaining access to more reactive network interfaces than TCP. Similarly, external software libraries could take advantage of our highly optimized AM (active message) communication layer for their own purpose. UTK with support from Sandia, developped a version of Open MPI where the entire communication infrastucture has been moved down to OPAL (btl/rcache/allocator/mpool). Most of the moved components have been updated to match the new schema, with few exceptions (mainly BTLs where I have no way of compiling/testing them). Thus, the completion of this RFC is tied to being able to completing this move for all BTLs. For this we need help from the rest of the Open MPI community, especially those supporting some of the BTLs. A non-exhaustive list of BTLs that qualify here is: mx, portals4, scif, udapl, ugni, usnic.
This commit was SVN r32317.
