This is required to tighten up the BTL semantics. Ordering is not guaranteed,
but, if the BTL returns a order tag in a descriptor (other than
MCA_BTL_NO_ORDER) then we may request another descriptor that will obey
ordering w.r.t. to the other descriptor.
This will allow sane behavior for RDMA networks, where local completion of an
RDMA operation on the active side does not imply remote completion on the
passive side. If we send a FIN message after local completion and the FIN is
not ordered w.r.t. the RDMA operation then badness may occur as the passive
side may now try to deregister the memory and the RDMA operation may still be
pending on the passive side.
Note that this has no impact on networks that don't suffer from this
limitation as the ORDER tag can simply always be specified as
MCA_BTL_NO_ORDER.
This commit was SVN r14768.
latency is high and the network relatively fast. This will allow for more kernel
level buffering, which allow overlap between system calls and communications.
Somehow, even on fast clusters there is an improvement (non significant).
This patch create multiple modules for the same device, which in turn will
create multiple sockets between the peers. By default the number of BTL by
device is set to 1, so there is no fundamental difference with the current
version. Change the value of btl_tcp_links to enable multiple links between
peers.
This commit was SVN r14076.
This merge adds Checkpoint/Restart support to Open MPI. The initial
frameworks and components support a LAM/MPI-like implementation.
This commit follows the risk assessment presented to the Open MPI core
development group on Feb. 22, 2007.
This commit closes trac:158
More details to follow.
This commit was SVN r14051.
The following SVN revisions from the original message are invalid or
inconsistent and therefore were not cross-referenced:
r13912
The following Trac tickets were found above:
Ticket 158 --> https://svn.open-mpi.org/trac/ompi/ticket/158
In order to provide backwards compatability the framework versions are bumped
and the handler registeration function is at the end of the btl struct.
Testing done on sm, openib, and gm..
This commit was SVN r11256.
number of recv system call by caching the data. Each endpoint has a buffer
(the size is an MCA parameter) that can be use as a cache. Before each receive
operation this buffer is added at the end of the iovec list. All data that are
not expected by the fragment will go in this cache. If the cache contain data
all subsequent receive will just memcpy the data into the BTL buffers.
The only drawback is that we will spin around the receive_handle until all the
cached data is readed by the PML layer. This limitation come from the fact that
the event library is unable to call us if there is no events on the socket.
Therefore we are unable to keep the data in the cache until the next loop
into the progress engine.
This commit was SVN r8398.
