changes required to support MPI_Bsend(). Introduces concept of
attaching a buffer to a large segment that the PML can scribble into and
we will send from. The reason we don't use a pinned buffer and send
directly from that is that usnic_verbs does not (yes) support num_sge>1
for regular sends. This means the data gets copied twice, but that is
unavoidable.
changed the logic in handle_large_send to be more sensible
Incorporated David's review comments
This commit was SVN r29184.
- tag needs to be sent in *our* header, not the PML header
- usnic_alloc() should return smaller value if too much data requested
- be careful about callbacks vs removing items from lists
(we need to remove from outr lists *before* the callback)
- improve send callback handling
- add some more MSGDEBUG2 logging and cleanup
This commit was SVN r29181.
non-contiguous converter. We can't "convert on the fly" because the #
of bytes requested may not divide evenly into the convertor data type.
This commit was SVN r29014.
This BTL accesses the Cisco usNIC Linux device via the Linux verbs
API via Unreliable Datagram queue pairs. A few noteworthy points:
* This BTL does most of its own fragmentation; it tells the PML that
it has a very high max_send_size (much higher than the network
MTU).
* Since UD fragments are, by definition, unreliable, the usnic BTL
handles all of its own reliability via a sliding window approach
using the opal_hotel construct and many tricks stolen from the
corpus of knowledge surrounding efficient TCP.
* There is a fun PML latency-metric based optimization for NUMA
awareness of short messages.
* Note that this is ''not'' a generic UD verbs BTL; it is specific to
the Cisco usNIC device.
This commit was SVN r28879.
