- round segment buffer allocation to cache-line
- split some routines into an inline fast section and a called
slower section
- introduce receive fastpath in component_progress that:
o returns immediately if there is a packet available on priority
queue and fastpath is enabled
o disables fastpath for 1 time after use to provide fairness to
other processing
o defers receive buffer posting
o defers bookeeping for receive until next call
to usnic_component_progress
Authored-by: Reese Faucette <rfaucett@cisco.com>
Should be included in usnic v1.7.3 roll-up CMR (refs trac:3760)
This commit was SVN r29133.
The following Trac tickets were found above:
Ticket 3760 --> https://svn.open-mpi.org/trac/ompi/ticket/3760
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.
