Basically: since usnic is a connectionless transport, we do not get
OS-provided services "for free" that connection-oriented transports
get, namely: "hey, I wasn't able to make a connection to peer X", and
"hey, your connection to peer X has died."
This connectivity-checker runs in a separate progress thread in the
usnic BTL in local rank 0 on each server. Upon first send in any
process, the connectivty-checker agent will send some UDP pings to the
peer to ensure that we can reach it. If we can't, we'll abort the job
with a nice show_help message.
There's a lengthy comment in btl_usnic_connectivity.h explains the
scheme and how it works.
Reviewed by Dave Goodell.
cmr=v1.7.5:ticket=trac:4253
This commit was SVN r30860.
The following Trac tickets were found above:
Ticket 4253 --> https://svn.open-mpi.org/trac/ompi/ticket/4253
These includes only exist in the Cisco-internal usnic-v1.6 code base,
but they should not exist anywhere except btl_usnic_compat.h in order to
minimize source differences between usnic-v1.6 and v1.7/trunk.
Reviewed-by: Jeff Squyres <jsquyres@cisco.com>
cmr=v1.7.5:ticket=trac:4253
This commit was SVN r30844.
The following Trac tickets were found above:
Ticket 4253 --> https://svn.open-mpi.org/trac/ompi/ticket/4253
If we need to use a convertor, go back to stashing that convertor in the
frag and populating segments "on the fly" (in
ompi_btl_usnic_module_progress_sends). Previously we would pack into a
chain of chunk segments at prepare_src time, unnecessarily consuming
additional memory.
Reviewed-by: Jeff Squyres <jsquyres@cisco.com>
Reviewed-by: Reese Faucette <rfaucett@cisco.com>
This commit was SVN r29592.
This new routine can be called in exceptional situations, either
conditionally in BTL code or from a debugger, to help with debugging in
cases where MSGDEBUG1/2 or stats logging are impractical but more detail
is needed.
Reviewed-by: Jeff Squyres <jsquyres@cisco.com>
This commit was SVN r29483.
Brian (rightfully) hit me on the head with the
don't-use-ORTE-use-the-rte-framework clue bat; the usnic BTL now
nicely plays with the RTE framework.
This commit was SVN r28907.
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.
