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openmpi/opal/mca/common
Nathan Hjelm d5cdeb81d0 btl/ugni: improve multi-threaded performance
This commit updates the ugni btl to make use of multiple device
contexts to improve the multi-threaded RMA performance. This commit
contains the following:

 - Cleanup the endpoint structure by removing unnecessary field. The
   structure now also contains all the fields originally handled by the
   common/ugni endpoint.

 - Clean up the fragment allocation code to remove the need to
   initialize the my_list member of the fragment structure. This
   member is not initialized by the free list initializer function.

 - Remove the (now unused) common/ugni component. btl/ugni no longer
   need the component. common/ugni was originally split out of
   btl/ugni to support bcol/ugni. As that component exists there is no
   reason to keep this component.

 - Create wrappers for the ugni functionality required by
   btl/ugni. This was done to ease supporting multiple device
   contexts. The wrappers are thread safe and currently use a spin
   lock instead of a mutex. This produces better performance when
   using multiple threads spread over multiple cores. In the future
   this lock may be replaced by another serialization mechanism. The
   wrappers are located in a new file: btl_ugni_device.h.

 - Remove unnecessary device locking from serial parts of the ugni
   btl. This includes the first add-procs and module finalize.

 - Clean up fragment wait list code by moving enqueue into common
   function.

 - Expose the communication domain flags as an MCA variable. The
   defaults have been updated to reflect the recommended setting for
   knl and haswell.

 - Avoid allocating fragments for communication with already
   overloaded peers.

 - Allocate RDMA endpoints dyncamically. This is needed to support
   spreading RMA operations accross multiple contexts.

 - Add support for spreading RMA communication over multiple ugni
   device contexts. This should greatly improve the threading
   performance when communicating with multiple peers. By default the
   number of virtual devices depends on 1) whether
   opal_using_threads() is set, 2) how many local processes are in the
   job, and 3) how many bits are available in the pid. The last is
   used to ensure that each CDM is created with a unique id.

Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
2017-03-13 14:46:06 -06:00
..
cuda Don't refcount the predefined datatypes. 2017-01-11 16:48:59 -05:00
libfabric libfabric: fix wrappers for static builds 2015-07-02 07:58:16 -07:00
sm opal: rework mpool and rcache frameworks 2016-03-14 10:50:41 -06:00
verbs verbs: fix typo 2016-02-02 14:23:45 -08:00
verbs_usnic verbs_usnic: previous commit missed a symbol 2016-02-02 14:05:59 -08:00
Makefile.am Purge whitespace from the repo 2015-06-23 20:59:57 -07:00