User Manual

HPC FeaturesRev 2.2-1.0.1
Mellanox Technologies
156
5.6.2.1 Enabling FCA Operations through Environment Variables in ScalableUPC
This method can be used to control UPC FCA offload from environment using job scheduler srun
utility
. The valid values are: 1 - enable, 0 - disable.
 To enable a specific operation with shell environment variables in ScalableUPC:
% export GASNET_FCA_ENABLE_BARRIER=1
% export GASNET_FCA_ENABLE_BCAST=1
% export GASNET_FCA_ENABLE_REDUCE=1
5.6.2.2 Controlling FCA Offload in ScalableUPC using Environment Variables
 To enable FCA module under ScalableUPC:
% export GASNET_FCA_ENABLE_CMD_LINE=1
 To set FCA verbose level:
% export GASNET_FCA_VERBOSE_CMD_LINE=10
 To set the minimal number of processes threshold to activate FCA:
% export GASNET_FCA_NP_CMD_LINE=1
ScalableUPC contains modules configuration file (http://modules.sf.net) which can be
found at /opt/mellanox/bupc/2.2/etc/bupc_modulefile.
5.6.3 Various Executable Examples
The following are various executable examples.
 To run a ScalableUPC application without FCA support:
% upcrun -np 128 -fca_enable 0 <executable filename>
 To run UPC applications with FCA enabled for any number of processes:
% export GASNET_FCA_ENABLE_CMD_LINE=1 GASNET_FCA_NP_CMD_LINE=0
% upcrun -np 64 <executable filename>
-fca_ops <+/->[op_list]
op_list
- comma separated list of collective operations.
• -fca_ops <+/->[op_list] - Enables/disables only the
specified operations
• -fca_ops <+/-> - Enables/disables all operations
By default all operations are enabled. Allowed operation names are:
barrier (br), bcast (bt), reduce (rc), allgather (ag). Each operation can
be also enabled/disabled via environment variable:
• GASNET_FCA_ENABLE_BARRIER
• GASNET_FCA_ENABLE_BCAST,
• GASNET_FCA_ENABLE_REDUCE,
Note:
All the operations are enabled by default.
Table 18 - Runtime Parameters
Parameter Description