Build And Runtime¶

Derecho Build¶

cd /glade/u/home/wchen/lesgo-gpu-test
BUILD_JOBS=8 ./derecho_build_gpu.sh

The helper installs the executable here:

/glade/u/home/wchen/lesgo-gpu-test/test-cases/actuator_turbine_model/lesgo-mpi-ATM

Option	Current Role
`USE_MPI=ON`	Main production mode
`USE_ATM=ON`	Actuator turbine model; active in validation case
`USE_SAFETYMODE=ON`	Extra safety checks retained
`USE_LVLSET=OFF`	Optional level-set path; GPU coverage documented separately
`USE_TURBINES=OFF`	Optional actuator disk path
`USE_CPS=OFF`	Concurrent precursor path
`USE_HIT=OFF`	Homogeneous isotropic turbulence input
`USE_CGNS=OFF`	Optional CGNS output dependency
`USE_SCALARS=OFF`	Optional scalar transport

Switch	Default	Purpose
`LESGO_SGS_HALO_COMBINED`	on	Use optimized combined SGS tau halo path
`LESGO_SGS_CALCSIJ_EXPLICIT`	on	Use explicit CUDA Fortran calc_Sij interior path
`LESGO_SGS_STAGE_TIMING`	off	Enable SGS diagnostic stage timing
`LESGO_SGS_STRICT_SYNC`	off	Re-enable strict per-stage sync for diagnosis
`LESGO_PRESS_RHS_HALO_COMBINED`	on	Use optimized combined pressure RHS halo
`LESGO_PRESS_TRANSPOSE_GENERIC`	off	Force generic pressure transpose fallback
`LESGO_PRESS_DIRECT_THOMAS_OUT`	on	Use direct Thomas output path
`LESGO_PRESS_STAGE_TIMING`	off	Enable pressure stage timing
`LESGO_PRESS_TRANSPOSE_TIMING`	off	Enable transpose-Thomas helper timing
`LESGO_PROJECT_STAGE_TIMING`	off	Enable projection timing details
`LESGO_ATM_DIAG_TIMING`	off	Enable detailed ATM timing
`LESGO_ATM_POINT_OWNER_LB`	off	Experimental point-owner ATM load balance path
`LESGO_ATM_POINT_OWNER_TARGETED`	off	Experimental targeted ATM exchange path
`LESGO_ATM_LB_AUTO_SELECT`	off	Probe legacy vs LB and choose faster path
`LESGO_ATM_LB_VALIDATE`	off	Compare ATM LB path against legacy quantities
`LESGO_MPI_CUDA_DEBUG`	off	Print CUDA/MPI pointer and environment diagnostics
`LESGO_MPI_CUDA_SYNC`	off	Force CUDA sync around debug MPI wrappers

CPU reference timing checkpoints are intentionally preserved but not counted as GPU debug controls:

Switch	Purpose
`LESGO_CPU_REF_TIME_TOTAL`	Optional CPU total reference for reporting `Other` speedup
`LESGO_CPU_REF_TIME_FORCING`	Optional CPU forcing reference for reporting

System probes such as CUDA_VISIBLE_DEVICES and MPICH_GPU_SUPPORT_ENABLED are inspected for diagnostics but are not LESGO-owned checkpoints.