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Stop mucking about with THREAD_MULTIPLE

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This commit is contained in:
Peter Boyle
2026-08-28 07:06:45 -04:00
parent 2264afda84
commit 27e32b1633
6 changed files with 72 additions and 44 deletions
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tests/debug/Test_schur2d_scale.cc
+7 -14
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@@ -76,20 +76,13 @@ static ComplexD Fill(int64_t i, int64_t j, int64_t N)
int main(int argc, char **argv)
{
// Environment walk (2026-08-27): the SAME inverse runs 20.8 s in the SLATE
// harness and 26.5 s in the example, with the local GPU work (GEMM, leaf
// inverse) 25-40% slower in the example. Knobs to reproduce the example's
// environment here, one at a time (systems/Frontier/schur2d_env.job):
// GRID_MPI_THREAD_MULTIPLE=1 MPI_Init_thread(MULTIPLE) before Grid_init (SLATE harness does this)
// S2D_BALLAST_GB=x x GB of Lattice fields made device-resident before the invert
// (the example carries ~10.6 GB of fine-grid state in the MemoryManager)
// OMP_NUM_THREADS set in the job, read by nothing here but the runtime
if ( getenv("GRID_MPI_THREAD_MULTIPLE") ) {
int provided = 0;
MPI_Init_thread(&argc, &argv, MPI_THREAD_MULTIPLE, &provided);
std::cout << "GRID_MPI_THREAD_MULTIPLE: requested MPI_THREAD_MULTIPLE, provided " << provided
<< (provided==MPI_THREAD_MULTIPLE ? " (MULTIPLE)" : " (NOT multiple)") << std::endl;
}
// Environment walk (2026-08-27, systems/Frontier/schur2d_env.job): knobs to
// reproduce the example's environment here, one at a time. Result: thread
// level, OMP_NUM_THREADS, device residency and sustained load all NIL; only
// "first job step on fresh nodes" (+3 s) is real.
// S2D_BALLAST_GB=x x GB of Lattice fields made device-resident before the invert
// S2D_PREHEAT_S=x x seconds of back-to-back zgemm before the invert
// OMP_NUM_THREADS set in the job, read by nothing here but the runtime
Grid_init(&argc, &argv);
GridCartesian *grid = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(),