Do an all-process reduction rather than look for masses on a sngle processes

Martin D. Weinberg · Martin D. Weinberg · commit 3fd28ba039d0 · 2025-07-22T10:14:44.000-04:00
diff --git a/src/OutHDF5.cc b/src/OutHDF5.cc
@@ -794,8 +794,8 @@ void OutHDF5::checkParticleMasses()
       p = c->get_particles(&number);
     }
 
-    MPI_Bcast(&minMass, 1, MPI_DOUBLE, 0, MPI_COMM_WORLD);
-    MPI_Bcast(&maxMass, 1, MPI_DOUBLE, 0, MPI_COMM_WORLD);
+    MPI_Allreduce(MPI_IN_PLACE, &minMass, 1, MPI_DOUBLE, MPI_MIN, MPI_COMM_WORLD);
+    MPI_Allreduce(MPI_IN_PLACE, &maxMass, 1, MPI_DOUBLE, MPI_MAX, MPI_COMM_WORLD);
 
     if ( (maxMass - minMass)/maxMass < 1.0e-12) {
       masses.push_back(maxMass);

Original file line number	Diff line number	Diff line change
`@@ -794,8 +794,8 @@ void OutHDF5::checkParticleMasses()`
`794`	`794`	`p = c->get_particles(&number);`
`795`	`795`	`}`
`796`	`796`
`797`		`- MPI_Bcast(&minMass, 1, MPI_DOUBLE, 0, MPI_COMM_WORLD);`
`798`		`- MPI_Bcast(&maxMass, 1, MPI_DOUBLE, 0, MPI_COMM_WORLD);`
	`797`	`+ MPI_Allreduce(MPI_IN_PLACE, &minMass, 1, MPI_DOUBLE, MPI_MIN, MPI_COMM_WORLD);`
	`798`	`+ MPI_Allreduce(MPI_IN_PLACE, &maxMass, 1, MPI_DOUBLE, MPI_MAX, MPI_COMM_WORLD);`
`799`	`799`
`800`	`800`	`if ( (maxMass - minMass)/maxMass < 1.0e-12) {`
`801`	`801`	`masses.push_back(maxMass);`