have smp-aware algorithms use number of cores on the node as basis for their computat...

[simgrid.git] / src / smpi / colls / allreduce-smp-rdb.c

diff --git a/src/smpi/colls/allreduce-smp-rdb.c b/src/smpi/colls/allreduce-smp-rdb.c
index b6def2e..08d2324 100644 (file)
--- a/src/smpi/colls/allreduce-smp-rdb.c
+++ b/src/smpi/colls/allreduce-smp-rdb.c
@@ -34,7 +34,10 @@ int smpi_coll_tuned_allreduce_smp_rdb(void *send_buf, void *recv_buf, int count,
   int tag = COLL_TAG_ALLREDUCE;
   int mask, src, dst;
   MPI_Status status;
-  int num_core = NUM_CORE;
+  int num_core = simcall_host_get_core(SIMIX_host_self());
+  // do we use the default one or the number of cores in the platform ?
+  // if the number of cores is one, the platform may be simulated with 1 node = 1 core
+  if (num_core == 1) num_core = NUM_CORE;
   /*
      #ifdef MPICH2_REDUCTION
      MPI_User_function * uop = MPIR_Op_table[op % 16 - 1];