X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/1d18e615eaa617d3354bc22dfbe711d34be9f902..078e59c8562f1a12a828b8197689c1843d0b6e07:/src/smpi/colls/allgather-2dmesh.c

diff --git a/src/smpi/colls/allgather-2dmesh.c b/src/smpi/colls/allgather-2dmesh.c
index b5f50420e0..602d540e11 100644
--- a/src/smpi/colls/allgather-2dmesh.c
+++ b/src/smpi/colls/allgather-2dmesh.c
@@ -110,7 +110,7 @@ smpi_coll_tuned_allgather_2dmesh(void *send_buff, int send_count, MPI_Datatype
   int i, src, dst, rank, num_procs;
   int X, Y, send_offset, recv_offset;
   int my_row_base, my_col_base, src_row_base, block_size, num_reqs;
-  int tag = 1;
+  int tag = COLL_TAG_ALLGATHER;
 
   rank = smpi_comm_rank(comm);
   num_procs = smpi_comm_size(comm);
@@ -119,7 +119,9 @@ smpi_coll_tuned_allgather_2dmesh(void *send_buff, int send_count, MPI_Datatype
 
   block_size = extent * send_count;
 
-  is_2dmesh(num_procs, &X, &Y);
+  if (!is_2dmesh(num_procs, &X, &Y))
+    return MPI_ERR_COMM;
+
   my_row_base = (rank / Y) * Y;
   my_col_base = rank % Y;