Reduce mpi LU testcase in valgrind

mpi/examples/mpi_lu/plu_example.c

@@ -133,7 +133,10 @@ static void parse_args(int rank, int argc, char **argv)
 
 #ifdef STARPU_HAVE_VALGRIND_H
 	if (RUNNING_ON_VALGRIND)
-		size = 16;
+	{
+		size = 4;
+		nblocks = 4;
+	}
 #endif
 }
 

mpi/examples/mpi_lu/plu_implicit_example.c

@@ -112,7 +112,10 @@ static void parse_args(int argc, char **argv)
 
 #ifdef STARPU_HAVE_VALGRIND_H
 	if (RUNNING_ON_VALGRIND)
-		size = 16;
+	{
+		size = 4;
+		nblocks = 4;
+	}
 #endif
 }
 

mpi/examples/mpi_lu/plu_outofcore_example.c

@@ -123,7 +123,10 @@ static void parse_args(int argc, char **argv)
 
 #ifdef STARPU_HAVE_VALGRIND_H
 	if (RUNNING_ON_VALGRIND)
-		size = 16;
+	{
+		size = 4;
+		nblocks = 4;
+	}
 #endif
 }