- tmp_buff1 = (char *) xbt_malloc(block_size * num_procs * Y);
- tmp_buff2 = (char *) xbt_malloc(block_size * Y);
+ tmp_buff1 = (char *) smpi_get_tmp_sendbuffer(block_size * num_procs * Y);
+ tmp_buff2 = (char *) smpi_get_tmp_recvbuffer(block_size * Y);