[to be squashed] remove weird packing case

Author: raffenet

src/mpid/ch4/netmod/ucx/ucx_am.c

@@ -89,22 +89,14 @@ int MPIDI_UCX_do_am_recv(MPIR_Request * rreq)
     };
 
     MPIDIG_get_recv_buffer(&recv_buf, &data_sz, &is_contig, &in_data_sz, rreq);
-    if (in_data_sz > data_sz) {
-        /* ucx will error out if buffer size is less than the promised data size,
-         * use a pack buffer in this case */
-        /* FIXME: what? how does UCX know the buffer size differs? */
-        recv_buf = MPL_malloc(in_data_sz, MPL_MEM_OTHER);
-        MPIR_Assert(recv_buf);
-        MPIDI_UCX_AM_RECV_REQUEST(rreq, pack_buffer) = recv_buf;
-    } else {
-        MPIDI_UCX_AM_RECV_REQUEST(rreq, pack_buffer) = NULL;
-        if (!is_contig) {
-            MPIR_Datatype *dt_ptr;
-            MPIR_Datatype_get_ptr(MPIDIG_REQUEST(rreq, datatype), dt_ptr);
-            param.op_attr_mask |= UCP_OP_ATTR_FIELD_DATATYPE;
-            param.datatype = dt_ptr->dev.netmod.ucx.ucp_datatype;
-            MPIR_Datatype_ptr_add_ref(dt_ptr);
-        }
+    MPIDI_UCX_AM_RECV_REQUEST(rreq, pack_buffer) = NULL;
+    if (!is_contig) {
+        MPIR_Datatype *dt_ptr;
+        MPIR_Datatype_get_ptr(MPIDIG_REQUEST(rreq, datatype), dt_ptr);
+        param.op_attr_mask |= UCP_OP_ATTR_FIELD_DATATYPE;
+        param.datatype = dt_ptr->dev.netmod.ucx.ucp_datatype;
+        MPIR_Datatype_ptr_add_ref(dt_ptr);
+        in_data_sz = MPIDIG_REQUEST(rreq, count);
     }
 
     void *data_desc = MPIDI_UCX_AM_RECV_REQUEST(rreq, data_desc);