Can not set both UCP_OP_ATTR_FIELD_DATATYPE and UCP_OP_ATTR_FLAG_NO_IMM_CMPL to ucp_am_send_nbx()?

[huzhijiang]

If set both UCP_OP_ATTR_FIELD_DATATYPE and UCP_OP_ATTR_FLAG_NO_IMM_CMPL flags, the following line of code will always treat data type as contig? iov data type will be ignored ?

ucx/src/ucp/core/ucp_am.c

Line 997 in d4bb985

datatype = ucp_dt_make_contig(1);

[yosefe]

Seems like a bug; would need to apply same logic as in

ucx/src/ucp/tag/tag_send.c

Lines 273 to 280 in d4bb985

	} else {
	/* UCP_OP_ATTR_FIELD_DATATYPE | UCP_OP_ATTR_FLAG_NO_IMM_CMPL */
	datatype = param->datatype;
	if (UCP_DT_IS_CONTIG(datatype)) {
	contig_length = ucp_contig_dt_length(datatype, count);
	}
	}