On Thu, 29 Jun 2017 18:58:59 +0800 Jiayu Hu <jiayu...@intel.com> wrote:
> + /* allocate a reassembly table for TCP/IPv4 GRO */ > + uint32_t tcp_item_num = RTE_MIN(item_num, > + RTE_GRO_MAX_BURST_ITEM_NUM); > + struct gro_tcp_tbl tcp_tbl; > + struct gro_tcp_key tcp_keys[tcp_item_num]; > + struct gro_tcp_item tcp_items[tcp_item_num]; Variable size structures on stack were not supported by CLANG, last time I checked. Why not always max size? > + > + struct rte_mbuf *unprocess_pkts[nb_pkts]; > + uint16_t unprocess_num = 0; > + int32_t ret; > + uint64_t current_time; > + > + if ((param->desired_gro_types & RTE_GRO_TCP_IPV4) == 0) > + return nb_pkts; > + > + memset(tcp_keys, 0, sizeof(struct gro_tcp_key) * > + tcp_item_num); > + memset(tcp_items, 0, sizeof(struct gro_tcp_item) * > + tcp_item_num); Variable size memset's are slow. They generate 'rep; stoz' last I checked in GCC and because of rep instruction it kills multi-execution pipeline.
