>On 18/03/2020 21:35, jer...@marvell.com wrote: >> From: Pavan Nikhilesh <pbhagavat...@marvell.com> >> >> Add IPv4 lookup process function for ip4_lookup >> rte_node. This node performs LPM lookup using x86_64 >> vector supported RTE_LPM API on every packet received >> and forwards it to a next node that is identified by >> lookup result. >> >> Signed-off-by: Pavan Nikhilesh <pbhagavat...@marvell.com> >> Signed-off-by: Nithin Dabilpuram <ndabilpu...@marvell.com> >> Signed-off-by: Kiran Kumar K <kirankum...@marvell.com> >> --- >> lib/librte_node/ip4_lookup.c | 245 >+++++++++++++++++++++++++++++++++++ >> 1 file changed, 245 insertions(+) >> >> diff --git a/lib/librte_node/ip4_lookup.c >b/lib/librte_node/ip4_lookup.c >> index d7fcd1158..c003e9c91 100644 >> --- a/lib/librte_node/ip4_lookup.c >> +++ b/lib/librte_node/ip4_lookup.c >> @@ -264,6 +264,251 @@ ip4_lookup_node_process(struct rte_graph >*graph, struct rte_node *node, >> return nb_objs; >> } >> >> +#elif defined(RTE_ARCH_X86) >> + >> +/* X86 SSE */ >> +static uint16_t >> +ip4_lookup_node_process(struct rte_graph *graph, struct rte_node >*node, >> + void **objs, uint16_t nb_objs) >> +{ >> + struct rte_mbuf *mbuf0, *mbuf1, *mbuf2, *mbuf3, **pkts; >> + rte_edge_t next0, next1, next2, next3, next_index; >> + struct rte_ipv4_hdr *ipv4_hdr; >> + struct rte_ether_hdr *eth_hdr; >> + uint32_t ip0, ip1, ip2, ip3; >> + void **to_next, **from; >> + uint16_t last_spec = 0; >> + uint16_t n_left_from; >> + struct rte_lpm *lpm; >> + uint16_t held = 0; >> + uint32_t drop_nh; >> + rte_xmm_t dst; >> + __m128i dip; /* SSE register */ >> + int rc, i; >> + >> + /* Speculative next */ >> + next_index = RTE_NODE_IP4_LOOKUP_NEXT_REWRITE; >> + /* Drop node */ >> + drop_nh = >((uint32_t)RTE_NODE_IP4_LOOKUP_NEXT_PKT_DROP) << 16; >> + >> + /* Get socket specific LPM from ctx */ >> + lpm = *((struct rte_lpm **)node->ctx); >> + >> + pkts = (struct rte_mbuf **)objs; >> + from = objs; >> + n_left_from = nb_objs; > >I doubt this initial prefetch of the first 4 packets has any benefit.
Ack will remove in v2 for x86. > >> + if (n_left_from >= 4) { >> + for (i = 0; i < 4; i++) { >> + rte_prefetch0(rte_pktmbuf_mtod(pkts[i], >> + struct rte_ether_hdr >*) + >> + 1); >> + } >> + } >> + >> + /* Get stream for the speculated next node */ >> + to_next = rte_node_next_stream_get(graph, node, >next_index, nb_objs); > >Suggest you don't reuse the hand-unrolling optimization from FD.io >VPP. >I have never found any performance benefit from them, and they >make the code unnecessarily verbose. > How would be take the benefit of rte_lpm_lookupx4 without unrolling the loop?. Also, in future if we are using rte_rib and fib with a CPU supporting wider SIMD we might need to unroll them further (AVX256 AND 512 currently rte_lpm_lookup uses only 128bit since it is only uses SSE extension). > >> + while (n_left_from >= 4) { >> + /* Prefetch next-next mbufs */ >> + if (likely(n_left_from >= 11)) { >> + rte_prefetch0(pkts[8]); >> + rte_prefetch0(pkts[9]); >> + rte_prefetch0(pkts[10]); >> + rte_prefetch0(pkts[11]); >> + } >> + >> + /* Prefetch next mbuf data */ >> + if (likely(n_left_from >= 7)) { >> + rte_prefetch0(rte_pktmbuf_mtod(pkts[4], >> + struct rte_ether_hdr >*) + >> + 1); >> + rte_prefetch0(rte_pktmbuf_mtod(pkts[5], >> + struct rte_ether_hdr >*) + >> + 1); >> + rte_prefetch0(rte_pktmbuf_mtod(pkts[6], >> + struct rte_ether_hdr >*) + >> + 1); >> + rte_prefetch0(rte_pktmbuf_mtod(pkts[7], >> + struct rte_ether_hdr >*) + >> + 1); >> + } >> + >> + mbuf0 = pkts[0]; >> + mbuf1 = pkts[1]; >> + mbuf2 = pkts[2]; >> + mbuf3 = pkts[3]; >> + >> + pkts += 4; >> + n_left_from -= 4; >> + >> + /* Extract DIP of mbuf0 */ >> + eth_hdr = rte_pktmbuf_mtod(mbuf0, struct >rte_ether_hdr *); >> + ipv4_hdr = (struct rte_ipv4_hdr *)(eth_hdr + 1); >> + ip0 = ipv4_hdr->dst_addr; >> + /* Extract cksum, ttl as ipv4 hdr is in cache */ >> + rte_node_mbuf_priv1(mbuf0)->cksum = ipv4_hdr- >>hdr_checksum; >> + rte_node_mbuf_priv1(mbuf0)->ttl = ipv4_hdr- >>time_to_live; >> + >> + /* Extract DIP of mbuf1 */ >> + eth_hdr = rte_pktmbuf_mtod(mbuf1, struct >rte_ether_hdr *); >> + ipv4_hdr = (struct rte_ipv4_hdr *)(eth_hdr + 1); >> + ip1 = ipv4_hdr->dst_addr; >> + /* Extract cksum, ttl as ipv4 hdr is in cache */ >> + rte_node_mbuf_priv1(mbuf1)->cksum = ipv4_hdr- >>hdr_checksum; >> + rte_node_mbuf_priv1(mbuf1)->ttl = ipv4_hdr- >>time_to_live; >> + >> + /* Extract DIP of mbuf2 */ >> + eth_hdr = rte_pktmbuf_mtod(mbuf2, struct >rte_ether_hdr *); >> + ipv4_hdr = (struct rte_ipv4_hdr *)(eth_hdr + 1); >> + ip2 = ipv4_hdr->dst_addr; >> + /* Extract cksum, ttl as ipv4 hdr is in cache */ >> + rte_node_mbuf_priv1(mbuf2)->cksum = ipv4_hdr- >>hdr_checksum; >> + rte_node_mbuf_priv1(mbuf2)->ttl = ipv4_hdr- >>time_to_live; >> + >> + /* Extract DIP of mbuf3 */ >> + eth_hdr = rte_pktmbuf_mtod(mbuf3, struct >rte_ether_hdr *); >> + ipv4_hdr = (struct rte_ipv4_hdr *)(eth_hdr + 1); >> + ip3 = ipv4_hdr->dst_addr; >> + >> + /* Prepare for lookup x4 */ >> + dip = _mm_set_epi32(ip3, ip2, ip1, ip0); >> + >> + /* Byte swap 4 IPV4 addresses. */ >> + const __m128i bswap_mask = _mm_set_epi8( >> + 12, 13, 14, 15, 8, 9, 10, 11, 4, 5, 6, 7, 0, 1, 2, 3); >> + dip = _mm_shuffle_epi8(dip, bswap_mask); >> + >> + /* Extract cksum, ttl as ipv4 hdr is in cache */ >> + rte_node_mbuf_priv1(mbuf3)->cksum = ipv4_hdr- >>hdr_checksum; >> + rte_node_mbuf_priv1(mbuf3)->ttl = ipv4_hdr- >>time_to_live; >> + >> + /* Perform LPM lookup to get NH and next node */ >> + rte_lpm_lookupx4(lpm, dip, dst.u32, drop_nh); >> + >> + /* Extract next node id and NH */ >> + rte_node_mbuf_priv1(mbuf0)->nh = dst.u32[0] & >0xFFFF; >> + next0 = (dst.u32[0] >> 16); >> + >> + rte_node_mbuf_priv1(mbuf1)->nh = dst.u32[1] & >0xFFFF; >> + next1 = (dst.u32[1] >> 16); >> + >> + rte_node_mbuf_priv1(mbuf2)->nh = dst.u32[2] & >0xFFFF; >> + next2 = (dst.u32[2] >> 16); >> + >> + rte_node_mbuf_priv1(mbuf3)->nh = dst.u32[3] & >0xFFFF; >> + next3 = (dst.u32[3] >> 16); >> + >> + /* Enqueue four to next node */ >> + rte_edge_t fix_spec = >> + (next_index ^ next0) | (next_index ^ next1) | >> + (next_index ^ next2) | (next_index ^ next3); >> + >> + if (unlikely(fix_spec)) { >> + /* Copy things successfully speculated till now >*/ >> + rte_memcpy(to_next, from, last_spec * >sizeof(from[0])); >> + from += last_spec; >> + to_next += last_spec; >> + held += last_spec; >> + last_spec = 0; >> + >> + /* Next0 */ >> + if (next_index == next0) { >> + to_next[0] = from[0]; >> + to_next++; >> + held++; >> + } else { >> + rte_node_enqueue_x1(graph, node, >next0, >> + from[0]); >> + } >> + >> + /* Next1 */ >> + if (next_index == next1) { >> + to_next[0] = from[1]; >> + to_next++; >> + held++; >> + } else { >> + rte_node_enqueue_x1(graph, node, >next1, >> + from[1]); >> + } >> + >> + /* Next2 */ >> + if (next_index == next2) { >> + to_next[0] = from[2]; >> + to_next++; >> + held++; >> + } else { >> + rte_node_enqueue_x1(graph, node, >next2, >> + from[2]); >> + } >> + >> + /* Next3 */ >> + if (next_index == next3) { >> + to_next[0] = from[3]; >> + to_next++; >> + held++; >> + } else { >> + rte_node_enqueue_x1(graph, node, >next3, >> + from[3]); >> + } >> + >> + from += 4; >> + >> + } else { >> + last_spec += 4; >> + } >> + } >> + >> + while (n_left_from > 0) { >> + uint32_t next_hop; >> + >> + mbuf0 = pkts[0]; >> + >> + pkts += 1; >> + n_left_from -= 1; >> + >> + /* Extract DIP of mbuf0 */ >> + eth_hdr = rte_pktmbuf_mtod(mbuf0, struct >rte_ether_hdr *); >> + ipv4_hdr = (struct rte_ipv4_hdr *)(eth_hdr + 1); >> + /* Extract cksum, ttl as ipv4 hdr is in cache */ >> + rte_node_mbuf_priv1(mbuf0)->cksum = ipv4_hdr- >>hdr_checksum; >> + rte_node_mbuf_priv1(mbuf0)->ttl = ipv4_hdr- >>time_to_live; >> + >> + rc = rte_lpm_lookup(lpm, rte_be_to_cpu_32(ipv4_hdr- >>dst_addr), >> + &next_hop); >> + next_hop = (rc == 0) ? next_hop : drop_nh; >> + >> + rte_node_mbuf_priv1(mbuf0)->nh = next_hop & >0xFFFF; >> + next0 = (next_hop >> 16); >> + >> + if (unlikely(next_index ^ next0)) { >> + /* Copy things successfully speculated till now >*/ >> + rte_memcpy(to_next, from, last_spec * >sizeof(from[0])); >> + from += last_spec; >> + to_next += last_spec; >> + held += last_spec; >> + last_spec = 0; >> + >> + rte_node_enqueue_x1(graph, node, next0, >from[0]); >> + from += 1; >> + } else { >> + last_spec += 1; >> + } >> + } >> + >> + /* !!! Home run !!! */ >> + if (likely(last_spec == nb_objs)) { >> + rte_node_next_stream_move(graph, node, >next_index); >> + return nb_objs; >> + } >> + >> + held += last_spec; >> + /* Copy things successfully speculated till now */ >> + rte_memcpy(to_next, from, last_spec * sizeof(from[0])); >> + rte_node_next_stream_put(graph, node, next_index, held); >> + >> + return nb_objs; >> +} >> + >> #else >> >> static uint16_t >>