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.
> + 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.
> + 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
>
