ixgbe: improve slow-path perf with vector scattered Rx
authorBruce Richardson <bruce.richardson@intel.com>
Thu, 11 Sep 2014 13:15:47 +0000 (14:15 +0100)
committerThomas Monjalon <thomas.monjalon@6wind.com>
Wed, 17 Sep 2014 16:57:37 +0000 (18:57 +0200)
Provide a wrapper routine to enable receive of scattered packets with a
vector driver. This improves the performance of the slow-path RX.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
lib/librte_pmd_ixgbe/ixgbe_rxtx.c
lib/librte_pmd_ixgbe/ixgbe_rxtx.h
lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c

index d6448a4..a80cade 100644 (file)
@@ -3476,12 +3476,20 @@ ixgbe_dev_rx_init(struct rte_eth_dev *dev)
                if ((dev->data->dev_conf.rxmode.max_rx_pkt_len +
                                2 * IXGBE_VLAN_TAG_SIZE) > buf_size){
                        dev->data->scattered_rx = 1;
+#ifdef RTE_IXGBE_INC_VECTOR
+                       dev->rx_pkt_burst = ixgbe_recv_scattered_pkts_vec;
+#else
                        dev->rx_pkt_burst = ixgbe_recv_scattered_pkts;
+#endif
                }
        }
 
        if (dev->data->dev_conf.rxmode.enable_scatter) {
+#ifdef RTE_IXGBE_INC_VECTOR
+               dev->rx_pkt_burst = ixgbe_recv_scattered_pkts_vec;
+#else
                dev->rx_pkt_burst = ixgbe_recv_scattered_pkts;
+#endif
                dev->data->scattered_rx = 1;
        }
 
@@ -3969,12 +3977,20 @@ ixgbevf_dev_rx_init(struct rte_eth_dev *dev)
                if ((dev->data->dev_conf.rxmode.max_rx_pkt_len +
                                2 * IXGBE_VLAN_TAG_SIZE) > buf_size) {
                        dev->data->scattered_rx = 1;
+#ifdef RTE_IXGBE_INC_VECTOR
+                       dev->rx_pkt_burst = ixgbe_recv_scattered_pkts_vec;
+#else
                        dev->rx_pkt_burst = ixgbe_recv_scattered_pkts;
+#endif
                }
        }
 
        if (dev->data->dev_conf.rxmode.enable_scatter) {
+#ifdef RTE_IXGBE_INC_VECTOR
+               dev->rx_pkt_burst = ixgbe_recv_scattered_pkts_vec;
+#else
                dev->rx_pkt_burst = ixgbe_recv_scattered_pkts;
+#endif
                dev->data->scattered_rx = 1;
        }
 
index a97fddb..7b5ac0e 100644 (file)
@@ -244,8 +244,12 @@ struct ixgbe_txq_ops {
                         IXGBE_ADVTXD_DCMD_EOP)
 
 #ifdef RTE_IXGBE_INC_VECTOR
-uint16_t ixgbe_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts);
-uint16_t ixgbe_xmit_pkts_vec(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts);
+uint16_t ixgbe_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
+               uint16_t nb_pkts);
+uint16_t ixgbe_recv_scattered_pkts_vec(void *rx_queue,
+               struct rte_mbuf **rx_pkts, uint16_t nb_pkts);
+uint16_t ixgbe_xmit_pkts_vec(void *tx_queue, struct rte_mbuf **tx_pkts,
+               uint16_t nb_pkts);
 int ixgbe_txq_vec_setup(struct igb_tx_queue *txq);
 int ixgbe_rxq_vec_setup(struct igb_rx_queue *rxq);
 int ixgbe_rx_vec_condition_check(struct rte_eth_dev *dev);
index 9869b8b..a6f7fdf 100644 (file)
@@ -164,12 +164,11 @@ desc_to_olflags_v(__m128i descs[4], struct rte_mbuf **rx_pkts)
  *   numbers of DD bit
  * - don't support ol_flags for rss and csum err
  */
-uint16_t
-ixgbe_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
-               uint16_t nb_pkts)
+static inline uint16_t
+_recv_raw_pkts_vec(struct igb_rx_queue *rxq, struct rte_mbuf **rx_pkts,
+               uint16_t nb_pkts, uint8_t *split_packet)
 {
        volatile union ixgbe_adv_rx_desc *rxdp;
-       struct igb_rx_queue *rxq = rx_queue;
        struct igb_rx_entry *sw_ring;
        uint16_t nb_pkts_recd;
        int pos;
@@ -182,7 +181,7 @@ ixgbe_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
                                -rxq->crc_len, /* sub crc on data_len */
                                0            /* ignore pkt_type field */
                        );
-       __m128i dd_check;
+       __m128i dd_check, eop_check;
 
        if (unlikely(nb_pkts < RTE_IXGBE_VPMD_RX_BURST))
                return 0;
@@ -207,6 +206,9 @@ ixgbe_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
        /* 4 packets DD mask */
        dd_check = _mm_set_epi64x(0x0000000100000001LL, 0x0000000100000001LL);
 
+       /* 4 packets EOP mask */
+       eop_check = _mm_set_epi64x(0x0000000200000002LL, 0x0000000200000002LL);
+
        /* mask to shuffle from desc. to mbuf */
        shuf_msk = _mm_set_epi8(
                7, 6, 5, 4,  /* octet 4~7, 32bits rss */
@@ -218,7 +220,6 @@ ixgbe_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
                0xFF, 0xFF   /* skip pkt_type field */
                );
 
-
        /* Cache is empty -> need to scan the buffer rings, but first move
         * the next 'n' mbufs into the cache */
        sw_ring = &rxq->sw_ring[rxq->rx_tail];
@@ -227,6 +228,7 @@ ixgbe_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
         * A. load 4 packet in one loop
         * B. copy 4 mbuf point from swring to rx_pkts
         * C. calc the number of DD bits among the 4 packets
+        * [C*. extract the end-of-packet bit, if requested]
         * D. fill info. from desc to mbuf
         */
        for (pos = 0, nb_pkts_recd = 0; pos < RTE_IXGBE_VPMD_RX_BURST;
@@ -237,6 +239,13 @@ ixgbe_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
                __m128i zero, staterr, sterr_tmp1, sterr_tmp2;
                __m128i mbp1, mbp2; /* two mbuf pointer in one XMM reg. */
 
+               if (split_packet) {
+                       rte_prefetch0(&rx_pkts[pos]->cacheline1);
+                       rte_prefetch0(&rx_pkts[pos + 1]->cacheline1);
+                       rte_prefetch0(&rx_pkts[pos + 2]->cacheline1);
+                       rte_prefetch0(&rx_pkts[pos + 3]->cacheline1);
+               }
+
                /* B.1 load 1 mbuf point */
                mbp1 = _mm_loadu_si128((__m128i *)&sw_ring[pos]);
 
@@ -295,7 +304,34 @@ ixgbe_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
                pkt_mb2 = _mm_add_epi16(pkt_mb2, crc_adjust);
                pkt_mb1 = _mm_add_epi16(pkt_mb1, crc_adjust);
 
-               /* C.3 calc avaialbe number of desc */
+               /* C* extract and record EOP bit */
+               if (split_packet) {
+                       __m128i eop_shuf_mask = _mm_set_epi8(
+                                       0xFF, 0xFF, 0xFF, 0xFF,
+                                       0xFF, 0xFF, 0xFF, 0xFF,
+                                       0xFF, 0xFF, 0xFF, 0xFF,
+                                       0x04, 0x0C, 0x00, 0x08
+                                       );
+
+                       /* and with mask to extract bits, flipping 1-0 */
+                       __m128i eop_bits = _mm_andnot_si128(staterr, eop_check);
+                       /* the staterr values are not in order, as the count
+                        * count of dd bits doesn't care. However, for end of
+                        * packet tracking, we do care, so shuffle. This also
+                        * compresses the 32-bit values to 8-bit */
+                       eop_bits = _mm_shuffle_epi8(eop_bits, eop_shuf_mask);
+                       /* store the resulting 32-bit value */
+                       *(int *)split_packet = _mm_cvtsi128_si32(eop_bits);
+                       split_packet += RTE_IXGBE_DESCS_PER_LOOP;
+
+                       /* zero-out next pointers */
+                       rx_pkts[pos]->next = NULL;
+                       rx_pkts[pos + 1]->next = NULL;
+                       rx_pkts[pos + 2]->next = NULL;
+                       rx_pkts[pos + 3]->next = NULL;
+               }
+
+               /* C.3 calc available number of desc */
                staterr = _mm_and_si128(staterr, dd_check);
                staterr = _mm_packs_epi32(staterr, zero);
 
@@ -319,6 +355,127 @@ ixgbe_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
 
        return nb_pkts_recd;
 }
+
+/*
+ * vPMD receive routine, now only accept (nb_pkts == RTE_IXGBE_VPMD_RX_BURST)
+ * in one loop
+ *
+ * Notice:
+ * - nb_pkts < RTE_IXGBE_VPMD_RX_BURST, just return no packet
+ * - nb_pkts > RTE_IXGBE_VPMD_RX_BURST, only scan RTE_IXGBE_VPMD_RX_BURST
+ *   numbers of DD bit
+ * - don't support ol_flags for rss and csum err
+ */
+uint16_t
+ixgbe_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
+               uint16_t nb_pkts)
+{
+       return _recv_raw_pkts_vec(rx_queue, rx_pkts, nb_pkts, NULL);
+}
+
+static inline uint16_t
+reassemble_packets(struct igb_rx_queue *rxq, struct rte_mbuf **rx_bufs,
+               uint16_t nb_bufs, uint8_t *split_flags)
+{
+       struct rte_mbuf *pkts[RTE_IXGBE_VPMD_RX_BURST]; /*finished pkts*/
+       struct rte_mbuf *start = rxq->pkt_first_seg;
+       struct rte_mbuf *end =  rxq->pkt_last_seg;
+       unsigned pkt_idx = 0, buf_idx = 0;
+
+
+       while (buf_idx < nb_bufs) {
+               if (end != NULL) {
+                       /* processing a split packet */
+                       end->next = rx_bufs[buf_idx];
+                       rx_bufs[buf_idx]->data_len += rxq->crc_len;
+
+                       start->nb_segs++;
+                       start->pkt_len += rx_bufs[buf_idx]->data_len;
+                       end = end->next;
+
+                       if (!split_flags[buf_idx]) {
+                               /* it's the last packet of the set */
+                               start->hash = end->hash;
+                               start->ol_flags = end->ol_flags;
+                               /* we need to strip crc for the whole packet */
+                               start->pkt_len -= rxq->crc_len;
+                               if (end->data_len > rxq->crc_len)
+                                       end->data_len -= rxq->crc_len;
+                               else {
+                                       /* free up last mbuf */
+                                       struct rte_mbuf *secondlast = start;
+                                       while (secondlast->next != end)
+                                               secondlast = secondlast->next;
+                                       secondlast->data_len -= (rxq->crc_len -
+                                                       end->data_len);
+                                       secondlast->next = NULL;
+                                       rte_pktmbuf_free_seg(end);
+                                       end = secondlast;
+                               }
+                               pkts[pkt_idx++] = start;
+                               start = end = NULL;
+                       }
+               } else {
+                       /* not processing a split packet */
+                       if (!split_flags[buf_idx]) {
+                               /* not a split packet, save and skip */
+                               pkts[pkt_idx++] = rx_bufs[buf_idx];
+                               continue;
+                       }
+                       end = start = rx_bufs[buf_idx];
+                       rx_bufs[buf_idx]->data_len += rxq->crc_len;
+                       rx_bufs[buf_idx]->pkt_len += rxq->crc_len;
+               }
+               buf_idx++;
+       }
+
+       /* save the partial packet for next time */
+       rxq->pkt_first_seg = start;
+       rxq->pkt_last_seg = end;
+       memcpy(rx_bufs, pkts, pkt_idx * (sizeof(*pkts)));
+       return pkt_idx;
+}
+
+/*
+ * vPMD receive routine that reassembles scattered packets
+ *
+ * Notice:
+ * - don't support ol_flags for rss and csum err
+ * - now only accept (nb_pkts == RTE_IXGBE_VPMD_RX_BURST)
+ */
+uint16_t
+ixgbe_recv_scattered_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
+               uint16_t nb_pkts)
+{
+       struct igb_rx_queue *rxq = rx_queue;
+       uint8_t split_flags[RTE_IXGBE_VPMD_RX_BURST] = {0};
+
+       /* get some new buffers */
+       uint16_t nb_bufs = _recv_raw_pkts_vec(rxq, rx_pkts, nb_pkts,
+                       split_flags);
+       if (nb_bufs == 0)
+               return 0;
+
+       /* happy day case, full burst + no packets to be joined */
+       const uint32_t *split_fl32 = (uint32_t *)split_flags;
+       if (rxq->pkt_first_seg == NULL &&
+                       split_fl32[0] == 0 && split_fl32[1] == 0 &&
+                       split_fl32[2] == 0 && split_fl32[3] == 0)
+               return nb_bufs;
+
+       /* reassemble any packets that need reassembly*/
+       unsigned i = 0;
+       if (rxq->pkt_first_seg == NULL) {
+               /* find the first split flag, and only reassemble then*/
+               while (!split_flags[i] && i < nb_bufs)
+                       i++;
+               if (i == nb_bufs)
+                       return nb_bufs;
+       }
+       return i + reassemble_packets(rxq, &rx_pkts[i], nb_bufs - i,
+               &split_flags[i]);
+}
+
 static inline void
 vtx1(volatile union ixgbe_adv_tx_desc *txdp,
                struct rte_mbuf *pkt, uint64_t flags)