Hi Vlad,
> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Vlad Zolotarov
> Sent: Sunday, April 26, 2015 3:46 PM
> To: dev at dpdk.org
> Subject: [dpdk-dev] [PATCH v1 3/4] ixgbe: Kill ixgbe_recv_scattered_pkts()
>
> Kill ixgbe_recv_scattered_pkts() - use ixgbe_recv_pkts_lro_single_alloc()
> instead.
>
> Work against HW queues in LRO and scattered Rx cases is exactly the same.
> Therefore we may drop the inferior callback.
>
> Signed-off-by: Vlad Zolotarov <vladz at cloudius-systems.com>
> ---
> lib/librte_pmd_ixgbe/ixgbe_ethdev.c | 2 +-
> lib/librte_pmd_ixgbe/ixgbe_ethdev.h | 3 -
> lib/librte_pmd_ixgbe/ixgbe_rxtx.c | 243
> +-----------------------------------
> 3 files changed, 7 insertions(+), 241 deletions(-)
>
> diff --git a/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
> b/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
> index aec1de9..5f9a1cf 100644
> --- a/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
> +++ b/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
> @@ -986,7 +986,7 @@ eth_ixgbevf_dev_init(struct rte_eth_dev *eth_dev)
> * RX function */
> if (rte_eal_process_type() != RTE_PROC_PRIMARY){
> if (eth_dev->data->scattered_rx)
> - eth_dev->rx_pkt_burst = ixgbe_recv_scattered_pkts;
> + eth_dev->rx_pkt_burst =
> ixgbe_recv_pkts_lro_single_alloc;
> return 0;
> }
>
> diff --git a/lib/librte_pmd_ixgbe/ixgbe_ethdev.h
> b/lib/librte_pmd_ixgbe/ixgbe_ethdev.h
> index 5b90115..419ea5d 100644
> --- a/lib/librte_pmd_ixgbe/ixgbe_ethdev.h
> +++ b/lib/librte_pmd_ixgbe/ixgbe_ethdev.h
> @@ -352,9 +352,6 @@ void ixgbevf_dev_rxtx_start(struct rte_eth_dev *dev);
> uint16_t ixgbe_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
> uint16_t nb_pkts);
>
> -uint16_t ixgbe_recv_scattered_pkts(void *rx_queue,
> - struct rte_mbuf **rx_pkts, uint16_t nb_pkts);
> -
> uint16_t ixgbe_recv_pkts_lro_single_alloc(void *rx_queue,
> struct rte_mbuf **rx_pkts, uint16_t nb_pkts);
> uint16_t ixgbe_recv_pkts_lro_bulk_alloc(void *rx_queue,
> diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> index a45f51e..c23e20f 100644
> --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> @@ -1722,239 +1722,6 @@ ixgbe_recv_pkts_lro_bulk_alloc(void *rx_queue, struct
> rte_mbuf **rx_pkts,
> return ixgbe_recv_pkts_lro(rx_queue, rx_pkts, nb_pkts, true);
> }
>
> -uint16_t
> -ixgbe_recv_scattered_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
> - uint16_t nb_pkts)
> -{
> - struct ixgbe_rx_queue *rxq;
> - volatile union ixgbe_adv_rx_desc *rx_ring;
> - volatile union ixgbe_adv_rx_desc *rxdp;
> - struct ixgbe_rx_entry *sw_ring;
> - struct ixgbe_rx_entry *rxe;
> - struct rte_mbuf *first_seg;
> - struct rte_mbuf *last_seg;
> - struct rte_mbuf *rxm;
> - struct rte_mbuf *nmb;
> - union ixgbe_adv_rx_desc rxd;
> - uint64_t dma; /* Physical address of mbuf data buffer */
> - uint32_t staterr;
> - uint16_t rx_id;
> - uint16_t nb_rx;
> - uint16_t nb_hold;
> - uint16_t data_len;
> -
> - nb_rx = 0;
> - nb_hold = 0;
> - rxq = rx_queue;
> - rx_id = rxq->rx_tail;
> - rx_ring = rxq->rx_ring;
> - sw_ring = rxq->sw_ring;
> -
> - /*
> - * Retrieve RX context of current packet, if any.
> - */
> - first_seg = rxq->pkt_first_seg;
> - last_seg = rxq->pkt_last_seg;
> -
> - while (nb_rx < nb_pkts) {
> - next_desc:
> - /*
> - * The order of operations here is important as the DD status
> - * bit must not be read after any other descriptor fields.
> - * rx_ring and rxdp are pointing to volatile data so the order
> - * of accesses cannot be reordered by the compiler. If they were
> - * not volatile, they could be reordered which could lead to
> - * using invalid descriptor fields when read from rxd.
> - */
> - rxdp = &rx_ring[rx_id];
> - staterr = rxdp->wb.upper.status_error;
> - if (! (staterr & rte_cpu_to_le_32(IXGBE_RXDADV_STAT_DD)))
> - break;
> - rxd = *rxdp;
> -
> - /*
> - * Descriptor done.
> - *
> - * Allocate a new mbuf to replenish the RX ring descriptor.
> - * If the allocation fails:
> - * - arrange for that RX descriptor to be the first one
> - * being parsed the next time the receive function is
> - * invoked [on the same queue].
> - *
> - * - Stop parsing the RX ring and return immediately.
> - *
> - * This policy does not drop the packet received in the RX
> - * descriptor for which the allocation of a new mbuf failed.
> - * Thus, it allows that packet to be later retrieved if
> - * mbuf have been freed in the mean time.
> - * As a side effect, holding RX descriptors instead of
> - * systematically giving them back to the NIC may lead to
> - * RX ring exhaustion situations.
> - * However, the NIC can gracefully prevent such situations
> - * to happen by sending specific "back-pressure" flow control
> - * frames to its peer(s).
> - */
> - PMD_RX_LOG(DEBUG, "port_id=%u queue_id=%u rx_id=%u "
> - "staterr=0x%x data_len=%u",
> - (unsigned) rxq->port_id, (unsigned) rxq->queue_id,
> - (unsigned) rx_id, (unsigned) staterr,
> - (unsigned) rte_le_to_cpu_16(rxd.wb.upper.length));
> -
> - nmb = rte_rxmbuf_alloc(rxq->mb_pool);
> - if (nmb == NULL) {
> - PMD_RX_LOG(DEBUG, "RX mbuf alloc failed port_id=%u "
> - "queue_id=%u", (unsigned) rxq->port_id,
> - (unsigned) rxq->queue_id);
> -
> rte_eth_devices[rxq->port_id].data->rx_mbuf_alloc_failed++;
> - break;
> - }
> -
> - nb_hold++;
> - rxe = &sw_ring[rx_id];
> - rx_id++;
> - if (rx_id == rxq->nb_rx_desc)
> - rx_id = 0;
> -
> - /* Prefetch next mbuf while processing current one. */
> - rte_ixgbe_prefetch(sw_ring[rx_id].mbuf);
> -
> - /*
> - * When next RX descriptor is on a cache-line boundary,
> - * prefetch the next 4 RX descriptors and the next 8 pointers
> - * to mbufs.
> - */
> - if ((rx_id & 0x3) == 0) {
> - rte_ixgbe_prefetch(&rx_ring[rx_id]);
> - rte_ixgbe_prefetch(&sw_ring[rx_id]);
> - }
> -
> - /*
> - * Update RX descriptor with the physical address of the new
> - * data buffer of the new allocated mbuf.
> - */
> - rxm = rxe->mbuf;
> - rxe->mbuf = nmb;
> - dma = rte_cpu_to_le_64(RTE_MBUF_DATA_DMA_ADDR_DEFAULT(nmb));
> - rxdp->read.hdr_addr = dma;
> - rxdp->read.pkt_addr = dma;
> -
> - /*
> - * Set data length & data buffer address of mbuf.
> - */
> - data_len = rte_le_to_cpu_16(rxd.wb.upper.length);
> - rxm->data_len = data_len;
> - rxm->data_off = RTE_PKTMBUF_HEADROOM;
> -
> - /*
> - * If this is the first buffer of the received packet,
> - * set the pointer to the first mbuf of the packet and
> - * initialize its context.
> - * Otherwise, update the total length and the number of segments
> - * of the current scattered packet, and update the pointer to
> - * the last mbuf of the current packet.
> - */
> - if (first_seg == NULL) {
> - first_seg = rxm;
> - first_seg->pkt_len = data_len;
> - first_seg->nb_segs = 1;
> - } else {
> - first_seg->pkt_len = (uint16_t)(first_seg->pkt_len
> - + data_len);
> - first_seg->nb_segs++;
> - last_seg->next = rxm;
> - }
> -
> - /*
> - * If this is not the last buffer of the received packet,
> - * update the pointer to the last mbuf of the current scattered
> - * packet and continue to parse the RX ring.
> - */
> - if (! (staterr & IXGBE_RXDADV_STAT_EOP)) {
> - last_seg = rxm;
> - goto next_desc;
> - }
> -
> - /*
> - * This is the last buffer of the received packet.
> - * If the CRC is not stripped by the hardware:
> - * - Subtract the CRC length from the total packet length.
> - * - If the last buffer only contains the whole CRC or a part
> - * of it, free the mbuf associated to the last buffer.
> - * If part of the CRC is also contained in the previous
> - * mbuf, subtract the length of that CRC part from the
> - * data length of the previous mbuf.
> - */
> - rxm->next = NULL;
> - if (unlikely(rxq->crc_len > 0)) {
> - first_seg->pkt_len -= ETHER_CRC_LEN;
> - if (data_len <= ETHER_CRC_LEN) {
> - rte_pktmbuf_free_seg(rxm);
> - first_seg->nb_segs--;
> - last_seg->data_len = (uint16_t)
> - (last_seg->data_len -
> - (ETHER_CRC_LEN - data_len));
> - last_seg->next = NULL;
> - } else
> - rxm->data_len =
> - (uint16_t) (data_len - ETHER_CRC_LEN);
> - }
> -
> - /* Initialize the first mbuf of the returned packet */
> - ixgbe_fill_cluster_head_buf(first_seg, &rxd, rxq->port_id,
> - staterr);
> -
> - /* Prefetch data of first segment, if configured to do so. */
> - rte_packet_prefetch((char *)first_seg->buf_addr +
> - first_seg->data_off);
> -
> - /*
> - * Store the mbuf address into the next entry of the array
> - * of returned packets.
> - */
> - rx_pkts[nb_rx++] = first_seg;
> -
> - /*
> - * Setup receipt context for a new packet.
> - */
> - first_seg = NULL;
> - }
> -
> - /*
> - * Record index of the next RX descriptor to probe.
> - */
> - rxq->rx_tail = rx_id;
> -
> - /*
> - * Save receive context.
> - */
> - rxq->pkt_first_seg = first_seg;
> - rxq->pkt_last_seg = last_seg;
> -
> - /*
> - * If the number of free RX descriptors is greater than the RX free
> - * threshold of the queue, advance the Receive Descriptor Tail (RDT)
> - * register.
> - * Update the RDT with the value of the last processed RX descriptor
> - * minus 1, to guarantee that the RDT register is never equal to the
> - * RDH register, which creates a "full" ring situtation from the
> - * hardware point of view...
> - */
> - nb_hold = (uint16_t) (nb_hold + rxq->nb_rx_hold);
> - if (nb_hold > rxq->rx_free_thresh) {
> - PMD_RX_LOG(DEBUG, "port_id=%u queue_id=%u rx_tail=%u "
> - "nb_hold=%u nb_rx=%u",
> - (unsigned) rxq->port_id, (unsigned) rxq->queue_id,
> - (unsigned) rx_id, (unsigned) nb_hold,
> - (unsigned) nb_rx);
> - rx_id = (uint16_t) ((rx_id == 0) ?
> - (rxq->nb_rx_desc - 1) : (rx_id - 1));
> - IXGBE_PCI_REG_WRITE(rxq->rdt_reg_addr, rx_id);
> - nb_hold = 0;
> - }
> - rxq->nb_rx_hold = nb_hold;
> - return (nb_rx);
> -}
> -
> /*********************************************************************
> *
> * Queue management functions
> @@ -2623,7 +2390,7 @@ ixgbe_dev_rx_queue_setup(struct rte_eth_dev *dev,
> return (-ENOMEM);
> }
>
> - if (rsc_requested) {
> + if (rsc_requested || dev_rx_mode->enable_scatter) {
> rxq->sw_rsc_ring =
> rte_zmalloc_socket("rxq->sw_rsc_ring",
> sizeof(struct ixgbe_rsc_entry) * len,
I think here is a problem:
We allocate sw_rsc_ring only if user explicitly requested LRO or scattered rx.
Though later, ixgbe_dev_rx_init() might implicitly enable scattered rx, if the
provided mbufs are too small:
buf_size = (uint16_t) ((srrctl & IXGBE_SRRCTL_BSIZEPKT_MASK) <<
IXGBE_SRRCTL_BSIZEPKT_SHIFT);
/* It adds dual VLAN length for supporting dual VLAN */
if (dev->data->dev_conf.rxmode.max_rx_pkt_len +
2 * IXGBE_VLAN_TAG_SIZE > buf_size)
dev->data->scattered_rx = 1;
So, ixgbe_recv_pkts_lro_*_alloc() will be selected, but ixgbe_recv_pkts_lro
will be 0.
Probably the easiest and safest fix, is to always allocate sw_rsc_ring for the
queue.
After all, it would consume at max a bit more than 32KB - doesn't seem that
much to me.
Konstantin
> @@ -4017,12 +3784,13 @@ void ixgbe_set_rx_function(struct rte_eth_dev *dev)
>
> dev->rx_pkt_burst = ixgbe_recv_scattered_pkts_vec;
> } else {
> - PMD_INIT_LOG(DEBUG, "Using Regualr (non-vector) "
> + PMD_INIT_LOG(DEBUG, "Using Regualr (non-vector, "
> + "single allocation) "
> "Scattered Rx callback "
> "(port=%d).",
> dev->data->port_id);
>
> - dev->rx_pkt_burst = ixgbe_recv_scattered_pkts;
> + dev->rx_pkt_burst = ixgbe_recv_pkts_lro_single_alloc;
> }
> /*
> * Below we set "simple" callbacks according to port/queues parameters.
> @@ -4855,7 +4623,8 @@ ixgbevf_dev_rx_init(struct rte_eth_dev *dev)
> ixgbe_recv_scattered_pkts_vec;
> else
> #endif
> - dev->rx_pkt_burst = ixgbe_recv_scattered_pkts;
> + dev->rx_pkt_burst =
> + ixgbe_recv_pkts_lro_single_alloc;
> }
> }
>
> --
> 2.1.0
