On 4/11/2019 12:00 PM, Cian Ferriter wrote:
> It can be useful to use pcap files for some rudimental performance
> testing. This patch enables this functionality in the pcap driver.
>
> At a high level, this works by creaing a ring of sufficient size to
> store the packets in the pcap file passed to the application. When the
> rx function for this mode is called, packets are dequeued from the ring
> for use by the application and also enqueued back on to the ring to be
> "received" again.
>
> A tx_drop mode is also added since transmitting to a tx_pcap file isn't
> desirable at a high traffic rate.
>
> Jumbo frames are not supported in this mode. When filling the ring at rx
> queue setup time, the presence of multi segment mbufs is checked for.
> The PMD will exit on detection of these multi segment mbufs.
>
> Signed-off-by: Cian Ferriter <cian.ferri...@intel.com>
> ---
> doc/guides/nics/pcap_ring.rst | 15 +++
> drivers/net/pcap/rte_eth_pcap.c | 209 ++++++++++++++++++++++++++++++--
> 2 files changed, 215 insertions(+), 9 deletions(-)
>
> diff --git a/doc/guides/nics/pcap_ring.rst b/doc/guides/nics/pcap_ring.rst
> index c1ef9196b..45f55a345 100644
> --- a/doc/guides/nics/pcap_ring.rst
> +++ b/doc/guides/nics/pcap_ring.rst
> @@ -106,6 +106,21 @@ Runtime Config Options
>
> --vdev 'net_pcap0,iface=eth0,phy_mac=1'
>
> +- Use the RX PCAP file to infinitely receive packets
> +
> + In case ``rx_pcap=`` configuration is set, user may want to use the
> selected PCAP file for rudimental
> + performance testing. This can be done with a ``devarg`` ``infinite_rx``,
> for example::
> +
> + --vdev 'net_pcap0,rx_pcap=file_rx.pcap,infinite_rx=1,tx_drop=1'
> +
> + When this mode is used, it is recommended to use the ``tx_drop`` ``devarg``.
> +
> +- Drop all packets on transmit
> +
> + The user may want to drop all packets on tx for a device. This can be done
> with the ``tx_drop`` ``devarg``, for example::
> +
> + --vdev 'net_pcap0,rx_pcap=file_rx.pcap,tx_drop=1'
Is there a performance drop when tx files are directed to 'loopback' interface,
like: --vdev 'net_pcap0,rx_pcap=file_rx.pcap,tx_iface=lo' ?
If no performance drop I am for using 'lo' interface instead of adding new
devargs.
> +
> Examples of Usage
> ^^^^^^^^^^^^^^^^^
>
> diff --git a/drivers/net/pcap/rte_eth_pcap.c b/drivers/net/pcap/rte_eth_pcap.c
> index 353538f16..b72db973a 100644
> --- a/drivers/net/pcap/rte_eth_pcap.c
> +++ b/drivers/net/pcap/rte_eth_pcap.c
<...>
> @@ -178,6 +186,40 @@ eth_pcap_gather_data(unsigned char *data, struct
> rte_mbuf *mbuf)
> }
> }
>
> +static uint16_t
> +eth_pcap_rx_infinite(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
> +{
> + int i;
> + struct pcap_rx_queue *pcap_q = queue;
> +
> + if (unlikely(nb_pkts == 0))
> + return 0;
> +
> + if (rte_pktmbuf_alloc_bulk(pcap_q->mb_pool, bufs, nb_pkts) != 0)
> + return 0;
> +
> + for (i = 0; i < nb_pkts; i++) {
> + struct rte_mbuf *pcap_buf;
> + int err = rte_ring_dequeue(pcap_q->pkts, (void **)&pcap_buf);
> + if (err)
> + rte_panic("failed to dequeue from pcap pkts ring\n");
Please don't have any rte_panic() in the driver code, there are a few more in
patch.
> +
> + rte_memcpy(rte_pktmbuf_mtod(bufs[i], void *),
> + rte_pktmbuf_mtod(pcap_buf, void *),
> + pcap_buf->data_len);
> + bufs[i]->data_len = pcap_buf->data_len;
> + bufs[i]->pkt_len = pcap_buf->pkt_len;
> + bufs[i]->port = pcap_q->port_id;
> +
> + /* enqueue packet back on ring to allow infinite rx */
> + rte_ring_enqueue(pcap_q->pkts, pcap_buf);
> + }
> +
> + pcap_q->rx_stat.pkts += i;
For consistency, can you please update "pcap_q->rx_stat.bytes" too?
> +
> + return i;
> +}
> +
> static uint16_t
> eth_pcap_rx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
> {
<...>
> @@ -447,6 +509,24 @@ open_single_rx_pcap(const char *pcap_filename, pcap_t
> **pcap)
> return 0;
> }
>
> +static uint64_t
> +count_packets_in_pcaps(pcap_t **pcap, struct pcap_rx_queue *pcap_q)
> +{
> + const u_char *packet;
> + struct pcap_pkthdr header;
> + uint64_t pcap_pkt_count;
Compiler is complaining about uninitialized 'pcap_pkt_count'.
> +
> + while ((packet = pcap_next(*pcap, &header)))
> + pcap_pkt_count++;
It seems there is no quicker way to get number of packets from a pcap file, if
anyone know a way, comment is welcome.
> +
> + /* the pcap is reopened so it can be used as normal later */
> + pcap_close(*pcap);
> + *pcap = NULL;
> + open_single_rx_pcap(pcap_q->name, pcap);
> +
> + return pcap_pkt_count;
> +}
> +
> static int
> eth_dev_start(struct rte_eth_dev *dev)
> {
<...>
> @@ -671,6 +752,49 @@ eth_rx_queue_setup(struct rte_eth_dev *dev,
> pcap_q->queue_id = rx_queue_id;
> dev->data->rx_queues[rx_queue_id] = pcap_q;
>
> + if (internals->infinite_rx) {
> + struct pmd_process_private *pp;
> + char ring_name[NAME_MAX];
> + uint16_t num_rx = 0;
> + static uint32_t ring_number;
> + uint64_t pcap_pkt_count = 0;
> + pcap_t **pcap;
> +
> + pp = rte_eth_devices[pcap_q->port_id].process_private;
> + pcap = &pp->rx_pcap[pcap_q->queue_id];
> +
> + if (unlikely(*pcap == NULL))
> + rte_panic("no packets in pcap to fill ring with\n");
> +
> + pcap_pkt_count = count_packets_in_pcaps(pcap, pcap_q);
> +
> + snprintf(ring_name, sizeof(ring_name), "PCAP_RING%" PRIu16,
> + ring_number);
> +
> + pcap_q->pkts = rte_ring_create(ring_name,
> + rte_align64pow2(pcap_pkt_count + 1), 0,
> + RING_F_SP_ENQ | RING_F_SC_DEQ);
> + ring_number++;
> + if (!pcap_q->pkts)
> + rte_panic("failed to alloc ring\n");
> +
> +
> + struct rte_mbuf *bufs[pcap_pkt_count];
Can you please move deceleration to the beginning of the function.
> + if (rte_pktmbuf_alloc_bulk(mb_pool, bufs, pcap_pkt_count) != 0)
> + return 0;
Should this return error?
> +
> + num_rx = eth_pcap_rx(pcap_q, bufs, pcap_pkt_count);
> +
> + /* check for multiseg mbufs */
> + for (i = 0; i < num_rx; i++) {
> + if (bufs[i]->nb_segs != 1)
> + rte_panic("jumbo frames are not supported in
> infinite rx mode\n");
This need to be replaced with returning error, and please remember to cleanup in
that case.
> + }
> +
> + rte_ring_enqueue_bulk(pcap_q->pkts, (void * const *)bufs,
> + num_rx, NULL);
> + }
> +
> return 0;
> }
>
<...>
> @@ -1132,9 +1285,18 @@ eth_from_pcaps(struct rte_vdev_device *vdev,
> }
> }
>
> - eth_dev->rx_pkt_burst = eth_pcap_rx;
> + /* assign rx ops */
> + if (infinite_rx) {
> + eth_dev->rx_pkt_burst = eth_pcap_rx_infinite;
> + internals->infinite_rx = infinite_rx;
Since "infinite_rx" can be 0 or 1, isn't it better to set
"internals->infinite_rx" out of this check, although functionally it will be
same (since internals is all zero by default), logically better I think
> + } else {
> + eth_dev->rx_pkt_burst = eth_pcap_rx;
> + }
>
> - if (using_dumpers)
> + /* assign tx ops */
> + if (infinite_rx)
> + eth_dev->tx_pkt_burst = eth_tx_drop;
Shouldn't set 'tx_pkt_burst' with 'infinite_rx' check, I guess intention was
'tx_drop' check.
> + else if (using_dumpers)
> eth_dev->tx_pkt_burst = eth_pcap_tx_dumper;
> else
> eth_dev->tx_pkt_burst = eth_pcap_tx;
<...>
> @@ -1217,6 +1380,17 @@ pmd_pcap_probe(struct rte_vdev_device *dev)
> pcaps.num_of_queue = 0;
>
> if (is_rx_pcap) {
> + /*
> + * We check whether we want to infinitely rx the pcap file
> + */
> + if (rte_kvargs_count(kvlist, ETH_PCAP_INFINITE_RX_ARG) == 1) {
What do you think printing a warning if user provided the value more than once?
> + ret = rte_kvargs_process(kvlist,
> + ETH_PCAP_INFINITE_RX_ARG,
> + &get_infinite_rx_arg, &infinite_rx);
> + if (ret < 0)
> + goto free_kvlist;
> + }
> +
> ret = rte_kvargs_process(kvlist, ETH_PCAP_RX_PCAP_ARG,
> &open_rx_pcap, &pcaps);
> } else {
> @@ -1228,18 +1402,30 @@ pmd_pcap_probe(struct rte_vdev_device *dev)
> goto free_kvlist;
>
> /*
> - * We check whether we want to open a TX stream to a real NIC or a
> - * pcap file
> + * We check whether we want to open a TX stream to a real NIC,
> + * a pcap file, or drop packets on tx
> */
> is_tx_pcap = rte_kvargs_count(kvlist, ETH_PCAP_TX_PCAP_ARG) ? 1 : 0;
> dumpers.num_of_queue = 0;
>
> - if (is_tx_pcap)
> + tx_drop = rte_kvargs_count(kvlist, ETH_PCAP_TX_DROP_ARG) ? 1 : 0;
Can drop this line, below already getting the 'tx_drop' value, overwriting this
one.
> + if (rte_kvargs_count(kvlist, ETH_PCAP_TX_DROP_ARG) == 1) {
> + ret = rte_kvargs_process(kvlist, ETH_PCAP_TX_DROP_ARG,
> + &get_tx_drop_arg, &tx_drop);
> + if (ret < 0)
> + goto free_kvlist;
> + }
> +
> + if (tx_drop) {
> + /* add dummy queue which counts dropped packets */
> + ret = add_queue(&dumpers, "dummy", "tx_drop", NULL, NULL);
This will break the multiple queue use case. Instead of adding a single queue,
need to find a way to add multiple queues as user want and all will just ignore
the packtets.
> + } else if (is_tx_pcap) {
> ret = rte_kvargs_process(kvlist, ETH_PCAP_TX_PCAP_ARG,
> &open_tx_pcap, &dumpers);
> - else
> + } else {
> ret = rte_kvargs_process(kvlist, ETH_PCAP_TX_IFACE_ARG,
> &open_tx_iface, &dumpers);
> + }
>
> if (ret < 0)
> goto free_kvlist;
<...>
