On 1/11/21 6:52 AM, Cheng Jiang wrote:
> Change the vm2vm data path to batch enqueue for better performance.
> Support latest async vhost API, refactor vhost async data path,
> replace rte_atomicNN_xxx to atomic_XXX and clean some codes.
Wouldn't it be better to use GCC/Clang C11 atmoic built-ins like all
other code is being migrated to it? (i.e. __atomic_XXX)
> Signed-off-by: Cheng Jiang <cheng1.ji...@intel.com>
> Reviewed-by: Jiayu Hu <jiayu...@intel.com>
> ---
> examples/vhost/ioat.h | 2 +-
> examples/vhost/main.c | 226 ++++++++++++++++++++++++++++++------------
> examples/vhost/main.h | 7 +-
> 3 files changed, 168 insertions(+), 67 deletions(-)
>
> diff --git a/examples/vhost/ioat.h b/examples/vhost/ioat.h
> index d6e1e2e07..0a1dbb811 100644
> --- a/examples/vhost/ioat.h
> +++ b/examples/vhost/ioat.h
> @@ -11,7 +11,7 @@
>
> #define MAX_VHOST_DEVICE 1024
> #define IOAT_RING_SIZE 4096
> -#define MAX_ENQUEUED_SIZE 256
> +#define MAX_ENQUEUED_SIZE 512
>
> struct dma_info {
> struct rte_pci_addr addr;
> diff --git a/examples/vhost/main.c b/examples/vhost/main.c
> index 22309977c..45976c93c 100644
> --- a/examples/vhost/main.c
> +++ b/examples/vhost/main.c
> @@ -179,9 +179,22 @@ struct mbuf_table {
> struct rte_mbuf *m_table[MAX_PKT_BURST];
> };
>
> +struct vhost_bufftable {
> + uint32_t len;
> + uint64_t pre_tsc;
> + struct rte_mbuf *m_table[MAX_PKT_BURST];
> +};
> +
> /* TX queue for each data core. */
> struct mbuf_table lcore_tx_queue[RTE_MAX_LCORE];
>
> +/*
> + * Vhost TX buffer for each data core.
> + * Every data core maintains a TX buffer for every vhost device,
> + * which is used for batch pkts enqueue for higher performance.
> + */
> +struct vhost_bufftable *vhost_txbuff[RTE_MAX_LCORE * MAX_VHOST_DEVICE];
> +
> #define MBUF_TABLE_DRAIN_TSC ((rte_get_tsc_hz() + US_PER_S - 1) \
> / US_PER_S * BURST_TX_DRAIN_US)
> #define VLAN_HLEN 4
> @@ -804,43 +817,112 @@ unlink_vmdq(struct vhost_dev *vdev)
> }
> }
>
> +static inline void
> +free_pkts(struct rte_mbuf **pkts, uint16_t n)
> +{
> + while (n--)
> + rte_pktmbuf_free(pkts[n]);
> +}
> +
> static __rte_always_inline void
> -virtio_xmit(struct vhost_dev *dst_vdev, struct vhost_dev *src_vdev,
> +complete_async_pkts(struct vhost_dev *vdev)
> +{
> + struct rte_mbuf *p_cpl[MAX_PKT_BURST];
> + uint16_t complete_count;
> +
> + complete_count = rte_vhost_poll_enqueue_completed(vdev->vid,
> + VIRTIO_RXQ, p_cpl, MAX_PKT_BURST);
> + if (complete_count) {
> + atomic_fetch_sub(&vdev->nr_async_pkts, complete_count);
> + free_pkts(p_cpl, complete_count);
> + }
> +}
> +
> +static __rte_always_inline void
> +sync_virtio_xmit(struct vhost_dev *dst_vdev, struct vhost_dev *src_vdev,
> struct rte_mbuf *m)
> {
> uint16_t ret;
> - struct rte_mbuf *m_cpl[1], *comp_pkt;
> - uint32_t nr_comp = 0;
>
> if (builtin_net_driver) {
> ret = vs_enqueue_pkts(dst_vdev, VIRTIO_RXQ, &m, 1);
> - } else if (async_vhost_driver) {
> - ret = rte_vhost_submit_enqueue_burst(dst_vdev->vid, VIRTIO_RXQ,
> - &m, 1, &comp_pkt, &nr_comp);
> - if (nr_comp == 1)
> - goto done;
> -
> - if (likely(ret))
> - dst_vdev->nr_async_pkts++;
> -
> - while (likely(dst_vdev->nr_async_pkts)) {
> - if (rte_vhost_poll_enqueue_completed(dst_vdev->vid,
> - VIRTIO_RXQ, m_cpl, 1))
> - dst_vdev->nr_async_pkts--;
> - }
> } else {
> ret = rte_vhost_enqueue_burst(dst_vdev->vid, VIRTIO_RXQ, &m, 1);
> }
>
> -done:
> if (enable_stats) {
> - rte_atomic64_inc(&dst_vdev->stats.rx_total_atomic);
> - rte_atomic64_add(&dst_vdev->stats.rx_atomic, ret);
> + atomic_fetch_add(&dst_vdev->stats.rx_total_atomic, 1);
> + atomic_fetch_add(&dst_vdev->stats.rx_atomic, ret);
> src_vdev->stats.tx_total++;
> src_vdev->stats.tx += ret;
> }
> }
>
> +static __rte_always_inline void
> +drain_vhost(struct vhost_dev *vdev)
> +{
> + uint16_t ret;
> + uint64_t buff_idx = rte_lcore_id() * MAX_VHOST_DEVICE + vdev->vid;
> + uint16_t nr_xmit = vhost_txbuff[buff_idx]->len;
> + struct rte_mbuf **m = vhost_txbuff[buff_idx]->m_table;
> +
> + if (builtin_net_driver) {
> + ret = vs_enqueue_pkts(vdev, VIRTIO_RXQ, m, nr_xmit);
> + } else if (async_vhost_driver) {
> + uint32_t cpu_cpl_nr = 0;
> + uint16_t enqueue_fail = 0;
> + struct rte_mbuf *m_cpu_cpl[nr_xmit];
> +
> + complete_async_pkts(vdev);
> + ret = rte_vhost_submit_enqueue_burst(vdev->vid, VIRTIO_RXQ,
> + m, nr_xmit, m_cpu_cpl, &cpu_cpl_nr);
> + atomic_fetch_add(&vdev->nr_async_pkts, ret - cpu_cpl_nr);
> +
> + if (cpu_cpl_nr)
> + free_pkts(m_cpu_cpl, cpu_cpl_nr);
> +
> + enqueue_fail = nr_xmit - ret;
> + if (enqueue_fail)
> + free_pkts(&m[ret], nr_xmit - ret);
> + } else {
> + ret = rte_vhost_enqueue_burst(vdev->vid, VIRTIO_RXQ,
> + m, nr_xmit);
> + }
> +
> + if (enable_stats) {
> + atomic_fetch_add(&vdev->stats.rx_total_atomic, nr_xmit);
> + atomic_fetch_add(&vdev->stats.rx_atomic, ret);
> + }
> +
> + if (!async_vhost_driver)
> + free_pkts(m, nr_xmit);
> +}
> +
> +static __rte_always_inline void
> +drain_vhost_table(void)
> +{
> + uint16_t lcore_id = rte_lcore_id();
> + struct vhost_bufftable *vhost_txq;
> + struct vhost_dev *vdev;
> + uint64_t cur_tsc;
> +
> + TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
> + vhost_txq = vhost_txbuff[lcore_id * MAX_VHOST_DEVICE
> + + vdev->vid];
> +
> + cur_tsc = rte_rdtsc();
> + if (unlikely(cur_tsc - vhost_txq->pre_tsc
> + > MBUF_TABLE_DRAIN_TSC)) {
> + RTE_LOG_DP(DEBUG, VHOST_DATA,
> + "Vhost TX queue drained after timeout with
> burst size %u\n",
> + vhost_txq->len);
> + drain_vhost(vdev);
> + vhost_txq->len = 0;
> + vhost_txq->pre_tsc = cur_tsc;
> + }
> + }
> +}
> +
> /*
> * Check if the packet destination MAC address is for a local device. If so
> then put
> * the packet on that devices RX queue. If not then return.
> @@ -850,7 +932,8 @@ virtio_tx_local(struct vhost_dev *vdev, struct rte_mbuf
> *m)
> {
> struct rte_ether_hdr *pkt_hdr;
> struct vhost_dev *dst_vdev;
> -
> + struct vhost_bufftable *vhost_txq;
> + uint16_t lcore_id = rte_lcore_id();
> pkt_hdr = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
>
> dst_vdev = find_vhost_dev(&pkt_hdr->d_addr);
> @@ -873,7 +956,19 @@ virtio_tx_local(struct vhost_dev *vdev, struct rte_mbuf
> *m)
> return 0;
> }
>
> - virtio_xmit(dst_vdev, vdev, m);
> + vhost_txq = vhost_txbuff[lcore_id * MAX_VHOST_DEVICE + dst_vdev->vid];
> + vhost_txq->m_table[vhost_txq->len++] = m;
> +
> + if (enable_stats) {
> + vdev->stats.tx_total++;
> + vdev->stats.tx++;
> + }
> +
> + if (unlikely(vhost_txq->len == MAX_PKT_BURST)) {
> + drain_vhost(dst_vdev);
> + vhost_txq->len = 0;
> + vhost_txq->pre_tsc = rte_rdtsc();
> + }
> return 0;
> }
>
> @@ -944,13 +1039,6 @@ static void virtio_tx_offload(struct rte_mbuf *m)
> tcp_hdr->cksum = get_psd_sum(l3_hdr, m->ol_flags);
> }
>
> -static inline void
> -free_pkts(struct rte_mbuf **pkts, uint16_t n)
> -{
> - while (n--)
> - rte_pktmbuf_free(pkts[n]);
> -}
> -
> static __rte_always_inline void
> do_drain_mbuf_table(struct mbuf_table *tx_q)
> {
> @@ -983,16 +1071,14 @@ virtio_tx_route(struct vhost_dev *vdev, struct
> rte_mbuf *m, uint16_t vlan_tag)
>
> TAILQ_FOREACH(vdev2, &vhost_dev_list, global_vdev_entry) {
> if (vdev2 != vdev)
> - virtio_xmit(vdev2, vdev, m);
> + sync_virtio_xmit(vdev2, vdev, m);
> }
> goto queue2nic;
> }
>
> /*check if destination is local VM*/
> - if ((vm2vm_mode == VM2VM_SOFTWARE) && (virtio_tx_local(vdev, m) == 0)) {
> - rte_pktmbuf_free(m);
> + if ((vm2vm_mode == VM2VM_SOFTWARE) && (virtio_tx_local(vdev, m) == 0))
> return;
> - }
>
> if (unlikely(vm2vm_mode == VM2VM_HARDWARE)) {
> if (unlikely(find_local_dest(vdev, m, &offset,
> @@ -1077,32 +1163,15 @@ drain_mbuf_table(struct mbuf_table *tx_q)
> }
> }
>
> -static __rte_always_inline void
> -complete_async_pkts(struct vhost_dev *vdev, uint16_t qid)
> -{
> - struct rte_mbuf *p_cpl[MAX_PKT_BURST];
> - uint16_t complete_count;
> -
> - complete_count = rte_vhost_poll_enqueue_completed(vdev->vid,
> - qid, p_cpl, MAX_PKT_BURST);
> - vdev->nr_async_pkts -= complete_count;
> - if (complete_count)
> - free_pkts(p_cpl, complete_count);
> -}
> -
> static __rte_always_inline void
> drain_eth_rx(struct vhost_dev *vdev)
> {
> uint16_t rx_count, enqueue_count;
> - struct rte_mbuf *pkts[MAX_PKT_BURST], *comp_pkts[MAX_PKT_BURST];
> - uint32_t nr_comp = 0;
> + struct rte_mbuf *pkts[MAX_PKT_BURST];
>
> rx_count = rte_eth_rx_burst(ports[0], vdev->vmdq_rx_q,
> pkts, MAX_PKT_BURST);
>
> - while (likely(vdev->nr_async_pkts))
> - complete_async_pkts(vdev, VIRTIO_RXQ);
> -
> if (!rx_count)
> return;
>
> @@ -1128,22 +1197,31 @@ drain_eth_rx(struct vhost_dev *vdev)
> enqueue_count = vs_enqueue_pkts(vdev, VIRTIO_RXQ,
> pkts, rx_count);
> } else if (async_vhost_driver) {
> + uint32_t cpu_cpl_nr = 0;
> + uint16_t enqueue_fail = 0;
> + struct rte_mbuf *m_cpu_cpl[MAX_PKT_BURST];
> +
> + complete_async_pkts(vdev);
> enqueue_count = rte_vhost_submit_enqueue_burst(vdev->vid,
> - VIRTIO_RXQ, pkts, rx_count, comp_pkts,
> - &nr_comp);
> - if (nr_comp > 0) {
> - free_pkts(comp_pkts, nr_comp);
> - enqueue_count -= nr_comp;
> - }
> - vdev->nr_async_pkts += enqueue_count;
> + VIRTIO_RXQ, pkts, rx_count,
> + m_cpu_cpl, &cpu_cpl_nr);
> + atomic_fetch_add(&vdev->nr_async_pkts,
> + enqueue_count - cpu_cpl_nr);
> + if (cpu_cpl_nr)
> + free_pkts(m_cpu_cpl, cpu_cpl_nr);
> +
> + enqueue_fail = rx_count - enqueue_count;
> + if (enqueue_fail)
> + free_pkts(&pkts[enqueue_count], enqueue_fail);
> +
> } else {
> enqueue_count = rte_vhost_enqueue_burst(vdev->vid, VIRTIO_RXQ,
> pkts, rx_count);
> }
>
> if (enable_stats) {
> - rte_atomic64_add(&vdev->stats.rx_total_atomic, rx_count);
> - rte_atomic64_add(&vdev->stats.rx_atomic, enqueue_count);
> + atomic_fetch_add(&vdev->stats.rx_total_atomic, rx_count);
> + atomic_fetch_add(&vdev->stats.rx_atomic, enqueue_count);
> }
>
> if (!async_vhost_driver)
> @@ -1212,7 +1290,7 @@ switch_worker(void *arg __rte_unused)
>
> while(1) {
> drain_mbuf_table(tx_q);
> -
> + drain_vhost_table();
> /*
> * Inform the configuration core that we have exited the
> * linked list and that no devices are in use if requested.
> @@ -1253,6 +1331,7 @@ destroy_device(int vid)
> {
> struct vhost_dev *vdev = NULL;
> int lcore;
> + uint16_t i;
>
> TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
> if (vdev->vid == vid)
> @@ -1266,6 +1345,9 @@ destroy_device(int vid)
> rte_pause();
> }
>
> + for (i = 0; i < RTE_MAX_LCORE; i++)
> + rte_free(vhost_txbuff[i * MAX_VHOST_DEVICE + vid]);
> +
> if (builtin_net_driver)
> vs_vhost_net_remove(vdev);
>
> @@ -1308,6 +1390,7 @@ static int
> new_device(int vid)
> {
> int lcore, core_add = 0;
> + uint16_t i;
> uint32_t device_num_min = num_devices;
> struct vhost_dev *vdev;
> vdev = rte_zmalloc("vhost device", sizeof(*vdev), RTE_CACHE_LINE_SIZE);
> @@ -1319,6 +1402,19 @@ new_device(int vid)
> }
> vdev->vid = vid;
>
> + for (i = 0; i < RTE_MAX_LCORE; i++) {
> + vhost_txbuff[i * MAX_VHOST_DEVICE + vid]
> + = rte_zmalloc("vhost bufftable",
> + sizeof(struct vhost_bufftable),
> + RTE_CACHE_LINE_SIZE);
> +
> + if (vhost_txbuff[i * MAX_VHOST_DEVICE + vid] == NULL) {
> + RTE_LOG(INFO, VHOST_DATA,
> + "(%d) couldn't allocate memory for vhost TX\n", vid);
> + return -1;
> + }
> + }
> +
> if (builtin_net_driver)
> vs_vhost_net_setup(vdev);
>
> @@ -1353,12 +1449,15 @@ new_device(int vid)
> if (async_vhost_driver) {
> struct rte_vhost_async_features f;
> struct rte_vhost_async_channel_ops channel_ops;
> +
> if (strncmp(dma_type, "ioat", 4) == 0) {
> channel_ops.transfer_data = ioat_transfer_data_cb;
> channel_ops.check_completed_copies =
> ioat_check_completed_copies_cb;
> +
> f.async_inorder = 1;
> f.async_threshold = 256;
> +
> return rte_vhost_async_channel_register(vid, VIRTIO_RXQ,
> f.intval, &channel_ops);
> }
> @@ -1402,8 +1501,8 @@ print_stats(__rte_unused void *arg)
> tx = vdev->stats.tx;
> tx_dropped = tx_total - tx;
>
> - rx_total =
> rte_atomic64_read(&vdev->stats.rx_total_atomic);
> - rx = rte_atomic64_read(&vdev->stats.rx_atomic);
> + rx_total = atomic_load(&vdev->stats.rx_total_atomic);
> + rx = atomic_load(&vdev->stats.rx_atomic);
> rx_dropped = rx_total - rx;
>
> printf("Statistics for device %d\n"
> @@ -1602,6 +1701,7 @@ main(int argc, char *argv[])
> /* Register vhost user driver to handle vhost messages. */
> for (i = 0; i < nb_sockets; i++) {
> char *file = socket_files + i * PATH_MAX;
> +
> if (async_vhost_driver)
> flags = flags | RTE_VHOST_USER_ASYNC_COPY;
>
> diff --git a/examples/vhost/main.h b/examples/vhost/main.h
> index 4317b6ae8..6aa798a3e 100644
> --- a/examples/vhost/main.h
> +++ b/examples/vhost/main.h
> @@ -8,6 +8,7 @@
> #include <sys/queue.h>
>
> #include <rte_ether.h>
> +#include <stdatomic.h>
>
> /* Macros for printing using RTE_LOG */
> #define RTE_LOGTYPE_VHOST_CONFIG RTE_LOGTYPE_USER1
> @@ -21,8 +22,8 @@ enum {VIRTIO_RXQ, VIRTIO_TXQ, VIRTIO_QNUM};
> struct device_statistics {
> uint64_t tx;
> uint64_t tx_total;
> - rte_atomic64_t rx_atomic;
> - rte_atomic64_t rx_total_atomic;
> + atomic_int_least64_t rx_atomic;
> + atomic_int_least64_t rx_total_atomic;
> };
>
> struct vhost_queue {
> @@ -51,7 +52,7 @@ struct vhost_dev {
> uint64_t features;
> size_t hdr_len;
> uint16_t nr_vrings;
> - uint16_t nr_async_pkts;
> + atomic_int_least16_t nr_async_pkts;
> struct rte_vhost_memory *mem;
> struct device_statistics stats;
> TAILQ_ENTRY(vhost_dev) global_vdev_entry;
> --
> 2.29.2
>
