On Wed, Jan 08, 2025 at 05:47:57PM +0530, Shaiq Wani wrote:
> In case some CPUs don't support AVX512. Enable AVX2 for them to
> get better per-core performance.
>
> Signed-off-by: Shaiq Wani <shaiq.w...@intel.com>
> ---
Hi,
some review comments inline below.
/Bruce
> doc/guides/rel_notes/release_25_03.rst | 3 +
> drivers/common/idpf/idpf_common_device.h | 1 +
> drivers/common/idpf/idpf_common_rxtx.h | 4 +
> drivers/common/idpf/idpf_common_rxtx_avx2.c | 225 ++++++++++++++++++++
> drivers/common/idpf/version.map | 1 +
> drivers/net/idpf/idpf_rxtx.c | 14 ++
> 6 files changed, 248 insertions(+)
>
> diff --git a/doc/guides/rel_notes/release_25_03.rst
> b/doc/guides/rel_notes/release_25_03.rst
> index 426dfcd982..7ded85dac4 100644
> --- a/doc/guides/rel_notes/release_25_03.rst
> +++ b/doc/guides/rel_notes/release_25_03.rst
> @@ -55,6 +55,9 @@ New Features
> Also, make sure to start the actual text at the margin.
> =======================================================
>
> + * **Added support of vector instructions on IDPF.**
> +
> + Added support of AVX2 instructions in IDPF single queue RX and TX path.
>
Driver already had vector instructions so title is a little misleading.
Clarify the title to be AVX2-specific. For the body, please clarify singleq
vs splitq and what the differences are and when one might get the benefit
of the AVX2 code path.
> Removed Items
> -------------
> diff --git a/drivers/common/idpf/idpf_common_device.h
> b/drivers/common/idpf/idpf_common_device.h
> index 734be1c88a..5f3e4a4fcf 100644
> --- a/drivers/common/idpf/idpf_common_device.h
> +++ b/drivers/common/idpf/idpf_common_device.h
> @@ -124,6 +124,7 @@ struct idpf_vport {
> bool rx_vec_allowed;
> bool tx_vec_allowed;
Do we have vector paths other than the 2 AVX ones below. If not, why do we
need this flag?
> bool rx_use_avx2;
> + bool tx_use_avx2;
> bool rx_use_avx512;
> bool tx_use_avx512;
>
> diff --git a/drivers/common/idpf/idpf_common_rxtx.h
> b/drivers/common/idpf/idpf_common_rxtx.h
> index f50cf5ef46..e19e1878f3 100644
> --- a/drivers/common/idpf/idpf_common_rxtx.h
> +++ b/drivers/common/idpf/idpf_common_rxtx.h
> @@ -306,5 +306,9 @@ __rte_internal
> uint16_t idpf_dp_singleq_recv_pkts_avx2(void *rx_queue,
> struct rte_mbuf **rx_pkts,
> uint16_t nb_pkts);
> +__rte_internal
> +uint16_t idpf_dp_singleq_xmit_pkts_avx2(void *tx_queue,
> + struct rte_mbuf **tx_pkts,
> + uint16_t nb_pkts);
>
> #endif /* _IDPF_COMMON_RXTX_H_ */
> diff --git a/drivers/common/idpf/idpf_common_rxtx_avx2.c
> b/drivers/common/idpf/idpf_common_rxtx_avx2.c
> index a05b26c68a..a4bc8e2bef 100644
> --- a/drivers/common/idpf/idpf_common_rxtx_avx2.c
> +++ b/drivers/common/idpf/idpf_common_rxtx_avx2.c
> @@ -588,3 +588,228 @@ idpf_dp_singleq_recv_pkts_avx2(void *rx_queue, struct
> rte_mbuf **rx_pkts,
> {
> return _idpf_singleq_recv_raw_pkts_vec_avx2(rx_queue, rx_pkts, nb_pkts,
> NULL);
> }
> +
> +static __rte_always_inline void
> +idpf_tx_backlog_entry(struct idpf_tx_entry *txep,
> + struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
> +{
> + int i;
> +
> + for (i = 0; i < (int)nb_pkts; ++i)
> + txep[i].mbuf = tx_pkts[i];
> +}
> +
> +static __rte_always_inline int
> +idpf_singleq_tx_free_bufs_vec(struct idpf_tx_queue *txq)
> +{
> + struct idpf_tx_entry *txep;
> + uint32_t n;
> + uint32_t i;
> + int nb_free = 0;
> + struct rte_mbuf *m, *free[txq->rs_thresh];
> +
> + /* check DD bits on threshold descriptor */
> + if ((txq->tx_ring[txq->next_dd].qw1 &
> + rte_cpu_to_le_64(IDPF_TXD_QW1_DTYPE_M)) !=
> + rte_cpu_to_le_64(IDPF_TX_DESC_DTYPE_DESC_DONE))
> + return 0;
> +
> + n = txq->rs_thresh;
> +
> + /* first buffer to free from S/W ring is at index
> + * next_dd - (rs_thresh-1)
> + */
> + txep = &txq->sw_ring[txq->next_dd - (n - 1)];
> + m = rte_pktmbuf_prefree_seg(txep[0].mbuf);
> + if (likely(m)) {
> + free[0] = m;
> + nb_free = 1;
> + for (i = 1; i < n; i++) {
> + m = rte_pktmbuf_prefree_seg(txep[i].mbuf);
> + if (likely(m)) {
> + if (likely(m->pool == free[0]->pool)) {
> + free[nb_free++] = m;
> + } else {
> + rte_mempool_put_bulk(free[0]->pool,
> + (void *)free,
> + nb_free);
> + free[0] = m;
> + nb_free = 1;
> + }
> + }
> + }
> + rte_mempool_put_bulk(free[0]->pool, (void **)free, nb_free);
> + } else {
> + for (i = 1; i < n; i++) {
> + m = rte_pktmbuf_prefree_seg(txep[i].mbuf);
> + if (m)
> + rte_mempool_put(m->pool, m);
> + }
> + }
> +
> + /* buffers were freed, update counters */
> + txq->nb_free = (uint16_t)(txq->nb_free + txq->rs_thresh);
> + txq->next_dd = (uint16_t)(txq->next_dd + txq->rs_thresh);
> + if (txq->next_dd >= txq->nb_tx_desc)
> + txq->next_dd = (uint16_t)(txq->rs_thresh - 1);
> +
> + return txq->rs_thresh;
> +}
> +
If/when patchset [1] is merged, this code should be reworked to use the
common functions.
[1] https://patches.dpdk.org/project/dpdk/list/?series=34398
> +static inline void
> +idpf_singleq_vtx1(volatile struct idpf_base_tx_desc *txdp,
> + struct rte_mbuf *pkt, uint64_t flags)
> +{
> + uint64_t high_qw =
> + (IDPF_TX_DESC_DTYPE_DATA |
> + ((uint64_t)flags << IDPF_TXD_QW1_CMD_S) |
> + ((uint64_t)pkt->data_len << IDPF_TXD_QW1_TX_BUF_SZ_S));
> +
> + __m128i descriptor = _mm_set_epi64x(high_qw,
> + pkt->buf_iova + pkt->data_off);
> + _mm_store_si128((__m128i *)txdp, descriptor);
> +}
> +
> +static inline void
> +idpf_singleq_vtx(volatile struct idpf_base_tx_desc *txdp,
> + struct rte_mbuf **pkt, uint16_t nb_pkts, uint64_t flags)
> +{
> + const uint64_t hi_qw_tmpl = (IDPF_TX_DESC_DTYPE_DATA |
> + ((uint64_t)flags << IDPF_TXD_QW1_CMD_S));
> +
> + /* if unaligned on 32-bit boundary, do one to align */
> + if (((uintptr_t)txdp & 0x1F) != 0 && nb_pkts != 0) {
> + idpf_singleq_vtx1(txdp, *pkt, flags);
> + nb_pkts--, txdp++, pkt++;
> + }
> +
> + /* do two at a time while possible, in bursts */
> + for (; nb_pkts > 3; txdp += 4, pkt += 4, nb_pkts -= 4) {
> + uint64_t hi_qw3 =
> + hi_qw_tmpl |
> + ((uint64_t)pkt[3]->data_len <<
> + IDPF_TXD_QW1_TX_BUF_SZ_S);
> + uint64_t hi_qw2 =
> + hi_qw_tmpl |
> + ((uint64_t)pkt[2]->data_len <<
> + IDPF_TXD_QW1_TX_BUF_SZ_S);
> + uint64_t hi_qw1 =
> + hi_qw_tmpl |
> + ((uint64_t)pkt[1]->data_len <<
> + IDPF_TXD_QW1_TX_BUF_SZ_S);
> + uint64_t hi_qw0 =
> + hi_qw_tmpl |
> + ((uint64_t)pkt[0]->data_len <<
> + IDPF_TXD_QW1_TX_BUF_SZ_S);
> +
> + __m256i desc2_3 =
> + _mm256_set_epi64x
> + (hi_qw3,
> + pkt[3]->buf_iova + pkt[3]->data_off,
> + hi_qw2,
> + pkt[2]->buf_iova + pkt[2]->data_off);
> + __m256i desc0_1 =
> + _mm256_set_epi64x
> + (hi_qw1,
> + pkt[1]->buf_iova + pkt[1]->data_off,
> + hi_qw0,
> + pkt[0]->buf_iova + pkt[0]->data_off);
> + _mm256_store_si256((void *)(txdp + 2), desc2_3);
> + _mm256_store_si256((void *)txdp, desc0_1);
> + }
> +
> + /* do any last ones */
> + while (nb_pkts) {
> + idpf_singleq_vtx1(txdp, *pkt, flags);
> + txdp++, pkt++, nb_pkts--;
> + }
> +}
> +
> +static inline uint16_t
> +idpf_singleq_xmit_fixed_burst_vec_avx2(void *tx_queue, struct rte_mbuf
> **tx_pkts,
> + uint16_t nb_pkts)
> +{
> + struct idpf_tx_queue *txq = (struct idpf_tx_queue *)tx_queue;
> + volatile struct idpf_base_tx_desc *txdp;
> + struct idpf_tx_entry *txep;
> + uint16_t n, nb_commit, tx_id;
> + uint64_t flags = IDPF_TX_DESC_CMD_EOP;
> + uint64_t rs = IDPF_TX_DESC_CMD_RS | flags;
> +
> + /* cross rx_thresh boundary is not allowed */
> + nb_pkts = RTE_MIN(nb_pkts, txq->rs_thresh);
> +
> + if (txq->nb_free < txq->free_thresh)
> + idpf_singleq_tx_free_bufs_vec(txq);
> +
> + nb_commit = nb_pkts = (uint16_t)RTE_MIN(txq->nb_free, nb_pkts);
> + if (unlikely(nb_pkts == 0))
> + return 0;
> +
> + tx_id = txq->tx_tail;
> + txdp = &txq->tx_ring[tx_id];
> + txep = &txq->sw_ring[tx_id];
> +
> + txq->nb_free = (uint16_t)(txq->nb_free - nb_pkts);
> +
> + n = (uint16_t)(txq->nb_tx_desc - tx_id);
> + if (nb_commit >= n) {
> + idpf_tx_backlog_entry(txep, tx_pkts, n);
> +
> + idpf_singleq_vtx(txdp, tx_pkts, n - 1, flags);
> + tx_pkts += (n - 1);
> + txdp += (n - 1);
> +
> + idpf_singleq_vtx1(txdp, *tx_pkts++, rs);
> +
> + nb_commit = (uint16_t)(nb_commit - n);
> +
> + tx_id = 0;
> + txq->next_rs = (uint16_t)(txq->rs_thresh - 1);
> +
> + /* avoid reach the end of ring */
> + txdp = &txq->tx_ring[tx_id];
> + txep = &txq->sw_ring[tx_id];
> + }
> +
> + idpf_tx_backlog_entry(txep, tx_pkts, nb_commit);
> +
> + idpf_singleq_vtx(txdp, tx_pkts, nb_commit, flags);
> +
> + tx_id = (uint16_t)(tx_id + nb_commit);
> + if (tx_id > txq->next_rs) {
> + txq->tx_ring[txq->next_rs].qw1 |=
> + rte_cpu_to_le_64(((uint64_t)IDPF_TX_DESC_CMD_RS) <<
> + IDPF_TXD_QW1_CMD_S);
> + txq->next_rs =
> + (uint16_t)(txq->next_rs + txq->rs_thresh);
> + }
> +
> + txq->tx_tail = tx_id;
> +
> + IDPF_PCI_REG_WRITE(txq->qtx_tail, txq->tx_tail);
> +
> + return nb_pkts;
> +}
> +
> +uint16_t
> +idpf_dp_singleq_xmit_pkts_avx2(void *tx_queue, struct rte_mbuf **tx_pkts,
> + uint16_t nb_pkts)
> +{
> + uint16_t nb_tx = 0;
> + struct idpf_tx_queue *txq = (struct idpf_tx_queue *)tx_queue;
> +
> + while (nb_pkts) {
> + uint16_t ret, num;
> +
> + num = (uint16_t)RTE_MIN(nb_pkts, txq->rs_thresh);
> + ret = idpf_singleq_xmit_fixed_burst_vec_avx2(tx_queue,
> &tx_pkts[nb_tx],
> + num);
> + nb_tx += ret;
> + nb_pkts -= ret;
> + if (ret < num)
> + break;
> + }
> +
> + return nb_tx;
> +}
> diff --git a/drivers/common/idpf/version.map b/drivers/common/idpf/version.map
> index 4510aae6b3..eadcb9a2cf 100644
> --- a/drivers/common/idpf/version.map
> +++ b/drivers/common/idpf/version.map
> @@ -15,6 +15,7 @@ INTERNAL {
> idpf_dp_splitq_xmit_pkts;
> idpf_dp_splitq_xmit_pkts_avx512;
> idpf_dp_singleq_recv_pkts_avx2;
> + idpf_dp_singleq_xmit_pkts_avx2;
>
> idpf_qc_rx_thresh_check;
> idpf_qc_rx_queue_release;
> diff --git a/drivers/net/idpf/idpf_rxtx.c b/drivers/net/idpf/idpf_rxtx.c
> index 80c6c325e8..579293b2e8 100644
> --- a/drivers/net/idpf/idpf_rxtx.c
> +++ b/drivers/net/idpf/idpf_rxtx.c
> @@ -888,6 +888,12 @@ idpf_set_tx_function(struct rte_eth_dev *dev)
> if (idpf_tx_vec_dev_check_default(dev) == IDPF_VECTOR_PATH &&
> rte_vect_get_max_simd_bitwidth() >= RTE_VECT_SIMD_128) {
> vport->tx_vec_allowed = true;
> +
> + if ((rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX2) == 1 ||
> + rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX512F) == 1) &&
As with the Rx path, only check the AVX2 flag here.
> + rte_vect_get_max_simd_bitwidth() >= RTE_VECT_SIMD_256)
> + vport->tx_use_avx2 = true;
> +
> if (rte_vect_get_max_simd_bitwidth() >= RTE_VECT_SIMD_512)
> #ifdef CC_AVX512_SUPPORT
> {
> @@ -947,6 +953,14 @@ idpf_set_tx_function(struct rte_eth_dev *dev)
> return;
> }
> #endif /* CC_AVX512_SUPPORT */
> + if (vport->tx_use_avx2) {
> + PMD_DRV_LOG(NOTICE,
> + "Using Single AVX2 Vector Tx (port
> %d).",
> + dev->data->port_id);
> + dev->tx_pkt_burst =
> idpf_dp_singleq_xmit_pkts_avx2;
> + dev->tx_pkt_prepare = idpf_dp_prep_pkts;
> + return;
> + }
> }
> PMD_DRV_LOG(NOTICE,
> "Using Single Scalar Tx (port %d).",
> --
> 2.34.1
>
