On Sat 1 Feb 2025, 10:03 Ariel Otilibili, <ariel.otilib...@6wind.com> wrote:
> Both legs of the loop share the same logic: the common parts are about
> reserving and filling both address and length into the description.
>
> This is moved into reserve_and_fill().
>
> Bugzilla ID: 1440
> Suggested-by: Maryam Tahhan <mtah...@redhat.com>
> Signed-off-by: Ariel Otilibili <ariel.otilib...@6wind.com>
> ---
> drivers/net/af_xdp/rte_eth_af_xdp.c | 62 ++++++++++++++++-------------
> 1 file changed, 34 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c
> b/drivers/net/af_xdp/rte_eth_af_xdp.c
> index 092bcb73aa0a..840a12dbf508 100644
> --- a/drivers/net/af_xdp/rte_eth_af_xdp.c
> +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
> @@ -536,6 +536,31 @@ kick_tx(struct pkt_tx_queue *txq, struct
> xsk_ring_cons *cq)
> }
> }
>
> +static inline struct xdp_desc *
> +reserve_and_fill(struct pkt_tx_queue *txq, struct rte_mbuf *mbuf,
> + struct xsk_umem_info *umem)
> +{
> + struct xdp_desc *desc = NULL;
> + uint32_t *idx_tx = NULL;
> + uint64_t addr, offset;
> +
> + if (!xsk_ring_prod__reserve(&txq->tx, 1, idx_tx))
> + goto out;
> +
> + desc = xsk_ring_prod__tx_desc(&txq->tx, *idx_tx);
> + desc->len = mbuf->pkt_len;
> +
> + addr = (uint64_t)mbuf - (uint64_t)umem->buffer
> + - umem->mb_pool->header_size;
> + offset = rte_pktmbuf_mtod(mbuf, uint64_t) - (uint64_t)mbuf
> + + umem->mb_pool->header_size;
> + offset = offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT;
> + desc->addr = addr | offset;
> +
> +out:
> + return desc;
> +}
> +
> #if defined(XDP_UMEM_UNALIGNED_CHUNK_FLAG)
> static uint16_t
> af_xdp_tx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
> @@ -545,10 +570,8 @@ af_xdp_tx_zc(void *queue, struct rte_mbuf **bufs,
> uint16_t nb_pkts)
> struct rte_mbuf *mbuf;
> unsigned long tx_bytes = 0;
> int i;
> - uint32_t idx_tx;
> uint16_t count = 0;
> struct xdp_desc *desc;
> - uint64_t addr, offset;
> struct xsk_ring_cons *cq = &txq->pair->cq;
> uint32_t free_thresh = cq->size >> 1;
>
> @@ -559,21 +582,12 @@ af_xdp_tx_zc(void *queue, struct rte_mbuf **bufs,
> uint16_t nb_pkts)
> mbuf = bufs[i];
>
> if (mbuf->pool == umem->mb_pool) {
> - if (!xsk_ring_prod__reserve(&txq->tx, 1, &idx_tx))
> {
> + if (!(desc = reserve_and_fill(txq, mbuf, umem))) {
> kick_tx(txq, cq);
> - if (!xsk_ring_prod__reserve(&txq->tx, 1,
> - &idx_tx))
> + if (!(desc = reserve_and_fill(txq, mbuf,
> umem)))
> goto out;
> }
> - desc = xsk_ring_prod__tx_desc(&txq->tx, idx_tx);
> - desc->len = mbuf->pkt_len;
> - addr = (uint64_t)mbuf - (uint64_t)umem->buffer -
> - umem->mb_pool->header_size;
> - offset = rte_pktmbuf_mtod(mbuf, uint64_t) -
> - (uint64_t)mbuf +
> - umem->mb_pool->header_size;
> - offset = offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT;
> - desc->addr = addr | offset;
> +
> tx_bytes += desc->len;
> count++;
> } else {
> @@ -584,26 +598,18 @@ af_xdp_tx_zc(void *queue, struct rte_mbuf **bufs,
> uint16_t nb_pkts)
> if (local_mbuf == NULL)
> goto out;
>
> - if (!xsk_ring_prod__reserve(&txq->tx, 1, &idx_tx))
> {
> + if (!(desc = reserve_and_fill(txq, local_mbuf,
> umem))) {
> rte_pktmbuf_free(local_mbuf);
> goto out;
> }
>
> - desc = xsk_ring_prod__tx_desc(&txq->tx, idx_tx);
> - desc->len = mbuf->pkt_len;
> -
>
So I think i spotted one issue, you might need override desc->len after the
call to the reserve_and_fill function so as it's not taken supposed to be
from local_mbuf here.
- addr = (uint64_t)local_mbuf -
> (uint64_t)umem->buffer -
> - umem->mb_pool->header_size;
> - offset = rte_pktmbuf_mtod(local_mbuf, uint64_t) -
> - (uint64_t)local_mbuf +
> - umem->mb_pool->header_size;
> - pkt = xsk_umem__get_data(umem->buffer, addr +
> offset);
> - offset = offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT;
> - desc->addr = addr | offset;
> + pkt = xsk_umem__get_data(umem->buffer,
> + (desc->addr & ~0xFFF)
> + + (desc->addr & 0xFFF));
>
Would prefer to move this pkt assignment to reserve_and_fill()
What if we passed a void **ppkt to reserve_and_fill() then kept the
original logic just wrapped in a NULL check?
if (ppkt) {
*ppkt = xsk_umem__get_data(umem->buffer, addr + offset);
}
Before the offset and desc->addr
offset = offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT;
desc->addr = addr | offset;
WDYT?
rte_memcpy(pkt, rte_pktmbuf_mtod(mbuf, void *),
> - desc->len);
> - tx_bytes += desc->len;
> + desc->len);
> rte_pktmbuf_free(mbuf);
> + tx_bytes += desc->len;
> count++;
> }
> }
> --
> 2.30.2
>
>
