[dpdk-dev] [PATCH v4 4/5] net/af_xdp: use mbuf mempool for buffer management

[Maxime Coquelin]

On 3/22/19 2:01 PM, Xiaolong Ye wrote:
> Now, af_xdp registered memory buffer is managed by rte_mempool. mbuf be
s/mbuf be allocated/mbuf allocated/
> allocated from rte_mempool can be convert to xdp_desc's address and vice
s/convert/converted/
> versa.
> 
> Signed-off-by: Xiaolong Ye <xiaolong.ye at intel.com>
> ---
>   drivers/net/af_xdp/rte_eth_af_xdp.c | 117 +++++++++++++++++-----------
>   1 file changed, 72 insertions(+), 45 deletions(-)
> 
> diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
> index 9f0012347..6b1bc462a 100644
> --- a/drivers/net/af_xdp/rte_eth_af_xdp.c
> +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
> @@ -48,7 +48,11 @@ static int af_xdp_logtype;
>   
>   #define ETH_AF_XDP_FRAME_SIZE		XSK_UMEM__DEFAULT_FRAME_SIZE
>   #define ETH_AF_XDP_NUM_BUFFERS		4096
> -#define ETH_AF_XDP_DATA_HEADROOM	0
> +/* mempool hdrobj size (64 bytes) + sizeof(struct rte_mbuf) (128 bytes) */
> +#define ETH_AF_XDP_MBUF_OVERHEAD	192
> +/* data start from offset 320 (192 + 128) bytes */
> +#define ETH_AF_XDP_DATA_HEADROOM				\
> +	(ETH_AF_XDP_MBUF_OVERHEAD + RTE_PKTMBUF_HEADROOM)
>   #define ETH_AF_XDP_DFLT_NUM_DESCS	XSK_RING_CONS__DEFAULT_NUM_DESCS
>   #define ETH_AF_XDP_DFLT_QUEUE_IDX	0
>   
> @@ -61,7 +65,7 @@ struct xsk_umem_info {
>   	struct xsk_ring_prod fq;
>   	struct xsk_ring_cons cq;
>   	struct xsk_umem *umem;
> -	struct rte_ring *buf_ring;
> +	struct rte_mempool *mb_pool;
>   	void *buffer;
>   };
>   
> @@ -123,12 +127,32 @@ static struct rte_eth_link pmd_link = {
>   	.link_autoneg = ETH_LINK_AUTONEG
>   };
>   
> +static inline struct rte_mbuf *
> +addr_to_mbuf(struct xsk_umem_info *umem, uint64_t addr)
> +{
> +	uint64_t offset = (addr / ETH_AF_XDP_FRAME_SIZE *
> +			ETH_AF_XDP_FRAME_SIZE);
> +	struct rte_mbuf *mbuf = (struct rte_mbuf *)((uint64_t)umem->buffer +
> +				    offset + ETH_AF_XDP_MBUF_OVERHEAD -
> +				    sizeof(struct rte_mbuf));
> +	mbuf->data_off = addr - offset - ETH_AF_XDP_MBUF_OVERHEAD;
> +	return mbuf;
> +}
> +
> +static inline uint64_t
> +mbuf_to_addr(struct xsk_umem_info *umem, struct rte_mbuf *mbuf)
> +{
> +	return (uint64_t)mbuf->buf_addr + mbuf->data_off -
> +		(uint64_t)umem->buffer;
> +}
> +
>   static inline int
>   reserve_fill_queue(struct xsk_umem_info *umem, int reserve_size)
>   {
>   	struct xsk_ring_prod *fq = &umem->fq;
> +	struct rte_mbuf *mbuf;
>   	uint32_t idx;
> -	void *addr = NULL;
> +	uint64_t addr;
>   	int i, ret;
>   
>   	ret = xsk_ring_prod__reserve(fq, reserve_size, &idx);
> @@ -139,12 +163,14 @@ reserve_fill_queue(struct xsk_umem_info *umem, int reserve_size)
>   
>   	for (i = 0; i < reserve_size; i++) {
>   		__u64 *fq_addr;
> -		if (rte_ring_dequeue(umem->buf_ring, &addr)) {
> +		mbuf = rte_pktmbuf_alloc(umem->mb_pool);
> +		if (mbuf == NULL) {

unlikely()

>   			i--;
>   			break;
>   		}
> +		addr = mbuf_to_addr(umem, mbuf);
>   		fq_addr = xsk_ring_prod__fill_addr(fq, idx++);
> -		*fq_addr = (uint64_t)addr;
> +		*fq_addr = addr;
>   	}
>   
>   	xsk_ring_prod__submit(fq, i);
> @@ -196,7 +222,7 @@ eth_af_xdp_rx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
>   		rx_bytes += len;
>   		bufs[count++] = mbufs[i];
>   
> -		rte_ring_enqueue(umem->buf_ring, (void *)addr);
> +		rte_pktmbuf_free(addr_to_mbuf(umem, addr));
>   	}
>   
>   	xsk_ring_cons__release(rx, rcvd);
> @@ -219,7 +245,7 @@ static void pull_umem_cq(struct xsk_umem_info *umem, int size)
>   	for (i = 0; i < n; i++) {
>   		uint64_t addr;
>   		addr = *xsk_ring_cons__comp_addr(cq, idx_cq++);
> -		rte_ring_enqueue(umem->buf_ring, (void *)addr);
> +		rte_pktmbuf_free(addr_to_mbuf(umem, addr));
>   	}
>   
>   	xsk_ring_cons__release(cq, n);
> @@ -248,7 +274,7 @@ eth_af_xdp_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
>   	struct pkt_tx_queue *txq = queue;
>   	struct xsk_umem_info *umem = txq->pair->umem;
>   	struct rte_mbuf *mbuf;
> -	void *addrs[ETH_AF_XDP_TX_BATCH_SIZE];
> +	struct rte_mbuf *mbuf_to_tx;
>   	unsigned long tx_bytes = 0;
>   	int i, valid = 0;
>   	uint32_t idx_tx;
> @@ -257,11 +283,6 @@ eth_af_xdp_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
>   
>   	pull_umem_cq(umem, nb_pkts);
>   
> -	nb_pkts = rte_ring_dequeue_bulk(umem->buf_ring, addrs,
> -					nb_pkts, NULL);
> -	if (nb_pkts == 0)
> -		return 0;
> -
>   	if (xsk_ring_prod__reserve(&txq->tx, nb_pkts, &idx_tx) != nb_pkts) {
>   		kick_tx(txq);
>   		return 0;
> @@ -275,7 +296,12 @@ eth_af_xdp_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
>   		desc = xsk_ring_prod__tx_desc(&txq->tx, idx_tx + i);
>   		mbuf = bufs[i];
>   		if (mbuf->pkt_len <= buf_len) {
> -			desc->addr = (uint64_t)addrs[valid];
> +			mbuf_to_tx = rte_pktmbuf_alloc(umem->mb_pool);
> +			if (mbuf_to_tx == NULL) {

unlikely()

> +				rte_pktmbuf_free(mbuf);
> +				continue;
> +			}
> +			desc->addr = mbuf_to_addr(umem, mbuf_to_tx);
>   			desc->len = mbuf->pkt_len;
>   			pkt = xsk_umem__get_data(umem->buffer,
>   						 desc->addr);
> @@ -291,10 +317,6 @@ eth_af_xdp_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
>   
>   	kick_tx(txq);
>   
> -	if (valid < nb_pkts)
> -		rte_ring_enqueue_bulk(umem->buf_ring, &addrs[valid],
> -				 nb_pkts - valid, NULL);
> -
>   	txq->stats.err_pkts += nb_pkts - valid;
>   	txq->stats.tx_pkts += valid;
>   	txq->stats.tx_bytes += tx_bytes;
> @@ -443,16 +465,29 @@ eth_link_update(struct rte_eth_dev *dev __rte_unused,
>   
>   static void xdp_umem_destroy(struct xsk_umem_info *umem)
>   {
> -	free(umem->buffer);
> -	umem->buffer = NULL;
> -
> -	rte_ring_free(umem->buf_ring);
> -	umem->buf_ring = NULL;
> +	rte_mempool_free(umem->mb_pool);
> +	umem->mb_pool = NULL;
>   
>   	rte_free(umem);
>   	umem = NULL;
>   }
>   
> +static inline uint64_t get_base_addr(struct rte_mempool *mp)
> +{
> +	struct rte_mempool_memhdr *memhdr;
> +
> +	memhdr = STAILQ_FIRST(&mp->mem_list);
> +	return (uint64_t)(memhdr->addr);
> +}
> +
> +static inline uint64_t get_len(struct rte_mempool *mp)
> +{
> +	struct rte_mempool_memhdr *memhdr;
> +
> +	memhdr = STAILQ_FIRST(&mp->mem_list);
> +	return (uint64_t)(memhdr->len);
> +}
> +
>   static struct xsk_umem_info *xdp_umem_configure(void)
>   {
>   	struct xsk_umem_info *umem;
> @@ -461,9 +496,8 @@ static struct xsk_umem_info *xdp_umem_configure(void)
>   		.comp_size = ETH_AF_XDP_DFLT_NUM_DESCS,
>   		.frame_size = ETH_AF_XDP_FRAME_SIZE,
>   		.frame_headroom = ETH_AF_XDP_DATA_HEADROOM };
> -	void *bufs = NULL;
> +	void *base_addr = NULL;
>   	int ret;
> -	uint64_t i;
>   
>   	umem = rte_zmalloc_socket("umem", sizeof(*umem), 0, rte_socket_id());
>   	if (umem == NULL) {
> @@ -471,26 +505,20 @@ static struct xsk_umem_info *xdp_umem_configure(void)
>   		return NULL;
>   	}
>   
> -	umem->buf_ring = rte_ring_create("af_xdp_ring",
> -					 ETH_AF_XDP_NUM_BUFFERS,
> -					 SOCKET_ID_ANY,
> -					 0x0);
> -	if (umem->buf_ring == NULL) {
> -		AF_XDP_LOG(ERR, "Failed to create rte_ring\n");
> +	umem->mb_pool = rte_pktmbuf_pool_create_with_flags("af_xdp_mempool",
> +			ETH_AF_XDP_NUM_BUFFERS,
> +			250, 0,
> +			ETH_AF_XDP_FRAME_SIZE -
> +			ETH_AF_XDP_MBUF_OVERHEAD,
> +			MEMPOOL_F_NO_SPREAD | MEMPOOL_F_PAGE_ALIGN,
> +			SOCKET_ID_ANY);
> +	if (umem->mb_pool == NULL || umem->mb_pool->nb_mem_chunks != 1) {
> +		AF_XDP_LOG(ERR, "Failed to create mempool\n");
>   		goto err;
>   	}
> +	base_addr = (void *)get_base_addr(umem->mb_pool);
>   
> -	for (i = 0; i < ETH_AF_XDP_NUM_BUFFERS; i++)
> -		rte_ring_enqueue(umem->buf_ring,
> -				 (void *)(i * ETH_AF_XDP_FRAME_SIZE +
> -					  ETH_AF_XDP_DATA_HEADROOM));
> -
> -	if (posix_memalign(&bufs, getpagesize(),
> -			   ETH_AF_XDP_NUM_BUFFERS * ETH_AF_XDP_FRAME_SIZE)) {
> -		AF_XDP_LOG(ERR, "Failed to allocate memory pool.\n");
> -		goto err;
> -	}
> -	ret = xsk_umem__create(&umem->umem, bufs,
> +	ret = xsk_umem__create(&umem->umem, base_addr,
>   			       ETH_AF_XDP_NUM_BUFFERS * ETH_AF_XDP_FRAME_SIZE,
>   			       &umem->fq, &umem->cq,
>   			       &usr_config);
> @@ -499,7 +527,7 @@ static struct xsk_umem_info *xdp_umem_configure(void)
>   		AF_XDP_LOG(ERR, "Failed to create umem");
>   		goto err;

You need to destroy mb_pool if xsk_umem__create() fails.

>   	}
> -	umem->buffer = bufs;
> +	umem->buffer = base_addr;
>   
>   	return umem;
>   
> @@ -912,10 +940,9 @@ rte_pmd_af_xdp_remove(struct rte_vdev_device *dev)
>   
>   	internals = eth_dev->data->dev_private;
>   
> -	rte_ring_free(internals->umem->buf_ring);
> -	rte_free(internals->umem->buffer);
>   	rte_free(internals->umem);
>   
> +	rte_mempool_free(internals->umem->mb_pool);
>   	rte_eth_dev_release_port(eth_dev);
>   
>   
>