[v4] net/af_xdp: optimize RX path by removing the unneeded allocation mbuf
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Commit Message
when receive packets, the max bunch number of mbuf are allocated
if hardware does not receive the max bunch number packets, it
will free redundancy mbuf, this is low performance
so optimize rx performance, by allocating number of mbuf based on
result of xsk_ring_cons__peek, to avoid to redundancy allocation,
and free mbuf when receive packets
and rx cached_cons must be rollbacked if fail to allocating mbuf,
found by Ciara Loftus
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Dongsheng Rong <rongdongsheng@baidu.com>
---
V2: rollback rx cached_cons if mbuf failed to be allocated
V3: add comment when rollback rx cached_cons
V4: fix the comment
drivers/net/af_xdp/rte_eth_af_xdp.c | 73 ++++++++++++++---------------
1 file changed, 35 insertions(+), 38 deletions(-)
Comments
> Subject: [dpdk-dev] [PATCH][v4] net/af_xdp: optimize RX path by removing
> the unneeded allocation mbuf
>
> when receive packets, the max bunch number of mbuf are allocated
> if hardware does not receive the max bunch number packets, it
> will free redundancy mbuf, this is low performance
>
> so optimize rx performance, by allocating number of mbuf based on
> result of xsk_ring_cons__peek, to avoid to redundancy allocation,
> and free mbuf when receive packets
>
> and rx cached_cons must be rollbacked if fail to allocating mbuf,
> found by Ciara Loftus
>
> Signed-off-by: Li RongQing <lirongqing@baidu.com>
> Signed-off-by: Dongsheng Rong <rongdongsheng@baidu.com>
Thanks for the v4.
Acked-by: Ciara Loftus <ciara.loftus@intel.com>
> ---
> V2: rollback rx cached_cons if mbuf failed to be allocated
> V3: add comment when rollback rx cached_cons
> V4: fix the comment
>
> drivers/net/af_xdp/rte_eth_af_xdp.c | 73 ++++++++++++++---------------
> 1 file changed, 35 insertions(+), 38 deletions(-)
>
> diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c
> b/drivers/net/af_xdp/rte_eth_af_xdp.c
> index 2c7892bd7..d7dd7d125 100644
> --- a/drivers/net/af_xdp/rte_eth_af_xdp.c
> +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
> @@ -255,28 +255,32 @@ af_xdp_rx_zc(void *queue, struct rte_mbuf
> **bufs, uint16_t nb_pkts)
> struct xsk_umem_info *umem = rxq->umem;
> uint32_t idx_rx = 0;
> unsigned long rx_bytes = 0;
> - int rcvd, i;
> + int i;
> struct rte_mbuf *fq_bufs[ETH_AF_XDP_RX_BATCH_SIZE];
>
> - /* allocate bufs for fill queue replenishment after rx */
> - if (rte_pktmbuf_alloc_bulk(umem->mb_pool, fq_bufs, nb_pkts)) {
> - AF_XDP_LOG(DEBUG,
> - "Failed to get enough buffers for fq.\n");
> - return 0;
> - }
> + nb_pkts = xsk_ring_cons__peek(rx, nb_pkts, &idx_rx);
>
> - rcvd = xsk_ring_cons__peek(rx, nb_pkts, &idx_rx);
> -
> - if (rcvd == 0) {
> + if (nb_pkts == 0) {
> #if defined(XDP_USE_NEED_WAKEUP)
> if (xsk_ring_prod__needs_wakeup(fq))
> (void)poll(rxq->fds, 1, 1000);
> #endif
>
> - goto out;
> + return 0;
> + }
> +
> + /* allocate bufs for fill queue replenishment after rx */
> + if (rte_pktmbuf_alloc_bulk(umem->mb_pool, fq_bufs, nb_pkts)) {
> + AF_XDP_LOG(DEBUG,
> + "Failed to get enough buffers for fq.\n");
> + /* rollback cached_cons which is added by
> + * xsk_ring_cons__peek
> + */
> + rx->cached_cons -= nb_pkts;
> + return 0;
> }
>
> - for (i = 0; i < rcvd; i++) {
> + for (i = 0; i < nb_pkts; i++) {
> const struct xdp_desc *desc;
> uint64_t addr;
> uint32_t len;
> @@ -301,20 +305,14 @@ af_xdp_rx_zc(void *queue, struct rte_mbuf
> **bufs, uint16_t nb_pkts)
> rx_bytes += len;
> }
>
> - xsk_ring_cons__release(rx, rcvd);
> -
> - (void)reserve_fill_queue(umem, rcvd, fq_bufs, fq);
> + xsk_ring_cons__release(rx, nb_pkts);
> + (void)reserve_fill_queue(umem, nb_pkts, fq_bufs, fq);
>
> /* statistics */
> - rxq->stats.rx_pkts += rcvd;
> + rxq->stats.rx_pkts += nb_pkts;
> rxq->stats.rx_bytes += rx_bytes;
>
> -out:
> - if (rcvd != nb_pkts)
> - rte_mempool_put_bulk(umem->mb_pool, (void
> **)&fq_bufs[rcvd],
> - nb_pkts - rcvd);
> -
> - return rcvd;
> + return nb_pkts;
> }
> #else
> static uint16_t
> @@ -326,7 +324,7 @@ af_xdp_rx_cp(void *queue, struct rte_mbuf **bufs,
> uint16_t nb_pkts)
> struct xsk_ring_prod *fq = &rxq->fq;
> uint32_t idx_rx = 0;
> unsigned long rx_bytes = 0;
> - int rcvd, i;
> + int i;
> uint32_t free_thresh = fq->size >> 1;
> struct rte_mbuf *mbufs[ETH_AF_XDP_RX_BATCH_SIZE];
>
> @@ -334,20 +332,24 @@ af_xdp_rx_cp(void *queue, struct rte_mbuf
> **bufs, uint16_t nb_pkts)
> (void)reserve_fill_queue(umem,
> ETH_AF_XDP_RX_BATCH_SIZE,
> NULL, fq);
>
> - if (unlikely(rte_pktmbuf_alloc_bulk(rxq->mb_pool, mbufs, nb_pkts)
> != 0))
> - return 0;
> -
> - rcvd = xsk_ring_cons__peek(rx, nb_pkts, &idx_rx);
> - if (rcvd == 0) {
> + nb_pkts = xsk_ring_cons__peek(rx, nb_pkts, &idx_rx);
> + if (nb_pkts == 0) {
> #if defined(XDP_USE_NEED_WAKEUP)
> if (xsk_ring_prod__needs_wakeup(fq))
> (void)poll(rxq->fds, 1, 1000);
> #endif
> + return 0;
> + }
>
> - goto out;
> + if (unlikely(rte_pktmbuf_alloc_bulk(rxq->mb_pool, mbufs,
> nb_pkts))) {
> + /* rollback cached_cons which is added by
> + * xsk_ring_cons__peek
> + */
> + rx->cached_cons -= nb_pkts;
> + return 0;
> }
>
> - for (i = 0; i < rcvd; i++) {
> + for (i = 0; i < nb_pkts; i++) {
> const struct xdp_desc *desc;
> uint64_t addr;
> uint32_t len;
> @@ -366,18 +368,13 @@ af_xdp_rx_cp(void *queue, struct rte_mbuf
> **bufs, uint16_t nb_pkts)
> bufs[i] = mbufs[i];
> }
>
> - xsk_ring_cons__release(rx, rcvd);
> + xsk_ring_cons__release(rx, nb_pkts);
>
> /* statistics */
> - rxq->stats.rx_pkts += rcvd;
> + rxq->stats.rx_pkts += nb_pkts;
> rxq->stats.rx_bytes += rx_bytes;
>
> -out:
> - if (rcvd != nb_pkts)
> - rte_mempool_put_bulk(rxq->mb_pool, (void
> **)&mbufs[rcvd],
> - nb_pkts - rcvd);
> -
> - return rcvd;
> + return nb_pkts;
> }
> #endif
>
> --
> 2.17.3
On 11/25/2020 1:03 PM, Loftus, Ciara wrote:
>> Subject: [dpdk-dev] [PATCH][v4] net/af_xdp: optimize RX path by removing
>> the unneeded allocation mbuf
>>
>> when receive packets, the max bunch number of mbuf are allocated
>> if hardware does not receive the max bunch number packets, it
>> will free redundancy mbuf, this is low performance
>>
>> so optimize rx performance, by allocating number of mbuf based on
>> result of xsk_ring_cons__peek, to avoid to redundancy allocation,
>> and free mbuf when receive packets
>>
>> and rx cached_cons must be rollbacked if fail to allocating mbuf,
>> found by Ciara Loftus
>>
>> Signed-off-by: Li RongQing <lirongqing@baidu.com>
>> Signed-off-by: Dongsheng Rong <rongdongsheng@baidu.com>
>
> Thanks for the v4.
>
> Acked-by: Ciara Loftus <ciara.loftus@intel.com>
>
Applied to dpdk-next-net/main, thanks.
@@ -255,28 +255,32 @@ af_xdp_rx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
struct xsk_umem_info *umem = rxq->umem;
uint32_t idx_rx = 0;
unsigned long rx_bytes = 0;
- int rcvd, i;
+ int i;
struct rte_mbuf *fq_bufs[ETH_AF_XDP_RX_BATCH_SIZE];
- /* allocate bufs for fill queue replenishment after rx */
- if (rte_pktmbuf_alloc_bulk(umem->mb_pool, fq_bufs, nb_pkts)) {
- AF_XDP_LOG(DEBUG,
- "Failed to get enough buffers for fq.\n");
- return 0;
- }
+ nb_pkts = xsk_ring_cons__peek(rx, nb_pkts, &idx_rx);
- rcvd = xsk_ring_cons__peek(rx, nb_pkts, &idx_rx);
-
- if (rcvd == 0) {
+ if (nb_pkts == 0) {
#if defined(XDP_USE_NEED_WAKEUP)
if (xsk_ring_prod__needs_wakeup(fq))
(void)poll(rxq->fds, 1, 1000);
#endif
- goto out;
+ return 0;
+ }
+
+ /* allocate bufs for fill queue replenishment after rx */
+ if (rte_pktmbuf_alloc_bulk(umem->mb_pool, fq_bufs, nb_pkts)) {
+ AF_XDP_LOG(DEBUG,
+ "Failed to get enough buffers for fq.\n");
+ /* rollback cached_cons which is added by
+ * xsk_ring_cons__peek
+ */
+ rx->cached_cons -= nb_pkts;
+ return 0;
}
- for (i = 0; i < rcvd; i++) {
+ for (i = 0; i < nb_pkts; i++) {
const struct xdp_desc *desc;
uint64_t addr;
uint32_t len;
@@ -301,20 +305,14 @@ af_xdp_rx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
rx_bytes += len;
}
- xsk_ring_cons__release(rx, rcvd);
-
- (void)reserve_fill_queue(umem, rcvd, fq_bufs, fq);
+ xsk_ring_cons__release(rx, nb_pkts);
+ (void)reserve_fill_queue(umem, nb_pkts, fq_bufs, fq);
/* statistics */
- rxq->stats.rx_pkts += rcvd;
+ rxq->stats.rx_pkts += nb_pkts;
rxq->stats.rx_bytes += rx_bytes;
-out:
- if (rcvd != nb_pkts)
- rte_mempool_put_bulk(umem->mb_pool, (void **)&fq_bufs[rcvd],
- nb_pkts - rcvd);
-
- return rcvd;
+ return nb_pkts;
}
#else
static uint16_t
@@ -326,7 +324,7 @@ af_xdp_rx_cp(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
struct xsk_ring_prod *fq = &rxq->fq;
uint32_t idx_rx = 0;
unsigned long rx_bytes = 0;
- int rcvd, i;
+ int i;
uint32_t free_thresh = fq->size >> 1;
struct rte_mbuf *mbufs[ETH_AF_XDP_RX_BATCH_SIZE];
@@ -334,20 +332,24 @@ af_xdp_rx_cp(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
(void)reserve_fill_queue(umem, ETH_AF_XDP_RX_BATCH_SIZE,
NULL, fq);
- if (unlikely(rte_pktmbuf_alloc_bulk(rxq->mb_pool, mbufs, nb_pkts) != 0))
- return 0;
-
- rcvd = xsk_ring_cons__peek(rx, nb_pkts, &idx_rx);
- if (rcvd == 0) {
+ nb_pkts = xsk_ring_cons__peek(rx, nb_pkts, &idx_rx);
+ if (nb_pkts == 0) {
#if defined(XDP_USE_NEED_WAKEUP)
if (xsk_ring_prod__needs_wakeup(fq))
(void)poll(rxq->fds, 1, 1000);
#endif
+ return 0;
+ }
- goto out;
+ if (unlikely(rte_pktmbuf_alloc_bulk(rxq->mb_pool, mbufs, nb_pkts))) {
+ /* rollback cached_cons which is added by
+ * xsk_ring_cons__peek
+ */
+ rx->cached_cons -= nb_pkts;
+ return 0;
}
- for (i = 0; i < rcvd; i++) {
+ for (i = 0; i < nb_pkts; i++) {
const struct xdp_desc *desc;
uint64_t addr;
uint32_t len;
@@ -366,18 +368,13 @@ af_xdp_rx_cp(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
bufs[i] = mbufs[i];
}
- xsk_ring_cons__release(rx, rcvd);
+ xsk_ring_cons__release(rx, nb_pkts);
/* statistics */
- rxq->stats.rx_pkts += rcvd;
+ rxq->stats.rx_pkts += nb_pkts;
rxq->stats.rx_bytes += rx_bytes;
-out:
- if (rcvd != nb_pkts)
- rte_mempool_put_bulk(rxq->mb_pool, (void **)&mbufs[rcvd],
- nb_pkts - rcvd);
-
- return rcvd;
+ return nb_pkts;
}
#endif