[dpdk-dev] [PATCH 08/16] mlx4: avoid looking up WR ID to improve RX performance
Adrien Mazarguil
adrien.mazarguil at 6wind.com
Sat Jun 6 01:15:12 CEST 2015
From: Alex Rosenbaum <Alexr at mellanox.com>
This is done by storing the current index in the RX queue structure.
Signed-off-by: Alex Rosenbaum <Alexr at mellanox.com>
Signed-off-by: Adrien Mazarguil <adrien.mazarguil at 6wind.com>
---
drivers/net/mlx4/mlx4.c | 24 ++++++++++++++++++++++--
1 file changed, 22 insertions(+), 2 deletions(-)
diff --git a/drivers/net/mlx4/mlx4.c b/drivers/net/mlx4/mlx4.c
index 061f5e6..080602e 100644
--- a/drivers/net/mlx4/mlx4.c
+++ b/drivers/net/mlx4/mlx4.c
@@ -208,6 +208,7 @@ struct rxq {
struct ibv_exp_flow *allmulti_flow; /* Multicast flow. */
unsigned int port_id; /* Port ID for incoming packets. */
unsigned int elts_n; /* (*elts)[] length. */
+ unsigned int elts_head; /* Current index in (*elts)[]. */
union {
struct rxq_elt_sp (*sp)[]; /* Scattered RX elements. */
struct rxq_elt (*no_sp)[]; /* RX elements. */
@@ -1651,6 +1652,7 @@ rxq_alloc_elts_sp(struct rxq *rxq, unsigned int elts_n,
DEBUG("%p: allocated and configured %u WRs (%zu segments)",
(void *)rxq, elts_n, (elts_n * elemof((*elts)[0].sges)));
rxq->elts_n = elts_n;
+ rxq->elts_head = 0;
rxq->elts.sp = elts;
assert(ret == 0);
return 0;
@@ -1795,6 +1797,7 @@ rxq_alloc_elts(struct rxq *rxq, unsigned int elts_n, struct rte_mbuf **pool)
DEBUG("%p: allocated and configured %u single-segment WRs",
(void *)rxq, elts_n);
rxq->elts_n = elts_n;
+ rxq->elts_head = 0;
rxq->elts.no_sp = elts;
assert(ret == 0);
return 0;
@@ -2376,6 +2379,8 @@ mlx4_rx_burst_sp(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
{
struct rxq *rxq = (struct rxq *)dpdk_rxq;
struct rxq_elt_sp (*elts)[rxq->elts_n] = rxq->elts.sp;
+ const unsigned int elts_n = rxq->elts_n;
+ unsigned int elts_head = rxq->elts_head;
struct ibv_exp_wc wcs[pkts_n];
struct ibv_recv_wr head;
struct ibv_recv_wr **next = &head.next;
@@ -2402,7 +2407,7 @@ mlx4_rx_burst_sp(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
struct ibv_exp_wc *wc = &wcs[i];
uint64_t wr_id = wc->wr_id;
uint32_t len = wc->byte_len;
- struct rxq_elt_sp *elt = &(*elts)[wr_id];
+ struct rxq_elt_sp *elt = &(*elts)[elts_head];
struct ibv_recv_wr *wr = &elt->wr;
struct rte_mbuf *pkt_buf = NULL; /* Buffer returned in pkts. */
struct rte_mbuf **pkt_buf_next = &pkt_buf;
@@ -2410,10 +2415,15 @@ mlx4_rx_burst_sp(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
unsigned int j = 0;
/* Sanity checks. */
+#ifdef NDEBUG
+ (void)wr_id;
+#endif
assert(wr_id < rxq->elts_n);
assert(wr_id == wr->wr_id);
assert(wr->sg_list == elt->sges);
assert(wr->num_sge == elemof(elt->sges));
+ assert(elts_head < rxq->elts_n);
+ assert(rxq->elts_head < rxq->elts_n);
/* Link completed WRs together for repost. */
*next = wr;
next = &wr->next;
@@ -2522,6 +2532,8 @@ mlx4_rx_burst_sp(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
rxq->stats.ibytes += wc->byte_len;
#endif
repost:
+ if (++elts_head >= elts_n)
+ elts_head = 0;
continue;
}
*next = NULL;
@@ -2539,6 +2551,7 @@ repost:
strerror(i));
abort();
}
+ rxq->elts_head = elts_head;
#ifdef MLX4_PMD_SOFT_COUNTERS
/* Increase packets counter. */
rxq->stats.ipackets += ret;
@@ -2568,6 +2581,8 @@ mlx4_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
{
struct rxq *rxq = (struct rxq *)dpdk_rxq;
struct rxq_elt (*elts)[rxq->elts_n] = rxq->elts.no_sp;
+ const unsigned int elts_n = rxq->elts_n;
+ unsigned int elts_head = rxq->elts_head;
struct ibv_exp_wc wcs[pkts_n];
struct ibv_recv_wr head;
struct ibv_recv_wr **next = &head.next;
@@ -2592,7 +2607,7 @@ mlx4_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
struct ibv_exp_wc *wc = &wcs[i];
uint64_t wr_id = wc->wr_id;
uint32_t len = wc->byte_len;
- struct rxq_elt *elt = &(*elts)[WR_ID(wr_id).id];
+ struct rxq_elt *elt = &(*elts)[elts_head];
struct ibv_recv_wr *wr = &elt->wr;
struct rte_mbuf *seg =
(void *)(elt->sge.addr - WR_ID(wr_id).offset);
@@ -2603,6 +2618,8 @@ mlx4_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
assert(wr_id == wr->wr_id);
assert(wr->sg_list == &elt->sge);
assert(wr->num_sge == 1);
+ assert(elts_head < rxq->elts_n);
+ assert(rxq->elts_head < rxq->elts_n);
/* Link completed WRs together for repost. */
*next = wr;
next = &wr->next;
@@ -2663,6 +2680,8 @@ mlx4_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
rxq->stats.ibytes += wc->byte_len;
#endif
repost:
+ if (++elts_head >= elts_n)
+ elts_head = 0;
continue;
}
*next = NULL;
@@ -2680,6 +2699,7 @@ repost:
strerror(i));
abort();
}
+ rxq->elts_head = elts_head;
#ifdef MLX4_PMD_SOFT_COUNTERS
/* Increase packets counter. */
rxq->stats.ipackets += ret;
--
2.1.0
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