Calculate the number of scatters on the fly according to
the maximum expected packet size.
Signed-off-by: Vasily Philipov <vasi...@mellanox.com>
Signed-off-by: Ophir Munk <ophi...@mellanox.com>
---
drivers/net/mlx4/mlx4_rxq.c | 64 +++++++++++++++++++++++++++++++++++++-------
drivers/net/mlx4/mlx4_rxtx.c | 11 +++++---
drivers/net/mlx4/mlx4_rxtx.h | 1 +
3 files changed, 62 insertions(+), 14 deletions(-)
diff --git a/drivers/net/mlx4/mlx4_rxq.c b/drivers/net/mlx4/mlx4_rxq.c
index 9b98d86..44d095d 100644
--- a/drivers/net/mlx4/mlx4_rxq.c
+++ b/drivers/net/mlx4/mlx4_rxq.c
@@ -78,6 +78,7 @@
mlx4_rxq_alloc_elts(struct rxq *rxq, unsigned int elts_n)
{
unsigned int i;
+ const uint32_t sges_n = 1 << rxq->sges_n;
struct rte_mbuf *(*elts)[elts_n] =
rte_calloc_socket("RXQ", 1, sizeof(*elts), 0, rxq->socket);
@@ -101,6 +102,9 @@
/* Buffer is supposed to be empty. */
assert(rte_pktmbuf_data_len(buf) == 0);
assert(rte_pktmbuf_pkt_len(buf) == 0);
+ /* Only the first segment keeps headroom. */
+ if (i % sges_n)
+ buf->data_off = 0;
buf->port = rxq->port_id;
buf->data_len = rte_pktmbuf_tailroom(buf);
buf->pkt_len = rte_pktmbuf_tailroom(buf);
@@ -113,8 +117,8 @@
};
(*elts)[i] = buf;
}
- DEBUG("%p: allocated and configured %u single-segment WRs",
- (void *)rxq, elts_n);
+ DEBUG("%p: allocated and configured %u segments (max %u packets)",
+ (void *)rxq, elts_n, elts_n >> rxq->sges_n);
rxq->elts_n = log2above(elts_n);
rxq->elts = elts;
return 0;
@@ -185,12 +189,15 @@
* Completion queue to associate with QP.
* @param desc
* Number of descriptors in QP (hint only).
+ * @param sges_n
+ * Maximum number of segments per packet.
*
* @return
* QP pointer or NULL in case of error and rte_errno is set.
*/
static struct ibv_qp *
-mlx4_rxq_setup_qp(struct priv *priv, struct ibv_cq *cq, uint16_t desc)
+mlx4_rxq_setup_qp(struct priv *priv, struct ibv_cq *cq, uint16_t desc,
+ uint32_t sges_n)
{
struct ibv_qp *qp;
struct ibv_qp_init_attr attr = {
@@ -204,7 +211,7 @@
priv->device_attr.max_qp_wr :
desc),
/* Maximum number of segments per packet. */
- .max_recv_sge = 1,
+ .max_recv_sge = sges_n,
},
.qp_type = IBV_QPT_RAW_PACKET,
};
@@ -263,11 +270,31 @@
assert(mb_len >= RTE_PKTMBUF_HEADROOM);
if (dev->data->dev_conf.rxmode.max_rx_pkt_len <=
(mb_len - RTE_PKTMBUF_HEADROOM)) {
- ;
+ tmpl.sges_n = 0;
} else if (dev->data->dev_conf.rxmode.enable_scatter) {
- WARN("%p: scattered mode has been requested but is"
- " not supported, this may lead to packet loss",
- (void *)dev);
+ uint32_t size =
+ RTE_PKTMBUF_HEADROOM +
+ dev->data->dev_conf.rxmode.max_rx_pkt_len;
+ uint32_t sges_n;
+
+ /*
+ * Determine the number of SGEs needed for a full packet
+ * and round it to the next power of two.
+ */
+ sges_n = log2above((size / mb_len) + !!(size % mb_len));
+ tmpl.sges_n = sges_n;
+ /* Make sure sges_n did not overflow. */
+ size = mb_len * (1 << tmpl.sges_n);
+ size -= RTE_PKTMBUF_HEADROOM;
+ if (size < dev->data->dev_conf.rxmode.max_rx_pkt_len) {
+ rte_errno = EOVERFLOW;
+ ERROR("%p: too many SGEs (%u) needed to handle"
+ " requested maximum packet size %u",
+ (void *)dev,
+ 1 << sges_n,
+ dev->data->dev_conf.rxmode.max_rx_pkt_len);
+ goto error;
+ }
} else {
WARN("%p: the requested maximum Rx packet size (%u) is"
" larger than a single mbuf (%u) and scattered"
@@ -276,6 +303,17 @@
dev->data->dev_conf.rxmode.max_rx_pkt_len,
mb_len - RTE_PKTMBUF_HEADROOM);
}
+ DEBUG("%p: maximum number of segments per packet: %u",
+ (void *)dev, 1 << tmpl.sges_n);
+ if (desc % (1 << tmpl.sges_n)) {
+ rte_errno = EINVAL;
+ ERROR("%p: number of RX queue descriptors (%u) is not a"
+ " multiple of maximum segments per packet (%u)",
+ (void *)dev,
+ desc,
+ 1 << tmpl.sges_n);
+ goto error;
+ }
/* Use the entire Rx mempool as the memory region. */
tmpl.mr = mlx4_mp2mr(priv->pd, mp);
if (tmpl.mr == NULL) {
@@ -300,7 +338,8 @@
goto error;
}
}
- tmpl.cq = ibv_create_cq(priv->ctx, desc, NULL, tmpl.channel, 0);
+ tmpl.cq = ibv_create_cq(priv->ctx, desc >> tmpl.sges_n, NULL,
+ tmpl.channel, 0);
if (tmpl.cq == NULL) {
rte_errno = ENOMEM;
ERROR("%p: CQ creation failure: %s",
@@ -311,7 +350,8 @@
priv->device_attr.max_qp_wr);
DEBUG("priv->device_attr.max_sge is %d",
priv->device_attr.max_sge);
- tmpl.qp = mlx4_rxq_setup_qp(priv, tmpl.cq, desc);
+ tmpl.qp = mlx4_rxq_setup_qp(priv, tmpl.cq, desc >> tmpl.sges_n,
+ 1 << tmpl.sges_n);
if (tmpl.qp == NULL) {
ERROR("%p: QP creation failure: %s",
(void *)dev, strerror(rte_errno));
@@ -373,6 +413,10 @@
mlx4_rxq_cleanup(rxq);
*rxq = tmpl;
DEBUG("%p: rxq updated with %p", (void *)rxq, (void *)&tmpl);
+ /* Update doorbell counter. */
+ rxq->rq_ci = desc >> rxq->sges_n;
+ rte_wmb();
+ *rxq->rq_db = rte_cpu_to_be_32(rxq->rq_ci);
return 0;
error:
ret = rte_errno;
diff --git a/drivers/net/mlx4/mlx4_rxtx.c b/drivers/net/mlx4/mlx4_rxtx.c
index 5c1b8ef..fd8ef7b 100644
--- a/drivers/net/mlx4/mlx4_rxtx.c
+++ b/drivers/net/mlx4/mlx4_rxtx.c
@@ -563,10 +563,11 @@
{
struct rxq *rxq = dpdk_rxq;
const uint32_t wr_cnt = (1 << rxq->elts_n) - 1;
+ const uint16_t sges_n = rxq->sges_n;
struct rte_mbuf *pkt = NULL;
struct rte_mbuf *seg = NULL;
unsigned int i = 0;
- uint32_t rq_ci = rxq->rq_ci;
+ uint32_t rq_ci = rxq->rq_ci << sges_n;
int len = 0;
while (pkts_n) {
@@ -646,13 +647,15 @@
--pkts_n;
++i;
skip:
- /* Update consumer index */
+ /* Align consumer index to the next stride. */
+ rq_ci >>= sges_n;
++rq_ci;
+ rq_ci <<= sges_n;
}
- if (unlikely(i == 0 && rq_ci == rxq->rq_ci))
+ if (unlikely(i == 0 && (rq_ci >> sges_n) == rxq->rq_ci))
return 0;
/* Update the consumer index. */
- rxq->rq_ci = rq_ci;
+ rxq->rq_ci = rq_ci >> sges_n;
rte_wmb();
*rxq->rq_db = rte_cpu_to_be_32(rxq->rq_ci);
*rxq->mcq.set_ci_db = rte_cpu_to_be_32(rxq->mcq.cons_index & 0xffffff);
diff --git a/drivers/net/mlx4/mlx4_rxtx.h b/drivers/net/mlx4/mlx4_rxtx.h
index 939ae75..ac84177 100644
--- a/drivers/net/mlx4/mlx4_rxtx.h
+++ b/drivers/net/mlx4/mlx4_rxtx.h
@@ -72,6 +72,7 @@ struct rxq {
struct ibv_comp_channel *channel; /**< Rx completion channel. */
uint16_t rq_ci; /**< Saved RQ consumer index. */
uint16_t port_id; /**< Port ID for incoming packets. */
+ uint16_t sges_n; /**< Number of segments per packet (log2 value). */
uint16_t elts_n; /**< Mbuf queue size (log2 value). */
struct rte_mbuf *(*elts)[]; /**< Rx elements. */
volatile struct mlx4_wqe_data_seg (*wqes)[]; /**< HW queue entries. */
--
1.8.3.1
