From: Adrien Mazarguil <adrien.mazarg...@6wind.com>
The primary purpose of rxq_rehash() function is to stop and restart
reception on a queue after re-posting buffers. This may fail if the array
that temporarily stores existing buffers for reuse cannot be allocated.
Update rxq_rehash() to work on the target queue directly (not through a
template copy) and avoid this allocation.
rxq_alloc_elts() is modified accordingly to take buffers from an existing
queue directly and update their refcount.
Unlike rxq_rehash(), rxq_setup() must work on a temporary structure but
should not allocate new mbufs from the pool while reinitializing an
existing queue. This is achieved by using the refcount-aware
rxq_alloc_elts() before overwriting queue data.
Signed-off-by: Adrien Mazarguil <adrien.mazarguil at 6wind.com>
---
drivers/net/mlx5/mlx5_rxq.c | 94 ++++++++++++++++++++++++---------------------
1 file changed, 51 insertions(+), 43 deletions(-)
diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
index 20a236e..17a28e4 100644
--- a/drivers/net/mlx5/mlx5_rxq.c
+++ b/drivers/net/mlx5/mlx5_rxq.c
@@ -642,7 +642,7 @@ priv_rehash_flows(struct priv *priv)
*/
static int
rxq_alloc_elts(struct rxq_ctrl *rxq_ctrl, unsigned int elts_n,
- struct rte_mbuf **pool)
+ struct rte_mbuf *(*pool)[])
{
unsigned int i;
int ret = 0;
@@ -654,9 +654,10 @@ rxq_alloc_elts(struct rxq_ctrl *rxq_ctrl, unsigned int
elts_n,
&(*rxq_ctrl->rxq.wqes)[i];
if (pool != NULL) {
- buf = *(pool++);
+ buf = (*pool)[i];
assert(buf != NULL);
rte_pktmbuf_reset(buf);
+ rte_pktmbuf_refcnt_update(buf, 1);
} else
buf = rte_pktmbuf_alloc(rxq_ctrl->rxq.mp);
if (buf == NULL) {
@@ -781,7 +782,7 @@ rxq_cleanup(struct rxq_ctrl *rxq_ctrl)
}
/**
- * Reconfigure a RX queue with new parameters.
+ * Reconfigure RX queue buffers.
*
* rxq_rehash() does not allocate mbufs, which, if not done from the right
* thread (such as a control thread), may corrupt the pool.
@@ -798,67 +799,48 @@ rxq_cleanup(struct rxq_ctrl *rxq_ctrl)
int
rxq_rehash(struct rte_eth_dev *dev, struct rxq_ctrl *rxq_ctrl)
{
- struct rxq_ctrl tmpl = *rxq_ctrl;
- unsigned int mbuf_n;
- unsigned int desc_n;
- struct rte_mbuf **pool;
- unsigned int i, k;
+ unsigned int elts_n = rxq_ctrl->rxq.elts_n;
+ unsigned int i;
struct ibv_exp_wq_attr mod;
int err;
DEBUG("%p: rehashing queue %p", (void *)dev, (void *)rxq_ctrl);
- /* Number of descriptors and mbufs currently allocated. */
- desc_n = tmpl.rxq.elts_n;
- mbuf_n = desc_n;
/* From now on, any failure will render the queue unusable.
* Reinitialize WQ. */
mod = (struct ibv_exp_wq_attr){
.attr_mask = IBV_EXP_WQ_ATTR_STATE,
.wq_state = IBV_EXP_WQS_RESET,
};
- err = ibv_exp_modify_wq(tmpl.wq, &mod);
+ err = ibv_exp_modify_wq(rxq_ctrl->wq, &mod);
if (err) {
ERROR("%p: cannot reset WQ: %s", (void *)dev, strerror(err));
assert(err > 0);
return err;
}
- /* Allocate pool. */
- pool = rte_malloc(__func__, (mbuf_n * sizeof(*pool)), 0);
- if (pool == NULL) {
- ERROR("%p: cannot allocate memory", (void *)dev);
- return ENOBUFS;
- }
/* Snatch mbufs from original queue. */
- k = 0;
- for (i = 0; (i != desc_n); ++i)
- pool[k++] = (*rxq_ctrl->rxq.elts)[i];
- assert(k == mbuf_n);
- rte_free(pool);
+ claim_zero(rxq_alloc_elts(rxq_ctrl, elts_n, rxq_ctrl->rxq.elts));
+ for (i = 0; i != elts_n; ++i) {
+ struct rte_mbuf *buf = (*rxq_ctrl->rxq.elts)[i];
+
+ assert(rte_mbuf_refcnt_read(buf) == 2);
+ rte_pktmbuf_free_seg(buf);
+ }
/* Change queue state to ready. */
mod = (struct ibv_exp_wq_attr){
.attr_mask = IBV_EXP_WQ_ATTR_STATE,
.wq_state = IBV_EXP_WQS_RDY,
};
- err = ibv_exp_modify_wq(tmpl.wq, &mod);
+ err = ibv_exp_modify_wq(rxq_ctrl->wq, &mod);
if (err) {
ERROR("%p: WQ state to IBV_EXP_WQS_RDY failed: %s",
(void *)dev, strerror(err));
goto error;
}
- /* Post SGEs. */
- err = rxq_alloc_elts(&tmpl, desc_n, pool);
- if (err) {
- ERROR("%p: cannot reallocate WRs, aborting", (void *)dev);
- rte_free(pool);
- assert(err > 0);
- return err;
- }
/* Update doorbell counter. */
- rxq_ctrl->rxq.rq_ci = desc_n;
+ rxq_ctrl->rxq.rq_ci = elts_n;
rte_wmb();
*rxq_ctrl->rxq.rq_db = htonl(rxq_ctrl->rxq.rq_ci);
error:
- *rxq_ctrl = tmpl;
assert(err >= 0);
return err;
}
@@ -868,16 +850,21 @@ error:
*
* @param tmpl
* Pointer to RX queue control template.
- * @param rxq_ctrl
- * Pointer to RX queue control.
+ *
+ * @return
+ * 0 on success, errno value on failure.
*/
-static inline void
-rxq_setup(struct rxq_ctrl *tmpl, struct rxq_ctrl *rxq_ctrl)
+static inline int
+rxq_setup(struct rxq_ctrl *tmpl)
{
struct ibv_cq *ibcq = tmpl->cq;
struct mlx5_cq *cq = to_mxxx(cq, cq);
struct mlx5_rwq *rwq = container_of(tmpl->wq, struct mlx5_rwq, wq);
+ struct rte_mbuf *(*elts)[tmpl->rxq.elts_n] =
+ rte_calloc_socket("RXQ", 1, sizeof(*elts), 0, tmpl->socket);
+ if (elts == NULL)
+ return ENOMEM;
tmpl->rxq.rq_db = rwq->rq.db;
tmpl->rxq.cqe_n = ibcq->cqe + 1;
tmpl->rxq.cq_ci = 0;
@@ -889,9 +876,8 @@ rxq_setup(struct rxq_ctrl *tmpl, struct rxq_ctrl *rxq_ctrl)
tmpl->rxq.cqes =
(volatile struct mlx5_cqe64 (*)[])
(uintptr_t)cq->active_buf->buf;
- tmpl->rxq.elts =
- (struct rte_mbuf *(*)[tmpl->rxq.elts_n])
- ((uintptr_t)rxq_ctrl + sizeof(*rxq_ctrl));
+ tmpl->rxq.elts = elts;
+ return 0;
}
/**
@@ -938,6 +924,7 @@ rxq_ctrl_setup(struct rte_eth_dev *dev, struct rxq_ctrl
*rxq_ctrl,
enum ibv_exp_query_intf_status status;
unsigned int mb_len = rte_pktmbuf_data_room_size(mp);
unsigned int cqe_n = desc - 1;
+ struct rte_mbuf *(*elts)[desc] = NULL;
int ret = 0;
(void)conf; /* Thresholds configuration (ignored). */
@@ -1094,8 +1081,19 @@ rxq_ctrl_setup(struct rte_eth_dev *dev, struct rxq_ctrl
*rxq_ctrl,
(void *)dev, strerror(ret));
goto error;
}
- rxq_setup(&tmpl, rxq_ctrl);
- ret = rxq_alloc_elts(&tmpl, desc, NULL);
+ ret = rxq_setup(&tmpl);
+ if (ret) {
+ ERROR("%p: cannot initialize RX queue structure: %s",
+ (void *)dev, strerror(ret));
+ goto error;
+ }
+ /* Reuse buffers from original queue if possible. */
+ if (rxq_ctrl->rxq.elts_n) {
+ assert(rxq_ctrl->rxq.elts_n == desc);
+ assert(rxq_ctrl->rxq.elts != tmpl.rxq.elts);
+ ret = rxq_alloc_elts(&tmpl, desc, rxq_ctrl->rxq.elts);
+ } else
+ ret = rxq_alloc_elts(&tmpl, desc, NULL);
if (ret) {
ERROR("%p: RXQ allocation failed: %s",
(void *)dev, strerror(ret));
@@ -1104,6 +1102,14 @@ rxq_ctrl_setup(struct rte_eth_dev *dev, struct rxq_ctrl
*rxq_ctrl,
/* Clean up rxq in case we're reinitializing it. */
DEBUG("%p: cleaning-up old rxq just in case", (void *)rxq_ctrl);
rxq_cleanup(rxq_ctrl);
+ /* Move mbuf pointers to dedicated storage area in RX queue. */
+ elts = (void *)(rxq_ctrl + 1);
+ rte_memcpy(elts, tmpl.rxq.elts, sizeof(*elts));
+#ifndef NDEBUG
+ memset(tmpl.rxq.elts, 0x55, sizeof(*elts));
+#endif
+ rte_free(tmpl.rxq.elts);
+ tmpl.rxq.elts = elts;
*rxq_ctrl = tmpl;
/* Update doorbell counter. */
rxq_ctrl->rxq.rq_ci = desc;
@@ -1113,7 +1119,9 @@ rxq_ctrl_setup(struct rte_eth_dev *dev, struct rxq_ctrl
*rxq_ctrl,
assert(ret == 0);
return 0;
error:
+ elts = tmpl.rxq.elts;
rxq_cleanup(&tmpl);
+ rte_free(elts);
assert(ret > 0);
return ret;
}
--
2.1.4
