[dpdk-dev] [PATCH 1/4] net/mlx5: revert "fix Memory Region registration"

[dpdk-dev] [PATCH 1/4] net/mlx5: revert "fix Memory Region registration"

[Xueming Li]

This reverts commit 17fd4a504a4780455f79969803dc231521254ca8.

Fixes: 12ed59b702cc ("net/mlx5: fix Memory Region registration")
Signed-off-by: Xueming Li <xuemingl@mellanox.com>
---
 drivers/net/mlx5/mlx5_rxtx.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
index a239642ac..2eb2f0506 100644
--- a/drivers/net/mlx5/mlx5_rxtx.h
+++ b/drivers/net/mlx5/mlx5_rxtx.h
@@ -548,7 +548,7 @@ static __rte_always_inline uint32_t
 mlx5_tx_mb2mr(struct mlx5_txq_data *txq, struct rte_mbuf *mb)
 {
 	uint16_t i = txq->mr_cache_idx;
-	uintptr_t addr = rte_pktmbuf_mtod_offset(mb, uintptr_t, DATA_LEN(mb));
+	uintptr_t addr = rte_pktmbuf_mtod(mb, uintptr_t);
 	struct mlx5_mr *mr;
 
 	assert(i < RTE_DIM(txq->mp2mr));
-- 
2.13.3

[dpdk-dev] [PATCH 2/4] net/mlx5: forbid MR registration in secondary process

[Xueming Li]

Secondary process are not alloed to access verbs resources, add check to
prevent MR registration in data path.

Signed-off-by: Xueming Li <xuemingl@mellanox.com>
---
 doc/guides/nics/mlx5.rst     | 1 +
 drivers/net/mlx5/mlx5_mr.c   | 3 +++
 drivers/net/mlx5/mlx5_rxtx.h | 3 ---
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index bdc2216c0..4373c7990 100644
--- a/doc/guides/nics/mlx5.rst
+++ b/doc/guides/nics/mlx5.rst
@@ -107,6 +107,7 @@ Limitations
 - Inner RSS for VXLAN frames is not supported yet.
 - Hardware checksum RX offloads for VXLAN inner header are not supported yet.
 - Forked secondary process not supported.
+- Mempools used in secondary process TX have to be initialized in primary process before rte_eth_dev_start().
 - Flow pattern without any specific vlan will match for vlan packets as well:
 
   When VLAN spec is not specified in the pattern, the matching rule will be created with VLAN as a wild card.
diff --git a/drivers/net/mlx5/mlx5_mr.c b/drivers/net/mlx5/mlx5_mr.c
index 6b29eed55..3c80fbb89 100644
--- a/drivers/net/mlx5/mlx5_mr.c
+++ b/drivers/net/mlx5/mlx5_mr.c
@@ -278,6 +278,9 @@ priv_mr_new(struct priv *priv, struct rte_mempool *mp)
 	unsigned int i;
 	struct mlx5_mr *mr;
 
+	if (rte_eal_process_type() != RTE_PROC_PRIMARY)
+		rte_panic("Please init mempool before rte_eth_dev_start() in primary process: %s",
+			  mp->name);
 	mr = rte_zmalloc_socket(__func__, sizeof(*mr), 0, mp->socket_id);
 	if (!mr) {
 		DEBUG("unable to configure MR, ibv_reg_mr() failed.");
diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
index 2eb2f0506..18e1d26f3 100644
--- a/drivers/net/mlx5/mlx5_rxtx.h
+++ b/drivers/net/mlx5/mlx5_rxtx.h
@@ -561,9 +561,6 @@ mlx5_tx_mb2mr(struct mlx5_txq_data *txq, struct rte_mbuf *mb)
 		}
 		if (txq->mp2mr[i]->start <= addr &&
 		    txq->mp2mr[i]->end >= addr) {
-			assert(txq->mp2mr[i]->lkey != (uint32_t)-1);
-			assert(rte_cpu_to_be_32(txq->mp2mr[i]->mr->lkey) ==
-			       txq->mp2mr[i]->lkey);
 			txq->mr_cache_idx = i;
 			return txq->mp2mr[i]->lkey;
 		}
-- 
2.13.3

[dpdk-dev] [PATCH 3/4] net/mlx5: support mempool of multi-mem segments

[Xueming Li]

Previously, mempool of multiple memory segments would lead to MR
registration error "mempool not virtually contiguous". This patch
support multi-segments mempool by registering each memory segment of
mempool.

Signed-off-by: Xueming Li <xuemingl@mellanox.com>
---
 drivers/net/mlx5/mlx5.h         |   4 +-
 drivers/net/mlx5/mlx5_mr.c      | 284 ++++++++++++++--------------------------
 drivers/net/mlx5/mlx5_rxq.c     |  29 ++--
 drivers/net/mlx5/mlx5_rxtx.h    |  48 ++++---
 drivers/net/mlx5/mlx5_trigger.c |   7 -
 5 files changed, 143 insertions(+), 229 deletions(-)

diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h
index 8ee522069..a6cd1474c 100644
--- a/drivers/net/mlx5/mlx5.h
+++ b/drivers/net/mlx5/mlx5.h
@@ -316,9 +316,11 @@ int priv_socket_connect(struct priv *priv);
 
 /* mlx5_mr.c */
 
-struct mlx5_mr *priv_mr_new(struct priv *, struct rte_mempool *);
+struct mlx5_mr *priv_mr_new(struct priv *priv, struct rte_mempool *mp,
+			    uintptr_t addr);
 struct mlx5_mr *priv_mr_get(struct priv *, struct rte_mempool *);
 int priv_mr_release(struct priv *, struct mlx5_mr *);
 int priv_mr_verify(struct priv *);
+struct mlx5_mr *priv_mr_lookup(struct priv *priv, uintptr_t addr);
 
 #endif /* RTE_PMD_MLX5_H_ */
diff --git a/drivers/net/mlx5/mlx5_mr.c b/drivers/net/mlx5/mlx5_mr.c
index 3c80fbb89..8d8fabea1 100644
--- a/drivers/net/mlx5/mlx5_mr.c
+++ b/drivers/net/mlx5/mlx5_mr.c
@@ -47,158 +47,89 @@
 #include "mlx5.h"
 #include "mlx5_rxtx.h"
 
-struct mlx5_check_mempool_data {
-	int ret;
-	char *start;
-	char *end;
+struct mlx5_mempool_cb_data {
+	uintptr_t addr;
+	struct priv *priv;
+	int error;
+	struct mlx5_mr *mr;
 };
 
-/* Called by mlx5_check_mempool() when iterating the memory chunks. */
+/* Called by priv_mr_new() when iterating the memory chunks. */
 static void
-mlx5_check_mempool_cb(struct rte_mempool *mp,
-		      void *opaque, struct rte_mempool_memhdr *memhdr,
-		      unsigned int mem_idx)
+mlx5_mempool_register_cb(struct rte_mempool *mp, void *opaque,
+			 struct rte_mempool_memhdr *memhdr,
+			 unsigned int mem_idx __rte_unused)
 {
-	struct mlx5_check_mempool_data *data = opaque;
-
-	(void)mp;
-	(void)mem_idx;
+	struct mlx5_mempool_cb_data *cb = opaque;
+	struct priv *priv = cb->priv;
+	struct mlx5_mr *mr;
 
-	/* It already failed, skip the next chunks. */
-	if (data->ret != 0)
+	if (cb->error) /* skip on previous error */
 		return;
-	/* It is the first chunk. */
-	if (data->start == NULL && data->end == NULL) {
-		data->start = memhdr->addr;
-		data->end = data->start + memhdr->len;
+	if (cb->addr && (cb->addr < (uintptr_t)memhdr->addr ||
+			 cb->addr > (uintptr_t)memhdr->addr + memhdr->len))
+		return; /* not target mem segment */
+	mr = priv_mr_lookup(priv, (uintptr_t)memhdr->addr);
+	if (mr) { /* memory already registered */
+		cb->mr = mr;
 		return;
 	}
-	if (data->end == memhdr->addr) {
-		data->end += memhdr->len;
+	mr = rte_zmalloc_socket(__func__, sizeof(*mr), 0, mp->socket_id);
+	if (!mr) {
+		DEBUG("unable to allocate MR, pool %p:%u register failed.",
+		      (void *)mp, mem_idx);
+		cb->error = -ENOMEM;
 		return;
 	}
-	if (data->start == (char *)memhdr->addr + memhdr->len) {
-		data->start -= memhdr->len;
+	mr->mr = ibv_reg_mr(priv->pd, memhdr->addr, memhdr->len,
+			    IBV_ACCESS_LOCAL_WRITE);
+	if (!mr->mr) {
+		ERROR("unable to register MR, ibv_reg_mr() failed.");
+		cb->error = -1;
 		return;
 	}
-	/* Error, mempool is not virtually contiguous. */
-	data->ret = -1;
-}
-
-/**
- * Check if a mempool can be used: it must be virtually contiguous.
- *
- * @param[in] mp
- *   Pointer to memory pool.
- * @param[out] start
- *   Pointer to the start address of the mempool virtual memory area
- * @param[out] end
- *   Pointer to the end address of the mempool virtual memory area
- *
- * @return
- *   0 on success (mempool is virtually contiguous), -1 on error.
- */
-static int mlx5_check_mempool(struct rte_mempool *mp, uintptr_t *start,
-	uintptr_t *end)
-{
-	struct mlx5_check_mempool_data data;
-
-	memset(&data, 0, sizeof(data));
-	rte_mempool_mem_iter(mp, mlx5_check_mempool_cb, &data);
-	*start = (uintptr_t)data.start;
-	*end = (uintptr_t)data.end;
-
-	return data.ret;
+	mr->mp = mp;
+	DEBUG("mempool %p:%u area start=%p size=%zu lkey=0x%08x",
+	      (void *)mp, mem_idx, memhdr->addr, memhdr->len, mr->mr->lkey);
+	mr->lkey = rte_cpu_to_be_32(mr->mr->lkey);
+	mr->start = (uintptr_t)memhdr->addr;
+	mr->end = (uintptr_t)mr->mr->addr + mr->mr->length;
+	rte_atomic32_inc(&mr->refcnt);
+	DEBUG("%p: new Memory Region %p refcnt: %d", (void *)priv,
+	      (void *)mr, rte_atomic32_read(&mr->refcnt));
+	LIST_INSERT_HEAD(&priv->mr, mr, next);
+	cb->mr = mr;
 }
 
 /**
- * Register a Memory Region (MR) <-> Memory Pool (MP) association in
- * txq->mp2mr[]. If mp2mr[] is full, remove an entry first.
- *
- * This function should only be called by txq_mp2mr().
+ * Lookup or register a Memory Region (MR).
  *
  * @param priv
- *   Pointer to private structure.
- * @param txq
- *   Pointer to TX queue structure.
- * @param[in] mp
- *   Memory Pool for which a Memory Region lkey must be returned.
- * @param idx
- *   Index of the next available entry.
+ *   Pointer to priv structure.
+ * @param mp
+ *   Pointer to the memory pool to register.
+ * @param addr
+ *   Address to register
  *
  * @return
  *   mr on success, NULL on failure.
  */
 struct mlx5_mr*
-priv_txq_mp2mr_reg(struct priv *priv, struct mlx5_txq_data *txq,
-		   struct rte_mempool *mp, unsigned int idx)
+mlx5_mp2mr(struct priv *priv, struct rte_mempool *mp, uintptr_t addr)
 {
-	struct mlx5_txq_ctrl *txq_ctrl =
-		container_of(txq, struct mlx5_txq_ctrl, txq);
 	struct mlx5_mr *mr;
 
-	/* Add a new entry, register MR first. */
-	DEBUG("%p: discovered new memory pool \"%s\" (%p)",
-	      (void *)txq_ctrl, mp->name, (void *)mp);
-	mr = priv_mr_get(priv, mp);
-	if (mr == NULL)
-		mr = priv_mr_new(priv, mp);
-	if (unlikely(mr == NULL)) {
-		DEBUG("%p: unable to configure MR, ibv_reg_mr() failed.",
-		      (void *)txq_ctrl);
-		return NULL;
-	}
-	if (unlikely(idx == RTE_DIM(txq->mp2mr))) {
-		/* Table is full, remove oldest entry. */
-		DEBUG("%p: MR <-> MP table full, dropping oldest entry.",
-		      (void *)txq_ctrl);
-		--idx;
-		priv_mr_release(priv, txq->mp2mr[0]);
-		memmove(&txq->mp2mr[0], &txq->mp2mr[1],
-			(sizeof(txq->mp2mr) - sizeof(txq->mp2mr[0])));
+	priv_lock(priv);
+	mr = priv_mr_lookup(priv, addr);
+	if (!mr) {
+		mr = priv_mr_new(priv, mp, addr);
+		if (mr)
+			rte_atomic32_inc(&mr->refcnt);
 	}
-	/* Store the new entry. */
-	txq_ctrl->txq.mp2mr[idx] = mr;
-	DEBUG("%p: new MR lkey for MP \"%s\" (%p): 0x%08" PRIu32,
-	      (void *)txq_ctrl, mp->name, (void *)mp,
-	      txq_ctrl->txq.mp2mr[idx]->lkey);
-	return mr;
-}
-
-/**
- * Register a Memory Region (MR) <-> Memory Pool (MP) association in
- * txq->mp2mr[]. If mp2mr[] is full, remove an entry first.
- *
- * This function should only be called by txq_mp2mr().
- *
- * @param txq
- *   Pointer to TX queue structure.
- * @param[in] mp
- *   Memory Pool for which a Memory Region lkey must be returned.
- * @param idx
- *   Index of the next available entry.
- *
- * @return
- *   mr on success, NULL on failure.
- */
-struct mlx5_mr*
-mlx5_txq_mp2mr_reg(struct mlx5_txq_data *txq, struct rte_mempool *mp,
-		   unsigned int idx)
-{
-	struct mlx5_txq_ctrl *txq_ctrl =
-		container_of(txq, struct mlx5_txq_ctrl, txq);
-	struct mlx5_mr *mr;
-
-	priv_lock(txq_ctrl->priv);
-	mr = priv_txq_mp2mr_reg(txq_ctrl->priv, txq, mp, idx);
-	priv_unlock(txq_ctrl->priv);
+	priv_unlock(priv);
 	return mr;
 }
 
-struct mlx5_mp2mr_mbuf_check_data {
-	int ret;
-};
-
 /**
  * Callback function for rte_mempool_obj_iter() to check whether a given
  * mempool object looks like a mbuf.
@@ -214,10 +145,10 @@ struct mlx5_mp2mr_mbuf_check_data {
  *   Object index, unused.
  */
 static void
-txq_mp2mr_mbuf_check(struct rte_mempool *mp, void *arg, void *obj,
+mp2mr_mbuf_check_cb(struct rte_mempool *mp, void *arg, void *obj,
 	uint32_t index __rte_unused)
 {
-	struct mlx5_mp2mr_mbuf_check_data *data = arg;
+	struct mlx5_mempool_cb_data *data = arg;
 	struct rte_mbuf *buf = obj;
 
 	/*
@@ -225,7 +156,7 @@ txq_mp2mr_mbuf_check(struct rte_mempool *mp, void *arg, void *obj,
 	 * pointer is valid.
 	 */
 	if (sizeof(*buf) > mp->elt_size || buf->pool != mp)
-		data->ret = -1;
+		data->error = -1;
 }
 
 /**
@@ -241,21 +172,14 @@ void
 mlx5_mp2mr_iter(struct rte_mempool *mp, void *arg)
 {
 	struct priv *priv = (struct priv *)arg;
-	struct mlx5_mp2mr_mbuf_check_data data = {
-		.ret = 0,
-	};
-	struct mlx5_mr *mr;
+	struct mlx5_mempool_cb_data data = {0};
 
-	/* Register mempool only if the first element looks like a mbuf. */
-	if (rte_mempool_obj_iter(mp, txq_mp2mr_mbuf_check, &data) == 0 ||
-			data.ret == -1)
+	/* Register mempool only if all element looks like a mbuf. */
+	/* TODO less efficient to iterate all objects in pool */
+	if (rte_mempool_obj_iter(mp, mp2mr_mbuf_check_cb, &data) == 0 ||
+			data.error == -1)
 		return;
-	mr = priv_mr_get(priv, mp);
-	if (mr) {
-		priv_mr_release(priv, mr);
-		return;
-	}
-	priv_mr_new(priv, mp);
+	priv_mr_new(priv, mp, 0);
 }
 
 /**
@@ -266,59 +190,30 @@ mlx5_mp2mr_iter(struct rte_mempool *mp, void *arg)
  *   Pointer to private structure.
  * @param mp
  *   Pointer to the memory pool to register.
+ * @param addr
+ *   Address to register
  * @return
- *   The memory region on success.
+ *   Registered MR or the last if multiple MR registered.
  */
-struct mlx5_mr*
-priv_mr_new(struct priv *priv, struct rte_mempool *mp)
+struct mlx5_mr *
+priv_mr_new(struct priv *priv, struct rte_mempool *mp, uintptr_t addr)
 {
-	const struct rte_memseg *ms = rte_eal_get_physmem_layout();
-	uintptr_t start;
-	uintptr_t end;
-	unsigned int i;
-	struct mlx5_mr *mr;
+	struct mlx5_mempool_cb_data cb_data = {
+		.priv = priv,
+		.addr = addr,
+	};
 
 	if (rte_eal_process_type() != RTE_PROC_PRIMARY)
 		rte_panic("Please init mempool before rte_eth_dev_start() in primary process: %s",
 			  mp->name);
-	mr = rte_zmalloc_socket(__func__, sizeof(*mr), 0, mp->socket_id);
-	if (!mr) {
-		DEBUG("unable to configure MR, ibv_reg_mr() failed.");
-		return NULL;
-	}
-	if (mlx5_check_mempool(mp, &start, &end) != 0) {
-		ERROR("mempool %p: not virtually contiguous",
-		      (void *)mp);
+	DEBUG("%p: discovered new memory pool \"%s\" (%p)",
+	      (void *)priv, mp->name, (void *)mp);
+	rte_mempool_mem_iter(mp, mlx5_mempool_register_cb, &cb_data);
+	if (cb_data.error) {
+		DEBUG("%p: unable to configure MR.", (void *)priv);
 		return NULL;
 	}
-	DEBUG("mempool %p area start=%p end=%p size=%zu",
-	      (void *)mp, (void *)start, (void *)end,
-	      (size_t)(end - start));
-	/* Round start and end to page boundary if found in memory segments. */
-	for (i = 0; (i < RTE_MAX_MEMSEG) && (ms[i].addr != NULL); ++i) {
-		uintptr_t addr = (uintptr_t)ms[i].addr;
-		size_t len = ms[i].len;
-		unsigned int align = ms[i].hugepage_sz;
-
-		if ((start > addr) && (start < addr + len))
-			start = RTE_ALIGN_FLOOR(start, align);
-		if ((end > addr) && (end < addr + len))
-			end = RTE_ALIGN_CEIL(end, align);
-	}
-	DEBUG("mempool %p using start=%p end=%p size=%zu for MR",
-	      (void *)mp, (void *)start, (void *)end,
-	      (size_t)(end - start));
-	mr->mr = ibv_reg_mr(priv->pd, (void *)start, end - start,
-			    IBV_ACCESS_LOCAL_WRITE);
-	mr->mp = mp;
-	mr->lkey = rte_cpu_to_be_32(mr->mr->lkey);
-	mr->start = start;
-	mr->end = (uintptr_t)mr->mr->addr + mr->mr->length;
-	rte_atomic32_inc(&mr->refcnt);
-	DEBUG("%p: new Memory Region %p refcnt: %d", (void *)priv,
-	      (void *)mr, rte_atomic32_read(&mr->refcnt));
-	LIST_INSERT_HEAD(&priv->mr, mr, next);
-	return mr;
+	return cb_data.mr;
 }
 
 /**
@@ -396,3 +291,26 @@ priv_mr_verify(struct priv *priv)
 	}
 	return ret;
 }
+
+/**
+ * Memory Region (MR) lookup by address
+ *
+ * @param priv
+ *   Pointer to priv structure.
+ * @param[in] addr
+ *   Address to lookup.
+ * @return
+ *   mr on success, (uint32_t)-1 on failure.
+ */
+struct mlx5_mr *
+priv_mr_lookup(struct priv *priv, uintptr_t addr)
+{
+	struct mlx5_mr *mr;
+
+	LIST_FOREACH(mr, &priv->mr, next) {
+		if (addr >= mr->start && addr <= mr->end)
+			return mr;
+	}
+	return NULL;
+}
+
diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
index 950472754..a581a2d61 100644
--- a/drivers/net/mlx5/mlx5_rxq.c
+++ b/drivers/net/mlx5/mlx5_rxq.c
@@ -652,6 +652,7 @@ mlx5_priv_rxq_ibv_new(struct priv *priv, uint16_t idx)
 	int ret = 0;
 	struct mlx5dv_obj obj;
 	struct mlx5_dev_config *config = &priv->config;
+	struct mlx5_mr *last_mr = NULL;
 
 	assert(rxq_data);
 	assert(!rxq_ctrl->ibv);
@@ -664,13 +665,9 @@ mlx5_priv_rxq_ibv_new(struct priv *priv, uint16_t idx)
 	}
 	tmpl->rxq_ctrl = rxq_ctrl;
 	/* Use the entire RX mempool as the memory region. */
-	tmpl->mr = priv_mr_get(priv, rxq_data->mp);
-	if (!tmpl->mr) {
-		tmpl->mr = priv_mr_new(priv, rxq_data->mp);
-		if (!tmpl->mr) {
-			ERROR("%p: MR creation failure", (void *)rxq_ctrl);
-			goto error;
-		}
+	if (!priv_mr_new(priv, rxq_data->mp, 0)) {
+		ERROR("%p: MR creation failure", (void *)rxq_ctrl);
+		goto error;
 	}
 	if (rxq_ctrl->irq) {
 		tmpl->channel = ibv_create_comp_channel(priv->ctx);
@@ -786,14 +783,17 @@ mlx5_priv_rxq_ibv_new(struct priv *priv, uint16_t idx)
 	for (i = 0; (i != (unsigned int)(1 << rxq_data->elts_n)); ++i) {
 		struct rte_mbuf *buf = (*rxq_data->elts)[i];
 		volatile struct mlx5_wqe_data_seg *scat = &(*rxq_data->wqes)[i];
+		uintptr_t addr = rte_pktmbuf_mtod(buf, uintptr_t);
 
+		if (!last_mr || addr < last_mr->start || addr > last_mr->end)
+			last_mr = priv_mr_lookup(priv, addr);
+		assert(last_mr);
 		/* scat->addr must be able to store a pointer. */
 		assert(sizeof(scat->addr) >= sizeof(uintptr_t));
 		*scat = (struct mlx5_wqe_data_seg){
-			.addr = rte_cpu_to_be_64(rte_pktmbuf_mtod(buf,
-								  uintptr_t)),
+			.addr = rte_cpu_to_be_64(addr),
 			.byte_count = rte_cpu_to_be_32(DATA_LEN(buf)),
-			.lkey = tmpl->mr->lkey,
+			.lkey = last_mr->lkey,
 		};
 	}
 	rxq_data->rq_db = rwq.dbrec;
@@ -826,8 +826,6 @@ mlx5_priv_rxq_ibv_new(struct priv *priv, uint16_t idx)
 		claim_zero(ibv_destroy_cq(tmpl->cq));
 	if (tmpl->channel)
 		claim_zero(ibv_destroy_comp_channel(tmpl->channel));
-	if (tmpl->mr)
-		priv_mr_release(priv, tmpl->mr);
 	return NULL;
 }
 
@@ -877,17 +875,12 @@ mlx5_priv_rxq_ibv_get(struct priv *priv, uint16_t idx)
 int
 mlx5_priv_rxq_ibv_release(struct priv *priv, struct mlx5_rxq_ibv *rxq_ibv)
 {
-	int ret;
-
 	assert(rxq_ibv);
 	assert(rxq_ibv->wq);
 	assert(rxq_ibv->cq);
-	assert(rxq_ibv->mr);
-	ret = priv_mr_release(priv, rxq_ibv->mr);
-	if (!ret)
-		rxq_ibv->mr = NULL;
 	DEBUG("%p: Verbs Rx queue %p: refcnt %d", (void *)priv,
 	      (void *)rxq_ibv, rte_atomic32_read(&rxq_ibv->refcnt));
+	(void)priv;
 	if (rte_atomic32_dec_and_test(&rxq_ibv->refcnt)) {
 		rxq_free_elts(rxq_ibv->rxq_ctrl);
 		claim_zero(ibv_destroy_wq(rxq_ibv->wq));
diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
index 18e1d26f3..6589a662e 100644
--- a/drivers/net/mlx5/mlx5_rxtx.h
+++ b/drivers/net/mlx5/mlx5_rxtx.h
@@ -142,7 +142,6 @@ struct mlx5_rxq_ibv {
 	struct ibv_cq *cq; /* Completion Queue. */
 	struct ibv_wq *wq; /* Work Queue. */
 	struct ibv_comp_channel *channel;
-	struct mlx5_mr *mr; /* Memory Region (for mp). */
 };
 
 /* RX queue control descriptor. */
@@ -324,10 +323,8 @@ uint16_t mlx5_rx_burst_vec(void *, struct rte_mbuf **, uint16_t);
 /* mlx5_mr.c */
 
 void mlx5_mp2mr_iter(struct rte_mempool *, void *);
-struct mlx5_mr *priv_txq_mp2mr_reg(struct priv *priv, struct mlx5_txq_data *,
-				   struct rte_mempool *, unsigned int);
-struct mlx5_mr *mlx5_txq_mp2mr_reg(struct mlx5_txq_data *, struct rte_mempool *,
-				   unsigned int);
+struct mlx5_mr *mlx5_mp2mr(struct priv *priv, struct rte_mempool *mp,
+			   uintptr_t addr);
 
 #ifndef NDEBUG
 /**
@@ -523,7 +520,7 @@ mlx5_tx_complete(struct mlx5_txq_data *txq)
  * @return
  *   Memory pool where data is located for given mbuf.
  */
-static struct rte_mempool *
+static __rte_always_inline struct rte_mempool *
 mlx5_tx_mb2mp(struct rte_mbuf *buf)
 {
 	if (unlikely(RTE_MBUF_INDIRECT(buf)))
@@ -552,30 +549,41 @@ mlx5_tx_mb2mr(struct mlx5_txq_data *txq, struct rte_mbuf *mb)
 	struct mlx5_mr *mr;
 
 	assert(i < RTE_DIM(txq->mp2mr));
-	if (likely(txq->mp2mr[i]->start <= addr && txq->mp2mr[i]->end >= addr))
+	if (likely(txq->mp2mr[i] && txq->mp2mr[i]->start <= addr &&
+		   txq->mp2mr[i]->end >= addr))
 		return txq->mp2mr[i]->lkey;
 	for (i = 0; (i != RTE_DIM(txq->mp2mr)); ++i) {
-		if (unlikely(txq->mp2mr[i]->mr == NULL)) {
-			/* Unknown MP, add a new MR for it. */
+		if (txq->mp2mr[i] == NULL)
 			break;
-		}
+		if (i == txq->mr_cache_idx)
+			continue;
 		if (txq->mp2mr[i]->start <= addr &&
 		    txq->mp2mr[i]->end >= addr) {
+#ifndef NDEBUG
+			if (rte_eal_process_type() == RTE_PROC_PRIMARY)
+				assert(rte_cpu_to_be_32(txq->mp2mr[i]->mr->lkey)
+				       == txq->mp2mr[i]->lkey);
+#endif
 			txq->mr_cache_idx = i;
 			return txq->mp2mr[i]->lkey;
 		}
 	}
-	txq->mr_cache_idx = 0;
-	mr = mlx5_txq_mp2mr_reg(txq, mlx5_tx_mb2mp(mb), i);
-	/*
-	 * Request the reference to use in this queue, the original one is
-	 * kept by the control plane.
-	 */
-	if (mr) {
-		rte_atomic32_inc(&mr->refcnt);
-		return mr->lkey;
+	mr = mlx5_mp2mr(container_of(txq, struct mlx5_txq_ctrl, txq)->priv,
+			mlx5_tx_mb2mp(mb), addr);
+	assert(mr);
+	/* recent used MR first */
+	if (i) {
+		if (i >= RTE_DIM(txq->mp2mr)) {
+			i = RTE_DIM(txq->mp2mr) - 1;
+			DEBUG("TXQ MR cache full, please consider increasing CONFIG_RTE_LIBRTE_MLX5_TX_MP_CACHE in config file");
+		}
+		memmove(&txq->mp2mr[1], &txq->mp2mr[0],
+			i * sizeof(sizeof(txq->mp2mr[0])));
 	}
-	return (uint32_t)-1;
+	/* Store the new entry. */
+	txq->mp2mr[0] = mr;
+	txq->mr_cache_idx = 0;
+	return mr ? mr->lkey : (uint32_t)-1;
 }
 
 /**
diff --git a/drivers/net/mlx5/mlx5_trigger.c b/drivers/net/mlx5/mlx5_trigger.c
index 1a20967a2..920cc0f46 100644
--- a/drivers/net/mlx5/mlx5_trigger.c
+++ b/drivers/net/mlx5/mlx5_trigger.c
@@ -58,17 +58,10 @@ priv_txq_start(struct priv *priv)
 
 	/* Add memory regions to Tx queues. */
 	for (i = 0; i != priv->txqs_n; ++i) {
-		unsigned int idx = 0;
-		struct mlx5_mr *mr;
 		struct mlx5_txq_ctrl *txq_ctrl = mlx5_priv_txq_get(priv, i);
 
 		if (!txq_ctrl)
 			continue;
-		LIST_FOREACH(mr, &priv->mr, next) {
-			priv_txq_mp2mr_reg(priv, &txq_ctrl->txq, mr->mp, idx++);
-			if (idx == MLX5_PMD_TX_MP_CACHE)
-				break;
-		}
 		txq_alloc_elts(txq_ctrl);
 		txq_ctrl->ibv = mlx5_priv_txq_ibv_new(priv, i);
 		if (!txq_ctrl->ibv) {
-- 
2.13.3

[dpdk-dev] [PATCH 4/4] net/mlx5: remove MR refcnt

[Xueming Li]

MRs are registered to priv at device start or on the fly, destroyied
when device stop.
No mR registration to perticular TXQ, MR references cache in TXQ just
part of device MR list, no reason to keep MR refcnt.

Signed-off-by: Xueming Li <xuemingl@mellanox.com>
---
 drivers/net/mlx5/mlx5.h      |  1 -
 drivers/net/mlx5/mlx5_mr.c   | 51 +++++---------------------------------------
 drivers/net/mlx5/mlx5_rxq.c  |  1 -
 drivers/net/mlx5/mlx5_rxtx.h |  2 --
 drivers/net/mlx5/mlx5_txq.c  | 18 ----------------
 5 files changed, 5 insertions(+), 68 deletions(-)

diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h
index a6cd1474c..df6a70d96 100644
--- a/drivers/net/mlx5/mlx5.h
+++ b/drivers/net/mlx5/mlx5.h
@@ -318,7 +318,6 @@ int priv_socket_connect(struct priv *priv);
 
 struct mlx5_mr *priv_mr_new(struct priv *priv, struct rte_mempool *mp,
 			    uintptr_t addr);
-struct mlx5_mr *priv_mr_get(struct priv *, struct rte_mempool *);
 int priv_mr_release(struct priv *, struct mlx5_mr *);
 int priv_mr_verify(struct priv *);
 struct mlx5_mr *priv_mr_lookup(struct priv *priv, uintptr_t addr);
diff --git a/drivers/net/mlx5/mlx5_mr.c b/drivers/net/mlx5/mlx5_mr.c
index 8d8fabea1..bd1be5606 100644
--- a/drivers/net/mlx5/mlx5_mr.c
+++ b/drivers/net/mlx5/mlx5_mr.c
@@ -88,15 +88,11 @@ mlx5_mempool_register_cb(struct rte_mempool *mp, void *opaque,
 		cb->error = -1;
 		return;
 	}
-	mr->mp = mp;
 	DEBUG("mempool %p:%u area start=%p size=%zu lkey=0x%08x",
 	      (void *)mp, mem_idx, memhdr->addr, memhdr->len, mr->mr->lkey);
 	mr->lkey = rte_cpu_to_be_32(mr->mr->lkey);
 	mr->start = (uintptr_t)memhdr->addr;
 	mr->end = (uintptr_t)mr->mr->addr + mr->mr->length;
-	rte_atomic32_inc(&mr->refcnt);
-	DEBUG("%p: new Memory Region %p refcnt: %d", (void *)priv,
-	      (void *)mr, rte_atomic32_read(&mr->refcnt));
 	LIST_INSERT_HEAD(&priv->mr, mr, next);
 	cb->mr = mr;
 }
@@ -121,11 +117,8 @@ mlx5_mp2mr(struct priv *priv, struct rte_mempool *mp, uintptr_t addr)
 
 	priv_lock(priv);
 	mr = priv_mr_lookup(priv, addr);
-	if (!mr) {
+	if (!mr)
 		mr = priv_mr_new(priv, mp, addr);
-		if (mr)
-			rte_atomic32_inc(&mr->refcnt);
-	}
 	priv_unlock(priv);
 	return mr;
 }
@@ -217,35 +210,6 @@ priv_mr_new(struct priv *priv, struct rte_mempool *mp, uintptr_t addr)
 }
 
 /**
- * Search the memory region object in the memory region list.
- *
- * @param  priv
- *   Pointer to private structure.
- * @param mp
- *   Pointer to the memory pool to register.
- * @return
- *   The memory region on success.
- */
-struct mlx5_mr*
-priv_mr_get(struct priv *priv, struct rte_mempool *mp)
-{
-	struct mlx5_mr *mr;
-
-	assert(mp);
-	if (LIST_EMPTY(&priv->mr))
-		return NULL;
-	LIST_FOREACH(mr, &priv->mr, next) {
-		if (mr->mp == mp) {
-			rte_atomic32_inc(&mr->refcnt);
-			DEBUG("Memory Region %p refcnt: %d",
-			      (void *)mr, rte_atomic32_read(&mr->refcnt));
-			return mr;
-		}
-	}
-	return NULL;
-}
-
-/**
  * Release the memory region object.
  *
  * @param  mr
@@ -259,15 +223,10 @@ priv_mr_release(struct priv *priv, struct mlx5_mr *mr)
 {
 	(void)priv;
 	assert(mr);
-	DEBUG("Memory Region %p refcnt: %d",
-	      (void *)mr, rte_atomic32_read(&mr->refcnt));
-	if (rte_atomic32_dec_and_test(&mr->refcnt)) {
-		claim_zero(ibv_dereg_mr(mr->mr));
-		LIST_REMOVE(mr, next);
-		rte_free(mr);
-		return 0;
-	}
-	return EBUSY;
+	claim_zero(ibv_dereg_mr(mr->mr));
+	LIST_REMOVE(mr, next);
+	rte_free(mr);
+	return 0;
 }
 
 /**
diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
index a581a2d61..461b4ff91 100644
--- a/drivers/net/mlx5/mlx5_rxq.c
+++ b/drivers/net/mlx5/mlx5_rxq.c
@@ -852,7 +852,6 @@ mlx5_priv_rxq_ibv_get(struct priv *priv, uint16_t idx)
 		return NULL;
 	rxq_ctrl = container_of(rxq_data, struct mlx5_rxq_ctrl, rxq);
 	if (rxq_ctrl->ibv) {
-		priv_mr_get(priv, rxq_data->mp);
 		rte_atomic32_inc(&rxq_ctrl->ibv->refcnt);
 		DEBUG("%p: Verbs Rx queue %p: refcnt %d", (void *)priv,
 		      (void *)rxq_ctrl->ibv,
diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
index 6589a662e..0b8332cc0 100644
--- a/drivers/net/mlx5/mlx5_rxtx.h
+++ b/drivers/net/mlx5/mlx5_rxtx.h
@@ -85,12 +85,10 @@ struct priv;
 /* Memory region queue object. */
 struct mlx5_mr {
 	LIST_ENTRY(mlx5_mr) next; /**< Pointer to the next element. */
-	rte_atomic32_t refcnt; /*<< Reference counter. */
 	uint32_t lkey; /*<< rte_cpu_to_be_32(mr->lkey) */
 	uintptr_t start; /* Start address of MR */
 	uintptr_t end; /* End address of MR */
 	struct ibv_mr *mr; /*<< Memory Region. */
-	struct rte_mempool *mp; /*<< Memory Pool. */
 };
 
 /* Compressed CQE context. */
diff --git a/drivers/net/mlx5/mlx5_txq.c b/drivers/net/mlx5/mlx5_txq.c
index 26db15a4f..3c337a4ac 100644
--- a/drivers/net/mlx5/mlx5_txq.c
+++ b/drivers/net/mlx5/mlx5_txq.c
@@ -801,18 +801,7 @@ mlx5_priv_txq_get(struct priv *priv, uint16_t idx)
 	if ((*priv->txqs)[idx]) {
 		ctrl = container_of((*priv->txqs)[idx], struct mlx5_txq_ctrl,
 				    txq);
-		unsigned int i;
-
 		mlx5_priv_txq_ibv_get(priv, idx);
-		for (i = 0; i != MLX5_PMD_TX_MP_CACHE; ++i) {
-			struct mlx5_mr *mr = NULL;
-
-			(void)mr;
-			if (ctrl->txq.mp2mr[i]) {
-				mr = priv_mr_get(priv, ctrl->txq.mp2mr[i]->mp);
-				assert(mr);
-			}
-		}
 		rte_atomic32_inc(&ctrl->refcnt);
 		DEBUG("%p: Tx queue %p: refcnt %d", (void *)priv,
 		      (void *)ctrl, rte_atomic32_read(&ctrl->refcnt));
@@ -834,7 +823,6 @@ mlx5_priv_txq_get(struct priv *priv, uint16_t idx)
 int
 mlx5_priv_txq_release(struct priv *priv, uint16_t idx)
 {
-	unsigned int i;
 	struct mlx5_txq_ctrl *txq;
 
 	if (!(*priv->txqs)[idx])
@@ -849,12 +837,6 @@ mlx5_priv_txq_release(struct priv *priv, uint16_t idx)
 		if (!ret)
 			txq->ibv = NULL;
 	}
-	for (i = 0; i != MLX5_PMD_TX_MP_CACHE; ++i) {
-		if (txq->txq.mp2mr[i]) {
-			priv_mr_release(priv, txq->txq.mp2mr[i]);
-			txq->txq.mp2mr[i] = NULL;
-		}
-	}
 	if (rte_atomic32_dec_and_test(&txq->refcnt)) {
 		txq_free_elts(txq);
 		LIST_REMOVE(txq, next);
-- 
2.13.3

Re: [dpdk-dev] [PATCH 1/4] net/mlx5: revert "fix Memory Region registration"

[Nélio Laranjeiro]

On Mon, Jan 15, 2018 at 02:54:17PM +0800, Xueming Li wrote:
> This reverts commit 17fd4a504a4780455f79969803dc231521254ca8.
> 
> Fixes: 12ed59b702cc ("net/mlx5: fix Memory Region registration")
> Signed-off-by: Xueming Li <xuemingl@mellanox.com>

Is it possible to have a more explicit reason why this patch is
reverted?

> ---
>  drivers/net/mlx5/mlx5_rxtx.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
> index a239642ac..2eb2f0506 100644
> --- a/drivers/net/mlx5/mlx5_rxtx.h
> +++ b/drivers/net/mlx5/mlx5_rxtx.h
> @@ -548,7 +548,7 @@ static __rte_always_inline uint32_t
>  mlx5_tx_mb2mr(struct mlx5_txq_data *txq, struct rte_mbuf *mb)
>  {
>  	uint16_t i = txq->mr_cache_idx;
> -	uintptr_t addr = rte_pktmbuf_mtod_offset(mb, uintptr_t, DATA_LEN(mb));
> +	uintptr_t addr = rte_pktmbuf_mtod(mb, uintptr_t);
>  	struct mlx5_mr *mr;
>  
>  	assert(i < RTE_DIM(txq->mp2mr));
> -- 
> 2.13.3
> 

Thanks,

-- 
Nélio Laranjeiro
6WIND

Re: [dpdk-dev] [PATCH 2/4] net/mlx5: forbid MR registration in secondary process

[Nélio Laranjeiro]

Hi Xueming,

On Mon, Jan 15, 2018 at 02:54:18PM +0800, Xueming Li wrote:
> Secondary process are not alloed to access verbs resources, add check to
> prevent MR registration in data path.
> 
> Signed-off-by: Xueming Li <xuemingl@mellanox.com>
> ---
>  doc/guides/nics/mlx5.rst     | 1 +
>  drivers/net/mlx5/mlx5_mr.c   | 3 +++
>  drivers/net/mlx5/mlx5_rxtx.h | 3 ---
>  3 files changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
> index bdc2216c0..4373c7990 100644
> --- a/doc/guides/nics/mlx5.rst
> +++ b/doc/guides/nics/mlx5.rst
> @@ -107,6 +107,7 @@ Limitations
>  - Inner RSS for VXLAN frames is not supported yet.
>  - Hardware checksum RX offloads for VXLAN inner header are not supported yet.
>  - Forked secondary process not supported.
> +- Mempools used in secondary process TX have to be initialized in primary process before rte_eth_dev_start().
>  - Flow pattern without any specific vlan will match for vlan packets as well:
>  
>    When VLAN spec is not specified in the pattern, the matching rule will be created with VLAN as a wild card.
> diff --git a/drivers/net/mlx5/mlx5_mr.c b/drivers/net/mlx5/mlx5_mr.c
> index 6b29eed55..3c80fbb89 100644
> --- a/drivers/net/mlx5/mlx5_mr.c
> +++ b/drivers/net/mlx5/mlx5_mr.c
> @@ -278,6 +278,9 @@ priv_mr_new(struct priv *priv, struct rte_mempool *mp)
>  	unsigned int i;
>  	struct mlx5_mr *mr;
>  
> +	if (rte_eal_process_type() != RTE_PROC_PRIMARY)
> +		rte_panic("Please init mempool before rte_eth_dev_start() in primary process: %s",
> +			  mp->name);

Panic should be avoided unless the situation becomes totally
un-predectible.

Here you can return NULL and stop the Tx burst increasing at the same
time the error statistics.  The panic message can remain as a warning.
This don't deserve a panic.

>  	mr = rte_zmalloc_socket(__func__, sizeof(*mr), 0, mp->socket_id);
>  	if (!mr) {
>  		DEBUG("unable to configure MR, ibv_reg_mr() failed.");
> diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
> index 2eb2f0506..18e1d26f3 100644
> --- a/drivers/net/mlx5/mlx5_rxtx.h
> +++ b/drivers/net/mlx5/mlx5_rxtx.h
> @@ -561,9 +561,6 @@ mlx5_tx_mb2mr(struct mlx5_txq_data *txq, struct rte_mbuf *mb)
>  		}
>  		if (txq->mp2mr[i]->start <= addr &&
>  		    txq->mp2mr[i]->end >= addr) {
> -			assert(txq->mp2mr[i]->lkey != (uint32_t)-1);
> -			assert(rte_cpu_to_be_32(txq->mp2mr[i]->mr->lkey) ==
> -			       txq->mp2mr[i]->lkey);
>  			txq->mr_cache_idx = i;
>  			return txq->mp2mr[i]->lkey;
>  		}
> -- 
> 2.13.3
> 

Thanks,

-- 
Nélio Laranjeiro
6WIND

Re: [dpdk-dev] [PATCH 3/4] net/mlx5: support mempool of multi-mem segments

[Nélio Laranjeiro]

Hi Xueming,

On Mon, Jan 15, 2018 at 02:54:19PM +0800, Xueming Li wrote:
> Previously, mempool of multiple memory segments would lead to MR
> registration error "mempool not virtually contiguous". This patch
> support multi-segments mempool by registering each memory segment of
> mempool.
> 
> Signed-off-by: Xueming Li <xuemingl@mellanox.com>
> ---
>  drivers/net/mlx5/mlx5.h         |   4 +-
>  drivers/net/mlx5/mlx5_mr.c      | 284 ++++++++++++++--------------------------
>  drivers/net/mlx5/mlx5_rxq.c     |  29 ++--
>  drivers/net/mlx5/mlx5_rxtx.h    |  48 ++++---
>  drivers/net/mlx5/mlx5_trigger.c |   7 -
>  5 files changed, 143 insertions(+), 229 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h
> index 8ee522069..a6cd1474c 100644
> --- a/drivers/net/mlx5/mlx5.h
> +++ b/drivers/net/mlx5/mlx5.h
> @@ -316,9 +316,11 @@ int priv_socket_connect(struct priv *priv);
>  
>  /* mlx5_mr.c */
>  
> -struct mlx5_mr *priv_mr_new(struct priv *, struct rte_mempool *);
> +struct mlx5_mr *priv_mr_new(struct priv *priv, struct rte_mempool *mp,
> +			    uintptr_t addr);
>  struct mlx5_mr *priv_mr_get(struct priv *, struct rte_mempool *);
>  int priv_mr_release(struct priv *, struct mlx5_mr *);
>  int priv_mr_verify(struct priv *);
> +struct mlx5_mr *priv_mr_lookup(struct priv *priv, uintptr_t addr);
>  
>  #endif /* RTE_PMD_MLX5_H_ */
> diff --git a/drivers/net/mlx5/mlx5_mr.c b/drivers/net/mlx5/mlx5_mr.c
> index 3c80fbb89..8d8fabea1 100644
> --- a/drivers/net/mlx5/mlx5_mr.c
> +++ b/drivers/net/mlx5/mlx5_mr.c
> @@ -47,158 +47,89 @@
>  #include "mlx5.h"
>  #include "mlx5_rxtx.h"
>  
> -struct mlx5_check_mempool_data {
> -	int ret;
> -	char *start;
> -	char *end;
> +struct mlx5_mempool_cb_data {
> +	uintptr_t addr;
> +	struct priv *priv;
> +	int error;
> +	struct mlx5_mr *mr;
>  };
>  
> -/* Called by mlx5_check_mempool() when iterating the memory chunks. */
> +/* Called by priv_mr_new() when iterating the memory chunks. */
>  static void
> -mlx5_check_mempool_cb(struct rte_mempool *mp,
> -		      void *opaque, struct rte_mempool_memhdr *memhdr,
> -		      unsigned int mem_idx)
> +mlx5_mempool_register_cb(struct rte_mempool *mp, void *opaque,
> +			 struct rte_mempool_memhdr *memhdr,
> +			 unsigned int mem_idx __rte_unused)
>  {
> -	struct mlx5_check_mempool_data *data = opaque;
> -
> -	(void)mp;
> -	(void)mem_idx;
> +	struct mlx5_mempool_cb_data *cb = opaque;
> +	struct priv *priv = cb->priv;
> +	struct mlx5_mr *mr;
>  
> -	/* It already failed, skip the next chunks. */
> -	if (data->ret != 0)
> +	if (cb->error) /* skip on previous error */
>  		return;
> -	/* It is the first chunk. */
> -	if (data->start == NULL && data->end == NULL) {
> -		data->start = memhdr->addr;
> -		data->end = data->start + memhdr->len;
> +	if (cb->addr && (cb->addr < (uintptr_t)memhdr->addr ||
> +			 cb->addr > (uintptr_t)memhdr->addr + memhdr->len))
> +		return; /* not target mem segment */
> +	mr = priv_mr_lookup(priv, (uintptr_t)memhdr->addr);
> +	if (mr) { /* memory already registered */
> +		cb->mr = mr;
>  		return;
>  	}
> -	if (data->end == memhdr->addr) {
> -		data->end += memhdr->len;
> +	mr = rte_zmalloc_socket(__func__, sizeof(*mr), 0, mp->socket_id);
> +	if (!mr) {
> +		DEBUG("unable to allocate MR, pool %p:%u register failed.",
> +		      (void *)mp, mem_idx);
> +		cb->error = -ENOMEM;
>  		return;
>  	}
> -	if (data->start == (char *)memhdr->addr + memhdr->len) {
> -		data->start -= memhdr->len;
> +	mr->mr = ibv_reg_mr(priv->pd, memhdr->addr, memhdr->len,
> +			    IBV_ACCESS_LOCAL_WRITE);
> +	if (!mr->mr) {
> +		ERROR("unable to register MR, ibv_reg_mr() failed.");
> +		cb->error = -1;
>  		return;
>  	}
> -	/* Error, mempool is not virtually contiguous. */
> -	data->ret = -1;
> -}
> -
> -/**
> - * Check if a mempool can be used: it must be virtually contiguous.
> - *
> - * @param[in] mp
> - *   Pointer to memory pool.
> - * @param[out] start
> - *   Pointer to the start address of the mempool virtual memory area
> - * @param[out] end
> - *   Pointer to the end address of the mempool virtual memory area
> - *
> - * @return
> - *   0 on success (mempool is virtually contiguous), -1 on error.
> - */
> -static int mlx5_check_mempool(struct rte_mempool *mp, uintptr_t *start,
> -	uintptr_t *end)
> -{
> -	struct mlx5_check_mempool_data data;
> -
> -	memset(&data, 0, sizeof(data));
> -	rte_mempool_mem_iter(mp, mlx5_check_mempool_cb, &data);
> -	*start = (uintptr_t)data.start;
> -	*end = (uintptr_t)data.end;
> -
> -	return data.ret;
> +	mr->mp = mp;
> +	DEBUG("mempool %p:%u area start=%p size=%zu lkey=0x%08x",
> +	      (void *)mp, mem_idx, memhdr->addr, memhdr->len, mr->mr->lkey);
> +	mr->lkey = rte_cpu_to_be_32(mr->mr->lkey);
> +	mr->start = (uintptr_t)memhdr->addr;
> +	mr->end = (uintptr_t)mr->mr->addr + mr->mr->length;
> +	rte_atomic32_inc(&mr->refcnt);
> +	DEBUG("%p: new Memory Region %p refcnt: %d", (void *)priv,
> +	      (void *)mr, rte_atomic32_read(&mr->refcnt));
> +	LIST_INSERT_HEAD(&priv->mr, mr, next);
> +	cb->mr = mr;
>  }
>  
>  /**
> - * Register a Memory Region (MR) <-> Memory Pool (MP) association in
> - * txq->mp2mr[]. If mp2mr[] is full, remove an entry first.
> - *
> - * This function should only be called by txq_mp2mr().
> + * Lookup or register a Memory Region (MR).
>   *
>   * @param priv
> - *   Pointer to private structure.
> - * @param txq
> - *   Pointer to TX queue structure.
> - * @param[in] mp
> - *   Memory Pool for which a Memory Region lkey must be returned.
> - * @param idx
> - *   Index of the next available entry.
> + *   Pointer to priv structure.
> + * @param mp
> + *   Pointer to the memory pool to register.
> + * @param addr
> + *   Address to register
>   *
>   * @return
>   *   mr on success, NULL on failure.
>   */
>  struct mlx5_mr*
> -priv_txq_mp2mr_reg(struct priv *priv, struct mlx5_txq_data *txq,
> -		   struct rte_mempool *mp, unsigned int idx)
> +mlx5_mp2mr(struct priv *priv, struct rte_mempool *mp, uintptr_t addr)
>  {
> -	struct mlx5_txq_ctrl *txq_ctrl =
> -		container_of(txq, struct mlx5_txq_ctrl, txq);
>  	struct mlx5_mr *mr;
>  
> -	/* Add a new entry, register MR first. */
> -	DEBUG("%p: discovered new memory pool \"%s\" (%p)",
> -	      (void *)txq_ctrl, mp->name, (void *)mp);
> -	mr = priv_mr_get(priv, mp);
> -	if (mr == NULL)
> -		mr = priv_mr_new(priv, mp);
> -	if (unlikely(mr == NULL)) {
> -		DEBUG("%p: unable to configure MR, ibv_reg_mr() failed.",
> -		      (void *)txq_ctrl);
> -		return NULL;
> -	}
> -	if (unlikely(idx == RTE_DIM(txq->mp2mr))) {
> -		/* Table is full, remove oldest entry. */
> -		DEBUG("%p: MR <-> MP table full, dropping oldest entry.",
> -		      (void *)txq_ctrl);
> -		--idx;
> -		priv_mr_release(priv, txq->mp2mr[0]);
> -		memmove(&txq->mp2mr[0], &txq->mp2mr[1],
> -			(sizeof(txq->mp2mr) - sizeof(txq->mp2mr[0])));
> +	priv_lock(priv);
> +	mr = priv_mr_lookup(priv, addr);
> +	if (!mr) {
> +		mr = priv_mr_new(priv, mp, addr);
> +		if (mr)
> +			rte_atomic32_inc(&mr->refcnt);
>  	}
> -	/* Store the new entry. */
> -	txq_ctrl->txq.mp2mr[idx] = mr;
> -	DEBUG("%p: new MR lkey for MP \"%s\" (%p): 0x%08" PRIu32,
> -	      (void *)txq_ctrl, mp->name, (void *)mp,
> -	      txq_ctrl->txq.mp2mr[idx]->lkey);
> -	return mr;
> -}
> -
> -/**
> - * Register a Memory Region (MR) <-> Memory Pool (MP) association in
> - * txq->mp2mr[]. If mp2mr[] is full, remove an entry first.
> - *
> - * This function should only be called by txq_mp2mr().
> - *
> - * @param txq
> - *   Pointer to TX queue structure.
> - * @param[in] mp
> - *   Memory Pool for which a Memory Region lkey must be returned.
> - * @param idx
> - *   Index of the next available entry.
> - *
> - * @return
> - *   mr on success, NULL on failure.
> - */
> -struct mlx5_mr*
> -mlx5_txq_mp2mr_reg(struct mlx5_txq_data *txq, struct rte_mempool *mp,
> -		   unsigned int idx)
> -{
> -	struct mlx5_txq_ctrl *txq_ctrl =
> -		container_of(txq, struct mlx5_txq_ctrl, txq);
> -	struct mlx5_mr *mr;
> -
> -	priv_lock(txq_ctrl->priv);
> -	mr = priv_txq_mp2mr_reg(txq_ctrl->priv, txq, mp, idx);
> -	priv_unlock(txq_ctrl->priv);
> +	priv_unlock(priv);
>  	return mr;
>  }
>  
> -struct mlx5_mp2mr_mbuf_check_data {
> -	int ret;
> -};
> -
>  /**
>   * Callback function for rte_mempool_obj_iter() to check whether a given
>   * mempool object looks like a mbuf.
> @@ -214,10 +145,10 @@ struct mlx5_mp2mr_mbuf_check_data {
>   *   Object index, unused.
>   */
>  static void
> -txq_mp2mr_mbuf_check(struct rte_mempool *mp, void *arg, void *obj,
> +mp2mr_mbuf_check_cb(struct rte_mempool *mp, void *arg, void *obj,
>  	uint32_t index __rte_unused)
>  {
> -	struct mlx5_mp2mr_mbuf_check_data *data = arg;
> +	struct mlx5_mempool_cb_data *data = arg;
>  	struct rte_mbuf *buf = obj;
>  
>  	/*
> @@ -225,7 +156,7 @@ txq_mp2mr_mbuf_check(struct rte_mempool *mp, void *arg, void *obj,
>  	 * pointer is valid.
>  	 */
>  	if (sizeof(*buf) > mp->elt_size || buf->pool != mp)
> -		data->ret = -1;
> +		data->error = -1;
>  }
>  
>  /**
> @@ -241,21 +172,14 @@ void
>  mlx5_mp2mr_iter(struct rte_mempool *mp, void *arg)
>  {
>  	struct priv *priv = (struct priv *)arg;
> -	struct mlx5_mp2mr_mbuf_check_data data = {
> -		.ret = 0,
> -	};
> -	struct mlx5_mr *mr;
> +	struct mlx5_mempool_cb_data data = {0};
>  
> -	/* Register mempool only if the first element looks like a mbuf. */
> -	if (rte_mempool_obj_iter(mp, txq_mp2mr_mbuf_check, &data) == 0 ||
> -			data.ret == -1)
> +	/* Register mempool only if all element looks like a mbuf. */
> +	/* TODO less efficient to iterate all objects in pool */
> +	if (rte_mempool_obj_iter(mp, mp2mr_mbuf_check_cb, &data) == 0 ||
> +			data.error == -1)
>  		return;

What are the performance impact of such lookup with several chunks in
the datapath?

> -	mr = priv_mr_get(priv, mp);
> -	if (mr) {
> -		priv_mr_release(priv, mr);
> -		return;
> -	}
> -	priv_mr_new(priv, mp);
> +	priv_mr_new(priv, mp, 0);
>  }
>  
>  /**
> @@ -266,59 +190,30 @@ mlx5_mp2mr_iter(struct rte_mempool *mp, void *arg)
>   *   Pointer to private structure.
>   * @param mp
>   *   Pointer to the memory pool to register.
> + * @param addr
> + *   Address to register
>   * @return
> - *   The memory region on success.
> + *   Registered MR or the last if multiple MR registered.
>   */
> -struct mlx5_mr*
> -priv_mr_new(struct priv *priv, struct rte_mempool *mp)
> +struct mlx5_mr *
> +priv_mr_new(struct priv *priv, struct rte_mempool *mp, uintptr_t addr)
>  {
> -	const struct rte_memseg *ms = rte_eal_get_physmem_layout();
> -	uintptr_t start;
> -	uintptr_t end;
> -	unsigned int i;
> -	struct mlx5_mr *mr;
> +	struct mlx5_mempool_cb_data cb_data = {
> +		.priv = priv,
> +		.addr = addr,
> +	};
>  
>  	if (rte_eal_process_type() != RTE_PROC_PRIMARY)
>  		rte_panic("Please init mempool before rte_eth_dev_start() in primary process: %s",
>  			  mp->name);
> -	mr = rte_zmalloc_socket(__func__, sizeof(*mr), 0, mp->socket_id);
> -	if (!mr) {
> -		DEBUG("unable to configure MR, ibv_reg_mr() failed.");
> -		return NULL;
> -	}
> -	if (mlx5_check_mempool(mp, &start, &end) != 0) {
> -		ERROR("mempool %p: not virtually contiguous",
> -		      (void *)mp);
> +	DEBUG("%p: discovered new memory pool \"%s\" (%p)",
> +	      (void *)priv, mp->name, (void *)mp);
> +	rte_mempool_mem_iter(mp, mlx5_mempool_register_cb, &cb_data);
> +	if (cb_data.error) {
> +		DEBUG("%p: unable to configure MR.", (void *)priv);
>  		return NULL;
>  	}
> -	DEBUG("mempool %p area start=%p end=%p size=%zu",
> -	      (void *)mp, (void *)start, (void *)end,
> -	      (size_t)(end - start));
> -	/* Round start and end to page boundary if found in memory segments. */
> -	for (i = 0; (i < RTE_MAX_MEMSEG) && (ms[i].addr != NULL); ++i) {
> -		uintptr_t addr = (uintptr_t)ms[i].addr;
> -		size_t len = ms[i].len;
> -		unsigned int align = ms[i].hugepage_sz;
> -
> -		if ((start > addr) && (start < addr + len))
> -			start = RTE_ALIGN_FLOOR(start, align);
> -		if ((end > addr) && (end < addr + len))
> -			end = RTE_ALIGN_CEIL(end, align);
> -	}
> -	DEBUG("mempool %p using start=%p end=%p size=%zu for MR",
> -	      (void *)mp, (void *)start, (void *)end,
> -	      (size_t)(end - start));
> -	mr->mr = ibv_reg_mr(priv->pd, (void *)start, end - start,
> -			    IBV_ACCESS_LOCAL_WRITE);
> -	mr->mp = mp;
> -	mr->lkey = rte_cpu_to_be_32(mr->mr->lkey);
> -	mr->start = start;
> -	mr->end = (uintptr_t)mr->mr->addr + mr->mr->length;
> -	rte_atomic32_inc(&mr->refcnt);
> -	DEBUG("%p: new Memory Region %p refcnt: %d", (void *)priv,
> -	      (void *)mr, rte_atomic32_read(&mr->refcnt));
> -	LIST_INSERT_HEAD(&priv->mr, mr, next);
> -	return mr;
> +	return cb_data.mr;
>  }
>  
>  /**
> @@ -396,3 +291,26 @@ priv_mr_verify(struct priv *priv)
>  	}
>  	return ret;
>  }
> +
> +/**
> + * Memory Region (MR) lookup by address
> + *
> + * @param priv
> + *   Pointer to priv structure.
> + * @param[in] addr
> + *   Address to lookup.
> + * @return
> + *   mr on success, (uint32_t)-1 on failure.
> + */
> +struct mlx5_mr *
> +priv_mr_lookup(struct priv *priv, uintptr_t addr)
> +{
> +	struct mlx5_mr *mr;
> +
> +	LIST_FOREACH(mr, &priv->mr, next) {
> +		if (addr >= mr->start && addr <= mr->end)
> +			return mr;
> +	}
> +	return NULL;
> +}
> +
> diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
> index 950472754..a581a2d61 100644
> --- a/drivers/net/mlx5/mlx5_rxq.c
> +++ b/drivers/net/mlx5/mlx5_rxq.c
> @@ -652,6 +652,7 @@ mlx5_priv_rxq_ibv_new(struct priv *priv, uint16_t idx)
>  	int ret = 0;
>  	struct mlx5dv_obj obj;
>  	struct mlx5_dev_config *config = &priv->config;
> +	struct mlx5_mr *last_mr = NULL;
>  
>  	assert(rxq_data);
>  	assert(!rxq_ctrl->ibv);
> @@ -664,13 +665,9 @@ mlx5_priv_rxq_ibv_new(struct priv *priv, uint16_t idx)
>  	}
>  	tmpl->rxq_ctrl = rxq_ctrl;
>  	/* Use the entire RX mempool as the memory region. */
> -	tmpl->mr = priv_mr_get(priv, rxq_data->mp);
> -	if (!tmpl->mr) {
> -		tmpl->mr = priv_mr_new(priv, rxq_data->mp);
> -		if (!tmpl->mr) {
> -			ERROR("%p: MR creation failure", (void *)rxq_ctrl);
> -			goto error;
> -		}
> +	if (!priv_mr_new(priv, rxq_data->mp, 0)) {
> +		ERROR("%p: MR creation failure", (void *)rxq_ctrl);
> +		goto error;
>  	}
>  	if (rxq_ctrl->irq) {
>  		tmpl->channel = ibv_create_comp_channel(priv->ctx);
> @@ -786,14 +783,17 @@ mlx5_priv_rxq_ibv_new(struct priv *priv, uint16_t idx)
>  	for (i = 0; (i != (unsigned int)(1 << rxq_data->elts_n)); ++i) {
>  		struct rte_mbuf *buf = (*rxq_data->elts)[i];
>  		volatile struct mlx5_wqe_data_seg *scat = &(*rxq_data->wqes)[i];
> +		uintptr_t addr = rte_pktmbuf_mtod(buf, uintptr_t);
>  
> +		if (!last_mr || addr < last_mr->start || addr > last_mr->end)
> +			last_mr = priv_mr_lookup(priv, addr);
> +		assert(last_mr);
>  		/* scat->addr must be able to store a pointer. */
>  		assert(sizeof(scat->addr) >= sizeof(uintptr_t));
>  		*scat = (struct mlx5_wqe_data_seg){
> -			.addr = rte_cpu_to_be_64(rte_pktmbuf_mtod(buf,
> -								  uintptr_t)),
> +			.addr = rte_cpu_to_be_64(addr),
>  			.byte_count = rte_cpu_to_be_32(DATA_LEN(buf)),
> -			.lkey = tmpl->mr->lkey,
> +			.lkey = last_mr->lkey,
>  		};
>  	}
>  	rxq_data->rq_db = rwq.dbrec;
> @@ -826,8 +826,6 @@ mlx5_priv_rxq_ibv_new(struct priv *priv, uint16_t idx)
>  		claim_zero(ibv_destroy_cq(tmpl->cq));
>  	if (tmpl->channel)
>  		claim_zero(ibv_destroy_comp_channel(tmpl->channel));
> -	if (tmpl->mr)
> -		priv_mr_release(priv, tmpl->mr);
>  	return NULL;
>  }
>  
> @@ -877,17 +875,12 @@ mlx5_priv_rxq_ibv_get(struct priv *priv, uint16_t idx)
>  int
>  mlx5_priv_rxq_ibv_release(struct priv *priv, struct mlx5_rxq_ibv *rxq_ibv)
>  {
> -	int ret;
> -
>  	assert(rxq_ibv);
>  	assert(rxq_ibv->wq);
>  	assert(rxq_ibv->cq);
> -	assert(rxq_ibv->mr);
> -	ret = priv_mr_release(priv, rxq_ibv->mr);
> -	if (!ret)
> -		rxq_ibv->mr = NULL;
>  	DEBUG("%p: Verbs Rx queue %p: refcnt %d", (void *)priv,
>  	      (void *)rxq_ibv, rte_atomic32_read(&rxq_ibv->refcnt));
> +	(void)priv;
>  	if (rte_atomic32_dec_and_test(&rxq_ibv->refcnt)) {
>  		rxq_free_elts(rxq_ibv->rxq_ctrl);
>  		claim_zero(ibv_destroy_wq(rxq_ibv->wq));
> diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
> index 18e1d26f3..6589a662e 100644
> --- a/drivers/net/mlx5/mlx5_rxtx.h
> +++ b/drivers/net/mlx5/mlx5_rxtx.h
> @@ -142,7 +142,6 @@ struct mlx5_rxq_ibv {
>  	struct ibv_cq *cq; /* Completion Queue. */
>  	struct ibv_wq *wq; /* Work Queue. */
>  	struct ibv_comp_channel *channel;
> -	struct mlx5_mr *mr; /* Memory Region (for mp). */
>  };
>  
>  /* RX queue control descriptor. */
> @@ -324,10 +323,8 @@ uint16_t mlx5_rx_burst_vec(void *, struct rte_mbuf **, uint16_t);
>  /* mlx5_mr.c */
>  
>  void mlx5_mp2mr_iter(struct rte_mempool *, void *);
> -struct mlx5_mr *priv_txq_mp2mr_reg(struct priv *priv, struct mlx5_txq_data *,
> -				   struct rte_mempool *, unsigned int);
> -struct mlx5_mr *mlx5_txq_mp2mr_reg(struct mlx5_txq_data *, struct rte_mempool *,
> -				   unsigned int);
> +struct mlx5_mr *mlx5_mp2mr(struct priv *priv, struct rte_mempool *mp,
> +			   uintptr_t addr);
>  
>  #ifndef NDEBUG
>  /**
> @@ -523,7 +520,7 @@ mlx5_tx_complete(struct mlx5_txq_data *txq)
>   * @return
>   *   Memory pool where data is located for given mbuf.
>   */
> -static struct rte_mempool *
> +static __rte_always_inline struct rte_mempool *
>  mlx5_tx_mb2mp(struct rte_mbuf *buf)
>  {
>  	if (unlikely(RTE_MBUF_INDIRECT(buf)))
> @@ -552,30 +549,41 @@ mlx5_tx_mb2mr(struct mlx5_txq_data *txq, struct rte_mbuf *mb)
>  	struct mlx5_mr *mr;
>  
>  	assert(i < RTE_DIM(txq->mp2mr));
> -	if (likely(txq->mp2mr[i]->start <= addr && txq->mp2mr[i]->end >= addr))
> +	if (likely(txq->mp2mr[i] && txq->mp2mr[i]->start <= addr &&
> +		   txq->mp2mr[i]->end >= addr))
>  		return txq->mp2mr[i]->lkey;
>  	for (i = 0; (i != RTE_DIM(txq->mp2mr)); ++i) {
> -		if (unlikely(txq->mp2mr[i]->mr == NULL)) {
> -			/* Unknown MP, add a new MR for it. */
> +		if (txq->mp2mr[i] == NULL)
>  			break;
> -		}
> +		if (i == txq->mr_cache_idx)
> +			continue;
>  		if (txq->mp2mr[i]->start <= addr &&
>  		    txq->mp2mr[i]->end >= addr) {
> +#ifndef NDEBUG
> +			if (rte_eal_process_type() == RTE_PROC_PRIMARY)
> +				assert(rte_cpu_to_be_32(txq->mp2mr[i]->mr->lkey)
> +				       == txq->mp2mr[i]->lkey);
> +#endif
>  			txq->mr_cache_idx = i;
>  			return txq->mp2mr[i]->lkey;
>  		}
>  	}
> -	txq->mr_cache_idx = 0;
> -	mr = mlx5_txq_mp2mr_reg(txq, mlx5_tx_mb2mp(mb), i);
> -	/*
> -	 * Request the reference to use in this queue, the original one is
> -	 * kept by the control plane.
> -	 */
> -	if (mr) {
> -		rte_atomic32_inc(&mr->refcnt);
> -		return mr->lkey;
> +	mr = mlx5_mp2mr(container_of(txq, struct mlx5_txq_ctrl, txq)->priv,
> +			mlx5_tx_mb2mp(mb), addr);
> +	assert(mr);
> +	/* recent used MR first */
> +	if (i) {
> +		if (i >= RTE_DIM(txq->mp2mr)) {
> +			i = RTE_DIM(txq->mp2mr) - 1;
> +			DEBUG("TXQ MR cache full, please consider increasing CONFIG_RTE_LIBRTE_MLX5_TX_MP_CACHE in config file");

Please respect the coding style of the PMD/file split those lines.

> +		}
> +		memmove(&txq->mp2mr[1], &txq->mp2mr[0],
> +			i * sizeof(sizeof(txq->mp2mr[0])));
>  	}
> -	return (uint32_t)-1;
> +	/* Store the new entry. */
> +	txq->mp2mr[0] = mr;
> +	txq->mr_cache_idx = 0;
> +	return mr ? mr->lkey : (uint32_t)-1;
>  }
>  
>  /**
> diff --git a/drivers/net/mlx5/mlx5_trigger.c b/drivers/net/mlx5/mlx5_trigger.c
> index 1a20967a2..920cc0f46 100644
> --- a/drivers/net/mlx5/mlx5_trigger.c
> +++ b/drivers/net/mlx5/mlx5_trigger.c
> @@ -58,17 +58,10 @@ priv_txq_start(struct priv *priv)
>  
>  	/* Add memory regions to Tx queues. */
>  	for (i = 0; i != priv->txqs_n; ++i) {
> -		unsigned int idx = 0;
> -		struct mlx5_mr *mr;
>  		struct mlx5_txq_ctrl *txq_ctrl = mlx5_priv_txq_get(priv, i);
>  
>  		if (!txq_ctrl)
>  			continue;
> -		LIST_FOREACH(mr, &priv->mr, next) {
> -			priv_txq_mp2mr_reg(priv, &txq_ctrl->txq, mr->mp, idx++);
> -			if (idx == MLX5_PMD_TX_MP_CACHE)
> -				break;
> -		}
>  		txq_alloc_elts(txq_ctrl);
>  		txq_ctrl->ibv = mlx5_priv_txq_ibv_new(priv, i);
>  		if (!txq_ctrl->ibv) {
> -- 
> 2.13.3
> 

Thanks,

-- 
Nélio Laranjeiro
6WIND

Re: [dpdk-dev] [PATCH 4/4] net/mlx5: remove MR refcnt

[Nélio Laranjeiro]

Hi Xueming,

On Mon, Jan 15, 2018 at 02:54:20PM +0800, Xueming Li wrote:
> MRs are registered to priv at device start or on the fly, destroyied
> when device stop.
> No mR registration to perticular TXQ, MR references cache in TXQ just
> part of device MR list, no reason to keep MR refcnt.
> 
> Signed-off-by: Xueming Li <xuemingl@mellanox.com>
> ---
>  drivers/net/mlx5/mlx5.h      |  1 -
>  drivers/net/mlx5/mlx5_mr.c   | 51 +++++---------------------------------------
>  drivers/net/mlx5/mlx5_rxq.c  |  1 -
>  drivers/net/mlx5/mlx5_rxtx.h |  2 --
>  drivers/net/mlx5/mlx5_txq.c  | 18 ----------------
>  5 files changed, 5 insertions(+), 68 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h
> index a6cd1474c..df6a70d96 100644
> --- a/drivers/net/mlx5/mlx5.h
> +++ b/drivers/net/mlx5/mlx5.h
> @@ -318,7 +318,6 @@ int priv_socket_connect(struct priv *priv);
>  
>  struct mlx5_mr *priv_mr_new(struct priv *priv, struct rte_mempool *mp,
>  			    uintptr_t addr);
> -struct mlx5_mr *priv_mr_get(struct priv *, struct rte_mempool *);
>  int priv_mr_release(struct priv *, struct mlx5_mr *);
>  int priv_mr_verify(struct priv *);
>  struct mlx5_mr *priv_mr_lookup(struct priv *priv, uintptr_t addr);
> diff --git a/drivers/net/mlx5/mlx5_mr.c b/drivers/net/mlx5/mlx5_mr.c
> index 8d8fabea1..bd1be5606 100644
> --- a/drivers/net/mlx5/mlx5_mr.c
> +++ b/drivers/net/mlx5/mlx5_mr.c
> @@ -88,15 +88,11 @@ mlx5_mempool_register_cb(struct rte_mempool *mp, void *opaque,
>  		cb->error = -1;
>  		return;
>  	}
> -	mr->mp = mp;
>  	DEBUG("mempool %p:%u area start=%p size=%zu lkey=0x%08x",
>  	      (void *)mp, mem_idx, memhdr->addr, memhdr->len, mr->mr->lkey);
>  	mr->lkey = rte_cpu_to_be_32(mr->mr->lkey);
>  	mr->start = (uintptr_t)memhdr->addr;
>  	mr->end = (uintptr_t)mr->mr->addr + mr->mr->length;
> -	rte_atomic32_inc(&mr->refcnt);
> -	DEBUG("%p: new Memory Region %p refcnt: %d", (void *)priv,
> -	      (void *)mr, rte_atomic32_read(&mr->refcnt));

Please keep the debug message.

>  	LIST_INSERT_HEAD(&priv->mr, mr, next);
>  	cb->mr = mr;
>  }
> @@ -121,11 +117,8 @@ mlx5_mp2mr(struct priv *priv, struct rte_mempool *mp, uintptr_t addr)
>  
>  	priv_lock(priv);
>  	mr = priv_mr_lookup(priv, addr);
> -	if (!mr) {
> +	if (!mr)
>  		mr = priv_mr_new(priv, mp, addr);
> -		if (mr)
> -			rte_atomic32_inc(&mr->refcnt);
> -	}
>  	priv_unlock(priv);
>  	return mr;
>  }
> @@ -217,35 +210,6 @@ priv_mr_new(struct priv *priv, struct rte_mempool *mp, uintptr_t addr)
>  }
>  
>  /**
> - * Search the memory region object in the memory region list.
> - *
> - * @param  priv
> - *   Pointer to private structure.
> - * @param mp
> - *   Pointer to the memory pool to register.
> - * @return
> - *   The memory region on success.
> - */
> -struct mlx5_mr*
> -priv_mr_get(struct priv *priv, struct rte_mempool *mp)
> -{
> -	struct mlx5_mr *mr;
> -
> -	assert(mp);
> -	if (LIST_EMPTY(&priv->mr))
> -		return NULL;
> -	LIST_FOREACH(mr, &priv->mr, next) {
> -		if (mr->mp == mp) {
> -			rte_atomic32_inc(&mr->refcnt);
> -			DEBUG("Memory Region %p refcnt: %d",
> -			      (void *)mr, rte_atomic32_read(&mr->refcnt));
> -			return mr;
> -		}
> -	}
> -	return NULL;
> -}
> -
> -/**
>   * Release the memory region object.
>   *
>   * @param  mr
> @@ -259,15 +223,10 @@ priv_mr_release(struct priv *priv, struct mlx5_mr *mr)
>  {
>  	(void)priv;
>  	assert(mr);
> -	DEBUG("Memory Region %p refcnt: %d",
> -	      (void *)mr, rte_atomic32_read(&mr->refcnt));
> -	if (rte_atomic32_dec_and_test(&mr->refcnt)) {
> -		claim_zero(ibv_dereg_mr(mr->mr));
> -		LIST_REMOVE(mr, next);
> -		rte_free(mr);
> -		return 0;
> -	}
> -	return EBUSY;
> +	claim_zero(ibv_dereg_mr(mr->mr));
> +	LIST_REMOVE(mr, next);
> +	rte_free(mr);
> +	return 0;
>  }
>  
>  /**
> diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
> index a581a2d61..461b4ff91 100644
> --- a/drivers/net/mlx5/mlx5_rxq.c
> +++ b/drivers/net/mlx5/mlx5_rxq.c
> @@ -852,7 +852,6 @@ mlx5_priv_rxq_ibv_get(struct priv *priv, uint16_t idx)
>  		return NULL;
>  	rxq_ctrl = container_of(rxq_data, struct mlx5_rxq_ctrl, rxq);
>  	if (rxq_ctrl->ibv) {
> -		priv_mr_get(priv, rxq_data->mp);
>  		rte_atomic32_inc(&rxq_ctrl->ibv->refcnt);
>  		DEBUG("%p: Verbs Rx queue %p: refcnt %d", (void *)priv,
>  		      (void *)rxq_ctrl->ibv,
> diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
> index 6589a662e..0b8332cc0 100644
> --- a/drivers/net/mlx5/mlx5_rxtx.h
> +++ b/drivers/net/mlx5/mlx5_rxtx.h
> @@ -85,12 +85,10 @@ struct priv;
>  /* Memory region queue object. */
>  struct mlx5_mr {
>  	LIST_ENTRY(mlx5_mr) next; /**< Pointer to the next element. */
> -	rte_atomic32_t refcnt; /*<< Reference counter. */
>  	uint32_t lkey; /*<< rte_cpu_to_be_32(mr->lkey) */
>  	uintptr_t start; /* Start address of MR */
>  	uintptr_t end; /* End address of MR */
>  	struct ibv_mr *mr; /*<< Memory Region. */
> -	struct rte_mempool *mp; /*<< Memory Pool. */
>  };
>  
>  /* Compressed CQE context. */
> diff --git a/drivers/net/mlx5/mlx5_txq.c b/drivers/net/mlx5/mlx5_txq.c
> index 26db15a4f..3c337a4ac 100644
> --- a/drivers/net/mlx5/mlx5_txq.c
> +++ b/drivers/net/mlx5/mlx5_txq.c
> @@ -801,18 +801,7 @@ mlx5_priv_txq_get(struct priv *priv, uint16_t idx)
>  	if ((*priv->txqs)[idx]) {
>  		ctrl = container_of((*priv->txqs)[idx], struct mlx5_txq_ctrl,
>  				    txq);
> -		unsigned int i;
> -
>  		mlx5_priv_txq_ibv_get(priv, idx);
> -		for (i = 0; i != MLX5_PMD_TX_MP_CACHE; ++i) {
> -			struct mlx5_mr *mr = NULL;
> -
> -			(void)mr;
> -			if (ctrl->txq.mp2mr[i]) {
> -				mr = priv_mr_get(priv, ctrl->txq.mp2mr[i]->mp);
> -				assert(mr);
> -			}
> -		}
>  		rte_atomic32_inc(&ctrl->refcnt);
>  		DEBUG("%p: Tx queue %p: refcnt %d", (void *)priv,
>  		      (void *)ctrl, rte_atomic32_read(&ctrl->refcnt));
> @@ -834,7 +823,6 @@ mlx5_priv_txq_get(struct priv *priv, uint16_t idx)
>  int
>  mlx5_priv_txq_release(struct priv *priv, uint16_t idx)
>  {
> -	unsigned int i;
>  	struct mlx5_txq_ctrl *txq;
>  
>  	if (!(*priv->txqs)[idx])
> @@ -849,12 +837,6 @@ mlx5_priv_txq_release(struct priv *priv, uint16_t idx)
>  		if (!ret)
>  			txq->ibv = NULL;
>  	}
> -	for (i = 0; i != MLX5_PMD_TX_MP_CACHE; ++i) {
> -		if (txq->txq.mp2mr[i]) {
> -			priv_mr_release(priv, txq->txq.mp2mr[i]);
> -			txq->txq.mp2mr[i] = NULL;
> -		}
> -	}

Nullifying the case when the queue is release should remain.  It is
better to detect an access to a null pointer than to a freed memory
space.

>  	if (rte_atomic32_dec_and_test(&txq->refcnt)) {
>  		txq_free_elts(txq);
>  		LIST_REMOVE(txq, next);
> -- 
> 2.13.3
> 

Thanks,

-- 
Nélio Laranjeiro
6WIND