When fast releasing mbufs, the mbufs are not accessed, so do not prefetch
them.
This saves a mbuf load operation for each fast released TX mbuf.
When fast release of mbufs is enabled for a TX queue, cache the mbuf
mempool pointer in the TX queue structure.
This saves one mbuf load operation for each burst of fast released TX
mbufs.
The txep->mbuf pointer is not used after the mbuf has been freed, so do
not reset the pointer.
This saves a txep store operation for each TX mbuf freed.
Signed-off-by: Morten Brørup <m...@smartsharesystems.com>
---
drivers/net/intel/common/tx.h | 5 +++
.../i40e/i40e_recycle_mbufs_vec_common.c | 4 +-
drivers/net/intel/i40e/i40e_rxtx.c | 39 ++++++++++---------
3 files changed, 28 insertions(+), 20 deletions(-)
diff --git a/drivers/net/intel/common/tx.h b/drivers/net/intel/common/tx.h
index b0a68bae44..54c9b845f7 100644
--- a/drivers/net/intel/common/tx.h
+++ b/drivers/net/intel/common/tx.h
@@ -62,6 +62,11 @@ struct ci_tx_queue {
uint16_t tx_next_dd;
uint16_t tx_next_rs;
uint64_t offloads;
+ /* Mempool pointer for fast release of mbufs.
+ * NULL if disabled, UINTPTR_MAX if enabled and not yet known.
+ * Initialized at first use.
+ */
+ struct rte_mempool *fast_free_mp;
uint64_t mbuf_errors;
rte_iova_t tx_ring_dma; /* TX ring DMA address */
bool tx_deferred_start; /* don't start this queue in dev start */
diff --git a/drivers/net/intel/i40e/i40e_recycle_mbufs_vec_common.c
b/drivers/net/intel/i40e/i40e_recycle_mbufs_vec_common.c
index 2875c578af..a46605cee9 100644
--- a/drivers/net/intel/i40e/i40e_recycle_mbufs_vec_common.c
+++ b/drivers/net/intel/i40e/i40e_recycle_mbufs_vec_common.c
@@ -106,7 +106,9 @@ i40e_recycle_tx_mbufs_reuse_vec(void *tx_queue,
if (txq->offloads & RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE) {
/* Avoid txq contains buffers from unexpected mempool. */
if (unlikely(recycle_rxq_info->mp
- != txep[0].mbuf->pool))
+ != (likely(txq->fast_free_mp != (void
*)UINTPTR_MAX) ?
+ txq->fast_free_mp :
+ (txq->fast_free_mp = txep[0].mbuf->pool))))
return 0;
/* Directly put mbufs from Tx to Rx. */
diff --git a/drivers/net/intel/i40e/i40e_rxtx.c
b/drivers/net/intel/i40e/i40e_rxtx.c
index c3ff2e05c3..679c1340b8 100644
--- a/drivers/net/intel/i40e/i40e_rxtx.c
+++ b/drivers/net/intel/i40e/i40e_rxtx.c
@@ -1332,7 +1332,7 @@ static __rte_always_inline int
i40e_tx_free_bufs(struct ci_tx_queue *txq)
{
struct ci_tx_entry *txep;
- uint16_t tx_rs_thresh = txq->tx_rs_thresh;
+ const uint16_t tx_rs_thresh = txq->tx_rs_thresh;
uint16_t i = 0, j = 0;
struct rte_mbuf *free[RTE_I40E_TX_MAX_FREE_BUF_SZ];
const uint16_t k = RTE_ALIGN_FLOOR(tx_rs_thresh,
RTE_I40E_TX_MAX_FREE_BUF_SZ);
@@ -1345,41 +1345,40 @@ i40e_tx_free_bufs(struct ci_tx_queue *txq)
txep = &txq->sw_ring[txq->tx_next_dd - (tx_rs_thresh - 1)];
- for (i = 0; i < tx_rs_thresh; i++)
- rte_prefetch0((txep + i)->mbuf);
-
if (txq->offloads & RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE) {
+ struct rte_mempool * const fast_free_mp =
+ likely(txq->fast_free_mp != (void
*)UINTPTR_MAX) ?
+ txq->fast_free_mp :
+ (txq->fast_free_mp = txep[0].mbuf->pool);
+
if (k) {
for (j = 0; j != k; j += RTE_I40E_TX_MAX_FREE_BUF_SZ) {
- for (i = 0; i < RTE_I40E_TX_MAX_FREE_BUF_SZ;
++i, ++txep) {
+ for (i = 0; i < RTE_I40E_TX_MAX_FREE_BUF_SZ;
++i, ++txep)
free[i] = txep->mbuf;
- txep->mbuf = NULL;
- }
- rte_mempool_put_bulk(free[0]->pool, (void
**)free,
+ rte_mempool_put_bulk(fast_free_mp, (void
**)free,
RTE_I40E_TX_MAX_FREE_BUF_SZ);
}
}
if (m) {
- for (i = 0; i < m; ++i, ++txep) {
+ for (i = 0; i < m; ++i, ++txep)
free[i] = txep->mbuf;
- txep->mbuf = NULL;
- }
- rte_mempool_put_bulk(free[0]->pool, (void **)free, m);
+ rte_mempool_put_bulk(fast_free_mp, (void **)free, m);
}
} else {
- for (i = 0; i < txq->tx_rs_thresh; ++i, ++txep) {
+ for (i = 0; i < tx_rs_thresh; i++)
+ rte_prefetch0((txep + i)->mbuf);
+
+ for (i = 0; i < tx_rs_thresh; ++i, ++txep)
rte_pktmbuf_free_seg(txep->mbuf);
- txep->mbuf = NULL;
- }
}
- txq->nb_tx_free = (uint16_t)(txq->nb_tx_free + txq->tx_rs_thresh);
- txq->tx_next_dd = (uint16_t)(txq->tx_next_dd + txq->tx_rs_thresh);
+ txq->nb_tx_free = (uint16_t)(txq->nb_tx_free + tx_rs_thresh);
+ txq->tx_next_dd = (uint16_t)(txq->tx_next_dd + tx_rs_thresh);
if (txq->tx_next_dd >= txq->nb_tx_desc)
- txq->tx_next_dd = (uint16_t)(txq->tx_rs_thresh - 1);
+ txq->tx_next_dd = (uint16_t)(tx_rs_thresh - 1);
- return txq->tx_rs_thresh;
+ return tx_rs_thresh;
}
/* Populate 4 descriptors with data from 4 mbufs */
@@ -2546,6 +2545,8 @@ i40e_dev_tx_queue_setup(struct rte_eth_dev *dev,
txq->reg_idx = reg_idx;
txq->port_id = dev->data->port_id;
txq->offloads = offloads;
+ txq->fast_free_mp = offloads & RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE ?
+ (void *)UINTPTR_MAX : NULL;
txq->i40e_vsi = vsi;
txq->tx_deferred_start = tx_conf->tx_deferred_start;
--
2.43.0
