ixgbe: fix perf regression due to moved pool ptr

Adjust the fast-path code to fix the regression caused by the pool
pointer moving to the second cache line. This change adjusts the
prefetching and also the way in which the mbufs are freed back to the
mempool.
Note: slow-path e.g. path supporting jumbo frames, is still slower, but
is dealt with by a later commit

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
This commit is contained in:
Bruce Richardson 2014-09-15 17:20:13 +01:00 committed by Thomas Monjalon
parent 0ff3324da2
commit 1f22652ca8
3 changed files with 38 additions and 78 deletions

View File

@ -142,10 +142,6 @@ ixgbe_tx_free_bufs(struct igb_tx_queue *txq)
*/
txep = &(txq->sw_ring[txq->tx_next_dd - (txq->tx_rs_thresh - 1)]);
/* prefetch the mbufs that are about to be freed */
for (i = 0; i < txq->tx_rs_thresh; ++i)
rte_prefetch0((txep + i)->mbuf);
/* free buffers one at a time */
if ((txq->txq_flags & (uint32_t)ETH_TXQ_FLAGS_NOREFCOUNT) != 0) {
for (i = 0; i < txq->tx_rs_thresh; ++i, ++txep) {
@ -186,6 +182,7 @@ tx4(volatile union ixgbe_adv_tx_desc *txdp, struct rte_mbuf **pkts)
((uint32_t)DCMD_DTYP_FLAGS | pkt_len);
txdp->read.olinfo_status =
(pkt_len << IXGBE_ADVTXD_PAYLEN_SHIFT);
rte_prefetch0(&(*pkts)->pool);
}
}
@ -205,6 +202,7 @@ tx1(volatile union ixgbe_adv_tx_desc *txdp, struct rte_mbuf **pkts)
((uint32_t)DCMD_DTYP_FLAGS | pkt_len);
txdp->read.olinfo_status =
(pkt_len << IXGBE_ADVTXD_PAYLEN_SHIFT);
rte_prefetch0(&(*pkts)->pool);
}
/*
@ -1875,7 +1873,7 @@ ixgbe_dev_tx_queue_setup(struct rte_eth_dev *dev,
PMD_INIT_LOG(INFO, "Using simple tx code path\n");
#ifdef RTE_IXGBE_INC_VECTOR
if (txq->tx_rs_thresh <= RTE_IXGBE_TX_MAX_FREE_BUF_SZ &&
ixgbe_txq_vec_setup(txq, socket_id) == 0) {
ixgbe_txq_vec_setup(txq) == 0) {
PMD_INIT_LOG(INFO, "Vector tx enabled.\n");
dev->tx_pkt_burst = ixgbe_xmit_pkts_vec;
}

View File

@ -95,14 +95,6 @@ struct igb_tx_entry_v {
struct rte_mbuf *mbuf; /**< mbuf associated with TX desc, if any. */
};
/**
* continuous entry sequence, gather by the same mempool
*/
struct igb_tx_entry_seq {
const struct rte_mempool* pool;
uint32_t same_pool;
};
/**
* Structure associated with each RX queue.
*/
@ -190,10 +182,6 @@ struct igb_tx_queue {
volatile union ixgbe_adv_tx_desc *tx_ring;
uint64_t tx_ring_phys_addr; /**< TX ring DMA address. */
struct igb_tx_entry *sw_ring; /**< virtual address of SW ring. */
#ifdef RTE_IXGBE_INC_VECTOR
/** continuous tx entry sequence within the same mempool */
struct igb_tx_entry_seq *sw_ring_seq;
#endif
volatile uint32_t *tdt_reg_addr; /**< Address of TDT register. */
uint16_t nb_tx_desc; /**< number of TX descriptors. */
uint16_t tx_tail; /**< current value of TDT reg. */
@ -258,7 +246,7 @@ struct ixgbe_txq_ops {
#ifdef RTE_IXGBE_INC_VECTOR
uint16_t ixgbe_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts);
uint16_t ixgbe_xmit_pkts_vec(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts);
int ixgbe_txq_vec_setup(struct igb_tx_queue *txq, unsigned int socket_id);
int ixgbe_txq_vec_setup(struct igb_tx_queue *txq);
int ixgbe_rxq_vec_setup(struct igb_rx_queue *rxq);
int ixgbe_rx_vec_condition_check(struct rte_eth_dev *dev);
#endif

View File

@ -342,14 +342,11 @@ static inline int __attribute__((always_inline))
ixgbe_tx_free_bufs(struct igb_tx_queue *txq)
{
struct igb_tx_entry_v *txep;
struct igb_tx_entry_seq *txsp;
uint32_t status;
uint32_t n, k;
#ifdef RTE_MBUF_REFCNT
uint32_t n;
uint32_t i;
int nb_free = 0;
struct rte_mbuf *m, *free[RTE_IXGBE_TX_MAX_FREE_BUF_SZ];
#endif
/* check DD bit on threshold descriptor */
status = txq->tx_ring[txq->tx_next_dd].wb.status;
@ -364,23 +361,38 @@ ixgbe_tx_free_bufs(struct igb_tx_queue *txq)
*/
txep = &((struct igb_tx_entry_v *)txq->sw_ring)[txq->tx_next_dd -
(n - 1)];
txsp = &txq->sw_ring_seq[txq->tx_next_dd - (n - 1)];
while (n > 0) {
k = RTE_MIN(n, txsp[n-1].same_pool);
#ifdef RTE_MBUF_REFCNT
for (i = 0; i < k; i++) {
m = __rte_pktmbuf_prefree_seg((txep+n-k+i)->mbuf);
if (m != NULL)
free[nb_free++] = m;
}
rte_mempool_put_bulk((void *)txsp[n-1].pool,
(void **)free, nb_free);
m = __rte_pktmbuf_prefree_seg(txep[0].mbuf);
#else
rte_mempool_put_bulk((void *)txsp[n-1].pool,
(void **)(txep+n-k), k);
m = txep[0].mbuf;
#endif
n -= k;
if (likely(m != NULL)) {
free[0] = m;
nb_free = 1;
for (i = 1; i < n; i++) {
#ifdef RTE_MBUF_REFCNT
m = __rte_pktmbuf_prefree_seg(txep[i].mbuf);
#else
m = txep[i]->mbuf;
#endif
if (likely(m != NULL)) {
if (likely(m->pool == free[0]->pool))
free[nb_free++] = m;
else {
rte_mempool_put_bulk(free[0]->pool,
(void *)free, nb_free);
free[0] = m;
nb_free = 1;
}
}
}
rte_mempool_put_bulk(free[0]->pool, (void **)free, nb_free);
} else {
for (i = 1; i < n; i++) {
m = __rte_pktmbuf_prefree_seg(txep[i].mbuf);
if (m != NULL)
rte_mempool_put(m->pool, m);
}
}
/* buffers were freed, update counters */
@ -394,19 +406,11 @@ ixgbe_tx_free_bufs(struct igb_tx_queue *txq)
static inline void __attribute__((always_inline))
tx_backlog_entry(struct igb_tx_entry_v *txep,
struct igb_tx_entry_seq *txsp,
struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
{
int i;
for (i = 0; i < (int)nb_pkts; ++i) {
for (i = 0; i < (int)nb_pkts; ++i)
txep[i].mbuf = tx_pkts[i];
/* check and update sequence number */
txsp[i].pool = tx_pkts[i]->pool;
if (txsp[i-1].pool == tx_pkts[i]->pool)
txsp[i].same_pool = txsp[i-1].same_pool + 1;
else
txsp[i].same_pool = 1;
}
}
uint16_t
@ -416,7 +420,6 @@ ixgbe_xmit_pkts_vec(void *tx_queue, struct rte_mbuf **tx_pkts,
struct igb_tx_queue *txq = (struct igb_tx_queue *)tx_queue;
volatile union ixgbe_adv_tx_desc *txdp;
struct igb_tx_entry_v *txep;
struct igb_tx_entry_seq *txsp;
uint16_t n, nb_commit, tx_id;
uint64_t flags = DCMD_DTYP_FLAGS;
uint64_t rs = IXGBE_ADVTXD_DCMD_RS|DCMD_DTYP_FLAGS;
@ -435,14 +438,13 @@ ixgbe_xmit_pkts_vec(void *tx_queue, struct rte_mbuf **tx_pkts,
tx_id = txq->tx_tail;
txdp = &txq->tx_ring[tx_id];
txep = &((struct igb_tx_entry_v *)txq->sw_ring)[tx_id];
txsp = &txq->sw_ring_seq[tx_id];
txq->nb_tx_free = (uint16_t)(txq->nb_tx_free - nb_pkts);
n = (uint16_t)(txq->nb_tx_desc - tx_id);
if (nb_commit >= n) {
tx_backlog_entry(txep, txsp, tx_pkts, n);
tx_backlog_entry(txep, tx_pkts, n);
for (i = 0; i < n - 1; ++i, ++tx_pkts, ++txdp)
vtx1(txdp, *tx_pkts, flags);
@ -457,10 +459,9 @@ ixgbe_xmit_pkts_vec(void *tx_queue, struct rte_mbuf **tx_pkts,
/* avoid reach the end of ring */
txdp = &(txq->tx_ring[tx_id]);
txep = &(((struct igb_tx_entry_v *)txq->sw_ring)[tx_id]);
txsp = &(txq->sw_ring_seq[tx_id]);
}
tx_backlog_entry(txep, txsp, tx_pkts, nb_commit);
tx_backlog_entry(txep, tx_pkts, nb_commit);
vtx(txdp, tx_pkts, nb_commit, flags);
@ -484,7 +485,6 @@ ixgbe_tx_queue_release_mbufs(struct igb_tx_queue *txq)
{
unsigned i;
struct igb_tx_entry_v *txe;
struct igb_tx_entry_seq *txs;
uint16_t nb_free, max_desc;
if (txq->sw_ring != NULL) {
@ -502,10 +502,6 @@ ixgbe_tx_queue_release_mbufs(struct igb_tx_queue *txq)
for (i = 0; i < txq->nb_tx_desc; i++) {
txe = (struct igb_tx_entry_v *)&txq->sw_ring[i];
txe->mbuf = NULL;
txs = &txq->sw_ring_seq[i];
txs->pool = NULL;
txs->same_pool = 0;
}
}
}
@ -520,11 +516,6 @@ ixgbe_tx_free_swring(struct igb_tx_queue *txq)
rte_free((struct igb_rx_entry *)txq->sw_ring - 1);
txq->sw_ring = NULL;
}
if (txq->sw_ring_seq != NULL) {
rte_free(txq->sw_ring_seq - 1);
txq->sw_ring_seq = NULL;
}
}
static void
@ -533,7 +524,6 @@ ixgbe_reset_tx_queue(struct igb_tx_queue *txq)
static const union ixgbe_adv_tx_desc zeroed_desc = { .read = {
.buffer_addr = 0} };
struct igb_tx_entry_v *txe = (struct igb_tx_entry_v *)txq->sw_ring;
struct igb_tx_entry_seq *txs = txq->sw_ring_seq;
uint16_t i;
/* Zero out HW ring memory */
@ -545,8 +535,6 @@ ixgbe_reset_tx_queue(struct igb_tx_queue *txq)
volatile union ixgbe_adv_tx_desc *txd = &txq->tx_ring[i];
txd->wb.status = IXGBE_TXD_STAT_DD;
txe[i].mbuf = NULL;
txs[i].pool = NULL;
txs[i].same_pool = 0;
}
txq->tx_next_dd = (uint16_t)(txq->tx_rs_thresh - 1);
@ -588,28 +576,14 @@ ixgbe_rxq_vec_setup(struct igb_rx_queue *rxq)
return 0;
}
int ixgbe_txq_vec_setup(struct igb_tx_queue *txq,
unsigned int socket_id)
int ixgbe_txq_vec_setup(struct igb_tx_queue *txq)
{
uint16_t nb_desc;
if (txq->sw_ring == NULL)
return -1;
/* request addtional one entry for continous sequence check */
nb_desc = (uint16_t)(txq->nb_tx_desc + 1);
txq->sw_ring_seq = rte_zmalloc_socket("txq->sw_ring_seq",
sizeof(struct igb_tx_entry_seq) * nb_desc,
CACHE_LINE_SIZE, socket_id);
if (txq->sw_ring_seq == NULL)
return -1;
/* leave the first one for overflow */
txq->sw_ring = (struct igb_tx_entry *)
((struct igb_tx_entry_v *)txq->sw_ring + 1);
txq->sw_ring_seq += 1;
txq->ops = &vec_txq_ops;
return 0;