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if_ntb: Reuse receive buffers correctly

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Discard the unused rx_free_q.  Instead, reuse inputed packets by putting
them back on the *pend* queue after reinitialization.

If tx or rx handlers are unavailable, free mbufs rather than leaking
them.

With this change, if_ntb can receive more than 100
(NTB_QP_DEF_NUM_ENTRIES) packets.

Sponsored by:	EMC / Isilon Storage Division
This commit is contained in:
cem 2015-11-18 22:20:49 +00:00
parent 48ceeb626e
commit 37b150b7e1
1 changed files with 22 additions and 10 deletions
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32
sys/dev/ntb/if_ntb/if_ntb.c
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@ -164,7 +164,6 @@ struct ntb_transport_qp {
void *data, int len);
struct ntb_queue_list rx_post_q;
struct ntb_queue_list rx_pend_q;
struct ntb_queue_list rx_free_q;
/* ntb_rx_q_lock: synchronize access to rx_XXXX_q */
struct mtx ntb_rx_q_lock;
struct task rx_completion_task;
@ -718,7 +717,6 @@ ntb_transport_init_queue(struct ntb_transport_ctx *nt, unsigned int qp_num)
STAILQ_INIT(&qp->rx_post_q);
STAILQ_INIT(&qp->rx_pend_q);
STAILQ_INIT(&qp->rx_free_q);
STAILQ_INIT(&qp->tx_free_q);
callout_reset(&qp->link_work, 0, ntb_qp_link_work, qp);
@ -743,9 +741,6 @@ ntb_transport_free_queue(struct ntb_transport_qp *qp)
qp->tx_handler = NULL;
qp->event_handler = NULL;
while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
free(entry, M_NTB_IF);
while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q)))
free(entry, M_NTB_IF);
@ -910,8 +905,11 @@ ntb_process_tx(struct ntb_transport_qp *qp, struct ntb_queue_entry *entry)
if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
if (qp->tx_handler != NULL)
qp->tx_handler(qp, qp->cb_data, entry->buf,
EIO);
EIO);
else
m_freem(entry->buf);
entry->buf = NULL;
ntb_list_add(&qp->ntb_tx_free_q_lock, entry, &qp->tx_free_q);
CTR1(KTR_NTB,
"TX: frame too big. returning entry %p to tx_free_q",
@ -969,8 +967,11 @@ ntb_memcpy_tx(struct ntb_transport_qp *qp, struct ntb_queue_entry *entry,
qp->tx_bytes += entry->len;
if (qp->tx_handler)
qp->tx_handler(qp, qp->cb_data, entry->cb_data,
entry->len);
qp->tx_handler(qp, qp->cb_data, entry->buf,
entry->len);
else
m_freem(entry->buf);
entry->buf = NULL;
}
CTR3(KTR_NTB,
@ -1146,17 +1147,28 @@ ntb_complete_rxc(void *arg, int pending)
entry->x_hdr->flags = 0;
iowrite32(entry->index, &qp->rx_info->entry);
STAILQ_REMOVE_HEAD(&qp->rx_post_q, entry);
len = entry->len;
m = entry->buf;
STAILQ_REMOVE_HEAD(&qp->rx_post_q, entry);
STAILQ_INSERT_TAIL(&qp->rx_free_q, entry, entry);
/*
* Re-initialize queue_entry for reuse; rx_handler takes
* ownership of the mbuf.
*/
entry->buf = NULL;
entry->len = transport_mtu;
entry->cb_data = qp->transport->ifp;
STAILQ_INSERT_TAIL(&qp->rx_pend_q, entry, entry);
mtx_unlock_spin(&qp->ntb_rx_q_lock);
CTR2(KTR_NTB, "RX: completing entry %p, mbuf %p", entry, m);
if (qp->rx_handler != NULL && qp->client_ready)
qp->rx_handler(qp, qp->cb_data, m, len);
else
m_freem(m);
mtx_lock_spin(&qp->ntb_rx_q_lock);
}