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if_vtnet: Move the Tx interrupt threshold into the Txq structure

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Reviewed by: grehan (mentor)
Differential Revision: https://reviews.freebsd.org/D27911
This commit is contained in:
Bryan Venteicher 2021-01-19 04:55:24 +00:00
parent 05041794d0
commit baa5234fbe
2 changed files with 33 additions and 36 deletions
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67
sys/dev/virtio/network/if_vtnet.c
View File

@ -140,6 +140,7 @@ static void vtnet_rx_vq_process(struct vtnet_rxq *rxq, int tries);
static void vtnet_rx_vq_intr(void *);
static void vtnet_rxq_tq_intr(void *, int);
static int vtnet_txq_intr_threshold(struct vtnet_txq *);
static int vtnet_txq_below_threshold(struct vtnet_txq *);
static int vtnet_txq_notify(struct vtnet_txq *);
static void vtnet_txq_free_mbufs(struct vtnet_txq *);
@ -219,7 +220,6 @@ static void vtnet_set_macaddr(struct vtnet_softc *);
static void vtnet_attached_set_macaddr(struct vtnet_softc *);
static void vtnet_vlan_tag_remove(struct mbuf *);
static void vtnet_set_rx_process_limit(struct vtnet_softc *);
static void vtnet_set_tx_intr_threshold(struct vtnet_softc *);
static void vtnet_setup_rxq_sysctl(struct sysctl_ctx_list *,
struct sysctl_oid_list *, struct vtnet_rxq *);
@ -1090,7 +1090,6 @@ vtnet_setup_interface(struct vtnet_softc *sc)
}
vtnet_set_rx_process_limit(sc);
vtnet_set_tx_intr_threshold(sc);
DEBUGNET_SET(ifp, vtnet);
@ -2024,15 +2023,42 @@ vtnet_rxq_tq_intr(void *xrxq, int pending)
}
static int
vtnet_txq_below_threshold(struct vtnet_txq *txq)
vtnet_txq_intr_threshold(struct vtnet_txq *txq)
{
struct vtnet_softc *sc;
struct virtqueue *vq;
int threshold;
sc = txq->vtntx_sc;
/*
* The Tx interrupt is disabled until the queue free count falls
* below our threshold. Completed frames are drained from the Tx
* virtqueue before transmitting new frames and in the watchdog
* callout, so the frequency of Tx interrupts is greatly reduced,
* at the cost of not freeing mbufs as quickly as they otherwise
* would be.
*/
threshold = virtqueue_size(txq->vtntx_vq) / 4;
/*
* Without indirect descriptors, leave enough room for the most
* segments we handle.
*/
if ((sc->vtnet_flags & VTNET_FLAG_INDIRECT) == 0 &&
threshold < sc->vtnet_tx_nsegs)
threshold = sc->vtnet_tx_nsegs;
return (threshold);
}
static int
vtnet_txq_below_threshold(struct vtnet_txq *txq)
{
struct virtqueue *vq;
vq = txq->vtntx_vq;
return (virtqueue_nfree(vq) <= sc->vtnet_tx_intr_thresh);
return (virtqueue_nfree(vq) <= txq->vtntx_intr_threshold);
}
static int
@ -3058,6 +3084,7 @@ vtnet_init_tx_queues(struct vtnet_softc *sc)
for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
txq = &sc->vtnet_txqs[i];
txq->vtntx_watchdog = 0;
txq->vtntx_intr_threshold = vtnet_txq_intr_threshold(txq);
#ifdef DEV_NETMAP
netmap_reset(NA(sc->vtnet_ifp), NR_TX, i, 0);
#endif /* DEV_NETMAP */
@ -3749,36 +3776,6 @@ vtnet_set_rx_process_limit(struct vtnet_softc *sc)
sc->vtnet_rx_process_limit = limit;
}
static void
vtnet_set_tx_intr_threshold(struct vtnet_softc *sc)
{
int size, thresh;
size = virtqueue_size(sc->vtnet_txqs[0].vtntx_vq);
/*
* The Tx interrupt is disabled until the queue free count falls
* below our threshold. Completed frames are drained from the Tx
* virtqueue before transmitting new frames and in the watchdog
* callout, so the frequency of Tx interrupts is greatly reduced,
* at the cost of not freeing mbufs as quickly as they otherwise
* would be.
*
* N.B. We assume all the Tx queues are the same size.
*/
thresh = size / 4;
/*
* Without indirect descriptors, leave enough room for the most
* segments we handle.
*/
if ((sc->vtnet_flags & VTNET_FLAG_INDIRECT) == 0 &&
thresh < sc->vtnet_tx_nsegs)
thresh = sc->vtnet_tx_nsegs;
sc->vtnet_tx_intr_thresh = thresh;
}
static void
vtnet_setup_rxq_sysctl(struct sysctl_ctx_list *ctx,
struct sysctl_oid_list *child, struct vtnet_rxq *rxq)

2
sys/dev/virtio/network/if_vtnetvar.h
View File

@ -112,6 +112,7 @@ struct vtnet_txq {
#endif
int vtntx_id;
int vtntx_watchdog;
int vtntx_intr_threshold;
struct vtnet_txq_stats vtntx_stats;
struct taskqueue *vtntx_tq;
struct task vtntx_intrtask;
@ -161,7 +162,6 @@ struct vtnet_softc {
int vtnet_rx_nsegs;
int vtnet_rx_nmbufs;
int vtnet_rx_clustersz;
int vtnet_tx_intr_thresh;
int vtnet_tx_nsegs;
int vtnet_if_flags;
int vtnet_max_mtu;