svn commit: r341908 - stable/12/sys/dev/mlx4/mlx4_en
Hans Petter Selasky
hselasky at FreeBSD.org
Wed Dec 12 11:47:31 UTC 2018
Author: hselasky
Date: Wed Dec 12 11:47:29 2018
New Revision: 341908
URL: https://svnweb.freebsd.org/changeset/base/341908
Log:
MFC r341547:
mlx4en: Remove the DRBR and associated logic in the transmit path.
The hardware queues are deep enough currently and using the DRBR and associated
callbacks only leads to more task switching in the TX path. The is also a race
setting the queue_state which can lead to hung TX rings.
Sponsored by: Mellanox Technologies
Modified:
stable/12/sys/dev/mlx4/mlx4_en/en.h
stable/12/sys/dev/mlx4/mlx4_en/mlx4_en_cq.c
stable/12/sys/dev/mlx4/mlx4_en/mlx4_en_netdev.c
stable/12/sys/dev/mlx4/mlx4_en/mlx4_en_tx.c
Directory Properties:
stable/12/ (props changed)
Modified: stable/12/sys/dev/mlx4/mlx4_en/en.h
==============================================================================
--- stable/12/sys/dev/mlx4/mlx4_en/en.h Wed Dec 12 11:45:06 2018 (r341907)
+++ stable/12/sys/dev/mlx4/mlx4_en/en.h Wed Dec 12 11:47:29 2018 (r341908)
@@ -271,10 +271,8 @@ struct mlx4_en_tx_ring {
u32 doorbell_qpn;
u8 *buf;
u16 poll_cnt;
- int blocked;
struct mlx4_en_tx_info *tx_info;
u8 queue_index;
- struct buf_ring *br;
u32 last_nr_txbb;
struct mlx4_qp qp;
struct mlx4_qp_context context;
@@ -806,7 +804,6 @@ int mlx4_en_create_rx_ring(struct mlx4_en_priv *priv,
void mlx4_en_destroy_rx_ring(struct mlx4_en_priv *priv,
struct mlx4_en_rx_ring **pring,
u32 size, u16 stride);
-void mlx4_en_tx_que(void *context, int pending);
void mlx4_en_rx_que(void *context, int pending);
int mlx4_en_activate_rx_rings(struct mlx4_en_priv *priv);
void mlx4_en_deactivate_rx_ring(struct mlx4_en_priv *priv,
Modified: stable/12/sys/dev/mlx4/mlx4_en/mlx4_en_cq.c
==============================================================================
--- stable/12/sys/dev/mlx4/mlx4_en/mlx4_en_cq.c Wed Dec 12 11:45:06 2018 (r341907)
+++ stable/12/sys/dev/mlx4/mlx4_en/mlx4_en_cq.c Wed Dec 12 11:47:29 2018 (r341908)
@@ -44,6 +44,10 @@ static void mlx4_en_cq_event(struct mlx4_cq *cq, enum
return;
}
+static void mlx4_en_tx_que(void *arg, int pending)
+{
+
+}
int mlx4_en_create_cq(struct mlx4_en_priv *priv,
struct mlx4_en_cq **pcq,
Modified: stable/12/sys/dev/mlx4/mlx4_en/mlx4_en_netdev.c
==============================================================================
--- stable/12/sys/dev/mlx4/mlx4_en/mlx4_en_netdev.c Wed Dec 12 11:45:06 2018 (r341907)
+++ stable/12/sys/dev/mlx4/mlx4_en/mlx4_en_netdev.c Wed Dec 12 11:47:29 2018 (r341908)
@@ -1574,9 +1574,12 @@ static void mlx4_en_restart(struct work_struct *work)
if (priv->blocked == 0 || priv->port_up == 0)
return;
for (i = 0; i < priv->tx_ring_num; i++) {
+ int watchdog_time;
+
ring = priv->tx_ring[i];
- if (ring->blocked &&
- ring->watchdog_time + MLX4_EN_WATCHDOG_TIMEOUT < ticks)
+ watchdog_time = READ_ONCE(ring->watchdog_time);
+ if (watchdog_time != 0 &&
+ time_after(ticks, ring->watchdog_time))
goto reset;
}
return;
Modified: stable/12/sys/dev/mlx4/mlx4_en/mlx4_en_tx.c
==============================================================================
--- stable/12/sys/dev/mlx4/mlx4_en/mlx4_en_tx.c Wed Dec 12 11:45:06 2018 (r341907)
+++ stable/12/sys/dev/mlx4/mlx4_en/mlx4_en_tx.c Wed Dec 12 11:47:29 2018 (r341908)
@@ -94,15 +94,6 @@ int mlx4_en_create_tx_ring(struct mlx4_en_priv *priv,
mtx_init(&ring->tx_lock.m, "mlx4 tx", NULL, MTX_DEF);
mtx_init(&ring->comp_lock.m, "mlx4 comp", NULL, MTX_DEF);
- /* Allocate the buf ring */
- ring->br = buf_ring_alloc(MLX4_EN_DEF_TX_QUEUE_SIZE, M_DEVBUF,
- M_WAITOK, &ring->tx_lock.m);
- if (ring->br == NULL) {
- en_err(priv, "Failed allocating tx_info ring\n");
- err = -ENOMEM;
- goto err_free_dma_tag;
- }
-
tmp = size * sizeof(struct mlx4_en_tx_info);
ring->tx_info = kzalloc_node(tmp, GFP_KERNEL, node);
if (!ring->tx_info) {
@@ -190,8 +181,6 @@ err_dma_map:
err_info:
vfree(ring->tx_info);
err_ring:
- buf_ring_free(ring->br, M_DEVBUF);
-err_free_dma_tag:
bus_dma_tag_destroy(ring->dma_tag);
done:
kfree(ring);
@@ -206,7 +195,6 @@ void mlx4_en_destroy_tx_ring(struct mlx4_en_priv *priv
uint32_t x;
en_dbg(DRV, priv, "Destroying tx ring, qpn: %d\n", ring->qpn);
- buf_ring_free(ring->br, M_DEVBUF);
if (ring->bf_enabled)
mlx4_bf_free(mdev->dev, &ring->bf);
mlx4_qp_remove(mdev->dev, &ring->qp);
@@ -236,8 +224,8 @@ int mlx4_en_activate_tx_ring(struct mlx4_en_priv *priv
ring->cons = 0xffffffff;
ring->last_nr_txbb = 1;
ring->poll_cnt = 0;
- ring->blocked = 0;
memset(ring->buf, 0, ring->buf_size);
+ ring->watchdog_time = 0;
ring->qp_state = MLX4_QP_STATE_RST;
ring->doorbell_qpn = ring->qp.qpn << 8;
@@ -429,14 +417,6 @@ static int mlx4_en_process_tx_cq(struct net_device *de
wmb();
ring->cons += txbbs_skipped;
- /* Wakeup Tx queue if it was stopped and ring is not full */
- if (unlikely(ring->blocked) && !mlx4_en_tx_ring_is_full(ring)) {
- ring->blocked = 0;
- if (atomic_fetchadd_int(&priv->blocked, -1) == 1)
- atomic_clear_int(&dev->if_drv_flags ,IFF_DRV_OACTIVE);
- priv->port_stats.wake_queue++;
- ring->wake_queue++;
- }
return (0);
}
@@ -682,15 +662,6 @@ static int mlx4_en_xmit(struct mlx4_en_priv *priv, int
/* check if TX ring is full */
if (unlikely(mlx4_en_tx_ring_is_full(ring))) {
- /* every full native Tx ring stops queue */
- if (ring->blocked == 0)
- atomic_add_int(&priv->blocked, 1);
- /* Set HW-queue-is-full flag */
- atomic_set_int(&ifp->if_drv_flags, IFF_DRV_OACTIVE);
- priv->port_stats.queue_stopped++;
- ring->blocked = 1;
- ring->queue_stopped++;
-
/* Use interrupts to find out when queue opened */
mlx4_en_arm_cq(priv, priv->tx_cq[tx_ind]);
return (ENOBUFS);
@@ -956,81 +927,35 @@ tx_drop:
}
static int
-mlx4_en_transmit_locked(struct ifnet *dev, int tx_ind, struct mbuf *m)
+mlx4_en_transmit_locked(struct ifnet *ifp, int tx_ind, struct mbuf *mb)
{
- struct mlx4_en_priv *priv = netdev_priv(dev);
- struct mlx4_en_tx_ring *ring;
- struct mbuf *next;
- int enqueued, err = 0;
+ struct mlx4_en_priv *priv = netdev_priv(ifp);
+ struct mlx4_en_tx_ring *ring = priv->tx_ring[tx_ind];
+ int err = 0;
- ring = priv->tx_ring[tx_ind];
- if ((dev->if_drv_flags & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
- IFF_DRV_RUNNING || priv->port_up == 0) {
- if (m != NULL)
- err = drbr_enqueue(dev, ring->br, m);
- return (err);
+ if (unlikely((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
+ READ_ONCE(priv->port_up) == 0)) {
+ m_freem(mb);
+ return (ENETDOWN);
}
- enqueued = 0;
- if (m != NULL)
- /*
- * If we can't insert mbuf into drbr, try to xmit anyway.
- * We keep the error we got so we could return that after xmit.
- */
- err = drbr_enqueue(dev, ring->br, m);
-
- /* Process the queue */
- while ((next = drbr_peek(dev, ring->br)) != NULL) {
- if (mlx4_en_xmit(priv, tx_ind, &next) != 0) {
- if (next == NULL) {
- drbr_advance(dev, ring->br);
- } else {
- drbr_putback(dev, ring->br, next);
- }
- break;
- }
- drbr_advance(dev, ring->br);
- enqueued++;
- if ((dev->if_drv_flags & IFF_DRV_RUNNING) == 0)
- break;
+ if (mlx4_en_xmit(priv, tx_ind, &mb) != 0) {
+ /* NOTE: m_freem() is NULL safe */
+ m_freem(mb);
+ err = ENOBUFS;
+ if (ring->watchdog_time == 0)
+ ring->watchdog_time = ticks + MLX4_EN_WATCHDOG_TIMEOUT;
+ } else {
+ ring->watchdog_time = 0;
}
-
- if (enqueued > 0)
- ring->watchdog_time = ticks;
-
return (err);
}
-void
-mlx4_en_tx_que(void *context, int pending)
-{
- struct mlx4_en_tx_ring *ring;
- struct mlx4_en_priv *priv;
- struct net_device *dev;
- struct mlx4_en_cq *cq;
- int tx_ind;
- cq = context;
- dev = cq->dev;
- priv = dev->if_softc;
- tx_ind = cq->ring;
- ring = priv->tx_ring[tx_ind];
-
- if (priv->port_up != 0 &&
- (dev->if_drv_flags & IFF_DRV_RUNNING) != 0) {
- mlx4_en_xmit_poll(priv, tx_ind);
- spin_lock(&ring->tx_lock);
- if (!drbr_empty(dev, ring->br))
- mlx4_en_transmit_locked(dev, tx_ind, NULL);
- spin_unlock(&ring->tx_lock);
- }
-}
-
int
mlx4_en_transmit(struct ifnet *dev, struct mbuf *m)
{
struct mlx4_en_priv *priv = netdev_priv(dev);
struct mlx4_en_tx_ring *ring;
- struct mlx4_en_cq *cq;
int i, err = 0;
if (priv->port_up == 0) {
@@ -1047,17 +972,15 @@ mlx4_en_transmit(struct ifnet *dev, struct mbuf *m)
}
ring = priv->tx_ring[i];
- if (spin_trylock(&ring->tx_lock)) {
- err = mlx4_en_transmit_locked(dev, i, m);
- spin_unlock(&ring->tx_lock);
- /* Poll CQ here */
- mlx4_en_xmit_poll(priv, i);
- } else {
- err = drbr_enqueue(dev, ring->br, m);
- cq = priv->tx_cq[i];
- taskqueue_enqueue(cq->tq, &cq->cq_task);
- }
+ spin_lock(&ring->tx_lock);
+
+ err = mlx4_en_transmit_locked(dev, i, m);
+ spin_unlock(&ring->tx_lock);
+
+ /* Poll CQ here */
+ mlx4_en_xmit_poll(priv, i);
+
#if __FreeBSD_version >= 1100000
if (unlikely(err != 0))
if_inc_counter(dev, IFCOUNTER_IQDROPS, 1);
@@ -1072,18 +995,9 @@ void
mlx4_en_qflush(struct ifnet *dev)
{
struct mlx4_en_priv *priv = netdev_priv(dev);
- struct mlx4_en_tx_ring *ring;
- struct mbuf *m;
if (priv->port_up == 0)
return;
- for (int i = 0; i < priv->tx_ring_num; i++) {
- ring = priv->tx_ring[i];
- spin_lock(&ring->tx_lock);
- while ((m = buf_ring_dequeue_sc(ring->br)) != NULL)
- m_freem(m);
- spin_unlock(&ring->tx_lock);
- }
if_qflush(dev);
}
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