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Message-Id: <20180119213457.23378-12-saeedm@mellanox.com>
Date: Fri, 19 Jan 2018 23:34:53 +0200
From: Saeed Mahameed <saeedm@...lanox.com>
To: "David S. Miller" <davem@...emloft.net>
Cc: netdev@...r.kernel.org, Eran Ben Elisha <eranbe@...lanox.com>,
Saeed Mahameed <saeedm@...lanox.com>
Subject: [net-next 11/15] net/mlx5e: Poll event queue upon TX timeout before performing full channels recovery
From: Eran Ben Elisha <eranbe@...lanox.com>
Up until this patch, on every TX timeout we would try to do channels
recovery. However, in case of a lost interrupt for an EQ, the channel
associated to it cannot be recovered if reopened as it would never get
another interrupt on sent/received traffic, and eventually ends up with
another TX timeout (Restarting the EQ is not part of channel recovery).
This patch adds a mechanism for explicitly polling EQ in case of a TX
timeout in order to recover from a lost interrupt. If this is not the
case (no pending EQEs), perform a channels full recovery as usual.
Once a lost EQE is recovered, it triggers the NAPI to run and handle all
pending completions. This will free some budget in the bql (via calling
netdev_tx_completed_queue) or by clearing pending TXWQEs and waking up
the queue. One of the above actions will move the queue to be ready for
transmit again.
Signed-off-by: Eran Ben Elisha <eranbe@...lanox.com>
Reviewed-by: Tariq Toukan <tariqt@...lanox.com>
Signed-off-by: Saeed Mahameed <saeedm@...lanox.com>
---
drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 51 +++++++++++++++-------
drivers/net/ethernet/mellanox/mlx5/core/eq.c | 18 ++++++++
.../net/ethernet/mellanox/mlx5/core/mlx5_core.h | 1 +
3 files changed, 55 insertions(+), 15 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 71b8b171c565..12ea5e319e38 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -3757,10 +3757,37 @@ static netdev_features_t mlx5e_features_check(struct sk_buff *skb,
return features;
}
+static bool mlx5e_tx_timeout_eq_recover(struct net_device *dev,
+ struct mlx5e_txqsq *sq)
+{
+ struct mlx5e_priv *priv = netdev_priv(dev);
+ struct mlx5_core_dev *mdev = priv->mdev;
+ int irqn_not_used, eqn;
+ struct mlx5_eq *eq;
+ u32 eqe_count;
+
+ if (mlx5_vector2eqn(mdev, sq->cq.mcq.vector, &eqn, &irqn_not_used))
+ return false;
+
+ eq = mlx5_eqn2eq(mdev, eqn);
+ if (IS_ERR(eq))
+ return false;
+
+ netdev_err(dev, "EQ 0x%x: Cons = 0x%x, irqn = 0x%x\n",
+ eqn, eq->cons_index, eq->irqn);
+
+ eqe_count = mlx5_eq_poll_irq_disabled(eq);
+ if (!eqe_count)
+ return false;
+
+ netdev_err(dev, "Recover %d eqes on EQ 0x%x\n", eqe_count, eq->eqn);
+ return true;
+}
+
static void mlx5e_tx_timeout(struct net_device *dev)
{
struct mlx5e_priv *priv = netdev_priv(dev);
- bool sched_work = false;
+ bool reopen_channels = false;
int i;
netdev_err(dev, "TX timeout detected\n");
@@ -3768,29 +3795,23 @@ static void mlx5e_tx_timeout(struct net_device *dev)
for (i = 0; i < priv->channels.num * priv->channels.params.num_tc; i++) {
struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, i);
struct mlx5e_txqsq *sq = priv->txq2sq[i];
- struct mlx5_core_dev *mdev = priv->mdev;
- int irqn_not_used, eqn;
- struct mlx5_eq *eq;
if (!netif_xmit_stopped(dev_queue))
continue;
- sched_work = true;
- clear_bit(MLX5E_SQ_STATE_ENABLED, &sq->state);
netdev_err(dev, "TX timeout on queue: %d, SQ: 0x%x, CQ: 0x%x, SQ Cons: 0x%x SQ Prod: 0x%x, usecs since last trans: %u\n",
i, sq->sqn, sq->cq.mcq.cqn, sq->cc, sq->pc,
jiffies_to_usecs(jiffies - dev_queue->trans_start));
- if (mlx5_vector2eqn(mdev, sq->cq.mcq.vector, &eqn,
- &irqn_not_used))
- continue;
-
- eq = mlx5_eqn2eq(mdev, eqn);
- if (!IS_ERR(eq))
- netdev_err(dev, "EQ 0x%x: Cons = 0x%x, irqn = 0x%x\n",
- eqn, eq->cons_index, eq->irqn);
+ /* If we recover a lost interrupt, most likely TX timeout will
+ * be resolved, skip reopening channels
+ */
+ if (!mlx5e_tx_timeout_eq_recover(dev, sq)) {
+ clear_bit(MLX5E_SQ_STATE_ENABLED, &sq->state);
+ reopen_channels = true;
+ }
}
- if (sched_work && test_bit(MLX5E_STATE_OPENED, &priv->state))
+ if (reopen_channels && test_bit(MLX5E_STATE_OPENED, &priv->state))
schedule_work(&priv->tx_timeout_work);
}
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eq.c b/drivers/net/ethernet/mellanox/mlx5/core/eq.c
index e7e7cef2bde4..4d98ce0901af 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eq.c
@@ -530,6 +530,24 @@ static irqreturn_t mlx5_eq_int(int irq, void *eq_ptr)
return IRQ_HANDLED;
}
+/* Some architectures don't latch interrupts when they are disabled, so using
+ * mlx5_eq_poll_irq_disabled could end up losing interrupts while trying to
+ * avoid losing them. It is not recommended to use it, unless this is the last
+ * resort.
+ */
+u32 mlx5_eq_poll_irq_disabled(struct mlx5_eq *eq)
+{
+ u32 count_eqe;
+
+ disable_irq(eq->irqn);
+ count_eqe = eq->cons_index;
+ mlx5_eq_int(eq->irqn, eq);
+ count_eqe = eq->cons_index - count_eqe;
+ enable_irq(eq->irqn);
+
+ return count_eqe;
+}
+
static void init_eq_buf(struct mlx5_eq *eq)
{
struct mlx5_eqe *eqe;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
index ff4a0b889a6f..b5a46c128b28 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
@@ -116,6 +116,7 @@ int mlx5_destroy_scheduling_element_cmd(struct mlx5_core_dev *dev, u8 hierarchy,
int mlx5_wait_for_vf_pages(struct mlx5_core_dev *dev);
u64 mlx5_read_internal_timer(struct mlx5_core_dev *dev);
struct mlx5_eq *mlx5_eqn2eq(struct mlx5_core_dev *dev, int eqn);
+u32 mlx5_eq_poll_irq_disabled(struct mlx5_eq *eq);
void mlx5_cq_tasklet_cb(unsigned long data);
int mlx5_query_pcam_reg(struct mlx5_core_dev *dev, u32 *pcam, u8 feature_group,
--
2.13.0
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