[PATCH net 0/3] Mellanox EN driver fixes 2014-06-23

[PATCH net 0/3] Mellanox EN driver fixes 2014-06-23

[Amir Vadai]

Hi,

Below are some fixes to patches submitted to 3.16.

First patch is according to discussions with Ben [1] and Thomas [2] - to do not
use affinity notifier, since it breaks RFS. Instead detect changes in IRQ
affinity map, by checking if current CPU is set in affinity map on NAPI poll.
The two other patches fix some bugs introduced by commit [3].

Patches were applied and tested on commit b58537a ('net: sctp: fix
permissions for rto_alpha and rto_beta knobs')

Thanks,
Amir

[1] - http://www.spinics.net/lists/netdev/msg283096.html
[2] - https://lkml.org/lkml/2014/5/25/31
[3] - 554e101: ('lib/cpumask: cpumask_set_cpu_local_first to use all cores when
      numa node is not defined')

Amir Vadai (3):
  net/mlx4_en: Don't use irq_affinity_notifier to track changes in IRQ
    affinity map
  lib/cpumask: cpumask_set_cpu_local_first to use all cores when numa
    node is not defined
  net/mlx4_en: IRQ affinity hint is not cleared on port down

 drivers/net/ethernet/mellanox/mlx4/cq.c      |  2 -
 drivers/net/ethernet/mellanox/mlx4/en_cq.c   |  7 ++-
 drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 15 ++++--
 drivers/net/ethernet/mellanox/mlx4/en_tx.c   |  6 ---
 drivers/net/ethernet/mellanox/mlx4/eq.c      | 69 ++++------------------------
 drivers/net/ethernet/mellanox/mlx4/mlx4_en.h |  1 +
 include/linux/mlx4/device.h                  |  4 +-
 lib/cpumask.c                                |  2 +-
 8 files changed, 29 insertions(+), 77 deletions(-)

-- 
1.8.3.4

[PATCH net 1/3] net/mlx4_en: Don't use irq_affinity_notifier to track changes in IRQ affinity map

[Amir Vadai]

IRQ affinity notifier can only have a single notifier - cpu_rmap
notifier. Can't use it to track changes in IRQ affinity map.
Detect IRQ affinity changes by comparing CPU to current IRQ affinity map
during NAPI poll thread.

Fixes: 2eacc23 ("net/mlx4_core: Enforce irq affinity changes immediatly")
Signed-off-by: Amir Vadai <amirv@mellanox.com>
---
 drivers/net/ethernet/mellanox/mlx4/cq.c      |  2 -
 drivers/net/ethernet/mellanox/mlx4/en_cq.c   |  4 ++
 drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 15 ++++--
 drivers/net/ethernet/mellanox/mlx4/en_tx.c   |  6 ---
 drivers/net/ethernet/mellanox/mlx4/eq.c      | 69 ++++------------------------
 drivers/net/ethernet/mellanox/mlx4/mlx4_en.h |  1 +
 include/linux/mlx4/device.h                  |  4 +-
 7 files changed, 27 insertions(+), 74 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/cq.c b/drivers/net/ethernet/mellanox/mlx4/cq.c
index 80f7252..56022d6 100644
--- a/drivers/net/ethernet/mellanox/mlx4/cq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/cq.c
@@ -294,8 +294,6 @@ int mlx4_cq_alloc(struct mlx4_dev *dev, int nent,
 	init_completion(&cq->free);
 
 	cq->irq = priv->eq_table.eq[cq->vector].irq;
-	cq->irq_affinity_change = false;
-
 	return 0;
 
 err_radix:
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_cq.c b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
index 4b21307..1213cc7 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_cq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
@@ -128,6 +128,10 @@ int mlx4_en_activate_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq,
 					mlx4_warn(mdev, "Failed assigning an EQ to %s, falling back to legacy EQ's\n",
 						  name);
 				}
+
+				cq->irq_desc =
+					irq_to_desc(mlx4_eq_get_irq(mdev->dev,
+								    cq->vector));
 			}
 		} else {
 			cq->vector = (cq->ring + 1 + priv->port) %
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index d2d4157..1e2c143 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -896,16 +896,25 @@ int mlx4_en_poll_rx_cq(struct napi_struct *napi, int budget)
 
 	/* If we used up all the quota - we're probably not done yet... */
 	if (done == budget) {
+		int cpu_curr;
+		const struct cpumask *aff;
+
 		INC_PERF_COUNTER(priv->pstats.napi_quota);
-		if (unlikely(cq->mcq.irq_affinity_change)) {
-			cq->mcq.irq_affinity_change = false;
+
+		cpu_curr = smp_processor_id();
+		aff = cq->irq_desc->irq_data.affinity;
+
+		if (unlikely(!cpumask_test_cpu(cpu_curr, aff))) {
+			/* Current cpu is not according to smp_irq_affinity -
+			 * probably affinity changed. need to stop this NAPI
+			 * poll, and restart it on the right CPU
+			 */
 			napi_complete(napi);
 			mlx4_en_arm_cq(priv, cq);
 			return 0;
 		}
 	} else {
 		/* Done for now */
-		cq->mcq.irq_affinity_change = false;
 		napi_complete(napi);
 		mlx4_en_arm_cq(priv, cq);
 	}
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
index 8be7483..ac3dead 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
@@ -474,15 +474,9 @@ int mlx4_en_poll_tx_cq(struct napi_struct *napi, int budget)
 	/* If we used up all the quota - we're probably not done yet... */
 	if (done < budget) {
 		/* Done for now */
-		cq->mcq.irq_affinity_change = false;
 		napi_complete(napi);
 		mlx4_en_arm_cq(priv, cq);
 		return done;
-	} else if (unlikely(cq->mcq.irq_affinity_change)) {
-		cq->mcq.irq_affinity_change = false;
-		napi_complete(napi);
-		mlx4_en_arm_cq(priv, cq);
-		return 0;
 	}
 	return budget;
 }
diff --git a/drivers/net/ethernet/mellanox/mlx4/eq.c b/drivers/net/ethernet/mellanox/mlx4/eq.c
index d954ec1..2a004b3 100644
--- a/drivers/net/ethernet/mellanox/mlx4/eq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/eq.c
@@ -53,11 +53,6 @@ enum {
 	MLX4_EQ_ENTRY_SIZE	= 0x20
 };
 
-struct mlx4_irq_notify {
-	void *arg;
-	struct irq_affinity_notify notify;
-};
-
 #define MLX4_EQ_STATUS_OK	   ( 0 << 28)
 #define MLX4_EQ_STATUS_WRITE_FAIL  (10 << 28)
 #define MLX4_EQ_OWNER_SW	   ( 0 << 24)
@@ -1088,57 +1083,6 @@ static void mlx4_unmap_clr_int(struct mlx4_dev *dev)
 	iounmap(priv->clr_base);
 }
 
-static void mlx4_irq_notifier_notify(struct irq_affinity_notify *notify,
-				     const cpumask_t *mask)
-{
-	struct mlx4_irq_notify *n = container_of(notify,
-						 struct mlx4_irq_notify,
-						 notify);
-	struct mlx4_priv *priv = (struct mlx4_priv *)n->arg;
-	struct radix_tree_iter iter;
-	void **slot;
-
-	radix_tree_for_each_slot(slot, &priv->cq_table.tree, &iter, 0) {
-		struct mlx4_cq *cq = (struct mlx4_cq *)(*slot);
-
-		if (cq->irq == notify->irq)
-			cq->irq_affinity_change = true;
-	}
-}
-
-static void mlx4_release_irq_notifier(struct kref *ref)
-{
-	struct mlx4_irq_notify *n = container_of(ref, struct mlx4_irq_notify,
-						 notify.kref);
-	kfree(n);
-}
-
-static void mlx4_assign_irq_notifier(struct mlx4_priv *priv,
-				     struct mlx4_dev *dev, int irq)
-{
-	struct mlx4_irq_notify *irq_notifier = NULL;
-	int err = 0;
-
-	irq_notifier = kzalloc(sizeof(*irq_notifier), GFP_KERNEL);
-	if (!irq_notifier) {
-		mlx4_warn(dev, "Failed to allocate irq notifier. irq %d\n",
-			  irq);
-		return;
-	}
-
-	irq_notifier->notify.irq = irq;
-	irq_notifier->notify.notify = mlx4_irq_notifier_notify;
-	irq_notifier->notify.release = mlx4_release_irq_notifier;
-	irq_notifier->arg = priv;
-	err = irq_set_affinity_notifier(irq, &irq_notifier->notify);
-	if (err) {
-		kfree(irq_notifier);
-		irq_notifier = NULL;
-		mlx4_warn(dev, "Failed to set irq notifier. irq %d\n", irq);
-	}
-}
-
-
 int mlx4_alloc_eq_table(struct mlx4_dev *dev)
 {
 	struct mlx4_priv *priv = mlx4_priv(dev);
@@ -1409,8 +1353,6 @@ int mlx4_assign_eq(struct mlx4_dev *dev, char *name, struct cpu_rmap *rmap,
 				continue;
 				/*we dont want to break here*/
 			}
-			mlx4_assign_irq_notifier(priv, dev,
-						 priv->eq_table.eq[vec].irq);
 
 			eq_set_ci(&priv->eq_table.eq[vec], 1);
 		}
@@ -1427,6 +1369,14 @@ int mlx4_assign_eq(struct mlx4_dev *dev, char *name, struct cpu_rmap *rmap,
 }
 EXPORT_SYMBOL(mlx4_assign_eq);
 
+int mlx4_eq_get_irq(struct mlx4_dev *dev, int vec)
+{
+	struct mlx4_priv *priv = mlx4_priv(dev);
+
+	return priv->eq_table.eq[vec].irq;
+}
+EXPORT_SYMBOL(mlx4_eq_get_irq);
+
 void mlx4_release_eq(struct mlx4_dev *dev, int vec)
 {
 	struct mlx4_priv *priv = mlx4_priv(dev);
@@ -1438,9 +1388,6 @@ void mlx4_release_eq(struct mlx4_dev *dev, int vec)
 		  Belonging to a legacy EQ*/
 		mutex_lock(&priv->msix_ctl.pool_lock);
 		if (priv->msix_ctl.pool_bm & 1ULL << i) {
-			irq_set_affinity_notifier(
-				priv->eq_table.eq[vec].irq,
-				NULL);
 			free_irq(priv->eq_table.eq[vec].irq,
 				 &priv->eq_table.eq[vec]);
 			priv->msix_ctl.pool_bm &= ~(1ULL << i);
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 0e15295..624e193 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -343,6 +343,7 @@ struct mlx4_en_cq {
 #define CQ_USER_PEND (MLX4_EN_CQ_STATE_POLL | MLX4_EN_CQ_STATE_POLL_YIELD)
 	spinlock_t poll_lock; /* protects from LLS/napi conflicts */
 #endif  /* CONFIG_NET_RX_BUSY_POLL */
+	struct irq_desc *irq_desc;
 };
 
 struct mlx4_en_port_profile {
diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h
index b12f4bb..35b51e7 100644
--- a/include/linux/mlx4/device.h
+++ b/include/linux/mlx4/device.h
@@ -578,8 +578,6 @@ struct mlx4_cq {
 	u32			cons_index;
 
 	u16                     irq;
-	bool                    irq_affinity_change;
-
 	__be32		       *set_ci_db;
 	__be32		       *arm_db;
 	int			arm_sn;
@@ -1167,6 +1165,8 @@ int mlx4_assign_eq(struct mlx4_dev *dev, char *name, struct cpu_rmap *rmap,
 		   int *vector);
 void mlx4_release_eq(struct mlx4_dev *dev, int vec);
 
+int mlx4_eq_get_irq(struct mlx4_dev *dev, int vec);
+
 int mlx4_get_phys_port_id(struct mlx4_dev *dev);
 int mlx4_wol_read(struct mlx4_dev *dev, u64 *config, int port);
 int mlx4_wol_write(struct mlx4_dev *dev, u64 config, int port);
-- 
1.8.3.4

[PATCH net 2/3] lib/cpumask: cpumask_set_cpu_local_first to use all cores when numa node is not defined

[Amir Vadai]

When device is non numa aware (numa_node == -1), use all online cpu's.

Signed-off-by: Amir Vadai <amirv@mellanox.com>
---
 lib/cpumask.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/cpumask.c b/lib/cpumask.c
index c101230..b6513a9 100644
--- a/lib/cpumask.c
+++ b/lib/cpumask.c
@@ -191,7 +191,7 @@ int cpumask_set_cpu_local_first(int i, int numa_node, cpumask_t *dstp)
 
 	i %= num_online_cpus();
 
-	if (!cpumask_of_node(numa_node)) {
+	if (numa_node == -1 || !cpumask_of_node(numa_node)) {
 		/* Use all online cpu's for non numa aware system */
 		cpumask_copy(mask, cpu_online_mask);
 	} else {
-- 
1.8.3.4

[PATCH net 3/3] net/mlx4_en: IRQ affinity hint is not cleared on port down

[Amir Vadai]

Need to free affinity_mask at mlx4_en_deactivate_cq() and not at
mlx4_en_destroy_cq() - since affinity_mask might be free'd while still
being used by procfs.

Signed-off-by: Amir Vadai <amirv@mellanox.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_cq.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_cq.c b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
index 1213cc7..14c0004 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_cq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
@@ -191,8 +191,6 @@ void mlx4_en_destroy_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq **pcq)
 	mlx4_en_unmap_buffer(&cq->wqres.buf);
 	mlx4_free_hwq_res(mdev->dev, &cq->wqres, cq->buf_size);
 	if (priv->mdev->dev->caps.comp_pool && cq->vector) {
-		if (!cq->is_tx)
-			irq_set_affinity_hint(cq->mcq.irq, NULL);
 		mlx4_release_eq(priv->mdev->dev, cq->vector);
 	}
 	cq->vector = 0;
@@ -208,6 +206,7 @@ void mlx4_en_deactivate_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq)
 	if (!cq->is_tx) {
 		napi_hash_del(&cq->napi);
 		synchronize_rcu();
+		irq_set_affinity_hint(cq->mcq.irq, NULL);
 	}
 	netif_napi_del(&cq->napi);
 
-- 
1.8.3.4

Re: [PATCH net 1/3] net/mlx4_en: Don't use irq_affinity_notifier to track changes in IRQ affinity map

[Amir Vadai]

On 6/23/2014 5:41 PM, Amir Vadai wrote:
> IRQ affinity notifier can only have a single notifier - cpu_rmap
> notifier. Can't use it to track changes in IRQ affinity map.
> Detect IRQ affinity changes by comparing CPU to current IRQ affinity map
> during NAPI poll thread.
> 
> Fixes: 2eacc23 ("net/mlx4_core: Enforce irq affinity changes immediatly")
> Signed-off-by: Amir Vadai <amirv@mellanox.com>

Hi,

It seems that this patch will break compilation on s390 architecture.
Please don't pull it - I will do some more work on it and send a V1 of
the patch set.

Amir