[Intel-wired-lan] [PATCH 7/9] ixgbevf: allocate the rings as part of q_vector
Emil Tantilov
emil.s.tantilov at intel.com
Wed Jan 31 00:51:43 UTC 2018
Make it so that all rings allocations are made as part of q_vector.
The advantage to this is that we can keep all of the memory related to
a single interrupt in one page.
The goal is to bring the logic of handling rings closer to ixgbe.
Signed-off-by: Emil Tantilov <emil.s.tantilov at intel.com>
---
drivers/net/ethernet/intel/ixgbevf/ixgbevf.h | 7
drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c | 392 +++++++++------------
2 files changed, 182 insertions(+), 217 deletions(-)
diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
index fe7111c..97e1267 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
@@ -97,6 +97,7 @@ enum ixgbevf_ring_state_t {
struct ixgbevf_ring {
struct ixgbevf_ring *next;
+ struct ixgbevf_q_vector *q_vector; /* backpointer to q_vector */
struct net_device *netdev;
struct device *dev;
void *desc; /* descriptor ring memory */
@@ -128,7 +129,7 @@ struct ixgbevf_ring {
*/
u16 reg_idx;
int queue_index; /* needed for multiqueue queue management */
-};
+} ____cacheline_internodealigned_in_smp;
/* How many Rx Buffers do we bundle into one write to the hardware ? */
#define IXGBEVF_RX_BUFFER_WRITE 16 /* Must be power of 2 */
@@ -241,7 +242,11 @@ struct ixgbevf_q_vector {
u16 itr; /* Interrupt throttle rate written to EITR */
struct napi_struct napi;
struct ixgbevf_ring_container rx, tx;
+ struct rcu_head rcu; /* to avoid race with update stats on free */
char name[IFNAMSIZ + 9];
+
+ /* for dynamic allocation of rings associated with this q_vector */
+ struct ixgbevf_ring ring[0] ____cacheline_internodealigned_in_smp;
#ifdef CONFIG_NET_RX_BUSY_POLL
unsigned int state;
#define IXGBEVF_QV_STATE_IDLE 0
diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index b381127..754efb4 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -1270,85 +1270,6 @@ static irqreturn_t ixgbevf_msix_clean_rings(int irq, void *data)
return IRQ_HANDLED;
}
-static inline void map_vector_to_rxq(struct ixgbevf_adapter *a, int v_idx,
- int r_idx)
-{
- struct ixgbevf_q_vector *q_vector = a->q_vector[v_idx];
-
- a->rx_ring[r_idx]->next = q_vector->rx.ring;
- q_vector->rx.ring = a->rx_ring[r_idx];
- q_vector->rx.count++;
-}
-
-static inline void map_vector_to_txq(struct ixgbevf_adapter *a, int v_idx,
- int t_idx)
-{
- struct ixgbevf_q_vector *q_vector = a->q_vector[v_idx];
-
- a->tx_ring[t_idx]->next = q_vector->tx.ring;
- q_vector->tx.ring = a->tx_ring[t_idx];
- q_vector->tx.count++;
-}
-
-/**
- * ixgbevf_map_rings_to_vectors - Maps descriptor rings to vectors
- * @adapter: board private structure to initialize
- *
- * This function maps descriptor rings to the queue-specific vectors
- * we were allotted through the MSI-X enabling code. Ideally, we'd have
- * one vector per ring/queue, but on a constrained vector budget, we
- * group the rings as "efficiently" as possible. You would add new
- * mapping configurations in here.
- **/
-static int ixgbevf_map_rings_to_vectors(struct ixgbevf_adapter *adapter)
-{
- int q_vectors;
- int v_start = 0;
- int rxr_idx = 0, txr_idx = 0;
- int rxr_remaining = adapter->num_rx_queues;
- int txr_remaining = adapter->num_tx_queues;
- int i, j;
- int rqpv, tqpv;
-
- q_vectors = adapter->num_msix_vectors - NON_Q_VECTORS;
-
- /* The ideal configuration...
- * We have enough vectors to map one per queue.
- */
- if (q_vectors == adapter->num_rx_queues + adapter->num_tx_queues) {
- for (; rxr_idx < rxr_remaining; v_start++, rxr_idx++)
- map_vector_to_rxq(adapter, v_start, rxr_idx);
-
- for (; txr_idx < txr_remaining; v_start++, txr_idx++)
- map_vector_to_txq(adapter, v_start, txr_idx);
- return 0;
- }
-
- /* If we don't have enough vectors for a 1-to-1
- * mapping, we'll have to group them so there are
- * multiple queues per vector.
- */
- /* Re-adjusting *qpv takes care of the remainder. */
- for (i = v_start; i < q_vectors; i++) {
- rqpv = DIV_ROUND_UP(rxr_remaining, q_vectors - i);
- for (j = 0; j < rqpv; j++) {
- map_vector_to_rxq(adapter, i, rxr_idx);
- rxr_idx++;
- rxr_remaining--;
- }
- }
- for (i = v_start; i < q_vectors; i++) {
- tqpv = DIV_ROUND_UP(txr_remaining, q_vectors - i);
- for (j = 0; j < tqpv; j++) {
- map_vector_to_txq(adapter, i, txr_idx);
- txr_idx++;
- txr_remaining--;
- }
- }
-
- return 0;
-}
-
/**
* ixgbevf_request_msix_irqs - Initialize MSI-X interrupts
* @adapter: board private structure
@@ -1421,20 +1342,6 @@ static int ixgbevf_request_msix_irqs(struct ixgbevf_adapter *adapter)
return err;
}
-static inline void ixgbevf_reset_q_vectors(struct ixgbevf_adapter *adapter)
-{
- int i, q_vectors = adapter->num_msix_vectors - NON_Q_VECTORS;
-
- for (i = 0; i < q_vectors; i++) {
- struct ixgbevf_q_vector *q_vector = adapter->q_vector[i];
-
- q_vector->rx.ring = NULL;
- q_vector->tx.ring = NULL;
- q_vector->rx.count = 0;
- q_vector->tx.count = 0;
- }
-}
-
/**
* ixgbevf_request_irq - initialize interrupts
* @adapter: board private structure
@@ -1474,8 +1381,6 @@ static void ixgbevf_free_irq(struct ixgbevf_adapter *adapter)
free_irq(adapter->msix_entries[i].vector,
adapter->q_vector[i]);
}
-
- ixgbevf_reset_q_vectors(adapter);
}
/**
@@ -2457,105 +2362,171 @@ static void ixgbevf_set_num_queues(struct ixgbevf_adapter *adapter)
}
/**
- * ixgbevf_alloc_queues - Allocate memory for all rings
+ * ixgbevf_set_interrupt_capability - set MSI-X or FAIL if not supported
+ * @adapter: board private structure to initialize
+ *
+ * Attempt to configure the interrupts using the best available
+ * capabilities of the hardware and the kernel.
+ **/
+static int ixgbevf_set_interrupt_capability(struct ixgbevf_adapter *adapter)
+{
+ int vector, v_budget;
+
+ /* It's easy to be greedy for MSI-X vectors, but it really
+ * doesn't do us much good if we have a lot more vectors
+ * than CPU's. So let's be conservative and only ask for
+ * (roughly) the same number of vectors as there are CPU's.
+ * The default is to use pairs of vectors.
+ */
+ v_budget = max(adapter->num_rx_queues, adapter->num_tx_queues);
+ v_budget = min_t(int, v_budget, num_online_cpus());
+ v_budget += NON_Q_VECTORS;
+
+ adapter->msix_entries = kcalloc(v_budget,
+ sizeof(struct msix_entry), GFP_KERNEL);
+ if (!adapter->msix_entries)
+ return -ENOMEM;
+
+ for (vector = 0; vector < v_budget; vector++)
+ adapter->msix_entries[vector].entry = vector;
+
+ /* A failure in MSI-X entry allocation isn't fatal, but the VF driver
+ * does not support any other modes, so we will simply fail here. Note
+ * that we clean up the msix_entries pointer else-where.
+ */
+ return ixgbevf_acquire_msix_vectors(adapter, v_budget);
+}
+
+static void ixgbevf_add_ring(struct ixgbevf_ring *ring,
+ struct ixgbevf_ring_container *head)
+{
+ ring->next = head->ring;
+ head->ring = ring;
+ head->count++;
+}
+
+/**
+ * ixgbevf_alloc_q_vector - Allocate memory for a single interrupt vector
* @adapter: board private structure to initialize
+ * @v_idx: index of vector in adapter struct
+ * @txr_count: number of Tx rings for q vector
+ * @txr_idx: index of first Tx ring to assign
+ * @rxr_count: number of Rx rings for q vector
+ * @rxr_idx: index of first Rx ring to assign
*
- * We allocate one ring per queue at run-time since we don't know the
- * number of queues at compile-time. The polling_netdev array is
- * intended for Multiqueue, but should work fine with a single queue.
+ * We allocate one q_vector. If allocation fails we return -ENOMEM.
**/
-static int ixgbevf_alloc_queues(struct ixgbevf_adapter *adapter)
+static int ixgbevf_alloc_q_vector(struct ixgbevf_adapter *adapter, int v_idx,
+ int txr_count, int txr_idx,
+ int rxr_count, int rxr_idx)
{
+ struct ixgbevf_q_vector *q_vector;
struct ixgbevf_ring *ring;
- int rx = 0, tx = 0;
+ int ring_count, size;
+
+ ring_count = txr_count + rxr_count;
+ size = sizeof(*q_vector) + (sizeof(*ring) * ring_count);
+
+ /* allocate q_vector and rings */
+ q_vector = kzalloc(size, GFP_KERNEL);
+ if (!q_vector)
+ return -ENOMEM;
+
+ /* initialize NAPI */
+ netif_napi_add(adapter->netdev, &q_vector->napi, ixgbevf_poll, 64);
+
+ /* tie q_vector and adapter together */
+ adapter->q_vector[v_idx] = q_vector;
+ q_vector->adapter = adapter;
+ q_vector->v_idx = v_idx;
- for (; tx < adapter->num_tx_queues; tx++) {
- ring = kzalloc(sizeof(*ring), GFP_KERNEL);
- if (!ring)
- goto err_allocation;
+ /* initialize pointer to rings */
+ ring = q_vector->ring;
+ while (txr_count) {
+ /* assign generic ring traits */
ring->dev = &adapter->pdev->dev;
ring->netdev = adapter->netdev;
+
+ /* configure backlink on ring */
+ ring->q_vector = q_vector;
+
+ /* update q_vector Tx values */
+ ixgbevf_add_ring(ring, &q_vector->tx);
+
+ /* apply Tx specific ring traits */
ring->count = adapter->tx_ring_count;
- ring->queue_index = tx;
- ring->reg_idx = tx;
+ ring->queue_index = txr_idx;
+ ring->reg_idx = txr_idx;
- adapter->tx_ring[tx] = ring;
- }
+ /* assign ring to adapter */
+ adapter->tx_ring[txr_idx] = ring;
+
+ /* update count and index */
+ txr_count--;
+ txr_idx++;
- for (; rx < adapter->num_rx_queues; rx++) {
- ring = kzalloc(sizeof(*ring), GFP_KERNEL);
- if (!ring)
- goto err_allocation;
+ /* push pointer to next ring */
+ ring++;
+ }
+ while (rxr_count) {
+ /* assign generic ring traits */
ring->dev = &adapter->pdev->dev;
ring->netdev = adapter->netdev;
+ /* configure backlink on ring */
+ ring->q_vector = q_vector;
+
+ /* update q_vector Rx values */
+ ixgbevf_add_ring(ring, &q_vector->rx);
+
+ /* apply Rx specific ring traits */
ring->count = adapter->rx_ring_count;
- ring->queue_index = rx;
- ring->reg_idx = rx;
+ ring->queue_index = rxr_idx;
+ ring->reg_idx = rxr_idx;
- adapter->rx_ring[rx] = ring;
- }
+ /* assign ring to adapter */
+ adapter->rx_ring[rxr_idx] = ring;
- return 0;
+ /* update count and index */
+ rxr_count--;
+ rxr_idx++;
-err_allocation:
- while (tx) {
- kfree(adapter->tx_ring[--tx]);
- adapter->tx_ring[tx] = NULL;
+ /* push pointer to next ring */
+ ring++;
}
- while (rx) {
- kfree(adapter->rx_ring[--rx]);
- adapter->rx_ring[rx] = NULL;
- }
- return -ENOMEM;
+ return 0;
}
/**
- * ixgbevf_set_interrupt_capability - set MSI-X or FAIL if not supported
+ * ixgbevf_free_q_vector - Free memory allocated for specific interrupt vector
* @adapter: board private structure to initialize
+ * @v_idx: index of vector in adapter struct
*
- * Attempt to configure the interrupts using the best available
- * capabilities of the hardware and the kernel.
+ * This function frees the memory allocated to the q_vector. In addition if
+ * NAPI is enabled it will delete any references to the NAPI struct prior
+ * to freeing the q_vector.
**/
-static int ixgbevf_set_interrupt_capability(struct ixgbevf_adapter *adapter)
+static void ixgbevf_free_q_vector(struct ixgbevf_adapter *adapter, int v_idx)
{
- struct net_device *netdev = adapter->netdev;
- int err;
- int vector, v_budget;
+ struct ixgbevf_q_vector *q_vector = adapter->q_vector[v_idx];
+ struct ixgbevf_ring *ring;
- /* It's easy to be greedy for MSI-X vectors, but it really
- * doesn't do us much good if we have a lot more vectors
- * than CPU's. So let's be conservative and only ask for
- * (roughly) the same number of vectors as there are CPU's.
- * The default is to use pairs of vectors.
- */
- v_budget = max(adapter->num_rx_queues, adapter->num_tx_queues);
- v_budget = min_t(int, v_budget, num_online_cpus());
- v_budget += NON_Q_VECTORS;
+ ixgbevf_for_each_ring(ring, q_vector->tx)
+ adapter->tx_ring[ring->queue_index] = NULL;
- /* A failure in MSI-X entry allocation isn't fatal, but it does
- * mean we disable MSI-X capabilities of the adapter.
- */
- adapter->msix_entries = kcalloc(v_budget,
- sizeof(struct msix_entry), GFP_KERNEL);
- if (!adapter->msix_entries)
- return -ENOMEM;
+ ixgbevf_for_each_ring(ring, q_vector->rx)
+ adapter->rx_ring[ring->queue_index] = NULL;
- for (vector = 0; vector < v_budget; vector++)
- adapter->msix_entries[vector].entry = vector;
+ adapter->q_vector[v_idx] = NULL;
+ netif_napi_del(&q_vector->napi);
- err = ixgbevf_acquire_msix_vectors(adapter, v_budget);
- if (err)
- return err;
-
- err = netif_set_real_num_tx_queues(netdev, adapter->num_tx_queues);
- if (err)
- return err;
-
- return netif_set_real_num_rx_queues(netdev, adapter->num_rx_queues);
+ /* ixgbevf_get_stats() might access the rings on this vector,
+ * we must wait a grace period before freeing it.
+ */
+ kfree_rcu(q_vector, rcu);
}
/**
@@ -2567,35 +2538,53 @@ static int ixgbevf_set_interrupt_capability(struct ixgbevf_adapter *adapter)
**/
static int ixgbevf_alloc_q_vectors(struct ixgbevf_adapter *adapter)
{
- int q_idx, num_q_vectors;
- struct ixgbevf_q_vector *q_vector;
+ int q_vectors = adapter->num_msix_vectors - NON_Q_VECTORS;
+ int rxr_remaining = adapter->num_rx_queues;
+ int txr_remaining = adapter->num_tx_queues;
+ int rxr_idx = 0, txr_idx = 0, v_idx = 0;
+ int err;
+
+ if (q_vectors >= (rxr_remaining + txr_remaining)) {
+ for (; rxr_remaining; v_idx++, q_vectors--) {
+ int rqpv = DIV_ROUND_UP(rxr_remaining, q_vectors);
+
+ err = ixgbevf_alloc_q_vector(adapter, v_idx,
+ 0, 0, rqpv, rxr_idx);
+ if (err)
+ goto err_out;
+
+ /* update counts and index */
+ rxr_remaining -= rqpv;
+ rxr_idx += rqpv;
+ }
+ }
+
+ for (; q_vectors; v_idx++, q_vectors--) {
+ int rqpv = DIV_ROUND_UP(rxr_remaining, q_vectors);
+ int tqpv = DIV_ROUND_UP(txr_remaining, q_vectors);
- num_q_vectors = adapter->num_msix_vectors - NON_Q_VECTORS;
+ err = ixgbevf_alloc_q_vector(adapter, v_idx,
+ tqpv, txr_idx,
+ rqpv, rxr_idx);
- for (q_idx = 0; q_idx < num_q_vectors; q_idx++) {
- q_vector = kzalloc(sizeof(struct ixgbevf_q_vector), GFP_KERNEL);
- if (!q_vector)
+ if (err)
goto err_out;
- q_vector->adapter = adapter;
- q_vector->v_idx = q_idx;
- netif_napi_add(adapter->netdev, &q_vector->napi,
- ixgbevf_poll, 64);
- adapter->q_vector[q_idx] = q_vector;
+
+ /* update counts and index */
+ rxr_remaining -= rqpv;
+ rxr_idx += rqpv;
+ txr_remaining -= tqpv;
+ txr_idx += tqpv;
}
return 0;
err_out:
- while (q_idx) {
- q_idx--;
- q_vector = adapter->q_vector[q_idx];
-#ifdef CONFIG_NET_RX_BUSY_POLL
- napi_hash_del(&q_vector->napi);
-#endif
- netif_napi_del(&q_vector->napi);
- kfree(q_vector);
- adapter->q_vector[q_idx] = NULL;
+ while (v_idx) {
+ v_idx--;
+ ixgbevf_free_q_vector(adapter, v_idx);
}
+
return -ENOMEM;
}
@@ -2609,17 +2598,11 @@ static int ixgbevf_alloc_q_vectors(struct ixgbevf_adapter *adapter)
**/
static void ixgbevf_free_q_vectors(struct ixgbevf_adapter *adapter)
{
- int q_idx, num_q_vectors = adapter->num_msix_vectors - NON_Q_VECTORS;
-
- for (q_idx = 0; q_idx < num_q_vectors; q_idx++) {
- struct ixgbevf_q_vector *q_vector = adapter->q_vector[q_idx];
+ int q_vectors = adapter->num_msix_vectors - NON_Q_VECTORS;
- adapter->q_vector[q_idx] = NULL;
-#ifdef CONFIG_NET_RX_BUSY_POLL
- napi_hash_del(&q_vector->napi);
-#endif
- netif_napi_del(&q_vector->napi);
- kfree(q_vector);
+ while (q_vectors) {
+ q_vectors--;
+ ixgbevf_free_q_vector(adapter, q_vectors);
}
}
@@ -2663,12 +2646,6 @@ static int ixgbevf_init_interrupt_scheme(struct ixgbevf_adapter *adapter)
goto err_alloc_q_vectors;
}
- err = ixgbevf_alloc_queues(adapter);
- if (err) {
- pr_err("Unable to allocate memory for queues\n");
- goto err_alloc_queues;
- }
-
hw_dbg(&adapter->hw, "Multiqueue %s: Rx Queue count = %u, Tx Queue count = %u\n",
(adapter->num_rx_queues > 1) ? "Enabled" :
"Disabled", adapter->num_rx_queues, adapter->num_tx_queues);
@@ -2676,8 +2653,6 @@ static int ixgbevf_init_interrupt_scheme(struct ixgbevf_adapter *adapter)
set_bit(__IXGBEVF_DOWN, &adapter->state);
return 0;
-err_alloc_queues:
- ixgbevf_free_q_vectors(adapter);
err_alloc_q_vectors:
ixgbevf_reset_interrupt_capability(adapter);
err_set_interrupt:
@@ -2693,17 +2668,6 @@ static int ixgbevf_init_interrupt_scheme(struct ixgbevf_adapter *adapter)
**/
static void ixgbevf_clear_interrupt_scheme(struct ixgbevf_adapter *adapter)
{
- int i;
-
- for (i = 0; i < adapter->num_tx_queues; i++) {
- kfree(adapter->tx_ring[i]);
- adapter->tx_ring[i] = NULL;
- }
- for (i = 0; i < adapter->num_rx_queues; i++) {
- kfree(adapter->rx_ring[i]);
- adapter->rx_ring[i] = NULL;
- }
-
adapter->num_tx_queues = 0;
adapter->num_rx_queues = 0;
@@ -3307,12 +3271,6 @@ int ixgbevf_open(struct net_device *netdev)
ixgbevf_configure(adapter);
- /* Map the Tx/Rx rings to the vectors we were allotted.
- * if request_irq will be called in this function map_rings
- * must be called *before* up_complete
- */
- ixgbevf_map_rings_to_vectors(adapter);
-
err = ixgbevf_request_irq(adapter);
if (err)
goto err_req_irq;
@@ -4042,6 +4000,7 @@ static void ixgbevf_get_stats(struct net_device *netdev,
stats->multicast = adapter->stats.vfmprc - adapter->stats.base_vfmprc;
+ rcu_read_lock();
for (i = 0; i < adapter->num_rx_queues; i++) {
ring = adapter->rx_ring[i];
do {
@@ -4063,6 +4022,7 @@ static void ixgbevf_get_stats(struct net_device *netdev,
stats->tx_bytes += bytes;
stats->tx_packets += packets;
}
+ rcu_read_unlock();
}
#define IXGBEVF_MAX_MAC_HDR_LEN 127
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