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Message-Id: <1317971926-23145-8-git-send-email-jeffrey.t.kirsher@intel.com>
Date: Fri, 7 Oct 2011 00:18:39 -0700
From: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
To: davem@...emloft.net
Cc: Alexander Duyck <alexander.h.duyck@...el.com>,
netdev@...r.kernel.org, gospo@...hat.com, sassmann@...hat.com,
Jeff Kirsher <jeffrey.t.kirsher@...el.com>
Subject: [net-next 06/13] igb: Make Tx budget for NAPI user adjustable
From: Alexander Duyck <alexander.h.duyck@...el.com>
This change is to make the NAPI budget limits for transmit
adjustable. Currently they are only set to 128, and when
the changes/improvements to NAPI occur to allow for adjustability,
it would be possible to tune the value for optimal
performance with applications such as routing.
v2: remove tie between NAPI and interrupt moderation
fix work limit define name (s/IXGBE/IGB/)
Update patch description to better reflect patch
Signed-off-by: Alexander Duyck <alexander.h.duyck@...el.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
Tested-by: Aaron Brown <aaron.f.brown@...el.com>
---
drivers/net/ethernet/intel/igb/igb.h | 3 +
drivers/net/ethernet/intel/igb/igb_ethtool.c | 1 +
drivers/net/ethernet/intel/igb/igb_main.c | 136 ++++++++++++++++----------
3 files changed, 87 insertions(+), 53 deletions(-)
diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h
index b725937..beab918 100644
--- a/drivers/net/ethernet/intel/igb/igb.h
+++ b/drivers/net/ethernet/intel/igb/igb.h
@@ -47,6 +47,7 @@ struct igb_adapter;
/* TX/RX descriptor defines */
#define IGB_DEFAULT_TXD 256
+#define IGB_DEFAULT_TX_WORK 128
#define IGB_MIN_TXD 80
#define IGB_MAX_TXD 4096
@@ -177,6 +178,7 @@ struct igb_q_vector {
u32 eims_value;
u16 cpu;
+ u16 tx_work_limit;
u16 itr_val;
u8 set_itr;
@@ -266,6 +268,7 @@ struct igb_adapter {
u16 rx_itr;
/* TX */
+ u16 tx_work_limit;
u32 tx_timeout_count;
int num_tx_queues;
struct igb_ring *tx_ring[16];
diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c b/drivers/net/ethernet/intel/igb/igb_ethtool.c
index f231d82..a445c4f 100644
--- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
+++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
@@ -2011,6 +2011,7 @@ static int igb_set_coalesce(struct net_device *netdev,
for (i = 0; i < adapter->num_q_vectors; i++) {
struct igb_q_vector *q_vector = adapter->q_vector[i];
+ q_vector->tx_work_limit = adapter->tx_work_limit;
if (q_vector->rx_ring)
q_vector->itr_val = adapter->rx_itr_setting;
else
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 7ad25e8..12faa99 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -136,8 +136,8 @@ static irqreturn_t igb_msix_ring(int irq, void *);
static void igb_update_dca(struct igb_q_vector *);
static void igb_setup_dca(struct igb_adapter *);
#endif /* CONFIG_IGB_DCA */
-static bool igb_clean_tx_irq(struct igb_q_vector *);
static int igb_poll(struct napi_struct *, int);
+static bool igb_clean_tx_irq(struct igb_q_vector *);
static bool igb_clean_rx_irq(struct igb_q_vector *, int);
static int igb_ioctl(struct net_device *, struct ifreq *, int cmd);
static void igb_tx_timeout(struct net_device *);
@@ -1120,6 +1120,7 @@ static void igb_map_tx_ring_to_vector(struct igb_adapter *adapter,
q_vector->tx_ring = adapter->tx_ring[ring_idx];
q_vector->tx_ring->q_vector = q_vector;
q_vector->itr_val = adapter->tx_itr_setting;
+ q_vector->tx_work_limit = adapter->tx_work_limit;
if (q_vector->itr_val && q_vector->itr_val <= 3)
q_vector->itr_val = IGB_START_ITR;
}
@@ -2388,11 +2389,17 @@ static int __devinit igb_sw_init(struct igb_adapter *adapter)
pci_read_config_word(pdev, PCI_COMMAND, &hw->bus.pci_cmd_word);
+ /* set default ring sizes */
adapter->tx_ring_count = IGB_DEFAULT_TXD;
adapter->rx_ring_count = IGB_DEFAULT_RXD;
+
+ /* set default ITR values */
adapter->rx_itr_setting = IGB_DEFAULT_ITR;
adapter->tx_itr_setting = IGB_DEFAULT_ITR;
+ /* set default work limits */
+ adapter->tx_work_limit = IGB_DEFAULT_TX_WORK;
+
adapter->max_frame_size = netdev->mtu + ETH_HLEN + ETH_FCS_LEN +
VLAN_HLEN;
adapter->min_frame_size = ETH_ZLEN + ETH_FCS_LEN;
@@ -5496,7 +5503,7 @@ static int igb_poll(struct napi_struct *napi, int budget)
igb_update_dca(q_vector);
#endif
if (q_vector->tx_ring)
- clean_complete = !!igb_clean_tx_irq(q_vector);
+ clean_complete = igb_clean_tx_irq(q_vector);
if (q_vector->rx_ring)
clean_complete &= igb_clean_rx_irq(q_vector, budget);
@@ -5578,64 +5585,69 @@ static bool igb_clean_tx_irq(struct igb_q_vector *q_vector)
{
struct igb_adapter *adapter = q_vector->adapter;
struct igb_ring *tx_ring = q_vector->tx_ring;
- struct net_device *netdev = tx_ring->netdev;
- struct e1000_hw *hw = &adapter->hw;
- struct igb_buffer *buffer_info;
- union e1000_adv_tx_desc *tx_desc, *eop_desc;
+ struct igb_buffer *tx_buffer;
+ union e1000_adv_tx_desc *tx_desc;
unsigned int total_bytes = 0, total_packets = 0;
- unsigned int i, eop, count = 0;
- bool cleaned = false;
+ unsigned int budget = q_vector->tx_work_limit;
+ u16 i = tx_ring->next_to_clean;
- i = tx_ring->next_to_clean;
- eop = tx_ring->buffer_info[i].next_to_watch;
- eop_desc = IGB_TX_DESC(tx_ring, eop);
+ if (test_bit(__IGB_DOWN, &adapter->state))
+ return true;
- while ((eop_desc->wb.status & cpu_to_le32(E1000_TXD_STAT_DD)) &&
- (count < tx_ring->count)) {
- rmb(); /* read buffer_info after eop_desc status */
- for (cleaned = false; !cleaned; count++) {
- tx_desc = IGB_TX_DESC(tx_ring, i);
- buffer_info = &tx_ring->buffer_info[i];
- cleaned = (i == eop);
+ tx_buffer = &tx_ring->buffer_info[i];
+ tx_desc = IGB_TX_DESC(tx_ring, i);
- if (buffer_info->skb) {
- total_bytes += buffer_info->bytecount;
- /* gso_segs is currently only valid for tcp */
- total_packets += buffer_info->gso_segs;
- igb_tx_hwtstamp(q_vector, buffer_info);
- }
+ for (; budget; budget--) {
+ u16 eop = tx_buffer->next_to_watch;
+ union e1000_adv_tx_desc *eop_desc;
+
+ eop_desc = IGB_TX_DESC(tx_ring, eop);
+
+ /* if DD is not set pending work has not been completed */
+ if (!(eop_desc->wb.status & cpu_to_le32(E1000_TXD_STAT_DD)))
+ break;
+
+ /* prevent any other reads prior to eop_desc being verified */
+ rmb();
- igb_unmap_and_free_tx_resource(tx_ring, buffer_info);
+ do {
tx_desc->wb.status = 0;
+ if (likely(tx_desc == eop_desc)) {
+ eop_desc = NULL;
+
+ total_bytes += tx_buffer->bytecount;
+ total_packets += tx_buffer->gso_segs;
+ igb_tx_hwtstamp(q_vector, tx_buffer);
+ }
+
+ igb_unmap_and_free_tx_resource(tx_ring, tx_buffer);
+ tx_buffer++;
+ tx_desc++;
i++;
- if (i == tx_ring->count)
+ if (unlikely(i == tx_ring->count)) {
i = 0;
- }
- eop = tx_ring->buffer_info[i].next_to_watch;
- eop_desc = IGB_TX_DESC(tx_ring, eop);
+ tx_buffer = tx_ring->buffer_info;
+ tx_desc = IGB_TX_DESC(tx_ring, 0);
+ }
+ } while (eop_desc);
}
tx_ring->next_to_clean = i;
+ u64_stats_update_begin(&tx_ring->tx_syncp);
+ tx_ring->tx_stats.bytes += total_bytes;
+ tx_ring->tx_stats.packets += total_packets;
+ u64_stats_update_end(&tx_ring->tx_syncp);
+ tx_ring->total_bytes += total_bytes;
+ tx_ring->total_packets += total_packets;
- if (unlikely(count &&
- netif_carrier_ok(netdev) &&
- igb_desc_unused(tx_ring) >= IGB_TX_QUEUE_WAKE)) {
- /* Make sure that anybody stopping the queue after this
- * sees the new next_to_clean.
- */
- smp_mb();
- if (__netif_subqueue_stopped(netdev, tx_ring->queue_index) &&
- !(test_bit(__IGB_DOWN, &adapter->state))) {
- netif_wake_subqueue(netdev, tx_ring->queue_index);
+ if (tx_ring->detect_tx_hung) {
+ struct e1000_hw *hw = &adapter->hw;
+ u16 eop = tx_ring->buffer_info[i].next_to_watch;
+ union e1000_adv_tx_desc *eop_desc;
- u64_stats_update_begin(&tx_ring->tx_syncp);
- tx_ring->tx_stats.restart_queue++;
- u64_stats_update_end(&tx_ring->tx_syncp);
- }
- }
+ eop_desc = IGB_TX_DESC(tx_ring, eop);
- if (tx_ring->detect_tx_hung) {
/* Detect a transmit hang in hardware, this serializes the
* check with the clearing of time_stamp and movement of i */
tx_ring->detect_tx_hung = false;
@@ -5666,16 +5678,34 @@ static bool igb_clean_tx_irq(struct igb_q_vector *q_vector)
eop,
jiffies,
eop_desc->wb.status);
- netif_stop_subqueue(netdev, tx_ring->queue_index);
+ netif_stop_subqueue(tx_ring->netdev,
+ tx_ring->queue_index);
+
+ /* we are about to reset, no point in enabling stuff */
+ return true;
}
}
- tx_ring->total_bytes += total_bytes;
- tx_ring->total_packets += total_packets;
- u64_stats_update_begin(&tx_ring->tx_syncp);
- tx_ring->tx_stats.bytes += total_bytes;
- tx_ring->tx_stats.packets += total_packets;
- u64_stats_update_end(&tx_ring->tx_syncp);
- return count < tx_ring->count;
+
+ if (unlikely(total_packets &&
+ netif_carrier_ok(tx_ring->netdev) &&
+ igb_desc_unused(tx_ring) >= IGB_TX_QUEUE_WAKE)) {
+ /* Make sure that anybody stopping the queue after this
+ * sees the new next_to_clean.
+ */
+ smp_mb();
+ if (__netif_subqueue_stopped(tx_ring->netdev,
+ tx_ring->queue_index) &&
+ !(test_bit(__IGB_DOWN, &adapter->state))) {
+ netif_wake_subqueue(tx_ring->netdev,
+ tx_ring->queue_index);
+
+ u64_stats_update_begin(&tx_ring->tx_syncp);
+ tx_ring->tx_stats.restart_queue++;
+ u64_stats_update_end(&tx_ring->tx_syncp);
+ }
+ }
+
+ return !!budget;
}
static inline void igb_rx_checksum(struct igb_ring *ring,
--
1.7.6.4
--
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