* [net-next 2/5] i40e/i40evf: refactor tx timeout logic
2015-09-28 19:33 [net-next 0/5][pull request] Intel Wired LAN Driver Updates 2015-09-28 Jeff Kirsher
2015-09-28 19:33 ` [net-next 1/5] i40e: Move i40e_get_head into header file Jeff Kirsher
@ 2015-09-28 19:33 ` Jeff Kirsher
2015-09-28 19:33 ` [net-next 3/5] i40e: add GRE tunnel type to csum encoding Jeff Kirsher
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Jeff Kirsher @ 2015-09-28 19:33 UTC (permalink / raw)
To: davem
Cc: Kiran Patil, netdev, nhorman, sassmann, jogreene, Shannon Nelson,
Jesse Brandeburg, Jeff Kirsher
From: Kiran Patil <kiran.patil@intel.com>
This patch modifies the driver timeout logic by issuing a writeback
request via a software interrupt to the hardware the first time the
driver detects a hang. The driver was too aggressive in resetting a hung
queue, so back that off by removing logic to down the netdevice after
too many hangs, and move the function to the service task.
Change-ID: Ife100b9d124cd08cbdb81ab659008c1b9abbedea
Signed-off-by: Kiran Patil <kiran.patil@intel.com>
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
drivers/net/ethernet/intel/i40e/i40e.h | 1 -
drivers/net/ethernet/intel/i40e/i40e_main.c | 272 +++++++++++++++-----------
drivers/net/ethernet/intel/i40e/i40e_txrx.c | 75 +------
drivers/net/ethernet/intel/i40e/i40e_txrx.h | 10 +-
drivers/net/ethernet/intel/i40evf/i40e_txrx.c | 94 +--------
drivers/net/ethernet/intel/i40evf/i40e_txrx.h | 8 -
6 files changed, 173 insertions(+), 287 deletions(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index e746279..4797269 100644
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -243,7 +243,6 @@ struct i40e_pf {
struct pci_dev *pdev;
struct i40e_hw hw;
unsigned long state;
- unsigned long link_check_timeout;
struct msix_entry *msix_entries;
bool fc_autoneg_status;
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 530d8b6..c246dca 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -299,25 +299,69 @@ static void i40e_tx_timeout(struct net_device *netdev)
struct i40e_netdev_priv *np = netdev_priv(netdev);
struct i40e_vsi *vsi = np->vsi;
struct i40e_pf *pf = vsi->back;
+ struct i40e_ring *tx_ring = NULL;
+ unsigned int i, hung_queue = 0;
+ u32 head, val;
pf->tx_timeout_count++;
+ /* find the stopped queue the same way the stack does */
+ for (i = 0; i < netdev->num_tx_queues; i++) {
+ struct netdev_queue *q;
+ unsigned long trans_start;
+
+ q = netdev_get_tx_queue(netdev, i);
+ trans_start = q->trans_start ? : netdev->trans_start;
+ if (netif_xmit_stopped(q) &&
+ time_after(jiffies,
+ (trans_start + netdev->watchdog_timeo))) {
+ hung_queue = i;
+ break;
+ }
+ }
+
+ if (i == netdev->num_tx_queues) {
+ netdev_info(netdev, "tx_timeout: no netdev hung queue found\n");
+ } else {
+ /* now that we have an index, find the tx_ring struct */
+ for (i = 0; i < vsi->num_queue_pairs; i++) {
+ if (vsi->tx_rings[i] && vsi->tx_rings[i]->desc) {
+ if (hung_queue ==
+ vsi->tx_rings[i]->queue_index) {
+ tx_ring = vsi->tx_rings[i];
+ break;
+ }
+ }
+ }
+ }
+
if (time_after(jiffies, (pf->tx_timeout_last_recovery + HZ*20)))
- pf->tx_timeout_recovery_level = 1;
+ pf->tx_timeout_recovery_level = 1; /* reset after some time */
+ else if (time_before(jiffies,
+ (pf->tx_timeout_last_recovery + netdev->watchdog_timeo)))
+ return; /* don't do any new action before the next timeout */
+
+ if (tx_ring) {
+ head = i40e_get_head(tx_ring);
+ /* Read interrupt register */
+ if (pf->flags & I40E_FLAG_MSIX_ENABLED)
+ val = rd32(&pf->hw,
+ I40E_PFINT_DYN_CTLN(tx_ring->q_vector->v_idx +
+ tx_ring->vsi->base_vector - 1));
+ else
+ val = rd32(&pf->hw, I40E_PFINT_DYN_CTL0);
+
+ netdev_info(netdev, "tx_timeout: VSI_seid: %d, Q %d, NTC: 0x%x, HWB: 0x%x, NTU: 0x%x, TAIL: 0x%x, INT: 0x%x\n",
+ vsi->seid, hung_queue, tx_ring->next_to_clean,
+ head, tx_ring->next_to_use,
+ readl(tx_ring->tail), val);
+ }
+
pf->tx_timeout_last_recovery = jiffies;
- netdev_info(netdev, "tx_timeout recovery level %d\n",
- pf->tx_timeout_recovery_level);
+ netdev_info(netdev, "tx_timeout recovery level %d, hung_queue %d\n",
+ pf->tx_timeout_recovery_level, hung_queue);
switch (pf->tx_timeout_recovery_level) {
- case 0:
- /* disable and re-enable queues for the VSI */
- if (in_interrupt()) {
- set_bit(__I40E_REINIT_REQUESTED, &pf->state);
- set_bit(__I40E_REINIT_REQUESTED, &vsi->state);
- } else {
- i40e_vsi_reinit_locked(vsi);
- }
- break;
case 1:
set_bit(__I40E_PF_RESET_REQUESTED, &pf->state);
break;
@@ -329,10 +373,9 @@ static void i40e_tx_timeout(struct net_device *netdev)
break;
default:
netdev_err(netdev, "tx_timeout recovery unsuccessful\n");
- set_bit(__I40E_DOWN_REQUESTED, &pf->state);
- set_bit(__I40E_DOWN_REQUESTED, &vsi->state);
break;
}
+
i40e_service_event_schedule(pf);
pf->tx_timeout_recovery_level++;
}
@@ -754,7 +797,6 @@ static void i40e_update_link_xoff_rx(struct i40e_pf *pf)
struct i40e_hw_port_stats *nsd = &pf->stats;
struct i40e_hw *hw = &pf->hw;
u64 xoff = 0;
- u16 i, v;
if ((hw->fc.current_mode != I40E_FC_FULL) &&
(hw->fc.current_mode != I40E_FC_RX_PAUSE))
@@ -769,18 +811,6 @@ static void i40e_update_link_xoff_rx(struct i40e_pf *pf)
if (!(nsd->link_xoff_rx - xoff))
return;
- /* Clear the __I40E_HANG_CHECK_ARMED bit for all Tx rings */
- for (v = 0; v < pf->num_alloc_vsi; v++) {
- struct i40e_vsi *vsi = pf->vsi[v];
-
- if (!vsi || !vsi->tx_rings[0])
- continue;
-
- for (i = 0; i < vsi->num_queue_pairs; i++) {
- struct i40e_ring *ring = vsi->tx_rings[i];
- clear_bit(__I40E_HANG_CHECK_ARMED, &ring->state);
- }
- }
}
/**
@@ -796,7 +826,7 @@ static void i40e_update_prio_xoff_rx(struct i40e_pf *pf)
bool xoff[I40E_MAX_TRAFFIC_CLASS] = {false};
struct i40e_dcbx_config *dcb_cfg;
struct i40e_hw *hw = &pf->hw;
- u16 i, v;
+ u16 i;
u8 tc;
dcb_cfg = &hw->local_dcbx_config;
@@ -821,23 +851,6 @@ static void i40e_update_prio_xoff_rx(struct i40e_pf *pf)
tc = dcb_cfg->etscfg.prioritytable[i];
xoff[tc] = true;
}
-
- /* Clear the __I40E_HANG_CHECK_ARMED bit for Tx rings */
- for (v = 0; v < pf->num_alloc_vsi; v++) {
- struct i40e_vsi *vsi = pf->vsi[v];
-
- if (!vsi || !vsi->tx_rings[0])
- continue;
-
- for (i = 0; i < vsi->num_queue_pairs; i++) {
- struct i40e_ring *ring = vsi->tx_rings[i];
-
- tc = ring->dcb_tc;
- if (xoff[tc])
- clear_bit(__I40E_HANG_CHECK_ARMED,
- &ring->state);
- }
- }
}
/**
@@ -2609,8 +2622,6 @@ static int i40e_configure_tx_ring(struct i40e_ring *ring)
wr32(hw, I40E_QTX_CTL(pf_q), qtx_ctl);
i40e_flush(hw);
- clear_bit(__I40E_HANG_CHECK_ARMED, &ring->state);
-
/* cache tail off for easier writes later */
ring->tail = hw->hw_addr + I40E_QTX_TAIL(pf_q);
@@ -4145,6 +4156,108 @@ static int i40e_pf_wait_txq_disabled(struct i40e_pf *pf)
}
#endif
+
+/**
+ * i40e_detect_recover_hung_queue - Function to detect and recover hung_queue
+ * @q_idx: TX queue number
+ * @vsi: Pointer to VSI struct
+ *
+ * This function checks specified queue for given VSI. Detects hung condition.
+ * Sets hung bit since it is two step process. Before next run of service task
+ * if napi_poll runs, it reset 'hung' bit for respective q_vector. If not,
+ * hung condition remain unchanged and during subsequent run, this function
+ * issues SW interrupt to recover from hung condition.
+ **/
+static void i40e_detect_recover_hung_queue(int q_idx, struct i40e_vsi *vsi)
+{
+ struct i40e_ring *tx_ring = NULL;
+ struct i40e_pf *pf;
+ u32 head, val, tx_pending;
+ int i;
+
+ pf = vsi->back;
+
+ /* now that we have an index, find the tx_ring struct */
+ for (i = 0; i < vsi->num_queue_pairs; i++) {
+ if (vsi->tx_rings[i] && vsi->tx_rings[i]->desc) {
+ if (q_idx == vsi->tx_rings[i]->queue_index) {
+ tx_ring = vsi->tx_rings[i];
+ break;
+ }
+ }
+ }
+
+ if (!tx_ring)
+ return;
+
+ /* Read interrupt register */
+ if (pf->flags & I40E_FLAG_MSIX_ENABLED)
+ val = rd32(&pf->hw,
+ I40E_PFINT_DYN_CTLN(tx_ring->q_vector->v_idx +
+ tx_ring->vsi->base_vector - 1));
+ else
+ val = rd32(&pf->hw, I40E_PFINT_DYN_CTL0);
+
+ head = i40e_get_head(tx_ring);
+
+ tx_pending = i40e_get_tx_pending(tx_ring);
+
+ /* Interrupts are disabled and TX pending is non-zero,
+ * trigger the SW interrupt (don't wait). Worst case
+ * there will be one extra interrupt which may result
+ * into not cleaning any queues because queues are cleaned.
+ */
+ if (tx_pending && (!(val & I40E_PFINT_DYN_CTLN_INTENA_MASK)))
+ i40e_force_wb(vsi, tx_ring->q_vector);
+}
+
+/**
+ * i40e_detect_recover_hung - Function to detect and recover hung_queues
+ * @pf: pointer to PF struct
+ *
+ * LAN VSI has netdev and netdev has TX queues. This function is to check
+ * each of those TX queues if they are hung, trigger recovery by issuing
+ * SW interrupt.
+ **/
+static void i40e_detect_recover_hung(struct i40e_pf *pf)
+{
+ struct net_device *netdev;
+ struct i40e_vsi *vsi;
+ int i;
+
+ /* Only for LAN VSI */
+ vsi = pf->vsi[pf->lan_vsi];
+
+ if (!vsi)
+ return;
+
+ /* Make sure, VSI state is not DOWN/RECOVERY_PENDING */
+ if (test_bit(__I40E_DOWN, &vsi->back->state) ||
+ test_bit(__I40E_RESET_RECOVERY_PENDING, &vsi->back->state))
+ return;
+
+ /* Make sure type is MAIN VSI */
+ if (vsi->type != I40E_VSI_MAIN)
+ return;
+
+ netdev = vsi->netdev;
+ if (!netdev)
+ return;
+
+ /* Bail out if netif_carrier is not OK */
+ if (!netif_carrier_ok(netdev))
+ return;
+
+ /* Go thru' TX queues for netdev */
+ for (i = 0; i < netdev->num_tx_queues; i++) {
+ struct netdev_queue *q;
+
+ q = netdev_get_tx_queue(netdev, i);
+ if (q)
+ i40e_detect_recover_hung_queue(i, vsi);
+ }
+}
+
/**
* i40e_get_iscsi_tc_map - Return TC map for iSCSI APP
* @pf: pointer to PF
@@ -5759,68 +5872,6 @@ static void i40e_link_event(struct i40e_pf *pf)
}
/**
- * i40e_check_hang_subtask - Check for hung queues and dropped interrupts
- * @pf: board private structure
- *
- * Set the per-queue flags to request a check for stuck queues in the irq
- * clean functions, then force interrupts to be sure the irq clean is called.
- **/
-static void i40e_check_hang_subtask(struct i40e_pf *pf)
-{
- int i, v;
-
- /* If we're down or resetting, just bail */
- if (test_bit(__I40E_DOWN, &pf->state) ||
- test_bit(__I40E_CONFIG_BUSY, &pf->state))
- return;
-
- /* for each VSI/netdev
- * for each Tx queue
- * set the check flag
- * for each q_vector
- * force an interrupt
- */
- for (v = 0; v < pf->num_alloc_vsi; v++) {
- struct i40e_vsi *vsi = pf->vsi[v];
- int armed = 0;
-
- if (!pf->vsi[v] ||
- test_bit(__I40E_DOWN, &vsi->state) ||
- (vsi->netdev && !netif_carrier_ok(vsi->netdev)))
- continue;
-
- for (i = 0; i < vsi->num_queue_pairs; i++) {
- set_check_for_tx_hang(vsi->tx_rings[i]);
- if (test_bit(__I40E_HANG_CHECK_ARMED,
- &vsi->tx_rings[i]->state))
- armed++;
- }
-
- if (armed) {
- if (!(pf->flags & I40E_FLAG_MSIX_ENABLED)) {
- wr32(&vsi->back->hw, I40E_PFINT_DYN_CTL0,
- (I40E_PFINT_DYN_CTL0_INTENA_MASK |
- I40E_PFINT_DYN_CTL0_SWINT_TRIG_MASK |
- I40E_PFINT_DYN_CTL0_ITR_INDX_MASK |
- I40E_PFINT_DYN_CTL0_SW_ITR_INDX_ENA_MASK |
- I40E_PFINT_DYN_CTL0_SW_ITR_INDX_MASK));
- } else {
- u16 vec = vsi->base_vector - 1;
- u32 val = (I40E_PFINT_DYN_CTLN_INTENA_MASK |
- I40E_PFINT_DYN_CTLN_SWINT_TRIG_MASK |
- I40E_PFINT_DYN_CTLN_ITR_INDX_MASK |
- I40E_PFINT_DYN_CTLN_SW_ITR_INDX_ENA_MASK |
- I40E_PFINT_DYN_CTLN_SW_ITR_INDX_MASK);
- for (i = 0; i < vsi->num_q_vectors; i++, vec++)
- wr32(&vsi->back->hw,
- I40E_PFINT_DYN_CTLN(vec), val);
- }
- i40e_flush(&vsi->back->hw);
- }
- }
-}
-
-/**
* i40e_watchdog_subtask - periodic checks not using event driven response
* @pf: board private structure
**/
@@ -5839,7 +5890,6 @@ static void i40e_watchdog_subtask(struct i40e_pf *pf)
return;
pf->service_timer_previous = jiffies;
- i40e_check_hang_subtask(pf);
i40e_link_event(pf);
/* Update the stats for active netdevs so the network stack
@@ -6807,6 +6857,7 @@ static void i40e_service_task(struct work_struct *work)
return;
}
+ i40e_detect_recover_hung(pf);
i40e_reset_subtask(pf);
i40e_handle_mdd_event(pf);
i40e_vc_process_vflr_event(pf);
@@ -10101,7 +10152,6 @@ static int i40e_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
INIT_WORK(&pf->service_task, i40e_service_task);
clear_bit(__I40E_SERVICE_SCHED, &pf->state);
pf->flags |= I40E_FLAG_NEED_LINK_UPDATE;
- pf->link_check_timeout = jiffies;
/* WoL defaults to disabled */
pf->wol_en = false;
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 9a800f9..4f9ff89 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -600,7 +600,6 @@ void i40e_free_tx_resources(struct i40e_ring *tx_ring)
}
}
-
/**
* i40e_get_tx_pending - how many tx descriptors not processed
* @tx_ring: the ring of descriptors
@@ -608,7 +607,7 @@ void i40e_free_tx_resources(struct i40e_ring *tx_ring)
* Since there is no access to the ring head register
* in XL710, we need to use our local copies
**/
-static u32 i40e_get_tx_pending(struct i40e_ring *ring)
+u32 i40e_get_tx_pending(struct i40e_ring *ring)
{
u32 head, tail;
@@ -622,50 +621,6 @@ static u32 i40e_get_tx_pending(struct i40e_ring *ring)
return 0;
}
-/**
- * i40e_check_tx_hang - Is there a hang in the Tx queue
- * @tx_ring: the ring of descriptors
- **/
-static bool i40e_check_tx_hang(struct i40e_ring *tx_ring)
-{
- u32 tx_done = tx_ring->stats.packets;
- u32 tx_done_old = tx_ring->tx_stats.tx_done_old;
- u32 tx_pending = i40e_get_tx_pending(tx_ring);
- struct i40e_pf *pf = tx_ring->vsi->back;
- bool ret = false;
-
- clear_check_for_tx_hang(tx_ring);
-
- /* Check for a hung queue, but be thorough. This verifies
- * that a transmit has been completed since the previous
- * check AND there is at least one packet pending. The
- * ARMED bit is set to indicate a potential hang. The
- * bit is cleared if a pause frame is received to remove
- * false hang detection due to PFC or 802.3x frames. By
- * requiring this to fail twice we avoid races with
- * PFC clearing the ARMED bit and conditions where we
- * run the check_tx_hang logic with a transmit completion
- * pending but without time to complete it yet.
- */
- if ((tx_done_old == tx_done) && tx_pending) {
- /* make sure it is true for two checks in a row */
- ret = test_and_set_bit(__I40E_HANG_CHECK_ARMED,
- &tx_ring->state);
- } else if (tx_done_old == tx_done &&
- (tx_pending < I40E_MIN_DESC_PENDING) && (tx_pending > 0)) {
- if (I40E_DEBUG_FLOW & pf->hw.debug_mask)
- dev_info(tx_ring->dev, "HW needs some more descs to do a cacheline flush. tx_pending %d, queue %d",
- tx_pending, tx_ring->queue_index);
- pf->tx_sluggish_count++;
- } else {
- /* update completed stats and disarm the hang check */
- tx_ring->tx_stats.tx_done_old = tx_done;
- clear_bit(__I40E_HANG_CHECK_ARMED, &tx_ring->state);
- }
-
- return ret;
-}
-
#define WB_STRIDE 0x3
/**
@@ -783,32 +738,6 @@ static bool i40e_clean_tx_irq(struct i40e_ring *tx_ring, int budget)
else
tx_ring->arm_wb = false;
- if (check_for_tx_hang(tx_ring) && i40e_check_tx_hang(tx_ring)) {
- /* schedule immediate reset if we believe we hung */
- dev_info(tx_ring->dev, "Detected Tx Unit Hang\n"
- " VSI <%d>\n"
- " Tx Queue <%d>\n"
- " next_to_use <%x>\n"
- " next_to_clean <%x>\n",
- tx_ring->vsi->seid,
- tx_ring->queue_index,
- tx_ring->next_to_use, i);
-
- netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
-
- dev_info(tx_ring->dev,
- "tx hang detected on queue %d, reset requested\n",
- tx_ring->queue_index);
-
- /* do not fire the reset immediately, wait for the stack to
- * decide we are truly stuck, also prevents every queue from
- * simultaneously requesting a reset
- */
-
- /* the adapter is about to reset, no point in enabling polling */
- budget = 1;
- }
-
netdev_tx_completed_queue(netdev_get_tx_queue(tx_ring->netdev,
tx_ring->queue_index),
total_packets, total_bytes);
@@ -838,7 +767,7 @@ static bool i40e_clean_tx_irq(struct i40e_ring *tx_ring, int budget)
* @q_vector: the vector on which to force writeback
*
**/
-static void i40e_force_wb(struct i40e_vsi *vsi, struct i40e_q_vector *q_vector)
+void i40e_force_wb(struct i40e_vsi *vsi, struct i40e_q_vector *q_vector)
{
u16 flags = q_vector->tx.ring[0].flags;
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
index 51487ef..977cb5b 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
@@ -199,8 +199,6 @@ struct i40e_rx_queue_stats {
enum i40e_ring_state_t {
__I40E_TX_FDIR_INIT_DONE,
__I40E_TX_XPS_INIT_DONE,
- __I40E_TX_DETECT_HANG,
- __I40E_HANG_CHECK_ARMED,
__I40E_RX_PS_ENABLED,
__I40E_RX_16BYTE_DESC_ENABLED,
};
@@ -211,12 +209,6 @@ enum i40e_ring_state_t {
set_bit(__I40E_RX_PS_ENABLED, &(ring)->state)
#define clear_ring_ps_enabled(ring) \
clear_bit(__I40E_RX_PS_ENABLED, &(ring)->state)
-#define check_for_tx_hang(ring) \
- test_bit(__I40E_TX_DETECT_HANG, &(ring)->state)
-#define set_check_for_tx_hang(ring) \
- set_bit(__I40E_TX_DETECT_HANG, &(ring)->state)
-#define clear_check_for_tx_hang(ring) \
- clear_bit(__I40E_TX_DETECT_HANG, &(ring)->state)
#define ring_is_16byte_desc_enabled(ring) \
test_bit(__I40E_RX_16BYTE_DESC_ENABLED, &(ring)->state)
#define set_ring_16byte_desc_enabled(ring) \
@@ -326,6 +318,8 @@ int i40e_xmit_descriptor_count(struct sk_buff *skb, struct i40e_ring *tx_ring);
int i40e_tx_prepare_vlan_flags(struct sk_buff *skb,
struct i40e_ring *tx_ring, u32 *flags);
#endif
+void i40e_force_wb(struct i40e_vsi *vsi, struct i40e_q_vector *q_vector);
+u32 i40e_get_tx_pending(struct i40e_ring *ring);
/**
* i40e_get_head - Retrieve head from head writeback
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
index 7e91d82..8309793 100644
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
@@ -140,65 +140,6 @@ static inline u32 i40e_get_head(struct i40e_ring *tx_ring)
return le32_to_cpu(*(volatile __le32 *)head);
}
-/**
- * i40e_get_tx_pending - how many tx descriptors not processed
- * @tx_ring: the ring of descriptors
- *
- * Since there is no access to the ring head register
- * in XL710, we need to use our local copies
- **/
-static u32 i40e_get_tx_pending(struct i40e_ring *ring)
-{
- u32 head, tail;
-
- head = i40e_get_head(ring);
- tail = readl(ring->tail);
-
- if (head != tail)
- return (head < tail) ?
- tail - head : (tail + ring->count - head);
-
- return 0;
-}
-
-/**
- * i40e_check_tx_hang - Is there a hang in the Tx queue
- * @tx_ring: the ring of descriptors
- **/
-static bool i40e_check_tx_hang(struct i40e_ring *tx_ring)
-{
- u32 tx_done = tx_ring->stats.packets;
- u32 tx_done_old = tx_ring->tx_stats.tx_done_old;
- u32 tx_pending = i40e_get_tx_pending(tx_ring);
- bool ret = false;
-
- clear_check_for_tx_hang(tx_ring);
-
- /* Check for a hung queue, but be thorough. This verifies
- * that a transmit has been completed since the previous
- * check AND there is at least one packet pending. The
- * ARMED bit is set to indicate a potential hang. The
- * bit is cleared if a pause frame is received to remove
- * false hang detection due to PFC or 802.3x frames. By
- * requiring this to fail twice we avoid races with
- * PFC clearing the ARMED bit and conditions where we
- * run the check_tx_hang logic with a transmit completion
- * pending but without time to complete it yet.
- */
- if ((tx_done_old == tx_done) && tx_pending) {
- /* make sure it is true for two checks in a row */
- ret = test_and_set_bit(__I40E_HANG_CHECK_ARMED,
- &tx_ring->state);
- } else if (tx_done_old == tx_done &&
- (tx_pending < I40E_MIN_DESC_PENDING) && (tx_pending > 0)) {
- /* update completed stats and disarm the hang check */
- tx_ring->tx_stats.tx_done_old = tx_done;
- clear_bit(__I40E_HANG_CHECK_ARMED, &tx_ring->state);
- }
-
- return ret;
-}
-
#define WB_STRIDE 0x3
/**
@@ -304,6 +245,10 @@ static bool i40e_clean_tx_irq(struct i40e_ring *tx_ring, int budget)
tx_ring->q_vector->tx.total_bytes += total_bytes;
tx_ring->q_vector->tx.total_packets += total_packets;
+ /* check to see if there are any non-cache aligned descriptors
+ * waiting to be written back, and kick the hardware to force
+ * them to be written back in case of napi polling
+ */
if (budget &&
!((i & WB_STRIDE) == WB_STRIDE) &&
!test_bit(__I40E_DOWN, &tx_ring->vsi->state) &&
@@ -312,29 +257,6 @@ static bool i40e_clean_tx_irq(struct i40e_ring *tx_ring, int budget)
else
tx_ring->arm_wb = false;
- if (check_for_tx_hang(tx_ring) && i40e_check_tx_hang(tx_ring)) {
- /* schedule immediate reset if we believe we hung */
- dev_info(tx_ring->dev, "Detected Tx Unit Hang\n"
- " VSI <%d>\n"
- " Tx Queue <%d>\n"
- " next_to_use <%x>\n"
- " next_to_clean <%x>\n",
- tx_ring->vsi->seid,
- tx_ring->queue_index,
- tx_ring->next_to_use, i);
-
- netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
-
- dev_info(tx_ring->dev,
- "tx hang detected on queue %d, resetting adapter\n",
- tx_ring->queue_index);
-
- tx_ring->netdev->netdev_ops->ndo_tx_timeout(tx_ring->netdev);
-
- /* the adapter is about to reset, no point in enabling stuff */
- return true;
- }
-
netdev_tx_completed_queue(netdev_get_tx_queue(tx_ring->netdev,
tx_ring->queue_index),
total_packets, total_bytes);
@@ -355,16 +277,16 @@ static bool i40e_clean_tx_irq(struct i40e_ring *tx_ring, int budget)
}
}
- return budget > 0;
+ return !!budget;
}
/**
- * i40e_force_wb -Arm hardware to do a wb on noncache aligned descriptors
+ * i40evf_force_wb -Arm hardware to do a wb on noncache aligned descriptors
* @vsi: the VSI we care about
* @q_vector: the vector on which to force writeback
*
**/
-static void i40e_force_wb(struct i40e_vsi *vsi, struct i40e_q_vector *q_vector)
+static void i40evf_force_wb(struct i40e_vsi *vsi, struct i40e_q_vector *q_vector)
{
u16 flags = q_vector->tx.ring[0].flags;
@@ -1385,7 +1307,7 @@ int i40evf_napi_poll(struct napi_struct *napi, int budget)
/* If work not completed, return budget and polling will return */
if (!clean_complete) {
if (arm_wb)
- i40e_force_wb(vsi, q_vector);
+ i40evf_force_wb(vsi, q_vector);
return budget;
}
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
index 9a30f5d..d5cb7ac 100644
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
@@ -198,8 +198,6 @@ struct i40e_rx_queue_stats {
enum i40e_ring_state_t {
__I40E_TX_FDIR_INIT_DONE,
__I40E_TX_XPS_INIT_DONE,
- __I40E_TX_DETECT_HANG,
- __I40E_HANG_CHECK_ARMED,
__I40E_RX_PS_ENABLED,
__I40E_RX_16BYTE_DESC_ENABLED,
};
@@ -210,12 +208,6 @@ enum i40e_ring_state_t {
set_bit(__I40E_RX_PS_ENABLED, &(ring)->state)
#define clear_ring_ps_enabled(ring) \
clear_bit(__I40E_RX_PS_ENABLED, &(ring)->state)
-#define check_for_tx_hang(ring) \
- test_bit(__I40E_TX_DETECT_HANG, &(ring)->state)
-#define set_check_for_tx_hang(ring) \
- set_bit(__I40E_TX_DETECT_HANG, &(ring)->state)
-#define clear_check_for_tx_hang(ring) \
- clear_bit(__I40E_TX_DETECT_HANG, &(ring)->state)
#define ring_is_16byte_desc_enabled(ring) \
test_bit(__I40E_RX_16BYTE_DESC_ENABLED, &(ring)->state)
#define set_ring_16byte_desc_enabled(ring) \
--
2.4.3
^ permalink raw reply related [flat|nested] 7+ messages in thread* [net-next 4/5] i40e: Fix RS bit update in Tx path and disable force WB workaround
2015-09-28 19:33 [net-next 0/5][pull request] Intel Wired LAN Driver Updates 2015-09-28 Jeff Kirsher
` (2 preceding siblings ...)
2015-09-28 19:33 ` [net-next 3/5] i40e: add GRE tunnel type to csum encoding Jeff Kirsher
@ 2015-09-28 19:33 ` Jeff Kirsher
2015-09-28 19:33 ` [net-next 5/5] igb: assume MSI-X interrupts during initialization Jeff Kirsher
2015-09-29 0:33 ` [net-next 0/5][pull request] Intel Wired LAN Driver Updates 2015-09-28 Jeff Kirsher
5 siblings, 0 replies; 7+ messages in thread
From: Jeff Kirsher @ 2015-09-28 19:33 UTC (permalink / raw)
To: davem; +Cc: Anjali Singhai, netdev, nhorman, sassmann, jogreene, Jeff Kirsher
From: Anjali Singhai <anjali.singhai@intel.com>
This patch fixes the issue of forcing WB too often causing us to not
benefit from NAPI.
Without this patch we were forcing WB/arming interrupt too often taking
away the benefits of NAPI and causing a performance impact.
With this patch we disable force WB in the clean routine for X710
and XL710 adapters. X722 adapters do not enable interrupt to force
a WB and benefit from WB_ON_ITR and hence force WB is left enabled
for those adapters.
For XL710 and X710 adapters if we have less than 4 packets pending
a software Interrupt triggered from service task will force a WB.
This patch also changes the conditions for setting RS bit as described
in code comments. This optimizes when the HW does a tail bump and when
it does a WB. It also optimizes when we do a wmb.
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
drivers/net/ethernet/intel/i40e/i40e_txrx.c | 129 ++++++++++++++++++----------
drivers/net/ethernet/intel/i40e/i40e_txrx.h | 2 +
2 files changed, 87 insertions(+), 44 deletions(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index d699fc9..3ce4900 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -726,17 +726,22 @@ static bool i40e_clean_tx_irq(struct i40e_ring *tx_ring, int budget)
tx_ring->q_vector->tx.total_bytes += total_bytes;
tx_ring->q_vector->tx.total_packets += total_packets;
- /* check to see if there are any non-cache aligned descriptors
- * waiting to be written back, and kick the hardware to force
- * them to be written back in case of napi polling
- */
- if (budget &&
- !((i & WB_STRIDE) == WB_STRIDE) &&
- !test_bit(__I40E_DOWN, &tx_ring->vsi->state) &&
- (I40E_DESC_UNUSED(tx_ring) != tx_ring->count))
- tx_ring->arm_wb = true;
- else
- tx_ring->arm_wb = false;
+ if (tx_ring->flags & I40E_TXR_FLAGS_WB_ON_ITR) {
+ unsigned int j = 0;
+
+ /* check to see if there are < 4 descriptors
+ * waiting to be written back, then kick the hardware to force
+ * them to be written back in case we stay in NAPI.
+ * In this mode on X722 we do not enable Interrupt.
+ */
+ j = i40e_get_tx_pending(tx_ring);
+
+ if (budget &&
+ ((j / (WB_STRIDE + 1)) == 0) && (j != 0) &&
+ !test_bit(__I40E_DOWN, &tx_ring->vsi->state) &&
+ (I40E_DESC_UNUSED(tx_ring) != tx_ring->count))
+ tx_ring->arm_wb = true;
+ }
netdev_tx_completed_queue(netdev_get_tx_queue(tx_ring->netdev,
tx_ring->queue_index),
@@ -2500,6 +2505,9 @@ static inline void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
u32 td_tag = 0;
dma_addr_t dma;
u16 gso_segs;
+ u16 desc_count = 0;
+ bool tail_bump = true;
+ bool do_rs = false;
if (tx_flags & I40E_TX_FLAGS_HW_VLAN) {
td_cmd |= I40E_TX_DESC_CMD_IL2TAG1;
@@ -2540,6 +2548,8 @@ static inline void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
tx_desc++;
i++;
+ desc_count++;
+
if (i == tx_ring->count) {
tx_desc = I40E_TX_DESC(tx_ring, 0);
i = 0;
@@ -2559,6 +2569,8 @@ static inline void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
tx_desc++;
i++;
+ desc_count++;
+
if (i == tx_ring->count) {
tx_desc = I40E_TX_DESC(tx_ring, 0);
i = 0;
@@ -2573,34 +2585,6 @@ static inline void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
tx_bi = &tx_ring->tx_bi[i];
}
- /* Place RS bit on last descriptor of any packet that spans across the
- * 4th descriptor (WB_STRIDE aka 0x3) in a 64B cacheline.
- */
- if (((i & WB_STRIDE) != WB_STRIDE) &&
- (first <= &tx_ring->tx_bi[i]) &&
- (first >= &tx_ring->tx_bi[i & ~WB_STRIDE])) {
- tx_desc->cmd_type_offset_bsz =
- build_ctob(td_cmd, td_offset, size, td_tag) |
- cpu_to_le64((u64)I40E_TX_DESC_CMD_EOP <<
- I40E_TXD_QW1_CMD_SHIFT);
- } else {
- tx_desc->cmd_type_offset_bsz =
- build_ctob(td_cmd, td_offset, size, td_tag) |
- cpu_to_le64((u64)I40E_TXD_CMD <<
- I40E_TXD_QW1_CMD_SHIFT);
- }
-
- netdev_tx_sent_queue(netdev_get_tx_queue(tx_ring->netdev,
- tx_ring->queue_index),
- first->bytecount);
-
- /* Force memory writes to complete before letting h/w
- * know there are new descriptors to fetch. (Only
- * applicable for weak-ordered memory model archs,
- * such as IA-64).
- */
- wmb();
-
/* set next_to_watch value indicating a packet is present */
first->next_to_watch = tx_desc;
@@ -2610,15 +2594,72 @@ static inline void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
tx_ring->next_to_use = i;
+ netdev_tx_sent_queue(netdev_get_tx_queue(tx_ring->netdev,
+ tx_ring->queue_index),
+ first->bytecount);
i40e_maybe_stop_tx(tx_ring, DESC_NEEDED);
+
+ /* Algorithm to optimize tail and RS bit setting:
+ * if xmit_more is supported
+ * if xmit_more is true
+ * do not update tail and do not mark RS bit.
+ * if xmit_more is false and last xmit_more was false
+ * if every packet spanned less than 4 desc
+ * then set RS bit on 4th packet and update tail
+ * on every packet
+ * else
+ * update tail and set RS bit on every packet.
+ * if xmit_more is false and last_xmit_more was true
+ * update tail and set RS bit.
+ *
+ * Optimization: wmb to be issued only in case of tail update.
+ * Also optimize the Descriptor WB path for RS bit with the same
+ * algorithm.
+ *
+ * Note: If there are less than 4 packets
+ * pending and interrupts were disabled the service task will
+ * trigger a force WB.
+ */
+ if (skb->xmit_more &&
+ !netif_xmit_stopped(netdev_get_tx_queue(tx_ring->netdev,
+ tx_ring->queue_index))) {
+ tx_ring->flags |= I40E_TXR_FLAGS_LAST_XMIT_MORE_SET;
+ tail_bump = false;
+ } else if (!skb->xmit_more &&
+ !netif_xmit_stopped(netdev_get_tx_queue(tx_ring->netdev,
+ tx_ring->queue_index)) &&
+ (!(tx_ring->flags & I40E_TXR_FLAGS_LAST_XMIT_MORE_SET)) &&
+ (tx_ring->packet_stride < WB_STRIDE) &&
+ (desc_count < WB_STRIDE)) {
+ tx_ring->packet_stride++;
+ } else {
+ tx_ring->packet_stride = 0;
+ tx_ring->flags &= ~I40E_TXR_FLAGS_LAST_XMIT_MORE_SET;
+ do_rs = true;
+ }
+ if (do_rs)
+ tx_ring->packet_stride = 0;
+
+ tx_desc->cmd_type_offset_bsz =
+ build_ctob(td_cmd, td_offset, size, td_tag) |
+ cpu_to_le64((u64)(do_rs ? I40E_TXD_CMD :
+ I40E_TX_DESC_CMD_EOP) <<
+ I40E_TXD_QW1_CMD_SHIFT);
+
/* notify HW of packet */
- if (!skb->xmit_more ||
- netif_xmit_stopped(netdev_get_tx_queue(tx_ring->netdev,
- tx_ring->queue_index)))
- writel(i, tx_ring->tail);
- else
+ if (!tail_bump)
prefetchw(tx_desc + 1);
+ if (tail_bump) {
+ /* Force memory writes to complete before letting h/w
+ * know there are new descriptors to fetch. (Only
+ * applicable for weak-ordered memory model archs,
+ * such as IA-64).
+ */
+ wmb();
+ writel(i, tx_ring->tail);
+ }
+
return;
dma_error:
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
index 977cb5b..a3978c2 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
@@ -256,10 +256,12 @@ struct i40e_ring {
bool ring_active; /* is ring online or not */
bool arm_wb; /* do something to arm write back */
+ u8 packet_stride;
u16 flags;
#define I40E_TXR_FLAGS_WB_ON_ITR BIT(0)
#define I40E_TXR_FLAGS_OUTER_UDP_CSUM BIT(1)
+#define I40E_TXR_FLAGS_LAST_XMIT_MORE_SET BIT(2)
/* stats structs */
struct i40e_queue_stats stats;
--
2.4.3
^ permalink raw reply related [flat|nested] 7+ messages in thread