vmxnet3: set RX interrupt pending only when needed

When an RX thread handles more than one RX queue and has a mix of
queues in interrupt mode and polling mode, the RX input routine is
naturally in polling mode. In that case, there is no need to set RX
interrupt pending when descriptor is available in the queue for
interrupt mode.

Type: fix

Signed-off-by: Steven Luong <sluong@cisco.com>
Change-Id: Iedbe57941eca3152c0e8ab9096cc81f315e0a915

diff --git a/src/plugins/vmxnet3/cli.c b/src/plugins/vmxnet3/cli.c
index 71342bd..574d86f 100644 (file)
--- a/src/plugins/vmxnet3/cli.c
+++ b/src/plugins/vmxnet3/cli.c
@@ -213,6 +213,15 @@ show_vmxnet3 (vlib_main_t * vm, u32 * hw_if_indices, u8 show_descr,
   vmxnet3_tx_comp *tx_comp;
   u16 qid;
 
+  vlib_cli_output (vm, "Global:");
+  for (u32 tid = 0; tid <= vlib_num_workers (); tid++)
+    {
+      vmxnet3_per_thread_data_t *ptd =
+       vec_elt_at_index (vmxm->per_thread_data, tid);
+      vlib_cli_output (vm, "  Thread %u: polling queue count %u", tid,
+                      ptd->polling_q_count);
+    }
+
   if (!hw_if_indices)
     return;
 
@@ -581,11 +590,14 @@ clib_error_t *
 vmxnet3_cli_init (vlib_main_t * vm)
 {
   vmxnet3_main_t *vmxm = &vmxnet3_main;
+  vlib_thread_main_t *tm = vlib_get_thread_main ();
 
   /* initialize binary API */
   vmxnet3_plugin_api_hookup (vm);
 
   vmxm->log_default = vlib_log_register_class ("vmxnet3", 0);
+
+  vec_validate (vmxm->per_thread_data, tm->n_vlib_mains - 1);
   return 0;
 }
 

diff --git a/src/plugins/vmxnet3/vmxnet3.c b/src/plugins/vmxnet3/vmxnet3.c
index ff0a7dc..16d7d86 100644 (file)
--- a/src/plugins/vmxnet3/vmxnet3.c
+++ b/src/plugins/vmxnet3/vmxnet3.c
@@ -69,11 +69,23 @@ vmxnet3_interface_rx_mode_change (vnet_main_t * vnm, u32 hw_if_index, u32 qid,
   vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
   vmxnet3_device_t *vd = pool_elt_at_index (vmxm->devices, hw->dev_instance);
   vmxnet3_rxq_t *rxq = vec_elt_at_index (vd->rxqs, qid);
+  vmxnet3_per_thread_data_t *ptd;
 
-  if (mode == VNET_HW_IF_RX_MODE_POLLING)
-    rxq->int_mode = 0;
+  if (mode == rxq->mode)
+    return 0;
+  if ((mode != VNET_HW_IF_RX_MODE_POLLING) &&
+      (mode != VNET_HW_IF_RX_MODE_INTERRUPT))
+    return clib_error_return (0, "Rx mode %U not supported",
+                             format_vnet_hw_if_rx_mode, mode);
+  rxq->mode = mode;
+  ptd = vec_elt_at_index (vmxm->per_thread_data, rxq->thread_index);
+  if (rxq->mode == VNET_HW_IF_RX_MODE_POLLING)
+    ptd->polling_q_count++;
   else
-    rxq->int_mode = 1;
+    {
+      ASSERT (ptd->polling_q_count != 0);
+      ptd->polling_q_count--;
+    }
 
   return 0;
 }
@@ -288,6 +300,7 @@ vmxnet3_rxq_init (vlib_main_t * vm, vmxnet3_device_t * vd, u16 qid, u16 qsz)
   rxq = vec_elt_at_index (vd->rxqs, qid);
   clib_memset (rxq, 0, sizeof (*rxq));
   rxq->size = qsz;
+  rxq->mode = VNET_HW_IF_RX_MODE_POLLING;
   for (rid = 0; rid < VMXNET3_RX_RING_SIZE; rid++)
     {
       rxq->rx_desc[rid] = vlib_physmem_alloc_aligned_on_numa
@@ -534,8 +547,13 @@ vmxnet3_rxq_irq_handler (vlib_main_t * vm, vlib_pci_dev_handle_t h, u16 line)
   u16 qid = line;
   vmxnet3_rxq_t *rxq = vec_elt_at_index (vd->rxqs, qid);
 
-  if (vec_len (vd->rxqs) > qid && vd->rxqs[qid].int_mode != 0)
-    vnet_hw_if_rx_queue_set_int_pending (vnm, rxq->queue_index);
+  if (vec_len (vd->rxqs) > qid && (rxq->mode != VNET_HW_IF_RX_MODE_POLLING))
+    {
+      vmxnet3_per_thread_data_t *ptd =
+       vec_elt_at_index (vmxm->per_thread_data, rxq->thread_index);
+      if (ptd->polling_q_count == 0)
+       vnet_hw_if_rx_queue_set_int_pending (vnm, rxq->queue_index);
+    }
 }
 
 static void
@@ -815,12 +833,20 @@ vmxnet3_create_if (vlib_main_t * vm, vmxnet3_create_if_args_t * args)
   {
     vmxnet3_rxq_t *rxq = vec_elt_at_index (vd->rxqs, qid);
     u32 qi, fi;
+    vmxnet3_per_thread_data_t *ptd;
 
     qi = vnet_hw_if_register_rx_queue (vnm, vd->hw_if_index, qid,
                                       VNET_HW_IF_RXQ_THREAD_ANY);
     fi = vlib_pci_get_msix_file_index (vm, vd->pci_dev_handle, qid);
     vnet_hw_if_set_rx_queue_file_index (vnm, qi, fi);
     rxq->queue_index = qi;
+    rxq->thread_index =
+      vnet_hw_if_get_rx_queue_thread_index (vnm, rxq->queue_index);
+    if (rxq->mode == VNET_HW_IF_RX_MODE_POLLING)
+      {
+       ptd = vec_elt_at_index (vmxm->per_thread_data, rxq->thread_index);
+       ptd->polling_q_count++;
+      }
     rxq->buffer_pool_index =
       vnet_hw_if_get_rx_queue_numa_node (vnm, rxq->queue_index);
     vmxnet3_rxq_refill_ring0 (vm, vd, rxq);
@@ -886,7 +912,14 @@ vmxnet3_delete_if (vlib_main_t * vm, vmxnet3_device_t * vd)
       vmxnet3_rxq_t *rxq = vec_elt_at_index (vd->rxqs, i);
       u16 mask = rxq->size - 1;
       u16 rid;
+      vmxnet3_per_thread_data_t *ptd =
+       vec_elt_at_index (vmxm->per_thread_data, rxq->thread_index);
 
+      if (rxq->mode == VNET_HW_IF_RX_MODE_POLLING)
+       {
+         ASSERT (ptd->polling_q_count != 0);
+         ptd->polling_q_count--;
+       }
       for (rid = 0; rid < VMXNET3_RX_RING_SIZE; rid++)
        {
          vmxnet3_rx_ring *ring;

diff --git a/src/plugins/vmxnet3/vmxnet3.h b/src/plugins/vmxnet3/vmxnet3.h
index 7510768..81aeec6 100644 (file)
--- a/src/plugins/vmxnet3/vmxnet3.h
+++ b/src/plugins/vmxnet3/vmxnet3.h
@@ -510,13 +510,20 @@ typedef struct
   u16 next;
 } vmxnet3_rx_comp_ring;
 
+typedef struct
+{
+  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
+  u32 polling_q_count;
+} vmxnet3_per_thread_data_t;
+
 typedef struct
 {
   CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
   u16 size;
-  u8 int_mode;
+  u32 mode;
   u8 buffer_pool_index;
   u32 queue_index;
+  u32 thread_index;
   vmxnet3_rx_ring rx_ring[VMXNET3_RX_RING_SIZE];
   vmxnet3_rx_desc *rx_desc[VMXNET3_RX_RING_SIZE];
   vmxnet3_rx_comp *rx_comp;
@@ -594,6 +601,7 @@ typedef struct
   vmxnet3_device_t *devices;
   u16 msg_id_base;
   vlib_log_class_t log_default;
+  vmxnet3_per_thread_data_t *per_thread_data;
 } vmxnet3_main_t;
 
 extern vmxnet3_main_t vmxnet3_main;