vlib: add node adaptive mode flag

Don't switch nodes from interrupt to polling state unless adaptive mode
flag set. For starters, flag set only on interface input nodes
with no polling rx queue and at least one in adaptive mode.

Type: improvement

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: Ica1c75f605ead82b7cf74c45c6a774461008f054

diff --git a/src/vlib/main.c b/src/vlib/main.c
index 41f74b9..fc6fadb 100644 (file)
--- a/src/vlib/main.c
+++ b/src/vlib/main.c
@@ -1056,13 +1056,9 @@ dispatch_node (vlib_main_t * vm,
                                      /* n_vectors */ n,
                                      /* n_clocks */ t - last_time_stamp);
 
-  /* When in interrupt mode and vector rate crosses threshold switch to
-     polling mode. */
-  if (PREDICT_FALSE ((dispatch_state == VLIB_NODE_STATE_INTERRUPT)
-                    || (dispatch_state == VLIB_NODE_STATE_POLLING
-                        && (node->flags
-                            &
-                            VLIB_NODE_FLAG_SWITCH_FROM_INTERRUPT_TO_POLLING_MODE))))
+  /* When in adaptive mode and vector rate crosses threshold switch to
+     polling mode and vice versa. */
+  if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_ADAPTIVE_MODE))
     {
       /* *INDENT-OFF* */
       ELOG_TYPE_DECLARE (e) =

diff --git a/src/vlib/node.h b/src/vlib/node.h
index 9a3bb83..aae5103 100644 (file)
--- a/src/vlib/node.h
+++ b/src/vlib/node.h
@@ -294,6 +294,7 @@ typedef struct vlib_node_t
 #define VLIB_NODE_FLAG_SWITCH_FROM_INTERRUPT_TO_POLLING_MODE (1 << 6)
 #define VLIB_NODE_FLAG_SWITCH_FROM_POLLING_TO_INTERRUPT_MODE (1 << 7)
 #define VLIB_NODE_FLAG_TRACE_SUPPORTED (1 << 8)
+#define VLIB_NODE_FLAG_ADAPTIVE_MODE                        (1 << 9)
 
   /* State for input nodes. */
   u8 state;

diff --git a/src/vlib/node_funcs.h b/src/vlib/node_funcs.h
index d65fd2e..3c90a88 100644 (file)
--- a/src/vlib/node_funcs.h
+++ b/src/vlib/node_funcs.h
@@ -224,6 +224,27 @@ vlib_node_get_state (vlib_main_t * vm, u32 node_index)
   return n->state;
 }
 
+always_inline void
+vlib_node_set_flag (vlib_main_t *vm, u32 node_index, u16 flag, u8 enable)
+{
+  vlib_node_runtime_t *r;
+  vlib_node_t *n;
+
+  n = vlib_get_node (vm, node_index);
+  r = vlib_node_get_runtime (vm, node_index);
+
+  if (enable)
+    {
+      n->flags |= flag;
+      r->flags |= flag;
+    }
+  else
+    {
+      n->flags &= ~flag;
+      r->flags &= ~flag;
+    }
+}
+
 always_inline void
 vlib_node_set_interrupt_pending (vlib_main_t *vm, u32 node_index)
 {

diff --git a/src/vnet/interface/runtime.c b/src/vnet/interface/runtime.c
index 019d3ee..c763127 100644 (file)
--- a/src/vnet/interface/runtime.c
+++ b/src/vnet/interface/runtime.c
@@ -64,6 +64,7 @@ vnet_hw_if_update_runtime_data (vnet_main_t *vnm, u32 hw_if_index)
   vnet_hw_if_rxq_poll_vector_t *pv, **d = 0;
   vlib_node_state_t *per_thread_node_state = 0;
   u32 n_threads = vec_len (vlib_mains);
+  u16 *per_thread_node_adaptive = 0;
   int something_changed = 0;
   clib_bitmap_t *pending_int = 0;
   int last_int = -1;
@@ -74,6 +75,7 @@ vnet_hw_if_update_runtime_data (vnet_main_t *vnm, u32 hw_if_index)
   vec_validate (d, n_threads - 1);
   vec_validate_init_empty (per_thread_node_state, n_threads - 1,
                           VLIB_NODE_STATE_DISABLED);
+  vec_validate_init_empty (per_thread_node_adaptive, n_threads - 1, 0);
 
   /* find out desired node state on each thread */
   pool_foreach (rxq, im->hw_if_rx_queues)
@@ -89,7 +91,10 @@ vnet_hw_if_update_runtime_data (vnet_main_t *vnm, u32 hw_if_index)
        continue;
 
       if (rxq->mode == VNET_HW_IF_RX_MODE_POLLING)
-       per_thread_node_state[ti] = VLIB_NODE_STATE_POLLING;
+       {
+         per_thread_node_state[ti] = VLIB_NODE_STATE_POLLING;
+         per_thread_node_adaptive[ti] = 0;
+       }
 
       if (per_thread_node_state[ti] == VLIB_NODE_STATE_POLLING)
        continue;
@@ -97,6 +102,9 @@ vnet_hw_if_update_runtime_data (vnet_main_t *vnm, u32 hw_if_index)
       if (rxq->mode == VNET_HW_IF_RX_MODE_INTERRUPT ||
          rxq->mode == VNET_HW_IF_RX_MODE_ADAPTIVE)
        per_thread_node_state[ti] = VLIB_NODE_STATE_INTERRUPT;
+
+      if (rxq->mode == VNET_HW_IF_RX_MODE_ADAPTIVE)
+       per_thread_node_adaptive[ti] = 1;
     }
 
   /* construct per-thread polling vectors */
@@ -190,6 +198,8 @@ vnet_hw_if_update_runtime_data (vnet_main_t *vnm, u32 hw_if_index)
            }
 
          vlib_node_set_state (vm, node_index, per_thread_node_state[i]);
+         vlib_node_set_flag (vm, node_index, VLIB_NODE_FLAG_ADAPTIVE_MODE,
+                             per_thread_node_adaptive[i]);
 
          if (last_int >= 0)
            clib_interrupt_resize (&rt->rxq_interrupts, last_int + 1);
@@ -219,4 +229,5 @@ vnet_hw_if_update_runtime_data (vnet_main_t *vnm, u32 hw_if_index)
 
   vec_free (d);
   vec_free (per_thread_node_state);
+  vec_free (per_thread_node_adaptive);
 }