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diff --git a/src/vlib/counter.h b/src/vlib/counter.h
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+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+ * counter.h: simple and packet/byte counters
+ *
+ * Copyright (c) 2008 Eliot Dresselhaus
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef included_vlib_counter_h
+#define included_vlib_counter_h
+
+/** \file
+
+    Optimized thread-safe counters.
+
+    Each vlib_[simple|combined]_counter_main_t consists of a single
+    vector of thread-safe / atomically-updated u64 counters [the
+    "maxi" vector], and a (u16 **) per-thread vector [the "minis"
+    vector] of narrow, per-thread counters.
+
+    The idea is to drastically reduce the number of atomic operations.
+    In the case of packet counts, we divide the number of atomic ops
+    by 2**16, etc.
+*/
+
+/** A collection of simple counters */
+
+typedef struct
+{
+  u16 **minis;	 /**< Per-thread u16 non-atomic counters */
+  u64 *maxi;	 /**< Shared wide counters */
+  u64 *value_at_last_clear; /**< Counter values as of last clear. */
+  u64 *value_at_last_serialize;	/**< Values as of last serialize. */
+  u32 last_incremental_serialize_index;	/**< Last counter index
+                                           serialized incrementally. */
+
+  char *name;			/**< The counter collection's name. */
+} vlib_simple_counter_main_t;
+
+/** Increment a simple counter
+    @param cm - (vlib_simple_counter_main_t *) simple counter main pointer
+    @param cpu_index - (u32) the current cpu index
+    @param index - (u32) index of the counter to increment
+    @param increment - (u32) quantitiy to add to the counter
+*/
+always_inline void
+vlib_increment_simple_counter (vlib_simple_counter_main_t * cm,
+			       u32 cpu_index, u32 index, u32 increment)
+{
+  u16 *my_minis;
+  u16 *mini;
+  u32 old, new;
+
+  my_minis = cm->minis[cpu_index];
+  mini = vec_elt_at_index (my_minis, index);
+  old = mini[0];
+  new = old + increment;
+  mini[0] = new;
+
+  if (PREDICT_FALSE (mini[0] != new))
+    {
+      __sync_fetch_and_add (&cm->maxi[index], new);
+      my_minis[index] = 0;
+    }
+}
+
+/** Get the value of a simple counter
+    Scrapes the entire set of mini counters. Innacurate unless
+    worker threads which might increment the counter are
+    barrier-synchronized
+
+    @param cm - (vlib_simple_counter_main_t *) simple counter main pointer
+    @param index - (u32) index of the counter to fetch
+    @returns - (u64) current counter value
+*/
+always_inline u64
+vlib_get_simple_counter (vlib_simple_counter_main_t * cm, u32 index)
+{
+  u16 *my_minis, *mini;
+  u64 v;
+  int i;
+
+  ASSERT (index < vec_len (cm->maxi));
+
+  v = 0;
+
+  for (i = 0; i < vec_len (cm->minis); i++)
+    {
+      my_minis = cm->minis[i];
+      mini = vec_elt_at_index (my_minis, index);
+      v += mini[0];
+    }
+
+  v += cm->maxi[index];
+
+  if (index < vec_len (cm->value_at_last_clear))
+    {
+      ASSERT (v >= cm->value_at_last_clear[index]);
+      v -= cm->value_at_last_clear[index];
+    }
+
+  return v;
+}
+
+/** Clear a simple counter
+    Clears the set of per-thread u16 counters, and the u64 counter
+
+    @param cm - (vlib_simple_counter_main_t *) simple counter main pointer
+    @param index - (u32) index of the counter to clear
+*/
+always_inline void
+vlib_zero_simple_counter (vlib_simple_counter_main_t * cm, u32 index)
+{
+  u16 *my_minis;
+  int i;
+
+  ASSERT (index < vec_len (cm->maxi));
+
+  for (i = 0; i < vec_len (cm->minis); i++)
+    {
+      my_minis = cm->minis[i];
+      my_minis[index] = 0;
+    }
+
+  cm->maxi[index] = 0;
+
+  if (index < vec_len (cm->value_at_last_clear))
+    cm->value_at_last_clear[index] = 0;
+}
+
+/** Combined counter to hold both packets and byte differences.
+ */
+typedef struct
+{
+  u64 packets;			/**< packet counter */
+  u64 bytes;			/**< byte counter  */
+} vlib_counter_t;
+
+/** Add two combined counters, results in the first counter
+    @param [in,out] a - (vlib_counter_t *) dst counter
+    @param b - (vlib_counter_t *) src counter
+*/
+
+always_inline void
+vlib_counter_add (vlib_counter_t * a, vlib_counter_t * b)
+{
+  a->packets += b->packets;
+  a->bytes += b->bytes;
+}
+
+/** Subtract combined counters, results in the first counter
+    @param [in,out] a - (vlib_counter_t *) dst counter
+    @param b - (vlib_counter_t *) src counter
+*/
+always_inline void
+vlib_counter_sub (vlib_counter_t * a, vlib_counter_t * b)
+{
+  ASSERT (a->packets >= b->packets);
+  ASSERT (a->bytes >= b->bytes);
+  a->packets -= b->packets;
+  a->bytes -= b->bytes;
+}
+
+/** Clear a combined counter
+    @param a - (vlib_counter_t *) counter to clear
+*/
+always_inline void
+vlib_counter_zero (vlib_counter_t * a)
+{
+  a->packets = a->bytes = 0;
+}
+
+/** Mini combined counter */
+typedef struct
+{
+  u16 packets;			/**< Packet count */
+  i16 bytes;			/**< Byte count */
+} vlib_mini_counter_t;
+
+/** A collection of combined counters */
+typedef struct
+{
+  vlib_mini_counter_t **minis;	/**< Per-thread u16 non-atomic counter pairs */
+  vlib_counter_t *maxi;		/**< Shared wide counter pairs */
+  vlib_counter_t *value_at_last_clear;	/**< Counter values as of last clear. */
+  vlib_counter_t *value_at_last_serialize; /**< Counter values as of last serialize. */
+  u32 last_incremental_serialize_index;	/**< Last counter index serialized incrementally. */
+  char *name; /**< The counter collection's name. */
+} vlib_combined_counter_main_t;
+
+/** Clear a collection of simple counters
+    @param cm - (vlib_simple_counter_main_t *) collection to clear
+*/
+void vlib_clear_simple_counters (vlib_simple_counter_main_t * cm);
+
+/** Clear a collection of combined counters
+    @param cm - (vlib_combined_counter_main_t *) collection to clear
+*/
+void vlib_clear_combined_counters (vlib_combined_counter_main_t * cm);
+
+/** Increment a combined counter
+    @param cm - (vlib_combined_counter_main_t *) comined counter main pointer
+    @param cpu_index - (u32) the current cpu index
+    @param index - (u32) index of the counter to increment
+    @param packet_increment - (u32) number of packets to add to the counter
+    @param byte_increment - (u32) number of bytes to add to the counter
+*/
+
+always_inline void
+vlib_increment_combined_counter (vlib_combined_counter_main_t * cm,
+				 u32 cpu_index,
+				 u32 index,
+				 u32 packet_increment, u32 byte_increment)
+{
+  vlib_mini_counter_t *my_minis, *mini;
+  u32 old_packets, new_packets;
+  i32 old_bytes, new_bytes;
+
+  /* Use this CPU's mini counter array */
+  my_minis = cm->minis[cpu_index];
+
+  mini = vec_elt_at_index (my_minis, index);
+  old_packets = mini->packets;
+  old_bytes = mini->bytes;
+
+  new_packets = old_packets + packet_increment;
+  new_bytes = old_bytes + byte_increment;
+
+  mini->packets = new_packets;
+  mini->bytes = new_bytes;
+
+  /* Bytes always overflow before packets.. */
+  if (PREDICT_FALSE (mini->bytes != new_bytes))
+    {
+      vlib_counter_t *maxi = vec_elt_at_index (cm->maxi, index);
+
+      __sync_fetch_and_add (&maxi->packets, new_packets);
+      __sync_fetch_and_add (&maxi->bytes, new_bytes);
+
+      mini->packets = 0;
+      mini->bytes = 0;
+    }
+}
+
+/** Get the value of a combined counter, never called in the speed path
+    Scrapes the entire set of mini counters. Innacurate unless
+    worker threads which might increment the counter are
+    barrier-synchronized
+
+    @param cm - (vlib_combined_counter_main_t *) combined counter main pointer
+    @param index - (u32) index of the combined counter to fetch
+    @param result [out] - (vlib_counter_t *) result stored here
+*/
+
+static inline void
+vlib_get_combined_counter (vlib_combined_counter_main_t * cm,
+			   u32 index, vlib_counter_t * result)
+{
+  vlib_mini_counter_t *my_minis, *mini;
+  vlib_counter_t *maxi;
+  int i;
+
+  result->packets = 0;
+  result->bytes = 0;
+
+  for (i = 0; i < vec_len (cm->minis); i++)
+    {
+      my_minis = cm->minis[i];
+
+      mini = vec_elt_at_index (my_minis, index);
+      result->packets += mini->packets;
+      result->bytes += mini->bytes;
+    }
+
+  maxi = vec_elt_at_index (cm->maxi, index);
+  result->packets += maxi->packets;
+  result->bytes += maxi->bytes;
+
+  if (index < vec_len (cm->value_at_last_clear))
+    vlib_counter_sub (result, &cm->value_at_last_clear[index]);
+}
+
+/** Clear a combined counter
+    Clears the set of per-thread u16 counters, and the shared vlib_counter_t
+
+    @param cm - (vlib_combined_counter_main_t *) combined counter main pointer
+    @param index - (u32) index of the counter to clear
+*/
+always_inline void
+vlib_zero_combined_counter (vlib_combined_counter_main_t * cm, u32 index)
+{
+  vlib_mini_counter_t *mini, *my_minis;
+  int i;
+
+  for (i = 0; i < vec_len (cm->minis); i++)
+    {
+      my_minis = cm->minis[i];
+
+      mini = vec_elt_at_index (my_minis, index);
+      mini->packets = 0;
+      mini->bytes = 0;
+    }
+
+  vlib_counter_zero (&cm->maxi[index]);
+  if (index < vec_len (cm->value_at_last_clear))
+    vlib_counter_zero (&cm->value_at_last_clear[index]);
+}
+
+/** validate a simple counter
+    @param cm - (vlib_simple_counter_main_t *) pointer to the counter collection
+    @param index - (u32) index of the counter to validate
+*/
+
+void vlib_validate_simple_counter (vlib_simple_counter_main_t * cm,
+				   u32 index);
+/** validate a combined counter
+    @param cm - (vlib_combined_counter_main_t *) pointer to the counter
+    collection
+    @param index - (u32) index of the counter to validate
+*/
+
+void vlib_validate_combined_counter (vlib_combined_counter_main_t * cm,
+				     u32 index);
+
+/** Obtain the number of simple or combined counters allocated.
+    A macro which reduces to to vec_len(cm->maxi), the answer in either
+    case.
+
+    @param cm - (vlib_simple_counter_main_t) or
+    (vlib_combined_counter_main_t) the counter collection to interrogate
+    @returns vec_len(cm->maxi)
+*/
+#define vlib_counter_len(cm) vec_len((cm)->maxi)
+
+serialize_function_t serialize_vlib_simple_counter_main,
+  unserialize_vlib_simple_counter_main;
+serialize_function_t serialize_vlib_combined_counter_main,
+  unserialize_vlib_combined_counter_main;
+
+#endif /* included_vlib_counter_h */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */