VPP-130: MagLev-like Load Balancer

This plugin provides load balancing for VPP in a way that is largely inspired
from Google's MagLev: http://research.google.com/pubs/pub44824.html

More info in the README.md

Change-Id: I1223f495d5c2d5200808a398504119f2830337e9
Signed-off-by: Pierre Pfister <ppfister@cisco.com>

1 files changed, 41 insertions, 0 deletions

diff --git a/plugins/lb-plugin/lb/refcount.c b/plugins/lb-plugin/lb/refcount.c
new file mode 100644
index 00000000000..22415c8889e
--- /dev/null
+++ b/plugins/lb-plugin/lb/refcount.c
@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2016 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.
+ */
+
+#include <lb/refcount.h>
+
+void __vlib_refcount_resize(vlib_refcount_per_cpu_t *per_cpu, u32 size)
+{
+  u32 *new_counter = 0, *old_counter;
+  vec_validate(new_counter, size);
+  memcpy(new_counter, per_cpu->counters, per_cpu->length);
+  old_counter = per_cpu->counters;
+  per_cpu->counters = new_counter;
+  CLIB_MEMORY_BARRIER();
+  per_cpu->length = vec_len(new_counter);
+  vec_free(old_counter);
+}
+
+u64 vlib_refcount_get(vlib_refcount_t *r, u32 index)
+{
+  u64 count = 0;
+  vlib_thread_main_t *tm = vlib_get_thread_main ();
+  u32 cpu_index;
+  for (cpu_index = 0; cpu_index < tm->n_vlib_mains; cpu_index++) {
+    if (r->per_cpu[cpu_index].length > index)
+      count += r->per_cpu[cpu_index].counters[index];
+  }
+  return count;
+}
+