rdma: improve rx loop

Type: improvement
Change-Id: If81847bc0c92d167ce03e1e94a2f8e18f8154af2
Signed-off-by: Damjan Marion <damarion@cisco.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/src/vlib/buffer_funcs.h b/src/vlib/buffer_funcs.h
index 58abdb18841..07f270c8c23 100644
--- a/src/vlib/buffer_funcs.h
+++ b/src/vlib/buffer_funcs.h
@@ -140,6 +140,24 @@ vlib_buffer_copy_indices (u32 * dst, u32 * src, u32 n_indices)
     }
 }
 
+always_inline void
+vlib_buffer_copy_indices_from_ring (u32 * dst, u32 * ring, u32 start,
+				    u32 ring_size, u32 n_buffers)
+{
+  ASSERT (n_buffers <= ring_size);
+
+  if (PREDICT_TRUE (start + n_buffers <= ring_size))
+    {
+      vlib_buffer_copy_indices (dst, ring + start, n_buffers);
+    }
+  else
+    {
+      u32 n = ring_size - start;
+      vlib_buffer_copy_indices (dst, ring + start, n);
+      vlib_buffer_copy_indices (dst + n, ring, n_buffers - n);
+    }
+}
+
 STATIC_ASSERT_OFFSET_OF (vlib_buffer_t, template_end, 64);
 static_always_inline void
 vlib_buffer_copy_template (vlib_buffer_t * b, vlib_buffer_t * bt)