buffers: support per-numa-domain buffer size

Currently, buffers-per-numa is used for all NUMA domains, and there's
no way to allocate different amounts for each domain.

Therefore, this adds a per-NUMA-domain buffer config section, which
currently has a single option to set the number of buffers.

If it's not specified or set to zero, the code falls back to
buffers-per-numa as before.

Type: improvement
Change-Id: If35d7a9eff6f8d1d78063ea7873dbf50780d0ec3
Signed-off-by: Lukas Stockner <lstockner@genesiscloud.com>
diff --git a/docs/configuration/reference.rst b/docs/configuration/reference.rst
index 598e195..d288a6d 100644
--- a/docs/configuration/reference.rst
+++ b/docs/configuration/reference.rst
@@ -497,6 +497,9 @@
       buffers-per-numa 128000
       default data-size 2048
       page-size default-hugepage
+      numa 1 {
+         buffers 64000
+      }
    }
 
 buffers-per-numa number
@@ -532,6 +535,31 @@
    page-size default
    page-size default-hugepage
 
+numa <numa index> { .. }
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Settings specific to a single NUMA domain.
+
+.. code-block:: console
+
+   buffers {
+      numa 0 {
+         buffers 32768
+      }
+   }
+
+buffers <n>
+^^^^^^^^^^^^^^^
+
+The number of buffers allocated for this specific NUMA domain.
+Default is 0, which falls back to the value configured in **buffers-per-numa**.
+
+.. code-block:: console
+
+   numa 0 {
+      buffers 32768
+   }
+
 
 The dpdk Section
 ----------------