[PATCH dpdk] doc: announce rte_graph ABI changes for 26.11

[Robin Jarry <rjarry@redhat.com>]

The graph library internal scheduling will change from a circular
buffer to a topological bitmap. This affects struct rte_graph and
struct rte_node layouts.

Signed-off-by: Robin Jarry <rjarry@redhat.com>
---
 doc/guides/rel_notes/deprecation.rst | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
index f5c12cc74762..6183f33b893a 100644
--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
@@ -61,6 +61,13 @@ Deprecation Notices
 * mempool: The object array in ``struct rte_mempool_cache`` is oversize by factor two,
   and will be reduced to ``RTE_MEMPOOL_CACHE_MAX_SIZE`` in DPDK 26.11.
 
+* graph: The internal scheduling mechanism of ``struct rte_graph`` will change
+  in DPDK 26.11. The circular buffer fields (``head``, ``tail``, ``cir_mask``,
+  ``cir_start``) will be replaced with a topological bitmap scheduler.
+  A new field will be added to ``struct rte_node`` for the scheduling order.
+  The graph walk functions will process nodes in topological order using bitmap
+  scanning instead of the circular buffer.
+
 * lib: will fix extending some enum/define breaking the ABI. There are multiple
   samples in DPDK that enum/define terminated with a ``.*MAX.*`` value which is
   used by iterators, and arrays holding these values are sized with this
-- 
2.55.0