mmap obmalloc arenas so that they may be immediately returned to the system when unused (closes #20494)
diff --git a/Misc/NEWS b/Misc/NEWS
index ed01564..b48cc85 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -9,6 +9,10 @@
Core and Builtins
-----------------
+- Issue #20494: Ensure that free()d memory arenas are really released on POSIX
+ systems supporting anonymous memory mappings. Patch by Charles-François
+ Natali.
+
- Issue #17825: Cursor "^" is correctly positioned for SyntaxError and
IndentationError.