Document `asyncio` performance improvement in What's New (#103370)

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

diff --git a/Doc/whatsnew/3.12.rst b/Doc/whatsnew/3.12.rst
index 66e40ef7326cc04721b669469e611bcaaadf9669..651caed864fef76b1faa119ac8caa59a27ffab47 100644 (file)
--- a/Doc/whatsnew/3.12.rst
+++ b/Doc/whatsnew/3.12.rst
@@ -210,6 +210,11 @@ array
 asyncio
 -------
 
+* The performance of writing to sockets in :mod:`asyncio` has been
+  significantly improved. ``asyncio`` now avoids unnecessary copying when
+  writing to sockets and uses :meth:`~socket.socket.sendmsg` if the platform
+  supports it. (Contributed by Kumar Aditya in :gh:`91166`.)
+
 * On Linux, :mod:`asyncio` uses :class:`~asyncio.PidfdChildWatcher` by default
   if :func:`os.pidfd_open` is available and functional instead of
   :class:`~asyncio.ThreadedChildWatcher`.