From 47c0cab248ca09deb9508ff29edfd1dfc11b5f31 Mon Sep 17 00:00:00 2001
From: Samuel Williams <samuel.williams@oriontransfer.co.nz>
Date: Mon, 1 Jul 2019 16:24:39 +1200
Subject: [PATCH] Add details of fiber pool and coroutine selection to NEWS.

---
 NEWS | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/NEWS b/NEWS
index 4b6e756ab5..3f841a6939 100644
--- a/NEWS
+++ b/NEWS
@@ -259,6 +259,19 @@ profile.rb, Profiler__::
 
 === Implementation improvements
 
+Fiber::
+
+  * Allow selecting different coroutine implementation by using
+    `--with-coroutine=`, e.g.
+
+         ./confgure --with-coroutine=ucontext
+         ./confgure --with-coroutine=copy
+
+  * Replace previous stack cache with fiber pool cache. The fiber pool
+    allocates many stacks in a single memory region. Stack allocation
+    becomes O(log N) and fiber creation is amortized O(1). Around 10x
+    performance improvement was measured in micro-benchmarks.
+
 Thread::
 
   * VM stack memory allocation is now combined with native thread stack,