bpo-36051: Drop GIL during large bytes.join() (GH-17757)
Improve multi-threaded performance by dropping the GIL in the fast path
of bytes.join. To avoid increasing overhead for small joins, it is only
done if the output size exceeds a threshold.
diff --git a/Misc/ACKS b/Misc/ACKS
index 7e4b81b..f3e3680 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1106,6 +1106,7 @@
Doug Mennella
Dimitri Merejkowsky
Brian Merrell
+Bruce Merry
Alexis Métaireau
Luke Mewburn
Carl Meyer
diff --git a/Misc/NEWS.d/next/Core and Builtins/2019-12-30-15-56-07.bpo-36051.imaVlq.rst b/Misc/NEWS.d/next/Core and Builtins/2019-12-30-15-56-07.bpo-36051.imaVlq.rst
new file mode 100644
index 0000000..f9d4492
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2019-12-30-15-56-07.bpo-36051.imaVlq.rst
@@ -0,0 +1 @@
+Drop the GIL during large ``bytes.join`` operations. Patch by Bruce Merry.