Merged revisions 87792 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k

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  r87792 | antoine.pitrou | 2011-01-06 17:31:28 +0100 (jeu., 06 janv. 2011) | 3 lines

  Elaborate about the GIL.
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diff --git a/Doc/library/threading.rst b/Doc/library/threading.rst
index c9ef294..efb0476 100644
--- a/Doc/library/threading.rst
+++ b/Doc/library/threading.rst
@@ -17,6 +17,17 @@
    methods and functions in this module in the Python 2.x series are still
    supported by this module.
 
+.. impl-detail::
+
+   Due to the :term:`Global Interpreter Lock`, in CPython only one thread
+   can execute Python code at once (even though certain performance-oriented
+   libraries might overcome this limitation).
+   If you want your application to make better of use of the computational
+   resources of multi-core machines, you are advised to use
+   :mod:`multiprocessing`. However, threading is still an appropriate model
+   if you want to run multiple I/O-bound tasks simultaneously.
+
+
 This module defines the following functions and objects: