--- a/src/Doc/JEdit/JEdit.thy Sun Nov 20 16:22:32 2016 +0100
+++ b/src/Doc/JEdit/JEdit.thy Sun Nov 20 17:10:30 2016 +0100
@@ -2020,6 +2020,27 @@
\<^bold>\<open>Workaround:\<close> Use native full-screen control of the window manager (notably
on Mac OS X).
+
+ \<^item> \<^bold>\<open>Problem:\<close> Heap space of the JVM may fill up and render the Prover IDE
+ unresponsive, e.g.\ when editing big Isabelle sessions with many theories.
+
+ \<^bold>\<open>Workaround:\<close> On a 64bit platform, ensure that the JVM runs in 64bit mode,
+ but the Isabelle/ML process remains in 32bit mode! Do not switch Isabelle/ML
+ into 64bit mode in the expectation to be ``more efficient'' --- this
+ requires approx.\ 32\,GB to make sense.
+
+ For the JVM, always use the 64bit version. That is the default on all
+ platforms, except for Windows: the standard download is for win32, but there
+ is a separate download for win64. This implicitly provides a larger default
+ heap for the JVM.
+
+ Moreover, it is possible to increase JVM heap parameters explicitly, by
+ editing platform-specific files (for ``properties'' or ``options'') that are
+ associated with the main app bundle.
+
+ Also note that jEdit provides a heap space monitor in the status line
+ (bottom-right). Double-clicking on that causes full garbage-collection,
+ which sometimes helps in low-memory situations.
\<close>
end
\ No newline at end of file