emacs-28 4cc22f8: * etc/PROBLEMS: Mention X forwarding slowdowns. (Bug#7092)

[Stefan Kangas]

branch: emacs-28
commit 4cc22f89189648621c42984110dade2c17647878
Author: Stefan Kangas <stefan@marxist.se>
Commit: Stefan Kangas <stefan@marxist.se>

    * etc/PROBLEMS: Mention X forwarding slowdowns.  (Bug#7092)
---
 etc/PROBLEMS | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/etc/PROBLEMS b/etc/PROBLEMS
index 8055d0e..19c6fed 100644
--- a/etc/PROBLEMS
+++ b/etc/PROBLEMS
@@ -1644,6 +1644,13 @@ restart the X server after the monitor configuration has 
been changed.
 
 * Runtime problems on character terminals
 
+*** With X forwarding, mouse highlighting can make Emacs slow.
+
+If you see slow updates when moving the mouse in an Emacs running on a
+remote X server, try this:
+
+    (setq mouse-highlight nil)
+
 ** The meta key does not work on xterm.
 
 Typing M-x rings the terminal bell, and inserts a string like ";120~".