Add post-gc-hook.

diff --git a/etc/NEWS b/etc/NEWS
index acfa045887f7e6e9b072c80080f2673c573baef4..d15bd07d70d193c9cd3bb5142de5358ddb6c9a55 100644 (file)
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -29,6 +29,9 @@ defined as an alias, the function returns VARIABLE.
 It might be noteworthy that variables aliases work for all kinds of
 variables, including buffer-local and frame-local variables.
 
+** Functions from `post-gc-hook' are run at the end of garbage
+collection.  The hook is run with GC inhibited, so use it with care.
+
 \f
 * Installation Changes in Emacs 21.1