Issue #11849: Make it more likely for the system allocator to release
free()d memory arenas on glibc-based systems. Patch by Charles-François
Natali.
diff --git a/pyconfig.h.in b/pyconfig.h.in
index 8b5c592..89565a3 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -491,6 +491,9 @@
/* Define this if you have the makedev macro. */
#undef HAVE_MAKEDEV
+/* Define this if mallopt can set malloc mmap threshold. */
+#undef HAVE_MALLOPT_MMAP_THRESHOLD
+
/* Define to 1 if you have the `mbrtowc' function. */
#undef HAVE_MBRTOWC