platforms define as 512K. For 64-bit platforms as 32MB. The lower

ChangeLog

@@ -1,7 +1,7 @@
 2006-08-21  Ulrich Drepper  <drepper@redhat.com>
 
 	* malloc/malloc.c (DEFAULT_MMAP_THRESHOLD_MAX): For 32-bit
-	platforms define as 1MB.  For 64-bit platforms as 32MB.  The lower
+	platforms define as 512K.  For 64-bit platforms as 32MB.  The lower
 	limit is needed to avoid the exploding of the address space
 	requirement for secondary heaps.
 	* malloc/arena.c (HEAP_MAX_SIZE): Define using

malloc/arena.c

@@ -25,7 +25,7 @@
 #define HEAP_MIN_SIZE (32*1024)
 #ifndef HEAP_MAX_SIZE
 # ifdef DEFAULT_MMAP_THRESHOLD_MAX
-#  define HEAP_MAX_SIZE DEFAULT_MMAP_THRESHOLD_MAX
+#  define HEAP_MAX_SIZE (2 * DEFAULT_MMAP_THRESHOLD_MAX)
 # else
 #  define HEAP_MAX_SIZE (1024*1024) /* must be a power of two */
 # endif

malloc/malloc.c

@@ -1427,12 +1427,12 @@ int      __posix_memalign(void **, size_t, size_t);
 #ifndef DEFAULT_MMAP_THRESHOLD_MAX
   /* For 32-bit platforms we cannot increase the maximum mmap
      threshold much because it is also the minimum value for the
-     maximum heap size and its alignment.  Going above 1MB wastes too
-     much address space.  */
+     maximum heap size and its alignment.  Going above 512k (i.e., 1M
+     for new heaps) wastes too much address space.  */
 # if __WORDSIZE == 32
-#  define DEFAULT_MMAP_THRESHOLD_MAX (1024 * 1024)
+#  define DEFAULT_MMAP_THRESHOLD_MAX (512 * 1024)
 # else
-#  define DEFAULT_MMAP_THRESHOLD_MAX (8 * 1024 * 1024 * sizeof(long))
+#  define DEFAULT_MMAP_THRESHOLD_MAX (4 * 1024 * 1024 * sizeof(long))
 # endif
 #endif