- nah->next_free = __malloc_head.next_free;
- nah->prev_free = &__malloc_head;
- __malloc_head.next_free = nah;
- nah->next_free->prev_free = nah;
+ if (newsize > oldsize) {
+ /* Hack: this free block is in the path of a memory object
+ which has already been grown at least once. As such, put
+ it at the *end* of the freelist instead of the beginning;
+ trying to save it for future realloc()s of the same block. */
+ nah->prev_free = __malloc_head.prev_free;
+ nah->next_free = &__malloc_head;
+ __malloc_head.prev_free = nah;
+ nah->prev_free->next_free = nah;
+ } else {
+ nah->next_free = __malloc_head.next_free;
+ nah->prev_free = &__malloc_head;
+ __malloc_head.next_free = nah;
+ nah->next_free->prev_free = nah;
+ }