realloc(): align the space to be de-allocated

src/realloc.c

@@ -97,21 +97,31 @@ void * realloc(void *ptr, size_t size) {
 #endif /* REQUEST_SIZE_INFO */
 
             LOCK_RAW_BLOCK(owner_raw_block);
-            owner_raw_block->size = full_size;
 #ifdef REQUEST_SIZE_INFO
             owner_raw_block->requested_size = size;
 #endif /* REQUEST_SIZE_INFO */
             UNLOCK_RAW_BLOCK(owner_raw_block);
 
+            // FIXME This is pagesize and mmap-specific
+#ifdef PAGESIZE_ALIGN
+            if(remaining_size > pagesize) {
+                remaining_size = pagesize * ((remaining_size + pagesize - 1) /
+                        pagesize);
+
+                LOCK_RAW_BLOCK(owner_raw_block);
+                owner_raw_block->size = full_size;
+                UNLOCK_RAW_BLOCK(owner_raw_block);
+
 #ifdef WITH_ALLOCATOR_STATS
-            LOCK_GLOBAL();
-            systemallocator.dmm_stats.total_mem_allocated -= remaining_size;
-            UNLOCK_GLOBAL();
+                LOCK_GLOBAL();
+                systemallocator.dmm_stats.total_mem_allocated -= remaining_size;
+                UNLOCK_GLOBAL();
 #endif /* WITH_ALLOCATOR_STATS */
 
-            // FIXME This is mmap-specific
-            munmap((void *)((uintptr_t) owner_raw_block +
-                        owner_raw_block->size), remaining_size);
+                munmap((void *)((uintptr_t) owner_raw_block +
+                            owner_raw_block->size), remaining_size);
+            }
+#endif /* PAGESIZE_ALIGN */
 
             return_ptr = ptr;