/**
* Sentinel used to keep trace of unset pages in disk->page_array.
*/
-#define PAGE_UNSET_SENTINEL ((1 << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t))) - 1)
+#define PAGE_UNSET_SENTINEL ((pgcnt_t)((1L << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t))) - 1))
/**
* Type interface for disk page read function.