diff --git a/sys/vm/swap_pager.c b/sys/vm/swap_pager.c
--- a/sys/vm/swap_pager.c
+++ b/sys/vm/swap_pager.c
@@ -2289,22 +2289,17 @@
 	VM_OBJECT_ASSERT_LOCKED(object);
 	MPASS((object->flags & OBJ_SWAP) != 0);
 
-	if (pctrie_is_empty(&object->un_pager.swp.swp_blks))
-		return (object->size);
 	sb = SWAP_PCTRIE_LOOKUP_GE(&object->un_pager.swp.swp_blks,
 	    rounddown(pindex, SWAP_META_PAGES));
 	if (sb == NULL)
 		return (object->size);
-	if (sb->p < pindex) {
-		for (i = pindex % SWAP_META_PAGES; i < SWAP_META_PAGES; i++) {
-			if (sb->d[i] != SWAPBLK_NONE)
-				return (sb->p + i);
-		}
-		sb = SWAP_PCTRIE_LOOKUP_GE(&object->un_pager.swp.swp_blks,
-		    roundup(pindex, SWAP_META_PAGES));
-		if (sb == NULL)
-			return (object->size);
+	for (i = pindex - sb->p; i < SWAP_META_PAGES; i++) {
+		if (sb->d[i] != SWAPBLK_NONE)
+			return (sb->p + i);
 	}
+	sb = SWAP_PCTRIE_LOOKUP_GE(&object->un_pager.swp.swp_blks, pindex);
+	if (sb == NULL)
+		return (object->size);
 	for (i = 0; i < SWAP_META_PAGES; i++) {
 		if (sb->d[i] != SWAPBLK_NONE)
 			return (sb->p + i);
@@ -2314,7 +2309,7 @@
 	 * We get here if a swblk is present in the trie but it
 	 * doesn't map any blocks.
 	 */
-	MPASS(0);
+	__unreachable();
 	return (object->size);
 }