Index: sys/vm/swap_pager.c
===================================================================
--- sys/vm/swap_pager.c
+++ sys/vm/swap_pager.c
@@ -155,10 +155,10 @@
 static u_long swap_total;
 static int sysctl_page_shift(SYSCTL_HANDLER_ARGS);
 SYSCTL_PROC(_vm, OID_AUTO, swap_reserved, CTLTYPE_U64 | CTLFLAG_RD | CTLFLAG_MPSAFE,
-    &swap_reserved, 0, sysctl_page_shift, "A", 
+    &swap_reserved, 0, sysctl_page_shift, "A",
     "Amount of swap storage needed to back all allocated anonymous memory.");
 SYSCTL_PROC(_vm, OID_AUTO, swap_total, CTLTYPE_U64 | CTLFLAG_RD | CTLFLAG_MPSAFE,
-    &swap_total, 0, sysctl_page_shift, "A", 
+    &swap_total, 0, sysctl_page_shift, "A",
     "Total amount of available swap storage.");
 
 static int overcommit = 0;
@@ -1650,9 +1650,41 @@
 	return (nswapdev);
 }
 
+static void
+swp_pager_force_dirty(vm_page_t m)
+{
+
+	vm_object_pip_wakeup(m->object);
+	vm_page_dirty(m);
+#ifdef INVARIANTS
+	vm_page_lock(m);
+	if (m->wire_count == 0 && m->queue == PQ_NONE)
+		panic("page %p is neither wired nor queued", m);
+	vm_page_unlock(m);
+#endif
+	vm_page_xunbusy(m);
+	vm_pager_page_unswapped(m);
+}
+
+static void
+swp_pager_force_launder(vm_page_t m)
+{
+
+	vm_object_pip_wakeup(m->object);
+	vm_page_dirty(m);
+	vm_page_lock(m);
+	vm_page_launder(m);
+	vm_page_unlock(m);
+	vm_page_xunbusy(m);
+	vm_pager_page_unswapped(m);
+}
+
 /*
  * SWP_PAGER_FORCE_PAGEIN() - force a swap block to be paged in
  *
+ *	Returns the number of pages that are paged in.  The maximum number of
+ *	pages this function can page in at a time is SWB_NPAGES.
+ *
  *	This routine dissociates the page at the given index within an object
  *	from its backing store, paging it in if it does not reside in memory.
  *	If the page is paged in, it is marked dirty and placed in the laundry
@@ -1663,40 +1695,32 @@
  *	We also attempt to swap in all other pages in the swap block.
  *	However, we only guarantee that the one at the specified index is
  *	paged in.
- *
- *	XXX - The code to page the whole block in doesn't work, so we
- *	      revert to the one-by-one behavior for now.  Sigh.
  */
-static inline void
+static int
 swp_pager_force_pagein(vm_object_t object, vm_pindex_t pindex)
 {
-	vm_page_t m;
+	vm_page_t ma[SWB_NPAGES];
+	int i, j, npages;
 
-	vm_object_pip_add(object, 1);
-	m = vm_page_grab(object, pindex, VM_ALLOC_NORMAL);
-	if (m->valid == VM_PAGE_BITS_ALL) {
-		vm_object_pip_wakeup(object);
-		vm_page_dirty(m);
-#ifdef INVARIANTS
-		vm_page_lock(m);
-		if (m->wire_count == 0 && m->queue == PQ_NONE)
-			panic("page %p is neither wired nor queued", m);
-		vm_page_unlock(m);
-#endif
-		vm_page_xunbusy(m);
-		vm_pager_page_unswapped(m);
-		return;
+	KASSERT(swap_pager_haspage(object, pindex, NULL, &npages),
+	    ("%s: missing page %llu", __func__, pindex));
+	npages += 1;
+	npages = vm_page_grab_pages(object, pindex, VM_ALLOC_NORMAL, ma, npages);
+	vm_object_pip_add(object, npages);
+	for (i = j = 0;; i++) {
+		if (i < npages && ma[i]->valid != VM_PAGE_BITS_ALL)
+			continue;
+		if (j < i && (swap_pager_getpages(object, &ma[j], i - j, NULL,
+		    NULL) != VM_PAGER_OK))
+			panic("swp_pager_force_pagein: read from swap failed "
+			    "for page %llu", ma[i]->pindex );
+		while (j < i)
+			swp_pager_force_launder(ma[j++]);
+		if (i == npages)
+			break;
+		swp_pager_force_dirty(ma[j++]);
 	}
-
-	if (swap_pager_getpages(object, &m, 1, NULL, NULL) != VM_PAGER_OK)
-		panic("swap_pager_force_pagein: read from swap failed");/*XXX*/
-	vm_object_pip_wakeup(object);
-	vm_page_dirty(m);
-	vm_page_lock(m);
-	vm_page_launder(m);
-	vm_page_unlock(m);
-	vm_page_xunbusy(m);
-	vm_pager_page_unswapped(m);
+	return (npages);
 }
 
 /*
@@ -1745,16 +1769,22 @@
 		if (object->type != OBJT_SWAP)
 			goto next_obj;
 
-		for (pi = 0; (sb = SWAP_PCTRIE_LOOKUP_GE(
-		    &object->un_pager.swp.swp_blks, pi)) != NULL; ) {
+		for (pi = 0, i = 0; (sb = SWAP_PCTRIE_LOOKUP_GE(
+		    &object->un_pager.swp.swp_blks, pi)) != NULL;) {
 			pi = sb->p + SWAP_META_PAGES;
-			for (i = 0; i < SWAP_META_PAGES; i++) {
-				if (sb->d[i] == SWAPBLK_NONE)
-					continue;
-				if (swp_pager_isondev(sb->d[i], sp))
-					swp_pager_force_pagein(object,
+			/*
+			 * If last swp_pager_force_pagein() call already
+			 * paged-in this block, we skip the while block
+			 * and advance to the next sb-d[] block.
+			 */
+			while (i < SWAP_META_PAGES) {
+				if (swp_pager_isondev(sb->d[i], sp)) {
+					i += swp_pager_force_pagein(object,
 					    sb->p + i);
+				} else
+					i++;
 			}
+			i -= SWAP_META_PAGES;
 		}
 next_obj:
 		VM_OBJECT_WUNLOCK(object);
@@ -1807,7 +1837,7 @@
 	}
 	return (true);
 }
-   
+
 /*
  * SWP_PAGER_META_BUILD() -	add swap block to swap meta data for object
  *
Index: sys/vm/vm_swapout.c
===================================================================
--- sys/vm/vm_swapout.c
+++ sys/vm/vm_swapout.c
@@ -570,7 +570,8 @@
 {
 	vm_object_t ksobj;
 	vm_page_t ma[KSTACK_MAX_PAGES];
-	int a, count, i, j, pages, rv;
+	int a, count, i, j, pages;
+	boolean_t rv;
 
 	pages = td->td_kstack_pages;
 	ksobj = td->td_kstack_obj;
@@ -588,8 +589,8 @@
 		for (j = i + 1; j < pages; j++)
 			if (ma[j]->valid == VM_PAGE_BITS_ALL)
 				break;
-		rv = vm_pager_has_page(ksobj, ma[i]->pindex, NULL, &a);
-		KASSERT(rv == 1, ("%s: missing page %p", __func__, ma[i]));
+		KASSERT(vm_pager_has_page(ksobj, ma[i]->pindex, NULL, &a),
+		    ("%s: missing page %p", __func__, ma[i]));
 		count = min(a + 1, j - i);
 		rv = vm_pager_get_pages(ksobj, ma + i, count, NULL, NULL);
 		KASSERT(rv == VM_PAGER_OK, ("%s: cannot get kstack for proc %d",