Index: vm/vm_pageout.c
===================================================================
--- vm/vm_pageout.c	(revision 236313)
+++ vm/vm_pageout.c	(working copy)
@@ -116,6 +116,7 @@
 static void vm_pageout_scan(int pass);
 
 struct proc *pageproc;
+static struct thread *pagethread;
 
 static struct kproc_desc page_kp = {
 	"pagedaemon",
@@ -1558,6 +1559,7 @@
 	if (vm_pageout_full_stats_interval == 0)
 		vm_pageout_full_stats_interval = vm_pageout_stats_interval * 4;
 
+	pagethread = curthread;
 	swap_pager_swap_init();
 	pass = 0;
 	/*
@@ -1574,7 +1576,13 @@
 		if (vm_pages_needed && !vm_page_count_min()) {
 			if (!vm_paging_needed())
 				vm_pages_needed = 0;
+			critical_enter();
+			thread_lock(pagethread);
+			if (pagethread->td_flags & TDF_BORROWING)
+				sched_unlend_prio(pagethread, PRI_MAX);
+			thread_unlock(pagethread);
 			wakeup(&cnt.v_free_count);
+			critical_exit();
 		}
 		if (vm_pages_needed) {
 			/*
@@ -1614,6 +1622,22 @@
 }
 
 /*
+ * Called by threads blocking on pagedaemon to lend their priority to
+ * pagedaemon while waiting for it to free pages.
+ */
+void
+pagedaemon_lendprio(void)
+{
+
+	if (curthread != pagethread) {
+		thread_lock(pagethread);
+		if (pagethread->td_priority > curthread->td_priority)
+			sched_lend_prio(pagethread, curthread->td_priority);
+		thread_unlock(pagethread);
+	}
+}
+
+/*
  * Unless the free page queue lock is held by the caller, this function
  * should be regarded as advisory.  Specifically, the caller should
  * not msleep() on &cnt.v_free_count following this function unless
Index: vm/vm_pageout.h
===================================================================
--- vm/vm_pageout.h	(revision 236313)
+++ vm/vm_pageout.h	(working copy)
@@ -94,6 +94,7 @@
  *	Signal pageout-daemon and wait for it.
  */
 
+void pagedaemon_lendprio(void);
 extern void pagedaemon_wakeup(void);
 #define VM_WAIT vm_wait()
 #define VM_WAITPFAULT vm_waitpfault()
Index: vm/vm_page.c
===================================================================
--- vm/vm_page.c	(revision 236313)
+++ vm/vm_page.c	(working copy)
@@ -1863,6 +1863,7 @@
 			vm_pages_needed = 1;
 			wakeup(&vm_pages_needed);
 		}
+		pagedaemon_lendprio();
 		msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PVM,
 		    "vmwait", 0);
 	}
@@ -1887,6 +1888,7 @@
 		vm_pages_needed = 1;
 		wakeup(&vm_pages_needed);
 	}
+	pagedaemon_lendprio();
 	msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PUSER,
 	    "pfault", 0);
 }