Index: sys/vm/swap_pager.c
===================================================================
RCS file: /home/ncvs/src/sys/vm/swap_pager.c,v
retrieving revision 1.273.2.2
diff -u -r1.273.2.2 swap_pager.c
--- sys/vm/swap_pager.c	10 May 2006 07:00:08 -0000	1.273.2.2
+++ sys/vm/swap_pager.c	2 Jun 2006 21:20:01 -0000
@@ -972,6 +972,9 @@
 	vm_page_t mreq;
 	int i;
 	int j;
+	int retry = 0;
+#define TIMO_CHUNK 1
+	static int timo_secs = 20; /* set low to force quick first timeout */
 	daddr_t blk;
 
 	mreq = m[reqpage];
@@ -1099,13 +1102,23 @@
 	 */
 	vm_page_lock_queues();
 	while ((mreq->flags & PG_SWAPINPROG) != 0) {
-		vm_page_flag_set(mreq, PG_WANTED | PG_REFERENCED);
-		cnt.v_intrans++;
-		if (msleep(mreq, &vm_page_queue_mtx, PSWP, "swread", hz*20)) {
-			printf(
-"swap_pager: indefinite wait buffer: bufobj: %p, blkno: %jd, size: %ld\n",
-			    bp->b_bufobj, (intmax_t)bp->b_blkno, bp->b_bcount);
+		if (retry == 0) {
+		  vm_page_flag_set(mreq, PG_WANTED | PG_REFERENCED);
+		  cnt.v_intrans++;
 		}
+		if (msleep(mreq, &vm_page_queue_mtx, PSWP, "swread", hz*timo_secs)) {
+			printf(
+"swap_pager: wait buffer timeout %d (%d secs): bufobj: %p, blkno: %jd, size: %ld\n",
+		  ++retry, timo_secs, bp->b_bufobj, (intmax_t)bp->b_blkno, bp->b_bcount);
+		  if ( retry+TIMO_CHUNK > timo_secs) {
+		    timo_secs = retry+TIMO_CHUNK;
+		  }
+		} else {
+		if (retry > 0) {
+			printf(
+"swap_pager: wait buffer completed (%d retry): bufobj: %p, blkno: %jd, size: %ld\n",
+		  retry, bp->b_bufobj, (intmax_t)bp->b_blkno, bp->b_bcount);
+		}}
 	}
 	vm_page_unlock_queues();
 
@@ -1584,6 +1597,7 @@
 swp_pager_force_pagein(vm_object_t object, vm_pindex_t pindex)
 {
 	vm_page_t m;
+	int ret;
 
 	vm_object_pip_add(object, 1);
 	m = vm_page_grab(object, pindex, VM_ALLOC_NORMAL|VM_ALLOC_RETRY);
@@ -1598,8 +1612,18 @@
 		return;
 	}
 
-	if (swap_pager_getpages(object, &m, 1, 0) != VM_PAGER_OK)
-		panic("swap_pager_force_pagein: read from swap failed");/*XXX*/
+	if ((ret=swap_pager_getpages(object, &m, 1, 0)) != VM_PAGER_OK) {
+		if (ret == VM_PAGER_FAIL) {
+			printf("swp_pager_force_pagein: VM_PAGER_FAIL\n");
+		}
+		else {
+			if (ret == VM_PAGER_ERROR) {
+				printf("swp_pager_force_pagein: VM_PAGER_ERROR\n");
+			}
+		else
+			panic("swap_pager_force_pagein: read from swap failed");/*XXX*/
+		}
+	}
 	vm_object_pip_subtract(object, 1);
 	vm_page_lock_queues();
 	vm_page_dirty(m);