Index: uvm_swap.c
===================================================================
--- uvm_swap.c	(revision 1160)
+++ uvm_swap.c	(revision 1164)
@@ -934,15 +934,6 @@ swap_on(p, sdp)
 		printf("leaving %d pages of swap\n", size);
 	}
 
-  	/*
-	 * try to add anons to reflect the new swap space.
-	 */
-
-	error = uvm_anon_add(size);
-	if (error) {
-		goto bad;
-	}
-
 	/*
 	 * add a ref to vp to reflect usage as a swap device.
 	 */
@@ -990,7 +981,8 @@ swap_off(p, sdp)
 	struct proc *p;
 	struct swapdev *sdp;
 {
-	int npages =  sdp->swd_npages;
+	int npages = sdp->swd_npages;
+	int error = 0;
 
 	UVMHIST_FUNC("swap_off"); UVMHIST_CALLED(pdhist);
 	UVMHIST_LOG(pdhist, "  dev=%x, npages=%d", sdp->swd_dev,npages,0,0);
@@ -1009,16 +1001,21 @@ swap_off(p, sdp)
 
 	if (uao_swap_off(sdp->swd_drumoffset,
 			 sdp->swd_drumoffset + sdp->swd_drumsize) ||
-	    anon_swap_off(sdp->swd_drumoffset,
+	    amap_swap_off(sdp->swd_drumoffset,
 			  sdp->swd_drumoffset + sdp->swd_drumsize)) {
+		error = ENOMEM;
+	} else if (sdp->swd_npginuse > sdp->swd_npgbad) {
+		error = EBUSY;
+	}
 
+	if (error) {
 		simple_lock(&uvm.swap_data_lock);
 		sdp->swd_flags |= SWF_ENABLE;
 		uvmexp.swpgavail += npages;
 		simple_unlock(&uvm.swap_data_lock);
-		return ENOMEM;
+
+		return error;
 	}
-	KASSERT(sdp->swd_npginuse == sdp->swd_npgbad);
 
 	/*
 	 * done with the vnode.
@@ -1029,9 +1026,6 @@ swap_off(p, sdp)
 	if (sdp->swd_vp != rootvp) {
 		(void) VOP_CLOSE(sdp->swd_vp, FREAD|FWRITE, p->p_ucred, p);
 	}
-
-	/* remove anons from the system */
-	uvm_anon_remove(npages);
 
 	simple_lock(&uvm.swap_data_lock);
 	uvmexp.swpages -= npages;
Index: uvm_page.c
===================================================================
--- uvm_page.c	(revision 1160)
+++ uvm_page.c	(revision 1164)
@@ -1183,7 +1183,7 @@ uvm_pagealloc_strat(obj, off, anon, flag
 	pg->uanon = anon;
 	pg->flags = PG_BUSY|PG_CLEAN|PG_FAKE;
 	if (anon) {
-		anon->u.an_page = pg;
+		anon->an_page = pg;
 		pg->pqflags = PQ_ANON;
 		uvmexp.anonpages++;
 	} else {
@@ -1364,7 +1364,7 @@ uvm_pagefree(pg)
 				pg->pqflags &= ~PQ_ANON;
 				uvmexp.anonpages--;
 			}
-			pg->uanon->u.an_page = NULL;
+			pg->uanon->an_page = NULL;
 			pg->uanon = NULL;
 		}
 		if (pg->flags & PG_WANTED) {
@@ -1387,7 +1387,7 @@ uvm_pagefree(pg)
 	if (pg->uobject != NULL) {
 		uvm_pageremove(pg);
 	} else if (pg->uanon != NULL) {
-		pg->uanon->u.an_page = NULL;
+		pg->uanon->an_page = NULL;
 		uvmexp.anonpages--;
 	}
 
Index: uvm_map.c
===================================================================
--- uvm_map.c	(revision 1160)
+++ uvm_map.c	(revision 1164)
@@ -3496,7 +3496,7 @@ uvm_map_clean(struct vm_map *map, vaddr_
 				continue;
 
 			simple_lock(&anon->an_lock);
-			pg = anon->u.an_page;
+			pg = anon->an_page;
 			if (pg == NULL) {
 				simple_unlock(&anon->an_lock);
 				continue;
@@ -4504,9 +4504,9 @@ uvm_page_printit(struct vm_page *pg, boo
 	/* cross-verify object/anon */
 	if ((pg->pqflags & PQ_FREE) == 0) {
 		if (pg->pqflags & PQ_ANON) {
-			if (pg->uanon == NULL || pg->uanon->u.an_page != pg)
+			if (pg->uanon == NULL || pg->uanon->an_page != pg)
 			    (*pr)("  >>> ANON DOES NOT POINT HERE <<< (%p)\n",
-				(pg->uanon) ? pg->uanon->u.an_page : NULL);
+				(pg->uanon) ? pg->uanon->an_page : NULL);
 			else
 				(*pr)("  anon backpointer is OK\n");
 		} else {
Index: uvm_pdaemon.c
===================================================================
--- uvm_pdaemon.c	(revision 1160)
+++ uvm_pdaemon.c	(revision 1164)
@@ -598,7 +598,7 @@ uvmpd_scan_inactive(pglst)
 
 				if (anon) {
 					KASSERT(anon->an_swslot != 0);
-					anon->u.an_page = NULL;
+					anon->an_page = NULL;
 					slot = anon->an_swslot;
 				} else {
 					slot = uao_find_swslot(uobj, pageidx);
Index: uvm_loan.c
===================================================================
--- uvm_loan.c	(revision 1160)
+++ uvm_loan.c	(revision 1164)
@@ -373,7 +373,7 @@ uvm_loananon(ufi, output, flags, anon)
 
 	if (flags & UVM_LOAN_TOANON) {
 		simple_lock(&anon->an_lock);
-		pg = anon->u.an_page;
+		pg = anon->an_page;
 		if (pg && (pg->pqflags & PQ_ANON) != 0 && anon->an_ref == 1) {
 			if (pg->wire_count > 0) {
 				UVMHIST_LOG(loanhist, "->A wired %p", pg,0,0,0);
@@ -428,7 +428,7 @@ uvm_loananon(ufi, output, flags, anon)
 	 * we have the page and its owner locked: do the loan now.
 	 */
 
-	pg = anon->u.an_page;
+	pg = anon->an_page;
 	uvm_lock_pageq();
 	if (pg->wire_count > 0) {
 		uvm_unlock_pageq();
@@ -795,14 +795,14 @@ uvm_loanuobj(ufi, output, flags, va)
 	if (anon == NULL) {
 		goto fail;
 	}
-	anon->u.an_page = pg;
+	anon->an_page = pg;
 	pg->uanon = anon;
 	uvm_lock_pageq();
 	if (pg->wire_count > 0) {
 		uvm_unlock_pageq();
 		UVMHIST_LOG(loanhist, "wired %p", pg,0,0,0);
 		pg->uanon = NULL;
-		anon->u.an_page = NULL;
+		anon->an_page = NULL;
 		anon->an_ref--;
 		simple_unlock(&anon->an_lock);
 		uvm_anfree(anon);
@@ -937,7 +937,7 @@ again:
 		uvmfault_unlockall(ufi, amap, uobj, NULL);
 		return (-1);
 	}
-	anon->u.an_page = pg;
+	anon->an_page = pg;
 	pg->uanon = anon;
 	uvm_lock_pageq();
 	pg->loan_count++;
Index: uvm_amap_i.h
===================================================================
--- uvm_amap_i.h	(revision 1160)
+++ uvm_amap_i.h	(revision 1164)
@@ -134,9 +134,9 @@ amap_add(aref, offset, anon, replace)
 
 		if (amap->am_anon[slot] == NULL)
 			panic("amap_add: replacing null anon");
-		if (amap->am_anon[slot]->u.an_page != NULL &&
+		if (amap->am_anon[slot]->an_page != NULL &&
 		    (amap->am_flags & AMAP_SHARED) != 0) {
-			pmap_page_protect(amap->am_anon[slot]->u.an_page,
+			pmap_page_protect(amap->am_anon[slot]->an_page,
 			    VM_PROT_NONE);
 			/*
 			 * XXX: suppose page is supposed to be wired somewhere?
@@ -253,11 +253,15 @@ amap_unref(amap, offset, len, all)
 	UVMHIST_LOG(maphist,"  amap=0x%x  refs=%d, nused=%d",
 	    amap, amap->am_ref, amap->am_nused, 0);
 
+	KASSERT(amap_refs(amap) > 0);
+
 	/*
 	 * if we are the last reference, free the amap and return.
 	 */
 
-	if (amap->am_ref == 1) {
+	amap->am_ref--;
+
+	if (amap_refs(amap) == 0) {
 		amap_wipeout(amap);	/* drops final ref and frees */
 		UVMHIST_LOG(maphist,"<- done (was last ref)!", 0, 0, 0, 0);
 		return;			/* no need to unlock */
@@ -267,8 +271,7 @@ amap_unref(amap, offset, len, all)
 	 * otherwise just drop the reference count(s)
 	 */
 
-	amap->am_ref--;
-	if (amap->am_ref == 1 && (amap->am_flags & AMAP_SHARED) != 0)
+	if (amap_refs(amap) == 1 && (amap->am_flags & AMAP_SHARED) != 0)
 		amap->am_flags &= ~AMAP_SHARED;	/* clear shared flag */
 #ifdef UVM_AMAP_PPREF
 	if (amap->am_ppref == NULL && all == 0 && len != amap->am_nslot)
Index: uvm_fault.c
===================================================================
--- uvm_fault.c	(revision 1160)
+++ uvm_fault.c	(revision 1164)
@@ -204,7 +204,7 @@ uvmfault_anonflush(anons, n)
 		if (anons[lcv] == NULL)
 			continue;
 		simple_lock(&anons[lcv]->an_lock);
-		pg = anons[lcv]->u.an_page;
+		pg = anons[lcv]->an_page;
 		if (pg && (pg->flags & PG_BUSY) == 0 && pg->loan_count == 0) {
 			uvm_lock_pageq();
 			if (pg->wire_count == 0) {
@@ -303,7 +303,7 @@ uvmfault_anonget(ufi, amap, anon)
 	error = 0;
 	uvmexp.fltanget++;
         /* bump rusage counters */
-	if (anon->u.an_page)
+	if (anon->an_page)
 		curproc->p_stats->p_ru.ru_minflt++;
 	else
 		curproc->p_stats->p_ru.ru_majflt++;
@@ -314,7 +314,7 @@ uvmfault_anonget(ufi, amap, anon)
 
 	for (;;) {
 		we_own = FALSE;		/* TRUE if we set PG_BUSY on a page */
-		pg = anon->u.an_page;
+		pg = anon->an_page;
 
 		/*
 		 * if there is a resident page and it is loaned, then anon
@@ -826,14 +826,14 @@ ReFault:
 		anon = anons[lcv];
 		simple_lock(&anon->an_lock);
 		/* ignore loaned pages */
-		if (anon->u.an_page && anon->u.an_page->loan_count == 0 &&
-		    (anon->u.an_page->flags & PG_BUSY) == 0) {
+		if (anon->an_page && anon->an_page->loan_count == 0 &&
+		    (anon->an_page->flags & PG_BUSY) == 0) {
 			uvm_lock_pageq();
-			uvm_pageactivate(anon->u.an_page);
+			uvm_pageactivate(anon->an_page);
 			uvm_unlock_pageq();
 			UVMHIST_LOG(maphist,
 			    "  MAPPING: n anon: pm=0x%x, va=0x%x, pg=0x%x",
-			    ufi.orig_map->pmap, currva, anon->u.an_page, 0);
+			    ufi.orig_map->pmap, currva, anon->an_page, 0);
 			uvmexp.fltnamap++;
 
 			/*
@@ -843,7 +843,7 @@ ReFault:
 			 */
 
 			(void) pmap_enter(ufi.orig_map->pmap, currva,
-			    VM_PAGE_TO_PHYS(anon->u.an_page),
+			    VM_PAGE_TO_PHYS(anon->an_page),
 			    (anon->an_ref > 1) ? (enter_prot & ~VM_PROT_WRITE) :
 			    enter_prot,
 			    PMAP_CANFAIL |
@@ -1070,7 +1070,7 @@ ReFault:
 	 * uobj is non null if the page is on loan from an object (i.e. uobj)
 	 */
 
-	uobj = anon->u.an_page->uobject;	/* locked by anonget if !NULL */
+	uobj = anon->an_page->uobject;	/* locked by anonget if !NULL */
 
 	/* locked: maps(read), amap, anon, uobj(if one) */
 
@@ -1078,7 +1078,7 @@ ReFault:
 	 * special handling for loaned pages
 	 */
 
-	if (anon->u.an_page->loan_count) {
+	if (anon->an_page->loan_count) {
 
 		if (!cow_now) {
 
@@ -1120,26 +1120,26 @@ ReFault:
 				 * (if any)
 				 */
 				/* copy old -> new */
-				uvm_pagecopy(anon->u.an_page, pg);
+				uvm_pagecopy(anon->an_page, pg);
 
 				/* force reload */
-				pmap_page_protect(anon->u.an_page,
+				pmap_page_protect(anon->an_page,
 						  VM_PROT_NONE);
 				uvm_lock_pageq();	  /* KILL loan */
 
-				anon->u.an_page->uanon = NULL;
+				anon->an_page->uanon = NULL;
 				/* in case we owned */
-				anon->u.an_page->pqflags &= ~PQ_ANON;
+				anon->an_page->pqflags &= ~PQ_ANON;
 
 				if (uobj) {
 					/* if we were receiver of loan */
-					anon->u.an_page->loan_count--;
+					anon->an_page->loan_count--;
 				} else {
 					/*
 					 * we were the lender (A->K); need
 					 * to remove the page from pageq's.
 					 */
-					uvm_pagedequeue(anon->u.an_page);
+					uvm_pagedequeue(anon->an_page);
 				}
 
 				uvm_pageactivate(pg);
@@ -1150,7 +1150,7 @@ ReFault:
 				}
 
 				/* install new page in anon */
-				anon->u.an_page = pg;
+				anon->an_page = pg;
 				pg->uanon = anon;
 				pg->pqflags |= PQ_ANON;
 				pg->flags &= ~(PG_BUSY|PG_FAKE);
@@ -1193,7 +1193,7 @@ ReFault:
 				uvm_anfree(anon);
 			}
 			uvmfault_unlockall(&ufi, amap, uobj, oanon);
-			if (anon == NULL || !uvm_reclaimable()) {
+			if (!uvm_reclaimable()) {
 				UVMHIST_LOG(maphist,
 				    "<- failed.  out of VM",0,0,0,0);
 				uvmexp.fltnoanon++;
@@ -1206,7 +1206,7 @@ ReFault:
 		}
 
 		/* got all resources, replace anon with nanon */
-		uvm_pagecopy(oanon->u.an_page, pg);
+		uvm_pagecopy(oanon->an_page, pg);
 		uvm_lock_pageq();
 		uvm_pageactivate(pg);
 		pg->flags &= ~(PG_BUSY|PG_FAKE);
@@ -1228,7 +1228,7 @@ ReFault:
 
 		uvmexp.flt_anon++;
 		oanon = anon;		/* old, locked anon is same as anon */
-		pg = anon->u.an_page;
+		pg = anon->an_page;
 		if (anon->an_ref > 1)     /* disallow writes to ref > 1 anons */
 			enter_prot = enter_prot & ~VM_PROT_WRITE;
 
@@ -1561,7 +1561,7 @@ Case2:
 
 			/* unlock and fail ... */
 			uvmfault_unlockall(&ufi, amap, uobj, NULL);
-			if (anon == NULL || !uvm_reclaimable()) {
+			if (!uvm_reclaimable()) {
 				UVMHIST_LOG(maphist, "  promote: out of VM",
 				    0,0,0,0);
 				uvmexp.fltnoanon++;
Index: uvm_amap.c
===================================================================
--- uvm_amap.c	(revision 1160)
+++ uvm_amap.c	(revision 1164)
@@ -71,12 +71,35 @@ POOL_INIT(uvm_amap_pool, sizeof(struct v
 
 MALLOC_DEFINE(M_UVMAMAP, "UVM amap", "UVM amap and related structures");
 
+static struct simplelock amap_list_lock = SIMPLELOCK_INITIALIZER;
+static LIST_HEAD(, vm_amap) amap_list;
+
 /*
  * local functions
  */
 
 static struct vm_amap *amap_alloc1(int, int, int);
+static __inline void amap_list_insert(struct vm_amap *);
+static __inline void amap_list_remove(struct vm_amap *);
 
+static __inline void
+amap_list_insert(struct vm_amap *amap)
+{
+
+	simple_lock(&amap_list_lock);
+	LIST_INSERT_HEAD(&amap_list, amap, am_list);
+	simple_unlock(&amap_list_lock);
+}
+
+static __inline void
+amap_list_remove(struct vm_amap *amap)
+{
+
+	simple_lock(&amap_list_lock);
+	LIST_REMOVE(amap, am_list);
+	simple_unlock(&amap_list_lock);
+}
+
 #ifdef UVM_AMAP_PPREF
 /*
  * what is ppref?   ppref is an _optional_ amap feature which is used
@@ -243,6 +266,8 @@ amap_alloc(sz, padsz, waitf)
 		memset(amap->am_anon, 0,
 		    amap->am_maxslot * sizeof(struct vm_anon *));
 
+	amap_list_insert(amap);
+
 	UVMHIST_LOG(maphist,"<- done, amap = 0x%x, sz=%d", amap, sz, 0, 0);
 	return(amap);
 }
@@ -261,6 +286,7 @@ amap_free(amap)
 	UVMHIST_FUNC("amap_free"); UVMHIST_CALLED(maphist);
 
 	KASSERT(amap->am_ref == 0 && amap->am_nused == 0);
+	KASSERT((amap->am_flags & AMAP_SWAPOFF) == 0);
 	LOCK_ASSERT(!simple_lock_held(&amap->am_l));
 	free(amap->am_slots, M_UVMAMAP);
 	free(amap->am_bckptr, M_UVMAMAP);
@@ -619,8 +645,8 @@ amap_share_protect(entry, prot)
 		for (lcv = entry->aref.ar_pageoff ; lcv < stop ; lcv++) {
 			if (amap->am_anon[lcv] == NULL)
 				continue;
-			if (amap->am_anon[lcv]->u.an_page != NULL)
-				pmap_page_protect(amap->am_anon[lcv]->u.an_page,
+			if (amap->am_anon[lcv]->an_page != NULL)
+				pmap_page_protect(amap->am_anon[lcv]->an_page,
 						  prot);
 		}
 		return;
@@ -631,8 +657,8 @@ amap_share_protect(entry, prot)
 		slot = amap->am_slots[lcv];
 		if (slot < entry->aref.ar_pageoff || slot >= stop)
 			continue;
-		if (amap->am_anon[slot]->u.an_page != NULL)
-			pmap_page_protect(amap->am_anon[slot]->u.an_page, prot);
+		if (amap->am_anon[slot]->an_page != NULL)
+			pmap_page_protect(amap->am_anon[slot]->an_page, prot);
 	}
 }
 
@@ -640,7 +666,7 @@ amap_share_protect(entry, prot)
  * amap_wipeout: wipeout all anon's in an amap; then free the amap!
  *
  * => called from amap_unref when the final reference to an amap is
- *	discarded (i.e. when reference count == 1)
+ *	discarded (i.e. when reference count drops to 0)
  * => the amap should be locked (by the caller)
  */
 
@@ -653,7 +679,18 @@ amap_wipeout(amap)
 	UVMHIST_FUNC("amap_wipeout"); UVMHIST_CALLED(maphist);
 	UVMHIST_LOG(maphist,"(amap=0x%x)", amap, 0,0,0);
 
+	KASSERT(amap->am_ref == 0);
+
+	if (__predict_false((amap->am_flags & AMAP_SWAPOFF) != 0)) {
+		/*
+		 * amap_swap_off will call us again.
+		 */
+		amap_unlock(amap);
+		return;
+	}
+	amap_list_remove(amap);
 	amap_unlock(amap);
+
 	for (lcv = 0 ; lcv < amap->am_nused ; lcv++) {
 		int refs;
 
@@ -685,7 +722,6 @@ amap_wipeout(amap)
 	 * now we free the map
 	 */
 
-	amap->am_ref = 0;	/* ... was one */
 	amap->am_nused = 0;
 	amap_free(amap);	/* will unlock and free amap */
 	UVMHIST_LOG(maphist,"<- done!", 0,0,0,0);
@@ -844,6 +880,8 @@ amap_copy(map, entry, waitf, canchunk, s
 
 	amap_unlock(srcamap);
 
+	amap_list_insert(amap);
+
 	/*
 	 * install new amap.
 	 */
@@ -904,7 +942,7 @@ ReStart:
 		slot = amap->am_slots[lcv];
 		anon = amap->am_anon[slot];
 		simple_lock(&anon->an_lock);
-		pg = anon->u.an_page;
+		pg = anon->an_page;
 
 		/*
 		 * page must be resident since parent is wired
@@ -1223,3 +1261,110 @@ amap_wiperange(amap, slotoff, slots)
 }
 
 #endif
+
+/*
+ * amap_swap_off: pagein anonymous pages in amaps and drop swap slots.
+ *
+ * => called with swap_syscall_lock held.
+ * => note that we don't always traverse all anons.
+ *    eg. amaps being wiped out, released anons.
+ * => return TRUE if failed.
+ */
+
+boolean_t
+amap_swap_off(int startslot, int endslot)
+{
+	struct vm_amap *am;
+	struct vm_amap *am_next;
+	struct vm_amap marker_prev;
+	struct vm_amap marker_next;
+	struct lwp *l = curlwp;
+	boolean_t rv = FALSE;
+
+#if defined(DIAGNOSTIC)
+	memset(&marker_prev, 0, sizeof(marker_prev));
+	memset(&marker_next, 0, sizeof(marker_next));
+#endif /* defined(DIAGNOSTIC) */
+
+	PHOLD(l);
+	simple_lock(&amap_list_lock);
+	for (am = LIST_FIRST(&amap_list); am != NULL && !rv; am = am_next) {
+		int i;
+
+		LIST_INSERT_BEFORE(am, &marker_prev, am_list);
+		LIST_INSERT_AFTER(am, &marker_next, am_list);
+
+		if (!amap_lock_try(am)) {
+			simple_unlock(&amap_list_lock);
+			preempt(1);
+			simple_lock(&amap_list_lock);
+			am_next = LIST_NEXT(&marker_prev, am_list);
+			if (am_next == &marker_next) {
+				am_next = LIST_NEXT(am_next, am_list);
+			} else {
+				KASSERT(LIST_NEXT(am_next, am_list) ==
+				    &marker_next);
+			}
+			LIST_REMOVE(&marker_prev, am_list);
+			LIST_REMOVE(&marker_next, am_list);
+			continue;
+		}
+
+		simple_unlock(&amap_list_lock);
+
+		if (am->am_nused <= 0) {
+			amap_unlock(am);
+			goto next;
+		}
+
+		for (i = 0; i < am->am_nused; i++) {
+			int slot;
+			int swslot;
+			struct vm_anon *anon;
+
+			slot = am->am_slots[i];
+			anon = am->am_anon[slot];
+			simple_lock(&anon->an_lock);
+
+			swslot = anon->an_swslot;
+			if (swslot < startslot || endslot <= swslot) {
+				simple_unlock(&anon->an_lock);
+				continue;
+			}
+
+			am->am_flags |= AMAP_SWAPOFF;
+			amap_unlock(am);
+
+			rv = uvm_anon_pagein(anon);
+
+			amap_lock(am);
+			am->am_flags &= ~AMAP_SWAPOFF;
+			if (amap_refs(am) == 0) {
+				amap_wipeout(am);
+				am = NULL;
+				break;
+			}
+			if (rv) {
+				break;
+			}
+			i = 0;
+		}
+
+		if (am) {
+			amap_unlock(am);
+		}
+		
+next:
+		simple_lock(&amap_list_lock);
+		KASSERT(LIST_NEXT(&marker_prev, am_list) == &marker_next ||
+		    LIST_NEXT(LIST_NEXT(&marker_prev, am_list), am_list) ==
+		    &marker_next);
+		am_next = LIST_NEXT(&marker_next, am_list);
+		LIST_REMOVE(&marker_prev, am_list);
+		LIST_REMOVE(&marker_next, am_list);
+	}
+	simple_unlock(&amap_list_lock);
+	PRELE(l);
+
+	return rv;
+}
Index: uvm_amap.h
===================================================================
--- uvm_amap.h	(revision 1160)
+++ uvm_amap.h	(revision 1164)
@@ -125,6 +125,8 @@ void		amap_unref	/* drop reference to an
 			(struct vm_amap *, vaddr_t, vsize_t, int);
 void		amap_wipeout	/* remove all anons from amap */
 			(struct vm_amap *);
+boolean_t	amap_swap_off
+			(int, int);
 
 /*
  * amap flag values
@@ -132,6 +134,7 @@ void		amap_wipeout	/* remove all anons f
 
 #define AMAP_SHARED	0x1	/* amap is shared */
 #define AMAP_REFALL	0x2	/* amap_ref: reference entire amap */
+#define AMAP_SWAPOFF	0x4	/* amap_swap_off() is in progress */
 
 /*
  * amap_extend flags
@@ -174,6 +177,7 @@ struct vm_amap {
 #ifdef UVM_AMAP_PPREF
 	int *am_ppref;		/* per page reference count (if !NULL) */
 #endif
+	LIST_ENTRY(vm_amap) am_list;
 };
 
 /*
@@ -264,6 +268,7 @@ MALLOC_DECLARE(M_UVMAMAP);
 
 #define amap_flags(AMAP)	((AMAP)->am_flags)
 #define amap_lock(AMAP)		simple_lock(&(AMAP)->am_l)
+#define amap_lock_try(AMAP)	simple_lock_try(&(AMAP)->am_l)
 #define amap_refs(AMAP)		((AMAP)->am_ref)
 #define amap_unlock(AMAP)	simple_unlock(&(AMAP)->am_l)
 
Index: uvm.h
===================================================================
--- uvm.h	(revision 1160)
+++ uvm.h	(revision 1164)
@@ -106,10 +106,6 @@ struct uvm {
 	int page_hashmask;		/* hash mask */
 	struct simplelock hashlock;	/* lock on page_hash array */
 
-	/* anon stuff */
-	struct vm_anon *afree;		/* anon free list */
-	struct simplelock afreelock; 	/* lock on anon free list */
-
 	struct simplelock kentry_lock;
 
 	/* aio_done is locked by uvm.pagedaemon_lock and splbio! */
Index: uvm_mmap.c
===================================================================
--- uvm_mmap.c	(revision 1160)
+++ uvm_mmap.c	(revision 1164)
@@ -228,7 +228,7 @@ sys_mincore(l, v, retval)
 				anon = amap_lookup(&entry->aref,
 				    start - entry->start);
 				/* Don't need to lock anon here. */
-				if (anon != NULL && anon->u.an_page != NULL) {
+				if (anon != NULL && anon->an_page != NULL) {
 
 					/*
 					 * Anon has the page for this entry
Index: uvm_anon.c
===================================================================
--- uvm_anon.c	(revision 1160)
+++ uvm_anon.c	(revision 1164)
@@ -51,107 +51,37 @@ __KERNEL_RCSID(0, "$NetBSD: uvm_anon.c,v
 #include <uvm/uvm.h>
 #include <uvm/uvm_swap.h>
 
-/*
- * anonblock_list: global list of anon blocks,
- * locked by swap_syscall_lock (since we never remove
- * anything from this list and we only add to it via swapctl(2)).
- */
+static POOL_INIT(uvm_anon_pool, sizeof(struct vm_anon), 0, 0, 0, "anonpl",
+    &pool_allocator_nointr);
+static struct pool_cache uvm_anon_pool_cache;
 
-struct uvm_anonblock {
-	LIST_ENTRY(uvm_anonblock) list;
-	int count;
-	struct vm_anon *anons;
-};
-static LIST_HEAD(anonlist, uvm_anonblock) anonblock_list;
+static int uvm_anon_ctor(void *, void *, int);
 
-
-static boolean_t anon_pagein(struct vm_anon *);
-
-
 /*
  * allocate anons
  */
 void
 uvm_anon_init()
 {
-	int nanon = uvmexp.free - (uvmexp.free / 16); /* XXXCDC ??? */
 
-	simple_lock_init(&uvm.afreelock);
-	LIST_INIT(&anonblock_list);
-
-	/*
-	 * Allocate the initial anons.
-	 */
-	uvm_anon_add(nanon);
+	pool_cache_init(&uvm_anon_pool_cache, &uvm_anon_pool,
+	    uvm_anon_ctor, NULL, NULL);
 }
 
-/*
- * add some more anons to the free pool.  called when we add
- * more swap space.
- *
- * => swap_syscall_lock should be held (protects anonblock_list).
- */
-int
-uvm_anon_add(count)
-	int	count;
+static int
+uvm_anon_ctor(void *arg, void *object, int flags)
 {
-	struct uvm_anonblock *anonblock;
-	struct vm_anon *anon;
-	int lcv, needed;
+	struct vm_anon *anon = object;
 
-	simple_lock(&uvm.afreelock);
-	uvmexp.nanonneeded += count;
-	needed = uvmexp.nanonneeded - uvmexp.nanon;
-	simple_unlock(&uvm.afreelock);
+	anon->an_ref = 0;
+	simple_lock_init(&anon->an_lock);
+	anon->an_page = NULL;
+	anon->an_swslot = 0;
 
-	if (needed <= 0) {
-		return 0;
-	}
-	anon = (void *)uvm_km_alloc(kernel_map, sizeof(*anon) * needed, 0, 
-	    UVM_KMF_WIRED);
-	if (anon == NULL) {
-		simple_lock(&uvm.afreelock);
-		uvmexp.nanonneeded -= count;
-		simple_unlock(&uvm.afreelock);
-		return ENOMEM;
-	}
-	MALLOC(anonblock, void *, sizeof(*anonblock), M_UVMAMAP, M_WAITOK);
-
-	anonblock->count = needed;
-	anonblock->anons = anon;
-	LIST_INSERT_HEAD(&anonblock_list, anonblock, list);
-	memset(anon, 0, sizeof(*anon) * needed);
-
-	simple_lock(&uvm.afreelock);
-	uvmexp.nanon += needed;
-	uvmexp.nfreeanon += needed;
-	for (lcv = 0; lcv < needed; lcv++) {
-		simple_lock_init(&anon[lcv].an_lock);
-		anon[lcv].u.an_nxt = uvm.afree;
-		uvm.afree = &anon[lcv];
-	}
-	simple_unlock(&uvm.afreelock);
 	return 0;
 }
 
 /*
- * remove anons from the free pool.
- */
-void
-uvm_anon_remove(count)
-	int count;
-{
-	/*
-	 * we never actually free any anons, to avoid allocation overhead.
-	 * XXX someday we might want to try to free anons.
-	 */
-
-	simple_lock(&uvm.afreelock);
-	uvmexp.nanonneeded -= count;
-	simple_unlock(&uvm.afreelock);
-}
-
-/*
  * allocate an anon
  *
  * => new anon is returned locked!
@@ -159,21 +89,18 @@ uvm_anon_remove(count)
 struct vm_anon *
 uvm_analloc()
 {
-	struct vm_anon *a;
+	struct vm_anon *anon;
 
-	simple_lock(&uvm.afreelock);
-	a = uvm.afree;
-	if (a) {
-		uvm.afree = a->u.an_nxt;
-		uvmexp.nfreeanon--;
-		a->an_ref = 1;
-		a->an_swslot = 0;
-		a->u.an_page = NULL;		/* so we can free quickly */
-		LOCK_ASSERT(simple_lock_held(&a->an_lock) == 0);
-		simple_lock(&a->an_lock);
+	anon = pool_cache_get(&uvm_anon_pool_cache, PR_NOWAIT);
+	if (anon) {
+		KASSERT(anon->an_ref == 0);
+		LOCK_ASSERT(simple_lock_held(&anon->an_lock) == 0);
+		KASSERT(anon->an_page == NULL);
+		KASSERT(anon->an_swslot == 0);
+		anon->an_ref = 1;
+		simple_lock(&anon->an_lock);
 	}
-	simple_unlock(&uvm.afreelock);
-	return(a);
+	return anon;
 }
 
 /*
@@ -200,7 +127,7 @@ uvm_anfree(anon)
 	 * get page
 	 */
 
-	pg = anon->u.an_page;
+	pg = anon->an_page;
 
 	/*
 	 * if there is a resident page and it is loaned, then anon may not
@@ -280,14 +207,10 @@ uvm_anfree(anon)
 	 * free the anon itself.
 	 */
 
-	KASSERT(anon->u.an_page == NULL);
+	KASSERT(anon->an_page == NULL);
 	KASSERT(anon->an_swslot == 0);
 
-	simple_lock(&uvm.afreelock);
-	anon->u.an_nxt = uvm.afree;
-	uvm.afree = anon;
-	uvmexp.nfreeanon++;
-	simple_unlock(&uvm.afreelock);
+	pool_cache_put(&uvm_anon_pool_cache, anon);
 	UVMHIST_LOG(maphist,"<- done!",0,0,0,0);
 }
 
@@ -346,7 +269,7 @@ uvm_anon_lockloanpg(anon)
 	 * not produce an incorrect result.
 	 */
 
-	while (((pg = anon->u.an_page) != NULL) && pg->loan_count != 0) {
+	while (((pg = anon->an_page) != NULL) && pg->loan_count != 0) {
 
 		/*
 		 * quickly check to see if the page has an object before
@@ -400,80 +323,15 @@ uvm_anon_lockloanpg(anon)
 	return(pg);
 }
 
-
-
 /*
- * page in every anon that is paged out to a range of swslots.
- *
- * swap_syscall_lock should be held (protects anonblock_list).
- */
-
-boolean_t
-anon_swap_off(startslot, endslot)
-	int startslot, endslot;
-{
-	struct uvm_anonblock *anonblock;
-
-	LIST_FOREACH(anonblock, &anonblock_list, list) {
-		int i;
-
-		/*
-		 * loop thru all the anons in the anonblock,
-		 * paging in where needed.
-		 */
-
-		for (i = 0; i < anonblock->count; i++) {
-			struct vm_anon *anon = &anonblock->anons[i];
-			int slot;
-
-			/*
-			 * lock anon to work on it.
-			 */
-
-			simple_lock(&anon->an_lock);
-
-			/*
-			 * is this anon's swap slot in range?
-			 */
-
-			slot = anon->an_swslot;
-			if (slot >= startslot && slot < endslot) {
-				boolean_t rv;
-
-				/*
-				 * yup, page it in.
-				 */
-
-				/* locked: anon */
-				rv = anon_pagein(anon);
-				/* unlocked: anon */
-
-				if (rv) {
-					return rv;
-				}
-			} else {
-
-				/*
-				 * nope, unlock and proceed.
-				 */
-
-				simple_unlock(&anon->an_lock);
-			}
-		}
-	}
-	return FALSE;
-}
-
-
-/*
  * fetch an anon's page.
  *
  * => anon must be locked, and is unlocked upon return.
  * => returns TRUE if pagein was aborted due to lack of memory.
  */
 
-static boolean_t
-anon_pagein(anon)
+boolean_t
+uvm_anon_pagein(anon)
 	struct vm_anon *anon;
 {
 	struct vm_page *pg;
@@ -514,7 +372,7 @@ anon_pagein(anon)
 	 * mark it as dirty, clear its swslot and un-busy it.
 	 */
 
-	pg = anon->u.an_page;
+	pg = anon->an_page;
 	uobj = pg->uobject;
 	if (anon->an_swslot > 0)
 		uvm_swap_free(anon->an_swslot, 1);
@@ -557,7 +415,7 @@ void
 uvm_anon_release(anon)
 	struct vm_anon *anon;
 {
-	struct vm_page *pg = anon->u.an_page;
+	struct vm_page *pg = anon->an_page;
 
 	LOCK_ASSERT(simple_lock_held(&anon->an_lock));
 
@@ -574,7 +432,7 @@ uvm_anon_release(anon)
 	uvm_unlock_pageq();
 	simple_unlock(&anon->an_lock);
 
-	KASSERT(anon->u.an_page == NULL);
+	KASSERT(anon->an_page == NULL);
 
 	uvm_anfree(anon);
 }
Index: uvm_anon.h
===================================================================
--- uvm_anon.h	(revision 1160)
+++ uvm_anon.h	(revision 1164)
@@ -50,22 +50,17 @@
 struct vm_anon {
 	int an_ref;			/* reference count [an_lock] */
 	struct simplelock an_lock;	/* lock for an_ref */
-	union {
-		struct vm_anon *an_nxt;	/* if on free list [afreelock] */
-		struct vm_page *an_page;/* if in RAM [an_lock] */
-	} u;
+	struct vm_page *an_page;/* if in RAM [an_lock] */
 	int an_swslot;		/* drum swap slot # (if != 0)
 				   [an_lock.  also, it is ok to read
 				   an_swslot if we hold an_page PG_BUSY] */
 };
 
 /*
- * a pool of vm_anon data structures is allocated and put on a global
- * free list at boot time.  vm_anon's on the free list use "an_nxt" as
- * a pointer to the next item on the free list.  for active vm_anon's
- * the data can be in one of the following state: [1] in a vm_page
- * with no backing store allocated yet, [2] in a vm_page with backing
- * store allocated, or [3] paged out to backing store (no vm_page).
+ * for active vm_anon's the data can be in one of the following state:
+ * [1] in a vm_page with no backing store allocated yet, [2] in a vm_page
+ * with backing store allocated, or [3] paged out to backing store
+ * (no vm_page).
  *
  * for pageout in case [2]: if the page has been modified then we must
  * flush it out to backing store, otherwise we can just dump the
@@ -101,12 +96,10 @@ struct vm_aref {
 struct vm_anon *uvm_analloc(void);
 void uvm_anfree(struct vm_anon *);
 void uvm_anon_init(void);
-int uvm_anon_add(int);
-void uvm_anon_remove(int);
 struct vm_page *uvm_anon_lockloanpg(struct vm_anon *);
 void uvm_anon_dropswap(struct vm_anon *);
-boolean_t anon_swap_off(int, int);
 void uvm_anon_release(struct vm_anon *);
+boolean_t uvm_anon_pagein(struct vm_anon *);
 #endif /* _KERNEL */
 
 #endif /* _UVM_UVM_ANON_H_ */
Index: uvm_init.c
===================================================================
--- uvm_init.c	(revision 1160)
+++ uvm_init.c	(revision 1164)
@@ -136,15 +136,9 @@ uvm_init()
 	uvm_pager_init();
 
 	/*
-	 * step 8: init anonymous memory systems
+	 * step 8: init the uvm_loan() facility.
 	 */
 
-	uvm_anon_init();	/* allocate initial anons */
-
-	/*
-	 * step 9: init the uvm_loan() facility.
-	 */
-
 	uvm_loan_init();
 
 	/*
@@ -163,4 +157,10 @@ uvm_init()
 	 */
 
 	link_pool_init();
+
+	/*
+	 * init anonymous memory systems
+	 */
+
+	uvm_anon_init();
 }