Do not call vm_object_deallocate() from vm_map_delete(), because we

hold the map lock there, and might need the vnode lock for OBJT_VNODE
objects. Postpone object deallocation until caller of vm_map_delete()
drops the map lock. Link the map entries to be freed into the freelist,
that is released by the new helper function vm_map_entry_free_freelist().

Reviewed by:	tegge, alc
Tested by:	pho

sys/vm/vm_kern.c

@@ -271,7 +271,7 @@ kmem_malloc(map, size, flags)
 	int flags;
 {
 	vm_offset_t offset, i;
-	vm_map_entry_t entry;
+	vm_map_entry_t entry, freelist;
 	vm_offset_t addr;
 	vm_page_t m;
 	int pflags;
@@ -355,8 +355,10 @@ kmem_malloc(map, size, flags)
 				vm_page_unlock_queues();
 			}
 			VM_OBJECT_UNLOCK(kmem_object);
-			vm_map_delete(map, addr, addr + size);
+			freelist = NULL;
+			vm_map_delete(map, addr, addr + size, &freelist);
 			vm_map_unlock(map);
+			vm_map_entry_free_freelist(map, freelist);
 			return (0);
 		}
 		if (flags & M_ZERO && (m->flags & PG_ZERO) == 0)
@@ -455,14 +457,18 @@ kmem_free_wakeup(map, addr, size)
 	vm_offset_t addr;
 	vm_size_t size;
 {
+	vm_map_entry_t freelist;
 
+	freelist = NULL;
 	vm_map_lock(map);
-	(void) vm_map_delete(map, trunc_page(addr), round_page(addr + size));
+	(void) vm_map_delete(map, trunc_page(addr), round_page(addr + size),
+	     &freelist);
 	if (map->needs_wakeup) {
 		map->needs_wakeup = FALSE;
 		vm_map_wakeup(map);
 	}
 	vm_map_unlock(map);
+	vm_map_entry_free_freelist(map, freelist);
 }
 
 /*

sys/vm/vm_map.c

@@ -1261,16 +1261,19 @@ vm_map_fixed(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
     vm_offset_t start, vm_size_t length, vm_prot_t prot,
     vm_prot_t max, int cow)
 {
+	vm_map_entry_t freelist;
 	vm_offset_t end;
 	int result;
 
-	vm_map_lock(map);
 	end = start + length;
+	freelist = NULL;
+	vm_map_lock(map);
 	VM_MAP_RANGE_CHECK(map, start, end);
-	(void) vm_map_delete(map, start, end);
+	(void) vm_map_delete(map, start, end, &freelist);
 	result = vm_map_insert(map, object, offset, start, end, prot,
 	    max, cow);
 	vm_map_unlock(map);
+	vm_map_entry_free_freelist(map, freelist);
 	return (result);
 }
 
@@ -2392,6 +2395,23 @@ vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry)
 	entry->wired_count = 0;
 }
 
+void
+vm_map_entry_free_freelist(vm_map_t map, vm_map_entry_t freelist)
+{
+	vm_map_entry_t e;
+	vm_object_t object;
+
+	while (freelist != NULL) {
+		e = freelist;
+		freelist = freelist->next;
+		if ((e->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) {
+			object = e->object.vm_object;
+			vm_object_deallocate(object);
+		}
+		vm_map_entry_dispose(map, e);
+	}
+}
+
 /*
  *	vm_map_entry_delete:	[ internal use only ]
  *
@@ -2424,10 +2444,8 @@ vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry)
 				object->size = offidxstart;
 		}
 		VM_OBJECT_UNLOCK(object);
-		vm_object_deallocate(object);
-	}
-
-	vm_map_entry_dispose(map, entry);
+	} else
+		entry->object.vm_object = NULL;
 }
 
 /*
@@ -2437,7 +2455,8 @@ vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry)
  *	map.
  */
 int
-vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end)
+vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end,
+    vm_map_entry_t *freelist)
 {
 	vm_map_entry_t entry;
 	vm_map_entry_t first_entry;
@@ -2514,6 +2533,8 @@ vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end)
 		 * modify bits will be set in the wrong object!)
 		 */
 		vm_map_entry_delete(map, entry);
+		entry->next = *freelist;
+		*freelist = entry;
 		entry = next;
 	}
 	return (KERN_SUCCESS);
@@ -2528,12 +2549,15 @@ vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end)
 int
 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end)
 {
+	vm_map_entry_t freelist;
 	int result;
 
+	freelist = NULL;
 	vm_map_lock(map);
 	VM_MAP_RANGE_CHECK(map, start, end);
-	result = vm_map_delete(map, start, end);
+	result = vm_map_delete(map, start, end, &freelist);
 	vm_map_unlock(map);
+	vm_map_entry_free_freelist(map, freelist);
 	return (result);
 }
 

sys/vm/vm_map.h

@@ -157,6 +157,8 @@ vm_map_entry_system_wired_count(vm_map_entry_t entry)
 {
 	return (entry->wired_count - vm_map_entry_user_wired_count(entry));
 }
+
+void vm_map_entry_free_freelist(vm_map_t map, vm_map_entry_t freelist);
 #endif	/* _KERNEL */
 
 /*
@@ -336,7 +338,7 @@ long vmspace_wired_count(struct vmspace *vmspace);
 #ifdef _KERNEL
 boolean_t vm_map_check_protection (vm_map_t, vm_offset_t, vm_offset_t, vm_prot_t);
 vm_map_t vm_map_create(pmap_t, vm_offset_t, vm_offset_t);
-int vm_map_delete (vm_map_t, vm_offset_t, vm_offset_t);
+int vm_map_delete(vm_map_t, vm_offset_t, vm_offset_t, vm_map_entry_t *);
 int vm_map_find(vm_map_t, vm_object_t, vm_ooffset_t, vm_offset_t *, vm_size_t,
     int, vm_prot_t, vm_prot_t, int);
 int vm_map_fixed(vm_map_t, vm_object_t, vm_ooffset_t, vm_offset_t, vm_size_t,

sys/vm/vm_mmap.c

@@ -552,6 +552,7 @@ munmap(td, uap)
 	vm_offset_t addr;
 	vm_size_t size, pageoff;
 	vm_map_t map;
+	vm_map_entry_t freelist;
 
 	addr = (vm_offset_t) uap->addr;
 	size = uap->len;
@@ -571,6 +572,7 @@ munmap(td, uap)
 	map = &td->td_proc->p_vmspace->vm_map;
 	if (addr < vm_map_min(map) || addr + size > vm_map_max(map))
 		return (EINVAL);
+	freelist = NULL;
 	vm_map_lock(map);
 #ifdef HWPMC_HOOKS
 	/*
@@ -593,8 +595,9 @@ munmap(td, uap)
 	}
 #endif
 	/* returns nothing but KERN_SUCCESS anyway */
-	vm_map_delete(map, addr, addr + size);
+	vm_map_delete(map, addr, addr + size, &freelist);
 	vm_map_unlock(map);
+	vm_map_entry_free_freelist(map, freelist);
 	return (0);
 }
 

sys/vm/vm_unix.c

@@ -72,6 +72,7 @@ obreak(td, uap)
 	struct obreak_args *uap;
 {
 	struct vmspace *vm = td->td_proc->p_vmspace;
+	vm_map_entry_t freelist;
 	vm_offset_t new, old, base;
 	rlim_t datalim, vmemlim;
 	int rv;
@@ -85,6 +86,7 @@ obreak(td, uap)
 
 	do_map_wirefuture = FALSE;
 	new = round_page((vm_offset_t)uap->nsize);
+	freelist = NULL;
 	vm_map_lock(&vm->vm_map);
 
 	base = round_page((vm_offset_t) vm->vm_daddr);
@@ -138,7 +140,7 @@ obreak(td, uap)
 			do_map_wirefuture = TRUE;
 		}
 	} else if (new < old) {
-		rv = vm_map_delete(&vm->vm_map, new, old);
+		rv = vm_map_delete(&vm->vm_map, new, old, &freelist);
 		if (rv != KERN_SUCCESS) {
 			error = ENOMEM;
 			goto done;
@@ -147,6 +149,7 @@ obreak(td, uap)
 	}
 done:
 	vm_map_unlock(&vm->vm_map);
+	vm_map_entry_free_freelist(&vm->vm_map, freelist);
 
 	if (do_map_wirefuture)
 		(void) vm_map_wire(&vm->vm_map, old, new,