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Date:      Sun, 9 Dec 2012 00:32:38 +0000 (UTC)
From:      Alan Cox <alc@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r244043 - head/sys/vm
Message-ID:  <201212090032.qB90WcWW050424@svn.freebsd.org>

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Author: alc
Date: Sun Dec  9 00:32:38 2012
New Revision: 244043
URL: http://svnweb.freebsd.org/changeset/base/244043

Log:
  In the past four years, we've added two new vm object types.  Each time,
  similar changes had to be made in various places throughout the machine-
  independent virtual memory layer to support the new vm object type.
  However, in most of these places, it's actually not the type of the vm
  object that matters to us but instead certain attributes of its pages.
  For example, OBJT_DEVICE, OBJT_MGTDEVICE, and OBJT_SG objects contain
  fictitious pages.  In other words, in most of these places, we were
  testing the vm object's type to determine if it contained fictitious (or
  unmanaged) pages.
  
  To both simplify the code in these places and make the addition of future
  vm object types easier, this change introduces two new vm object flags
  that describe attributes of the vm object's pages, specifically, whether
  they are fictitious or unmanaged.
  
  Reviewed and tested by:	kib

Modified:
  head/sys/vm/vm_fault.c
  head/sys/vm/vm_map.c
  head/sys/vm/vm_meter.c
  head/sys/vm/vm_object.c
  head/sys/vm/vm_object.h
  head/sys/vm/vm_page.c
  head/sys/vm/vm_pageout.c

Modified: head/sys/vm/vm_fault.c
==============================================================================
--- head/sys/vm/vm_fault.c	Sat Dec  8 22:52:39 2012	(r244042)
+++ head/sys/vm/vm_fault.c	Sun Dec  9 00:32:38 2012	(r244043)
@@ -968,8 +968,8 @@ vm_fault_cache_behind(const struct fault
 			VM_OBJECT_LOCK(object);
 		}
 	}
-	if (first_object->type != OBJT_DEVICE &&
-	    first_object->type != OBJT_PHYS && first_object->type != OBJT_SG) {
+	/* Neither fictitious nor unmanaged pages can be cached. */
+	if ((first_object->flags & (OBJ_FICTITIOUS | OBJ_UNMANAGED)) == 0) {
 		if (fs->first_pindex < distance)
 			pindex = 0;
 		else

Modified: head/sys/vm/vm_map.c
==============================================================================
--- head/sys/vm/vm_map.c	Sat Dec  8 22:52:39 2012	(r244042)
+++ head/sys/vm/vm_map.c	Sun Dec  9 00:32:38 2012	(r244043)
@@ -2324,8 +2324,8 @@ done:
 				 */
 				vm_fault_unwire(map, entry->start, entry->end,
 				    entry->object.vm_object != NULL &&
-				    (entry->object.vm_object->type == OBJT_DEVICE ||
-				    entry->object.vm_object->type == OBJT_SG));
+				    (entry->object.vm_object->flags &
+				    OBJ_FICTITIOUS) != 0);
 			}
 		}
 		KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION,
@@ -2445,8 +2445,8 @@ vm_map_wire(vm_map_t map, vm_offset_t st
 			saved_start = entry->start;
 			saved_end = entry->end;
 			fictitious = entry->object.vm_object != NULL &&
-			    (entry->object.vm_object->type == OBJT_DEVICE ||
-			    entry->object.vm_object->type == OBJT_SG);
+			    (entry->object.vm_object->flags &
+			    OBJ_FICTITIOUS) != 0;
 			/*
 			 * Release the map lock, relying on the in-transition
 			 * mark.  Mark the map busy for fork.
@@ -2544,8 +2544,8 @@ done:
 				 */
 				vm_fault_unwire(map, entry->start, entry->end,
 				    entry->object.vm_object != NULL &&
-				    (entry->object.vm_object->type == OBJT_DEVICE ||
-				    entry->object.vm_object->type == OBJT_SG));
+				    (entry->object.vm_object->flags &
+				    OBJ_FICTITIOUS) != 0);
 			}
 		}
 	next_entry_done:
@@ -2681,8 +2681,7 @@ vm_map_entry_unwire(vm_map_t map, vm_map
 {
 	vm_fault_unwire(map, entry->start, entry->end,
 	    entry->object.vm_object != NULL &&
-	    (entry->object.vm_object->type == OBJT_DEVICE ||
-	    entry->object.vm_object->type == OBJT_SG));
+	    (entry->object.vm_object->flags & OBJ_FICTITIOUS) != 0);
 	entry->wired_count = 0;
 }
 

Modified: head/sys/vm/vm_meter.c
==============================================================================
--- head/sys/vm/vm_meter.c	Sat Dec  8 22:52:39 2012	(r244042)
+++ head/sys/vm/vm_meter.c	Sun Dec  9 00:32:38 2012	(r244043)
@@ -200,7 +200,7 @@ vmtotal(SYSCTL_HANDLER_ARGS)
 		 * synchronization should not impair the accuracy of
 		 * the reported statistics. 
 		 */
-		if (object->type == OBJT_DEVICE || object->type == OBJT_SG) {
+		if ((object->flags & OBJ_FICTITIOUS) != 0) {
 			/*
 			 * Devices, like /dev/mem, will badly skew our totals.
 			 */

Modified: head/sys/vm/vm_object.c
==============================================================================
--- head/sys/vm/vm_object.c	Sat Dec  8 22:52:39 2012	(r244042)
+++ head/sys/vm/vm_object.c	Sun Dec  9 00:32:38 2012	(r244043)
@@ -212,15 +212,35 @@ _vm_object_allocate(objtype_t type, vm_p
 
 	object->root = NULL;
 	object->type = type;
+	switch (type) {
+	case OBJT_DEAD:
+		panic("_vm_object_allocate: can't create OBJT_DEAD");
+	case OBJT_DEFAULT:
+	case OBJT_SWAP:
+		object->flags = OBJ_ONEMAPPING;
+		break;
+	case OBJT_DEVICE:
+	case OBJT_SG:
+		object->flags = OBJ_FICTITIOUS | OBJ_UNMANAGED;
+		break;
+	case OBJT_MGTDEVICE:
+		object->flags = OBJ_FICTITIOUS;
+		break;
+	case OBJT_PHYS:
+		object->flags = OBJ_UNMANAGED;
+		break;
+	case OBJT_VNODE:
+		object->flags = 0;
+		break;
+	default:
+		panic("_vm_object_allocate: type %d is undefined", type);
+	}
 	object->size = size;
 	object->generation = 1;
 	object->ref_count = 1;
 	object->memattr = VM_MEMATTR_DEFAULT;
-	object->flags = 0;
 	object->cred = NULL;
 	object->charge = 0;
-	if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP))
-		object->flags = OBJ_ONEMAPPING;
 	object->pg_color = 0;
 	object->handle = NULL;
 	object->backing_object = NULL;
@@ -1064,7 +1084,7 @@ shadowlookup:
 			    (tobject->flags & OBJ_ONEMAPPING) == 0) {
 				goto unlock_tobject;
 			}
-		} else if (tobject->type == OBJT_PHYS)
+		} else if ((tobject->flags & OBJ_UNMANAGED) != 0)
 			goto unlock_tobject;
 		m = vm_page_lookup(tobject, tpindex);
 		if (m == NULL && advise == MADV_WILLNEED) {
@@ -1834,7 +1854,7 @@ vm_object_page_remove(vm_object_t object
 	int wirings;
 
 	VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
-	KASSERT((object->type != OBJT_DEVICE && object->type != OBJT_PHYS) ||
+	KASSERT((object->flags & OBJ_UNMANAGED) == 0 ||
 	    (options & (OBJPR_CLEANONLY | OBJPR_NOTMAPPED)) == OBJPR_NOTMAPPED,
 	    ("vm_object_page_remove: illegal options for object %p", object));
 	if (object->resident_page_count == 0)
@@ -1918,7 +1938,7 @@ skipmemq:
  *	pages are moved to the cache queue.
  *
  *	This operation should only be performed on objects that
- *	contain managed pages.
+ *	contain non-fictitious, managed pages.
  *
  *	The object must be locked.
  */
@@ -1929,8 +1949,7 @@ vm_object_page_cache(vm_object_t object,
 	vm_page_t p, next;
 
 	VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
-	KASSERT((object->type != OBJT_DEVICE && object->type != OBJT_SG &&
-	    object->type != OBJT_PHYS),
+	KASSERT((object->flags & (OBJ_FICTITIOUS | OBJ_UNMANAGED)) == 0,
 	    ("vm_object_page_cache: illegal object %p", object));
 	if (object->resident_page_count == 0)
 		return;

Modified: head/sys/vm/vm_object.h
==============================================================================
--- head/sys/vm/vm_object.h	Sat Dec  8 22:52:39 2012	(r244042)
+++ head/sys/vm/vm_object.h	Sun Dec  9 00:32:38 2012	(r244043)
@@ -165,6 +165,8 @@ struct vm_object {
 /*
  * Flags
  */
+#define	OBJ_FICTITIOUS	0x0001		/* (c) contains fictitious pages */
+#define	OBJ_UNMANAGED	0x0002		/* (c) contains unmanaged pages */
 #define OBJ_ACTIVE	0x0004		/* active objects */
 #define OBJ_DEAD	0x0008		/* dead objects (during rundown) */
 #define	OBJ_NOSPLIT	0x0010		/* dont split this object */

Modified: head/sys/vm/vm_page.c
==============================================================================
--- head/sys/vm/vm_page.c	Sat Dec  8 22:52:39 2012	(r244042)
+++ head/sys/vm/vm_page.c	Sun Dec  9 00:32:38 2012	(r244043)
@@ -1414,9 +1414,8 @@ vm_page_alloc(vm_object_t object, vm_pin
 			mtx_unlock(&vm_page_queue_free_mtx);
 			return (NULL);
 #if VM_NRESERVLEVEL > 0
-		} else if (object == NULL || object->type == OBJT_DEVICE ||
-		    object->type == OBJT_SG ||
-		    (object->flags & OBJ_COLORED) == 0 ||
+		} else if (object == NULL || (object->flags & (OBJ_COLORED |
+		    OBJ_FICTITIOUS)) != OBJ_COLORED ||
 		    (m = vm_reserv_alloc_page(object, pindex)) == NULL) {
 #else
 		} else {
@@ -1491,10 +1490,8 @@ vm_page_alloc(vm_object_t object, vm_pin
 	m->flags = flags;
 	mtx_unlock(&vm_page_queue_free_mtx);
 	m->aflags = 0;
-	if (object == NULL || object->type == OBJT_PHYS)
-		m->oflags = VPO_UNMANAGED;
-	else
-		m->oflags = 0;
+	m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ?
+	    VPO_UNMANAGED : 0;
 	if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ)) == 0)
 		m->oflags |= VPO_BUSY;
 	if (req & VM_ALLOC_WIRED) {
@@ -1510,7 +1507,7 @@ vm_page_alloc(vm_object_t object, vm_pin
 	if (object != NULL) {
 		/* Ignore device objects; the pager sets "memattr" for them. */
 		if (object->memattr != VM_MEMATTR_DEFAULT &&
-		    object->type != OBJT_DEVICE && object->type != OBJT_SG)
+		    (object->flags & OBJ_FICTITIOUS) == 0)
 			pmap_page_set_memattr(m, object->memattr);
 		vm_page_insert(m, object, pindex);
 	} else

Modified: head/sys/vm/vm_pageout.c
==============================================================================
--- head/sys/vm/vm_pageout.c	Sat Dec  8 22:52:39 2012	(r244042)
+++ head/sys/vm/vm_pageout.c	Sun Dec  9 00:32:38 2012	(r244043)
@@ -705,14 +705,14 @@ vm_pageout_object_deactivate_pages(pmap_
 	int actcount, remove_mode;
 
 	VM_OBJECT_LOCK_ASSERT(first_object, MA_OWNED);
-	if (first_object->type == OBJT_DEVICE ||
-	    first_object->type == OBJT_SG)
+	if ((first_object->flags & OBJ_FICTITIOUS) != 0)
 		return;
 	for (object = first_object;; object = backing_object) {
 		if (pmap_resident_count(pmap) <= desired)
 			goto unlock_return;
 		VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
-		if (object->type == OBJT_PHYS || object->paging_in_progress)
+		if ((object->flags & OBJ_UNMANAGED) != 0 ||
+		    object->paging_in_progress != 0)
 			goto unlock_return;
 
 		remove_mode = 0;



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