* Renamed VMAddressSpace::ResizeArea{Head,Tail}() to ShrinkArea{Head,Tail}()

to clarify that they never enlarge the area.
* Reimplemented VMKernelAddressSpace. It is somewhat inspired by Bonwick's
  vmem resource allocator (though we have different requirements):
  - We consider the complete address space to be divided into contiguous
    ranges of type free, reserved, or area, each range being represented by
    a VMKernelAddressRange object.
  - The range objects are managed in an AVL tree and a doubly linked list
    (the latter only for faster iteration) sorted by address. This provides
    O(log(n)) lookup, insertion and removal.
  - For each power of two size we maintain a list of free ranges of at least
    that size. Thus for the most common case of B_ANY*_ADDRESS area
    allocation, we find a free range in constant time (the rest of the
    processing being O(log(n))) with a rather good fit. This should also
    help avoiding address space fragmentation.
  While the new implementation should be faster, particularly with an
  increasing number of areas, I couldn't measure any difference in the -j2
  haiku build. From a cursory test the -j8 build hasn't tangibly benefitted
  either.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34528 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/vm/VMAddressSpace.h

@@ -62,6 +62,8 @@ public:
 
 			VMAddressSpace*&	HashTableLink()	{ return fHashTableLink; }
 
+	virtual	status_t			InitObject();
+
 	virtual	VMArea*				FirstArea() const = 0;
 	virtual	VMArea*				NextArea(VMArea* area) const = 0;
 
@@ -70,13 +72,15 @@ public:
 									uint32 protection) = 0;
 	virtual	void				DeleteArea(VMArea* area) = 0;
 	virtual	status_t			InsertArea(void** _address, uint32 addressSpec,
-									addr_t size, VMArea* area) = 0;
+									size_t size, VMArea* area) = 0;
 	virtual	void				RemoveArea(VMArea* area) = 0;
 
 	virtual	bool				CanResizeArea(VMArea* area, size_t newSize) = 0;
 	virtual	status_t			ResizeArea(VMArea* area, size_t newSize) = 0;
-	virtual	status_t			ResizeAreaHead(VMArea* area, size_t size) = 0;
-	virtual	status_t			ResizeAreaTail(VMArea* area, size_t size) = 0;
+	virtual	status_t			ShrinkAreaHead(VMArea* area, size_t newSize)
+									= 0;
+	virtual	status_t			ShrinkAreaTail(VMArea* area, size_t newSize)
+									= 0;
 
 	virtual	status_t			ReserveAddressRange(void** _address,
 									uint32 addressSpec, size_t size,

src/system/kernel/vm/VMAddressSpace.cpp

@@ -12,6 +12,8 @@
 
 #include <stdlib.h>
 
+#include <new>
+
 #include <KernelExport.h>
 
 #include <util/OpenHashTable.h>
@@ -181,17 +183,24 @@ VMAddressSpace::RemoveAndPut()
 }
 
 
+status_t
+VMAddressSpace::InitObject()
+{
+	return B_OK;
+}
+
+
 void
 VMAddressSpace::Dump() const
 {
 	kprintf("dump of address space at %p:\n", this);
-	kprintf("id: 0x%lx\n", fID);
-	kprintf("ref_count: %ld\n", fRefCount);
-	kprintf("fault_count: %ld\n", fFaultCount);
+	kprintf("id: %" B_PRId32 "\n", fID);
+	kprintf("ref_count: %" B_PRId32 "\n", fRefCount);
+	kprintf("fault_count: %" B_PRId32 "\n", fFaultCount);
 	kprintf("translation_map: %p\n", &fTranslationMap);
-	kprintf("base: 0x%lx\n", fBase);
-	kprintf("end: 0x%lx\n", fEndAddress);
-	kprintf("change_count: 0x%lx\n", fChangeCount);
+	kprintf("base: %#" B_PRIxADDR "\n", fBase);
+	kprintf("end: %#" B_PRIxADDR "\n", fEndAddress);
+	kprintf("change_count: %" B_PRId32 "\n", fChangeCount);
 }
 
 
@@ -205,11 +214,17 @@ VMAddressSpace::Create(team_id teamID, addr_t base, size_t size, bool kernel,
 	if (addressSpace == NULL)
 		return B_NO_MEMORY;
 
+	status_t status = addressSpace->InitObject();
+	if (status != B_OK) {
+		delete addressSpace;
+		return status;
+	}
+
 	TRACE(("vm_create_aspace: team %ld (%skernel): %#lx bytes starting at "
 		"%#lx => %p\n", id, kernel ? "!" : "", size, base, addressSpace));
 
 	// initialize the corresponding translation map
-	status_t status = arch_vm_translation_map_init_map(
+	status = arch_vm_translation_map_init_map(
 		&addressSpace->fTranslationMap, kernel);
 	if (status != B_OK) {
 		delete addressSpace;
@@ -321,9 +336,9 @@ VMAddressSpace::_DumpListCommand(int argc, char** argv)
 				areaSize += area->Size();
 			}
 		}
-		kprintf("%p  %6ld   %#010lx   %#10lx   %10ld   %10lld\n",
-			space, space->ID(), space->Base(), space->EndAddress(), areaCount,
-			areaSize);
+		kprintf("%p  %6" B_PRId32 "   %#010" B_PRIxADDR "   %#10" B_PRIxADDR
+			"   %10" B_PRId32 "   %10" B_PRIdOFF "\n", space, space->ID(),
+			space->Base(), space->EndAddress(), areaCount, areaSize);
 	}
 
 	return 0;

src/system/kernel/vm/VMArea.cpp

@@ -10,6 +10,8 @@
 
 #include <vm/VMArea.h>
 
+#include <new>
+
 #include <heap.h>
 
 

src/system/kernel/vm/VMKernelAddressSpace.h

@@ -1,10 +1,6 @@
 /*
  * Copyright 2009, Ingo Weinhold, [email protected].
- * Copyright 2002-2008, Axel Dörfler, [email protected]. All rights reserved.
  * Distributed under the terms of the MIT License.
- *
- * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
- * Distributed under the terms of the NewOS License.
  */
 #ifndef VM_KERNEL_ADDRESS_SPACE_H
 #define VM_KERNEL_ADDRESS_SPACE_H
@@ -21,6 +17,8 @@ public:
 									size_t size);
 	virtual						~VMKernelAddressSpace();
 
+	virtual	status_t			InitObject();
+
 	virtual	VMArea*				FirstArea() const;
 	virtual	VMArea*				NextArea(VMArea* area) const;
 
@@ -29,13 +27,13 @@ public:
 									uint32 protection);
 	virtual	void				DeleteArea(VMArea* area);
 	virtual	status_t			InsertArea(void** _address, uint32 addressSpec,
-									addr_t size, VMArea* area);
+									size_t size, VMArea* area);
 	virtual	void				RemoveArea(VMArea* area);
 
 	virtual	bool				CanResizeArea(VMArea* area, size_t newSize);
 	virtual	status_t			ResizeArea(VMArea* area, size_t newSize);
-	virtual	status_t			ResizeAreaHead(VMArea* area, size_t size);
-	virtual	status_t			ResizeAreaTail(VMArea* area, size_t size);
+	virtual	status_t			ShrinkAreaHead(VMArea* area, size_t newSize);
+	virtual	status_t			ShrinkAreaTail(VMArea* area, size_t newSize);
 
 	virtual	status_t			ReserveAddressRange(void** _address,
 									uint32 addressSpec, size_t size,
@@ -47,15 +45,37 @@ public:
 	virtual	void				Dump() const;
 
 private:
-			status_t			_InsertAreaIntoReservedRegion(addr_t start,
-									size_t size, VMKernelArea* area);
-			status_t			_InsertAreaSlot(addr_t start, addr_t size,
-									addr_t end, uint32 addressSpec,
-									VMKernelArea* area);
+			typedef VMKernelAddressRange Range;
+			typedef VMKernelAddressRangeTree RangeTree;
+			typedef DoublyLinkedList<Range,
+				DoublyLinkedListMemberGetLink<Range, &Range::listLink> >
+					RangeList;
+			typedef DoublyLinkedList<Range, VMKernelAddressRangeGetFreeListLink>
+				RangeFreeList;
 
 private:
-			VMKernelAreaList	fAreas;
-	mutable	VMArea*				fAreaHint;
+	inline	void				_FreeListInsertRange(Range* range, size_t size);
+	inline	void				_FreeListRemoveRange(Range* range, size_t size);
+
+			void				_InsertRange(Range* range);
+			void				_RemoveRange(Range* range);
+
+			status_t			_AllocateRange(addr_t address,
+									uint32 addressSpec, size_t size,
+									bool allowReservedRange, Range*& _range);
+			Range*				_FindFreeRange(addr_t start, size_t size,
+									size_t alignment, uint32 addressSpec,
+									bool allowReservedRange,
+									addr_t& _foundAddress);
+			void				_FreeRange(Range* range);
+
+			void				_CheckStructures() const;
+
+private:
+			RangeTree			fRangeTree;
+			RangeList			fRangeList;
+			RangeFreeList*		fFreeLists;
+			int					fFreeListCount;
 };
 
 

src/system/kernel/vm/VMKernelArea.cpp

@@ -39,13 +39,3 @@ VMKernelArea::Create(VMAddressSpace* addressSpace, const char* name,
 
 	return area;
 }
-
-
-/*static*/ VMKernelArea*
-VMKernelArea::CreateReserved(VMAddressSpace* addressSpace, uint32 flags)
-{
-	VMKernelArea* area = new(nogrow) VMKernelArea(addressSpace, 0, 0);
-	if (area != NULL)
-		area->id = RESERVED_AREA_ID;
-	return area;
-}

src/system/kernel/vm/VMKernelArea.h

@@ -6,13 +6,109 @@
 #define VM_KERNEL_AREA_H
 
 
+#include <util/AVLTree.h>
+
 #include <vm/VMArea.h>
 
 
 struct VMKernelAddressSpace;
+struct VMKernelArea;
 
 
-struct VMKernelArea : VMArea {
+struct VMKernelAddressRange : AVLTreeNode {
+public:
+	// range types
+	enum {
+		RANGE_FREE,
+		RANGE_RESERVED,
+		RANGE_AREA
+	};
+
+public:
+	DoublyLinkedListLink<VMKernelAddressRange>		listLink;
+	addr_t											base;
+	size_t											size;
+	union {
+		VMKernelArea* 								area;
+		struct {
+			addr_t									base;
+			uint32									flags;
+		} reserved;
+		DoublyLinkedListLink<VMKernelAddressRange>	freeListLink;
+	};
+	int												type;
+
+public:
+	VMKernelAddressRange(addr_t base, size_t size, int type)
+		:
+		base(base),
+		size(size),
+		type(type)
+	{
+	}
+
+	VMKernelAddressRange(addr_t base, size_t size,
+		const VMKernelAddressRange* other)
+		:
+		base(base),
+		size(size),
+		type(other->type)
+	{
+		if (type == RANGE_RESERVED) {
+			reserved.base = other->reserved.base;
+			reserved.flags = other->reserved.flags;
+		}
+	}
+};
+
+
+struct VMKernelAddressRangeTreeDefinition {
+	typedef addr_t					Key;
+	typedef VMKernelAddressRange	Value;
+
+	AVLTreeNode* GetAVLTreeNode(Value* value) const
+	{
+		return value;
+	}
+
+	Value* GetValue(AVLTreeNode* node) const
+	{
+		return static_cast<Value*>(node);
+	}
+
+	int Compare(addr_t a, const Value* _b) const
+	{
+		addr_t b = _b->base;
+		if (a == b)
+			return 0;
+		return a < b ? -1 : 1;
+	}
+
+	int Compare(const Value* a, const Value* b) const
+	{
+		return Compare(a->base, b);
+	}
+};
+
+typedef AVLTree<VMKernelAddressRangeTreeDefinition> VMKernelAddressRangeTree;
+
+
+struct VMKernelAddressRangeGetFreeListLink {
+	typedef DoublyLinkedListLink<VMKernelAddressRange> Link;
+
+	inline Link* operator()(VMKernelAddressRange* range) const
+	{
+		return &range->freeListLink;
+	}
+
+	inline const Link* operator()(const VMKernelAddressRange* range) const
+	{
+		return &range->freeListLink;
+	}
+};
+
+
+struct VMKernelArea : VMArea, AVLTreeNode {
 								VMKernelArea(VMAddressSpace* addressSpace,
 									uint32 wiring, uint32 protection);
 								~VMKernelArea();
@@ -20,34 +116,15 @@ struct VMKernelArea : VMArea {
 	static	VMKernelArea*		Create(VMAddressSpace* addressSpace,
 									const char* name, uint32 wiring,
 									uint32 protection);
-	static	VMKernelArea*		CreateReserved(VMAddressSpace* addressSpace,
-									uint32 flags);
 
-			DoublyLinkedListLink<VMKernelArea>& AddressSpaceLink()
-									{ return fAddressSpaceLink; }
-			const DoublyLinkedListLink<VMKernelArea>& AddressSpaceLink() const
-									{ return fAddressSpaceLink; }
+			VMKernelAddressRange* Range() const
+									{ return fRange; }
+			void				SetRange(VMKernelAddressRange* range)
+									{ fRange = range; }
 
 private:
-			DoublyLinkedListLink<VMKernelArea> fAddressSpaceLink;
+			VMKernelAddressRange* fRange;
 };
 
 
-struct VMKernelAreaGetLink {
-    inline DoublyLinkedListLink<VMKernelArea>* operator()(
-		VMKernelArea* area) const
-    {
-        return &area->AddressSpaceLink();
-    }
-
-    inline const DoublyLinkedListLink<VMKernelArea>* operator()(
-		const VMKernelArea* area) const
-    {
-        return &area->AddressSpaceLink();
-    }
-};
-
-typedef DoublyLinkedList<VMKernelArea, VMKernelAreaGetLink> VMKernelAreaList;
-
-
 #endif	// VM_KERNEL_AREA_H

src/system/kernel/vm/VMUserAddressSpace.cpp

@@ -41,7 +41,7 @@ is_valid_spot(addr_t base, addr_t alignedBase, addr_t size, addr_t limit)
 
 VMUserAddressSpace::VMUserAddressSpace(team_id id, addr_t base, size_t size)
 	:
-	VMAddressSpace(id, base, size, "kernel address space"),
+	VMAddressSpace(id, base, size, "address space"),
 	fAreaHint(NULL)
 {
 }
@@ -118,7 +118,7 @@ VMUserAddressSpace::LookupArea(addr_t address) const
 */
 status_t
 VMUserAddressSpace::InsertArea(void** _address, uint32 addressSpec,
-	addr_t size, VMArea* _area)
+	size_t size, VMArea* _area)
 {
 	VMUserArea* area = static_cast<VMUserArea*>(_area);
 
@@ -225,22 +225,21 @@ VMUserAddressSpace::ResizeArea(VMArea* _area, size_t newSize)
 		addr_t offset = area->Base() + newSize - next->Base();
 		if (next->Size() <= offset) {
 			RemoveArea(next);
-			free(next);
+			delete next;
 		} else {
-			status_t error = ResizeAreaHead(next, next->Size() - offset);
+			status_t error = ShrinkAreaHead(next, next->Size() - offset);
 			if (error != B_OK)
 				return error;
 		}
 	}
 
-	return ResizeAreaTail(area, newSize);
-		// TODO: In case of error we should undo the change to the reserved
-		// area.
+	area->SetSize(newSize);
+	return B_OK;
 }
 
 
 status_t
-VMUserAddressSpace::ResizeAreaHead(VMArea* area, size_t size)
+VMUserAddressSpace::ShrinkAreaHead(VMArea* area, size_t size)
 {
 	size_t oldSize = area->Size();
 	if (size == oldSize)
@@ -254,7 +253,7 @@ VMUserAddressSpace::ResizeAreaHead(VMArea* area, size_t size)
 
 
 status_t
-VMUserAddressSpace::ResizeAreaTail(VMArea* area, size_t size)
+VMUserAddressSpace::ShrinkAreaTail(VMArea* area, size_t size)
 {
 	size_t oldSize = area->Size();
 	if (size == oldSize)
@@ -283,7 +282,7 @@ VMUserAddressSpace::ReserveAddressRange(void** _address, uint32 addressSpec,
 
 	status_t status = InsertArea(_address, addressSpec, size, area);
 	if (status != B_OK) {
-		free(area);
+		delete area;
 		return status;
 	}
 
@@ -316,7 +315,7 @@ VMUserAddressSpace::UnreserveAddressRange(addr_t address, size_t size)
 			// remove reserved range
 			RemoveArea(area);
 			Put();
-			free(area);
+			delete area;
 		}
 	}
 
@@ -332,7 +331,7 @@ VMUserAddressSpace::UnreserveAllAddressRanges()
 		if (area->id == RESERVED_AREA_ID) {
 			RemoveArea(area);
 			Put();
-			free(area);
+			delete area;
 		}
 	}
 }
@@ -396,7 +395,7 @@ VMUserAddressSpace::_InsertAreaIntoReservedRegion(addr_t start, size_t size,
 			// the new area fully covers the reversed range
 			fAreas.Remove(next);
 			Put();
-			free(next);
+			delete next;
 		} else {
 			// resize the reserved range behind the area
 			next->SetBase(next->Base() + size);
@@ -556,7 +555,7 @@ second_chance:
 
 						foundSpot = true;
 						area->SetBase(alignedBase);
-						free(next);
+						delete next;
 						break;
 					}
 

src/system/kernel/vm/VMUserAddressSpace.h

@@ -1,10 +1,6 @@
 /*
  * Copyright 2009, Ingo Weinhold, ingo_weinhold@gmx.de.
- * Copyright 2002-2008, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
  * Distributed under the terms of the MIT License.
- *
- * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
- * Distributed under the terms of the NewOS License.
  */
 #ifndef VM_USER_ADDRESS_SPACE_H
 #define VM_USER_ADDRESS_SPACE_H
@@ -29,13 +25,13 @@ public:
 									uint32 protection);
 	virtual	void				DeleteArea(VMArea* area);
 	virtual	status_t			InsertArea(void** _address, uint32 addressSpec,
-									addr_t size, VMArea* area);
+									size_t size, VMArea* area);
 	virtual	void				RemoveArea(VMArea* area);
 
 	virtual	bool				CanResizeArea(VMArea* area, size_t newSize);
 	virtual	status_t			ResizeArea(VMArea* area, size_t newSize);
-	virtual	status_t			ResizeAreaHead(VMArea* area, size_t size);
-	virtual	status_t			ResizeAreaTail(VMArea* area, size_t size);
+	virtual	status_t			ShrinkAreaHead(VMArea* area, size_t newSize);
+	virtual	status_t			ShrinkAreaTail(VMArea* area, size_t newSize);
 
 	virtual	status_t			ReserveAddressRange(void** _address,
 									uint32 addressSpec, size_t size,

src/system/kernel/vm/VMUserArea.cpp

@@ -45,7 +45,9 @@ VMUserArea::Create(VMAddressSpace* addressSpace, const char* name,
 VMUserArea::CreateReserved(VMAddressSpace* addressSpace, uint32 flags)
 {
 	VMUserArea* area = new(nogrow) VMUserArea(addressSpace, 0, 0);
-	if (area != NULL)
+	if (area != NULL) {
 		area->id = RESERVED_AREA_ID;
+		area->protection = flags;
+	}
 	return area;
 }

src/system/kernel/vm/vm.cpp

@@ -338,7 +338,7 @@ cut_area(VMAddressSpace* addressSpace, VMArea* area, addr_t address,
 		size_t oldSize = area->Size();
 		size_t newSize = address - area->Base();
 
-		status_t error = addressSpace->ResizeAreaTail(area, newSize);
+		status_t error = addressSpace->ShrinkAreaTail(area, newSize);
 		if (error != B_OK)
 			return error;
 
@@ -350,7 +350,7 @@ cut_area(VMAddressSpace* addressSpace, VMArea* area, addr_t address,
 			&& list_is_empty(&cache->consumers)) {
 			error = cache->Resize(cache->virtual_base + newSize);
 			if (error != B_OK) {
-				addressSpace->ResizeAreaTail(area, oldSize);
+				addressSpace->ShrinkAreaTail(area, oldSize);
 				return error;
 			}
 		}
@@ -368,7 +368,7 @@ cut_area(VMAddressSpace* addressSpace, VMArea* area, addr_t address,
 		vm_unmap_pages(area, oldBase, newBase - oldBase, false);
 
 		// resize the area
-		status_t error = addressSpace->ResizeAreaHead(area, newSize);
+		status_t error = addressSpace->ShrinkAreaHead(area, newSize);
 		if (error != B_OK)
 			return error;
 
@@ -392,7 +392,7 @@ cut_area(VMAddressSpace* addressSpace, VMArea* area, addr_t address,
 
 	// resize the area
 	addr_t oldSize = area->Size();
-	status_t error = addressSpace->ResizeAreaTail(area, firstNewSize);
+	status_t error = addressSpace->ShrinkAreaTail(area, firstNewSize);
 	if (error != B_OK)
 		return error;
 
@@ -408,7 +408,7 @@ cut_area(VMAddressSpace* addressSpace, VMArea* area, addr_t address,
 		B_EXACT_ADDRESS, area->wiring, area->protection, REGION_NO_PRIVATE_MAP,
 		&secondArea, area->name, false, kernel);
 	if (error != B_OK) {
-		addressSpace->ResizeAreaTail(area, oldSize);
+		addressSpace->ShrinkAreaTail(area, oldSize);
 		return error;
 	}