Added an additional flag B_OVERCOMMITTING_AREA (currently to be specified

along the protection flags).
Changed the handling of B_STACK_AREA types and anonymous vm_areas: now
every area can overcommit if B_OVERCOMMITTING_AREA was specified.
B_STACK_AREA areas are still automatically overcommitting, but
B_KERNEL_STACK_AREA areas no longer.
vm_store_anonymous_noswap.c now only tests for guard pages if there were
any specified which is only done for B_STACK_AREA areas.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@12673 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/vm_store_anonymous_noswap.h

@@ -1,5 +1,5 @@
-/* 
- * Copyright 2004, Axel Dörfler, [email protected].
+/*
+ * Copyright 2004-2005, Axel Dörfler, [email protected].
  * Distributed under the terms of the MIT License.
  *
  * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
@@ -8,8 +8,13 @@
 #ifndef _KERNEL_VM_STORE_ANONYMOUS_H
 #define _KERNEL_VM_STORE_ANONYMOUS_H
 
+
 #include <vm_types.h>
 
-vm_store *vm_store_create_anonymous_noswap(bool stack, int32 numGuardPages);
+
+#ifdef __cplusplus
+extern "C"
+#endif
+vm_store *vm_store_create_anonymous_noswap(bool canOvercommit, int32 numGuardPages);
 
 #endif	/* _KERNEL_VM_STORE_ANONYMOUS_H */

headers/private/kernel/vm_types.h

@@ -187,7 +187,13 @@ enum {
 	(B_KERNEL_READ_AREA | B_KERNEL_WRITE_AREA | B_KERNEL_EXECUTE_AREA \
 	| B_KERNEL_STACK_AREA)
 
+#define B_OVERCOMMITTING_AREA	0x1000
+	// ToDo: this is not really a protection flag, but since the "protection"
+	//	field is the only flag field, we currently use it for this.
+	//	A cleaner approach would be appreciated - maybe just an official generic
+	//	flags region in the protection field.
+
 #define B_USER_AREA_FLAGS		(B_USER_PROTECTION)
-#define B_KERNEL_AREA_FLAGS		(B_KERNEL_PROTECTION | B_USER_CLONEABLE_AREA)
+#define B_KERNEL_AREA_FLAGS		(B_KERNEL_PROTECTION | B_USER_CLONEABLE_AREA | B_OVERCOMMITTING_AREA)
 
 #endif	/* _KERNEL_VM_TYPES_H */