mach/vm_purgable.h

Virtual memory map purgeable object definitions. Objects that will be needed in the future (forward cached objects) should be queued LIFO. Objects that have been used and are cached for reuse (backward cached) should be queued FIFO. Every user of purgeable memory is entitled to using the highest volatile group (7). Only if a client wants some of its objects to definitely be purged earlier, it can put those in another group. This could be used to make all FIFO objects (in the lower group) go away before any LIFO objects (in the higher group) go away. Objects that should not get any chance to stay around can be marked as "obsolete". They will be emptied before any other objects or pages are reclaimed. Obsolete objects are not emptied in any particular order. 'purgeable' is recognized as the correct spelling. For historical reasons, definitions in this file are spelled 'purgable'.

typedef int vm_purgable_t

#define VM_PURGABLE_SET_STATE ((vm_purgable_t) 0)

#define VM_PURGABLE_GET_STATE ((vm_purgable_t) 1)

#define VM_PURGABLE_PURGE_ALL ((vm_purgable_t) 2)

#define VM_PURGABLE_SET_STATE_FROM_KERNEL ((vm_purgable_t) 3)

#define VM_PURGABLE_NO_AGING_SHIFT 16

#define VM_PURGABLE_NO_AGING_MASK (0x1 << VM_PURGABLE_NO_AGING_SHIFT)

#define VM_PURGABLE_NO_AGING (0x1 << VM_PURGABLE_NO_AGING_SHIFT)

#define VM_PURGABLE_DEBUG_SHIFT 12

#define VM_PURGABLE_DEBUG_MASK (0x3 << VM_PURGABLE_DEBUG_SHIFT)

#define VM_PURGABLE_DEBUG_EMPTY (0x1 << VM_PURGABLE_DEBUG_SHIFT)

#define VM_PURGABLE_DEBUG_FAULT (0x2 << VM_PURGABLE_DEBUG_SHIFT)

#define VM_VOLATILE_GROUP_SHIFT 8

#define VM_VOLATILE_GROUP_MASK (7 << VM_VOLATILE_GROUP_SHIFT)

#define VM_VOLATILE_GROUP_DEFAULT VM_VOLATILE_GROUP_0

#define VM_VOLATILE_GROUP_0 (0 << VM_VOLATILE_GROUP_SHIFT)

#define VM_VOLATILE_GROUP_1 (1 << VM_VOLATILE_GROUP_SHIFT)

#define VM_VOLATILE_GROUP_2 (2 << VM_VOLATILE_GROUP_SHIFT)

#define VM_VOLATILE_GROUP_3 (3 << VM_VOLATILE_GROUP_SHIFT)

#define VM_VOLATILE_GROUP_4 (4 << VM_VOLATILE_GROUP_SHIFT)

#define VM_VOLATILE_GROUP_5 (5 << VM_VOLATILE_GROUP_SHIFT)

#define VM_VOLATILE_GROUP_6 (6 << VM_VOLATILE_GROUP_SHIFT)

#define VM_VOLATILE_GROUP_7 (7 << VM_VOLATILE_GROUP_SHIFT)

#define VM_PURGABLE_BEHAVIOR_SHIFT 6

#define VM_PURGABLE_BEHAVIOR_MASK (1 << VM_PURGABLE_BEHAVIOR_SHIFT)

#define VM_PURGABLE_BEHAVIOR_FIFO (0 << VM_PURGABLE_BEHAVIOR_SHIFT)

#define VM_PURGABLE_BEHAVIOR_LIFO (1 << VM_PURGABLE_BEHAVIOR_SHIFT)

#define VM_PURGABLE_ORDERING_SHIFT 5

#define VM_PURGABLE_ORDERING_MASK (1 << VM_PURGABLE_ORDERING_SHIFT)

#define VM_PURGABLE_ORDERING_OBSOLETE (1 << VM_PURGABLE_ORDERING_SHIFT)

#define VM_PURGABLE_ORDERING_NORMAL (0 << VM_PURGABLE_ORDERING_SHIFT)

#define VM_VOLATILE_ORDER_SHIFT 4

#define VM_VOLATILE_ORDER_MASK (1 << VM_VOLATILE_ORDER_SHIFT)

#define VM_VOLATILE_MAKE_FIRST_IN_GROUP (1 << VM_VOLATILE_ORDER_SHIFT)

#define VM_VOLATILE_MAKE_LAST_IN_GROUP (0 << VM_VOLATILE_ORDER_SHIFT)

#define VM_PURGABLE_STATE_MIN 0

#define VM_PURGABLE_STATE_MAX 3

#define VM_PURGABLE_STATE_MASK 3

#define VM_PURGABLE_NONVOLATILE 0

#define VM_PURGABLE_VOLATILE 1

#define VM_PURGABLE_EMPTY 2

#define VM_PURGABLE_DENY 3

#define VM_PURGABLE_ALL_MASKS (VM_PURGABLE_STATE_MASK |
	                         VM_VOLATILE_ORDER_MASK |
	                         VM_PURGABLE_ORDERING_MASK |
	                         VM_PURGABLE_BEHAVIOR_MASK |
	                         VM_VOLATILE_GROUP_MASK |
	                         VM_PURGABLE_DEBUG_MASK |
	                         VM_PURGABLE_NO_AGING_MASK)