Repo-copy numerous files from sys/emulation/posix4 to sys/sys and sys/kern
[dragonfly/vkernel-mp.git] / sys / vm / vm_page2.h
blob7124e344257e84915d9f2e96113e9939c706ebb4
1 /*-
2 * Copyright (c) 1982, 1986, 1993
3 * The Regents of the University of California. All rights reserved.
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16 * California, Berkeley and its contributors.
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33 * @(#)vmmeter.h 8.2 (Berkeley) 7/10/94
34 * $FreeBSD: src/sys/sys/vmmeter.h,v 1.21.2.2 2002/10/10 19:28:21 dillon Exp $
35 * $DragonFly: src/sys/vm/vm_page2.h,v 1.2 2006/05/20 04:42:15 dillon Exp $
38 #ifndef _VM_VM_PAGE2_H_
39 #define _VM_VM_PAGE2_H_
41 #ifndef _SYS_VMMETER_H_
42 #include <sys/vmmeter.h>
43 #endif
45 #ifdef _KERNEL
48 * Return TRUE if we are under our reserved low-free-pages threshold
51 static __inline
52 int
53 vm_page_count_reserved(void)
55 return (vmstats.v_free_reserved >
56 (vmstats.v_free_count + vmstats.v_cache_count));
60 * Return TRUE if we are under our severe low-free-pages threshold
62 * This routine is typically used at the user<->system interface to determine
63 * whether we need to block in order to avoid a low memory deadlock.
66 static __inline
67 int
68 vm_page_count_severe(void)
70 return (vmstats.v_free_severe >
71 (vmstats.v_free_count + vmstats.v_cache_count));
75 * Return TRUE if we are under our minimum low-free-pages threshold.
77 * This routine is typically used within the system to determine whether
78 * we can execute potentially very expensive code in terms of memory. It
79 * is also used by the pageout daemon to calculate when to sleep, when
80 * to wake waiters up, and when (after making a pass) to become more
81 * desparate.
84 static __inline
85 int
86 vm_page_count_min(void)
88 return (vmstats.v_free_min >
89 (vmstats.v_free_count + vmstats.v_cache_count));
93 * Return TRUE if we have not reached our free page target during
94 * free page recovery operations.
97 static __inline
98 int
99 vm_page_count_target(void)
101 return (vmstats.v_free_target >
102 (vmstats.v_free_count + vmstats.v_cache_count));
106 * Return the number of pages we need to free-up or cache
107 * A positive number indicates that we do not have enough free pages.
110 static __inline
112 vm_paging_target(void)
114 return (
115 (vmstats.v_free_target + vmstats.v_cache_min) -
116 (vmstats.v_free_count + vmstats.v_cache_count)
121 * Return a positive number if the pagedaemon needs to be woken up.
124 static __inline
126 vm_paging_needed(void)
128 return (
129 (vmstats.v_free_reserved + vmstats.v_cache_min) >
130 (vmstats.v_free_count + vmstats.v_cache_count)
134 #endif /* _KERNEL */
135 #endif /* _VM_VM_PAGE2_H_ */