1 /*- 2 * Copyright (c) 1982, 1986, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 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 1.3 2008/04/14 20:00:29 dillon Exp $ 36 */ 37 38 #ifndef _VM_VM_PAGE2_H_ 39 #define _VM_VM_PAGE2_H_ 40 41 #ifndef _SYS_VMMETER_H_ 42 #include <sys/vmmeter.h> 43 #endif 44 #ifndef _SYS_QUEUE_H_ 45 #include <sys/queue.h> 46 #endif 47 #ifndef _VM_PAGE_H_ 48 #include <vm/vm_page.h> 49 #endif 50 51 #ifdef _KERNEL 52 53 /* 54 * Return TRUE if we are under our reserved low-free-pages threshold 55 */ 56 57 static __inline 58 int 59 vm_page_count_reserved(void) 60 { 61 return (vmstats.v_free_reserved > 62 (vmstats.v_free_count + vmstats.v_cache_count)); 63 } 64 65 /* 66 * Return TRUE if we are under our severe low-free-pages threshold 67 * 68 * This routine is typically used at the user<->system interface to determine 69 * whether we need to block in order to avoid a low memory deadlock. 70 */ 71 72 static __inline 73 int 74 vm_page_count_severe(void) 75 { 76 return (vmstats.v_free_severe > 77 (vmstats.v_free_count + vmstats.v_cache_count)); 78 } 79 80 /* 81 * Return TRUE if we are under our minimum low-free-pages threshold. 82 * 83 * This routine is typically used within the system to determine whether 84 * we can execute potentially very expensive code in terms of memory. It 85 * is also used by the pageout daemon to calculate when to sleep, when 86 * to wake waiters up, and when (after making a pass) to become more 87 * desparate. 88 */ 89 90 static __inline 91 int 92 vm_page_count_min(void) 93 { 94 return (vmstats.v_free_min > 95 (vmstats.v_free_count + vmstats.v_cache_count)); 96 } 97 98 /* 99 * Return TRUE if we have not reached our free page target during 100 * free page recovery operations. 101 */ 102 103 static __inline 104 int 105 vm_page_count_target(void) 106 { 107 return (vmstats.v_free_target > 108 (vmstats.v_free_count + vmstats.v_cache_count)); 109 } 110 111 /* 112 * Return the number of pages we need to free-up or cache 113 * A positive number indicates that we do not have enough free pages. 114 */ 115 116 static __inline 117 int 118 vm_paging_target(void) 119 { 120 return ( 121 (vmstats.v_free_target + vmstats.v_cache_min) - 122 (vmstats.v_free_count + vmstats.v_cache_count) 123 ); 124 } 125 126 /* 127 * Return a positive number if the pagedaemon needs to be woken up. 128 */ 129 130 static __inline 131 int 132 vm_paging_needed(void) 133 { 134 return ( 135 (vmstats.v_free_reserved + vmstats.v_cache_min) > 136 (vmstats.v_free_count + vmstats.v_cache_count) 137 ); 138 } 139 140 static __inline 141 void 142 vm_page_event(vm_page_t m, vm_page_event_t event) 143 { 144 if (LIST_FIRST(&m->action_list)) 145 vm_page_event_internal(m, event); 146 } 147 148 static __inline 149 void 150 vm_page_init_action(vm_page_action_t action, 151 void (*func)(vm_page_t, vm_page_action_t), void *data) 152 { 153 action->func = func; 154 action->data = data; 155 } 156 157 static __inline 158 void 159 vm_page_register_action(vm_page_t m, vm_page_action_t action, 160 vm_page_event_t event) 161 { 162 action->event = event; 163 LIST_INSERT_HEAD(&m->action_list, action, entry); 164 } 165 166 static __inline 167 void 168 vm_page_unregister_action(vm_page_t m, vm_page_action_t action) 169 { 170 if (action->event != VMEVENT_NONE) { 171 action->event = VMEVENT_NONE; 172 LIST_REMOVE(action, entry); 173 } 174 } 175 176 #endif /* _KERNEL */ 177 #endif /* _VM_VM_PAGE2_H_ */ 178 179