1 /* 2 * Copyright (c) 1990 University of Utah. 3 * Copyright (c) 1991 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * from: @(#)swap_pager.h 7.1 (Berkeley) 12/5/90 39 * $FreeBSD: src/sys/vm/swap_pager.h,v 1.28.2.1 2000/10/13 07:13:23 dillon Exp $ 40 */ 41 42 /* 43 * Modifications to the block allocation data structure by John S. Dyson 44 * 18 Dec 93. 45 */ 46 47 #ifndef _VM_SWAP_PAGER_H_ 48 #define _VM_SWAP_PAGER_H_ 49 50 #ifndef _SYS_TYPES_H_ 51 #include <sys/types.h> 52 #endif 53 #ifndef _VM_VM_OBJECT_H_ 54 #include <vm/vm_object.h> 55 #endif 56 #ifndef _SYS_BLIST_H_ 57 #include <sys/blist.h> 58 #endif 59 60 /* 61 * SWB_NPAGES must be a power of 2. It may be set to 1, 2, 4, 8, or 16 62 * pages per allocation. We recommend you stick with the default of 8. 63 * The 16-page limit is due to the radix code (kern/subr_blist.c). 64 */ 65 #define SWB_NPAGES 16 66 67 /* 68 * Piecemeal swap metadata structure. Swap is stored in a hash table. 69 * 70 * Storage use is ~1:16384 or so. 71 * 72 * Overall memory utilization is about the same as the old swap structure. 73 */ 74 75 #define SWAP_META_PAGES (SWB_NPAGES * 2) 76 #define SWAP_META_MASK (SWAP_META_PAGES - 1) 77 78 struct swblock { 79 RB_ENTRY(swblock) swb_entry; 80 vm_pindex_t swb_index; 81 int swb_count; 82 swblk_t swb_pages[SWAP_META_PAGES]; 83 }; 84 85 #ifdef _KERNEL 86 extern int swap_pager_full; 87 extern int swap_pager_almost_full; 88 extern int swap_fail_ticks; 89 extern int vm_swap_size; 90 extern int vm_swap_max; 91 extern int vm_swap_cache_use; 92 extern int vm_swap_anon_use; 93 extern int vm_swapcache_read_enable; 94 extern int vm_swapcache_inactive_heuristic; 95 extern int vm_swapcache_use_chflags; 96 97 extern struct blist *swapblist; 98 extern int nswap_lowat, nswap_hiwat; 99 100 void swap_pager_putpages (vm_object_t, struct vm_page **, int, int, int *); 101 boolean_t swap_pager_haspage (vm_object_t object, vm_pindex_t pindex); 102 int swap_pager_swapoff (int devidx); 103 104 int swap_pager_swp_alloc (vm_object_t, int); 105 void swap_pager_copy (vm_object_t, vm_object_t, vm_pindex_t, int); 106 void swap_pager_freespace (vm_object_t, vm_pindex_t, vm_pindex_t); 107 void swap_pager_freespace_all (vm_object_t); 108 int swap_pager_condfree(vm_object_t, vm_pindex_t *, int); 109 110 void swap_pager_page_inserted(vm_page_t); 111 void swap_pager_swap_init (void); 112 void swap_pager_newswap (void); 113 int swap_pager_reserve (vm_object_t, vm_pindex_t, vm_size_t); 114 115 void swapacctspace(swblk_t base, swblk_t count); 116 117 /* 118 * newswap functions 119 */ 120 121 void swap_pager_page_removed (struct vm_page *, vm_object_t); 122 123 /* choose underlying swap device and queue up I/O */ 124 struct buf; 125 void swstrategy (struct buf *bp); /* probably needs to move elsewhere */ 126 127 #endif 128 129 #endif /* _VM_SWAP_PAGER_H_ */ 130