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. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * from: @(#)swap_pager.h 7.1 (Berkeley) 12/5/90 35 * $FreeBSD: src/sys/vm/swap_pager.h,v 1.28.2.1 2000/10/13 07:13:23 dillon Exp $ 36 */ 37 38 /* 39 * Modifications to the block allocation data structure by John S. Dyson 40 * 18 Dec 93. 41 */ 42 43 #ifndef _VM_SWAP_PAGER_H_ 44 #define _VM_SWAP_PAGER_H_ 45 46 #ifndef _SYS_TYPES_H_ 47 #include <sys/types.h> 48 #endif 49 #ifndef _VM_VM_OBJECT_H_ 50 #include <vm/vm_object.h> 51 #endif 52 #ifndef _SYS_BLIST_H_ 53 #include <sys/blist.h> 54 #endif 55 56 /* 57 * SWB_NPAGES must be a power of 2. Note that DMMAX may not exceed 58 * SWBLK_BITS, so the limit for SWB_NPAGES is (SWBLK_BITS / 2). 59 */ 60 #define SWB_NPAGES 16 61 62 /* 63 * DMMAX is the stripe size and must be a power of 2 >= SWBLK_BITS to ensure 64 * that the blist code does not allocate a contiguous range that crosses a 65 * stripe. 66 */ 67 #define SWB_DMMAX SWBLK_BITS 68 #define SWB_DMMASK (SWB_DMMAX - 1) 69 70 /* 71 * Piecemeal swap metadata structure. Swap is stored in a RBTREE. Swap 72 * blocks are page-sized. e.g. block 1 is offset +4096 from block 0. 73 * 74 * ram:swap is around 1:341 75 * 76 * Overall memory utilization is about the same as the old swap structure. 77 */ 78 79 #define SWAP_META_PAGES (SWB_NPAGES * 2) 80 #define SWAP_META_MASK (SWAP_META_PAGES - 1) 81 82 struct swblock { 83 RB_ENTRY(swblock) swb_entry; 84 vm_pindex_t swb_index; 85 int swb_count; 86 swblk_t swb_pages[SWAP_META_PAGES]; 87 }; 88 89 #ifdef _KERNEL 90 extern int swap_pager_full; 91 extern int swap_pager_almost_full; 92 extern int swap_fail_ticks; 93 extern int swap_user_async; 94 extern swblk_t vm_swap_size; 95 extern swblk_t vm_swap_max; 96 extern swblk_t vm_swap_cache_use; 97 extern swblk_t vm_swap_anon_use; 98 extern int vm_swapcache_read_enable; 99 extern int vm_swapcache_inactive_heuristic; 100 extern int vm_swapcache_use_chflags; 101 102 extern struct blist *swapblist; 103 extern int nswap_lowat, nswap_hiwat; 104 105 void swap_pager_putpages (vm_object_t, struct vm_page **, int, int, int *); 106 boolean_t swap_pager_haspage (vm_object_t object, vm_pindex_t pindex); 107 int swap_pager_swapoff (int devidx); 108 109 int swap_pager_swp_alloc (vm_object_t, int); 110 void swap_pager_copy (vm_object_t, vm_object_t, vm_pindex_t, int); 111 void swap_pager_freespace (vm_object_t, vm_pindex_t, vm_pindex_t); 112 void swap_pager_freespace_all (vm_object_t); 113 int swap_pager_condfree(vm_object_t, vm_pindex_t *, int); 114 115 void swap_pager_page_inserted(vm_page_t); 116 void swap_pager_swap_init (void); 117 void swap_pager_newswap (void); 118 int swap_pager_reserve (vm_object_t, vm_pindex_t, vm_size_t); 119 120 void swapacctspace(swblk_t base, swblk_t count); 121 122 /* 123 * newswap functions 124 */ 125 126 void swap_pager_page_removed (struct vm_page *, vm_object_t); 127 128 /* choose underlying swap device and queue up I/O */ 129 struct buf; 130 void swstrategy (struct buf *bp); /* probably needs to move elsewhere */ 131 132 #endif 133 134 #endif /* _VM_SWAP_PAGER_H_ */ 135