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 * $DragonFly: src/sys/vm/swap_pager.h,v 1.5 2006/05/21 03:43:47 dillon Exp $ 41 */ 42 43 /* 44 * Modifications to the block allocation data structure by John S. Dyson 45 * 18 Dec 93. 46 */ 47 48 #ifndef _VM_SWAP_PAGER_H_ 49 #define _VM_SWAP_PAGER_H_ 50 51 #ifndef _SYS_TYPES_H_ 52 #include <sys/types.h> 53 #endif 54 #ifndef _VM_VM_OBJECT_H_ 55 #include <vm/vm_object.h> 56 #endif 57 58 /* 59 * SWB_NPAGES must be a power of 2. It may be set to 1, 2, 4, 8, or 16 60 * pages per allocation. We recommend you stick with the default of 8. 61 * The 16-page limit is due to the radix code (kern/subr_blist.c). 62 */ 63 #if !defined(SWB_NPAGES) 64 #define SWB_NPAGES 8 65 #endif 66 67 /* 68 * Piecemeal swap metadata structure. Swap is stored in a radix tree. 69 * 70 * If SWB_NPAGES is 8 and sizeof(char *) == sizeof(daddr_t), our radix 71 * is basically 8. Assuming PAGE_SIZE == 4096, one tree level represents 72 * 32K worth of data, two levels represent 256K, three levels represent 73 * 2 MBytes. This is acceptable. 74 * 75 * Overall memory utilization is about the same as the old swap structure. 76 */ 77 78 #define SWCORRECT(n) (sizeof(void *) * (n) / sizeof(daddr_t)) 79 80 #define SWAP_META_PAGES (SWB_NPAGES * 2) 81 #define SWAP_META_MASK (SWAP_META_PAGES - 1) 82 83 struct swblock { 84 struct swblock *swb_hnext; 85 vm_object_t swb_object; 86 vm_pindex_t swb_index; 87 int swb_count; 88 daddr_t swb_pages[SWAP_META_PAGES]; 89 }; 90 91 #ifdef _KERNEL 92 extern struct pagerlst swap_pager_un_object_list; 93 extern int swap_pager_full; 94 extern struct blist *swapblist; 95 96 void swap_pager_putpages (vm_object_t, struct vm_page **, int, boolean_t, int *); 97 boolean_t swap_pager_haspage (vm_object_t object, vm_pindex_t pindex, int *before, int *after); 98 99 int swap_pager_swp_alloc (vm_object_t, int); 100 void swap_pager_copy (vm_object_t, vm_object_t, vm_pindex_t, int); 101 void swap_pager_freespace (vm_object_t, vm_pindex_t, vm_size_t); 102 void swap_pager_dmzspace (vm_object_t, vm_pindex_t, vm_size_t); 103 void swap_pager_swap_init (void); 104 int swap_pager_reserve (vm_object_t, vm_pindex_t, vm_size_t); 105 106 /* 107 * newswap functions 108 */ 109 110 void swap_pager_page_removed (struct vm_page *, vm_object_t); 111 112 /* choose underlying swap device and queue up I/O */ 113 struct buf; 114 void swstrategy (struct buf *bp); /* probably needs to move elsewhere */ 115 116 #endif 117 118 #endif /* _VM_SWAP_PAGER_H_ */ 119