swap_pager.h revision 117702
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: head/sys/vm/swap_pager.h 117702 2003-07-17 21:58:43Z phk $ 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_ 1 49 50/* 51 * Swap device table 52 */ 53struct swdevt { 54 udev_t sw_dev; /* For quasibogus swapdev reporting */ 55 int sw_flags; 56 int sw_nblks; 57 int sw_used; 58 struct vnode *sw_vp; 59 dev_t sw_device; 60}; 61#define SW_FREED 0x01 62#define SW_SEQUENTIAL 0x02 63#define SW_CLOSING 0x04 64#define sw_freed sw_flags /* XXX compat */ 65 66#ifdef _KERNEL 67 68/* 69 * SWB_NPAGES must be a power of 2. It may be set to 1, 2, 4, 8, or 16 70 * pages per allocation. We recommend you stick with the default of 8. 71 * The 16-page limit is due to the radix code (kern/subr_blist.c). 72 */ 73#ifndef MAX_PAGEOUT_CLUSTER 74#define MAX_PAGEOUT_CLUSTER 16 75#endif 76 77#if !defined(SWB_NPAGES) 78#define SWB_NPAGES MAX_PAGEOUT_CLUSTER 79#endif 80 81/* 82 * Piecemeal swap metadata structure. Swap is stored in a radix tree. 83 * 84 * If SWB_NPAGES is 8 and sizeof(char *) == sizeof(daddr_t), our radix 85 * is basically 8. Assuming PAGE_SIZE == 4096, one tree level represents 86 * 32K worth of data, two levels represent 256K, three levels represent 87 * 2 MBytes. This is acceptable. 88 * 89 * Overall memory utilization is about the same as the old swap structure. 90 */ 91#define SWCORRECT(n) (sizeof(void *) * (n) / sizeof(daddr_t)) 92#define SWAP_META_PAGES (SWB_NPAGES * 2) 93#define SWAP_META_MASK (SWAP_META_PAGES - 1) 94 95struct swblock { 96 struct swblock *swb_hnext; 97 vm_object_t swb_object; 98 vm_pindex_t swb_index; 99 int swb_count; 100 daddr_t swb_pages[SWAP_META_PAGES]; 101}; 102 103extern struct pagerlst swap_pager_un_object_list; 104extern int swap_pager_full; 105extern struct blist *swapblist; 106extern struct uma_zone *swap_zone; 107extern int nswap_lowat, nswap_hiwat; 108extern int dmmax, dmmax_mask; 109extern struct vnode *swapdev_vp; 110extern struct swdevt *swdevt; 111extern int nswdev; 112/* 113 * vm_swap_size is in page-sized chunks now. It was DEV_BSIZE'd chunks 114 * in the old system. 115 */ 116extern int vm_swap_size; /* number of free swap blocks, in pages */ 117 118void swap_pager_putpages(vm_object_t, vm_page_t *, int, boolean_t, int *); 119void swap_pager_swapoff(int devidx, int *sw_used); 120 121void swap_pager_copy(vm_object_t, vm_object_t, vm_pindex_t, int); 122void swap_pager_freespace(vm_object_t, vm_pindex_t, vm_size_t); 123void swap_pager_swap_init(void); 124int swap_pager_isswapped(vm_object_t, int); 125int swap_pager_reserve(vm_object_t, vm_pindex_t, vm_size_t); 126 127/* 128 * newswap functions 129 */ 130 131 132#endif /* _KERNEL */ 133#endif /* _VM_SWAP_PAGER_H_ */ 134