swap_pager.h revision 37546 
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 *	$Id: swap_pager.h,v 1.21 1998/04/29 04:28:02 dyson Exp $
40 */
41
42/*
43 * Modifications to the block allocation data structure by John S. Dyson
44 * 18 Dec 93.
45 */
46
47#ifndef	_SWAP_PAGER_
48#define	_SWAP_PAGER_	1
49
50/*
51 * SWB_NPAGES can be set to any value from 1 to 16 pages per allocation,
52 * however, due to the allocation spilling into non-swap pager backed memory,
53 * suggest keeping SWB_NPAGES small (1-4).  If high performance is mandatory
54 * perhaps up to 8 pages might be in order????
55 * Above problem has been fixed, now we support 16 pages per block.  Unused
56 * space is recovered by the swap pager now...
57 */
58#if !defined(SWB_NPAGES)
59#define SWB_NPAGES 8
60#endif
61
62struct swblock {
63	unsigned short swb_valid;	/* bitmask for valid pages */
64	unsigned short swb_locked;	/* block locked */
65	daddr_t swb_block[SWB_NPAGES];
66};
67typedef struct swblock *sw_blk_t;
68
69#ifdef KERNEL
70extern struct pagerlst swap_pager_un_object_list;
71extern int swap_pager_full;
72extern struct rlisthdr swaplist;
73
74int swap_pager_putpages __P((vm_object_t, vm_page_t *, int, boolean_t, int *));
75int swap_pager_swp_alloc __P((vm_object_t, int));
76void swap_pager_copy __P((vm_object_t, vm_pindex_t, vm_object_t,
77	vm_pindex_t, vm_pindex_t, int));
78void swap_pager_freespace __P((vm_object_t, vm_pindex_t, vm_size_t));
79void swap_pager_dmzspace __P((vm_object_t, vm_pindex_t, vm_size_t));
80void swap_pager_swap_init __P((void));
81void swap_pager_sync __P((void));
82#endif
83
84#endif				/* _SWAP_PAGER_ */
85