diff options
Diffstat (limited to 'sys/vm/swap_pager.h')
| -rw-r--r-- | sys/vm/swap_pager.h | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/sys/vm/swap_pager.h b/sys/vm/swap_pager.h new file mode 100644 index 0000000..853edd5 --- /dev/null +++ b/sys/vm/swap_pager.h @@ -0,0 +1,99 @@ +/* + * Copyright (c) 1990 University of Utah. + * Copyright (c) 1991 The Regents of the University of California. + * All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * the Systems Programming Group of the University of Utah Computer + * Science Department. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * from: @(#)swap_pager.h 7.1 (Berkeley) 12/5/90 + * $Id: swap_pager.h,v 1.9 1994/03/14 21:54:23 davidg Exp $ + */ + +/* + * Modifications to the block allocation data structure by John S. Dyson + * 18 Dec 93. + */ + +#ifndef _SWAP_PAGER_ +#define _SWAP_PAGER_ 1 + +/* + * SWB_NPAGES can be set to any value from 1 to 16 pages per allocation, + * however, due to the allocation spilling into non-swap pager backed memory, + * suggest keeping SWB_NPAGES small (1-4). If high performance is manditory + * perhaps up to 8 pages might be in order???? + * Above problem has been fixed, now we support 16 pages per block. Unused + * space is recovered by the swap pager now... + */ +#define SWB_NPAGES 8 +struct swblock { + unsigned short swb_valid; /* bitmask for valid pages */ + unsigned short swb_locked; /* block locked */ + int swb_block[SWB_NPAGES]; /* unfortunately int instead of daddr_t */ +}; +typedef struct swblock *sw_blk_t; + +/* + * Swap pager private data. + */ +struct swpager { + vm_size_t sw_osize; /* size of object we are backing (bytes) */ + int sw_nblocks;/* number of blocks in list (sw_blk_t units) */ + sw_blk_t sw_blocks; /* pointer to list of swap blocks */ + short sw_flags; /* flags */ + short sw_poip; /* pageouts in progress */ + short sw_piip; /* pageins in progress */ +}; +typedef struct swpager *sw_pager_t; + +#define SW_WANTED 0x01 +#define SW_NAMED 0x02 + +#ifdef KERNEL + +void swap_pager_init(void); +vm_pager_t swap_pager_alloc(caddr_t, vm_size_t, vm_prot_t, vm_offset_t); +void swap_pager_dealloc(vm_pager_t); +boolean_t swap_pager_getpage(vm_pager_t, vm_page_t, boolean_t); +boolean_t swap_pager_putpage(vm_pager_t, vm_page_t, boolean_t); +boolean_t swap_pager_getmulti(vm_pager_t, vm_page_t *, int, int, boolean_t); +boolean_t swap_pager_haspage(vm_pager_t, vm_offset_t); +int swap_pager_io(sw_pager_t, vm_page_t *, int, int, int); +void swap_pager_iodone(struct buf *); +boolean_t swap_pager_clean(); + +extern struct pagerops swappagerops; + +#endif + +#endif /* _SWAP_PAGER_ */ |
