freebsd-dev/sys/vm/swap_pager.h
John Dyson 836e5d1360 In order to fix some concurrency problems with the swap pager early
on in the FreeBSD development, I had made a global lock around the
rlist code.  This was bogus, and now the lock is maintained on a
per resource list basis.  This now allows the rlist code to be used for
almost any non-interrupt level application.
1996-03-03 21:11:08 +00:00

80 lines
3.4 KiB
C

/*
* 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 1.14 1996/01/30 23:02:29 mpp 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 mandatory
* 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 */
daddr_t swb_block[SWB_NPAGES]; /* unfortunately int instead of daddr_t */
};
typedef struct swblock *sw_blk_t;
#ifdef KERNEL
extern struct pagerlst swap_pager_un_object_list;
extern int swap_pager_full;
extern struct rlisthdr swaplist;
int swap_pager_putpages __P((vm_object_t, vm_page_t *, int, boolean_t, int *));
int swap_pager_swp_alloc __P((vm_object_t, int));
void swap_pager_copy __P((vm_object_t, vm_pindex_t, vm_object_t,
vm_pindex_t, vm_pindex_t));
void swap_pager_freespace __P((vm_object_t, vm_pindex_t, vm_size_t));
void swap_pager_swap_init __P((void));
#endif
#endif /* _SWAP_PAGER_ */