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/*
* Copyright (c) 1995, David Greenman
* All rights reserved.
*
* 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 David Greenman.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/queue.h>
#include <sys/vmmeter.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_prot.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>
#include <vm/default_pager.h>
#include <vm/swap_pager.h>
static vm_object_t default_pager_alloc __P((void *, vm_size_t, vm_prot_t,
vm_ooffset_t));
static void default_pager_dealloc __P((vm_object_t));
static int default_pager_getpages __P((vm_object_t, vm_page_t *, int, int));
static int default_pager_putpages __P((vm_object_t, vm_page_t *, int,
boolean_t, int *));
static boolean_t default_pager_haspage __P((vm_object_t, vm_pindex_t, int *,
int *));
/*
* pagerops for OBJT_DEFAULT - "default pager".
*/
struct pagerops defaultpagerops = {
NULL,
default_pager_alloc,
default_pager_dealloc,
default_pager_getpages,
default_pager_putpages,
default_pager_haspage,
NULL
};
/*
* no_pager_alloc just returns an initialized object.
*/
static vm_object_t
default_pager_alloc(handle, size, prot, offset)
void *handle;
register vm_size_t size;
vm_prot_t prot;
vm_ooffset_t offset;
{
if (handle != NULL)
panic("default_pager_alloc: handle specified");
return vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(offset) + size);
}
static void
default_pager_dealloc(object)
vm_object_t object;
{
/*
* OBJT_DEFAULT objects have no special resources allocated to them.
*/
}
/*
* The default pager has no backing store, so we always return
* failure.
*/
static int
default_pager_getpages(object, m, count, reqpage)
vm_object_t object;
vm_page_t *m;
int count;
int reqpage;
{
return VM_PAGER_FAIL;
}
static int
default_pager_putpages(object, m, c, sync, rtvals)
vm_object_t object;
vm_page_t *m;
int c;
boolean_t sync;
int *rtvals;
{
int i;
/*
* Try to convert the object type into a OBJT_SWAP.
* If the swp structure allocation fails, convert it
* back to OBJT_DEFAULT and return failure. Otherwise
* pass this putpages to the swap pager.
*/
object->type = OBJT_SWAP;
if (swap_pager_swp_alloc(object, M_KERNEL) != 0) {
object->type = OBJT_DEFAULT;
for (i = 0; i < c; i++)
rtvals[i] = VM_PAGER_FAIL;
return VM_PAGER_FAIL;
}
return swap_pager_putpages(object, m, c, sync, rtvals);
}
static boolean_t
default_pager_haspage(object, pindex, before, after)
vm_object_t object;
vm_pindex_t pindex;
int *before;
int *after;
{
return FALSE;
}
void
default_pager_convert_to_swap(object)
vm_object_t object;
{
object->type = OBJT_SWAP;
if (swap_pager_swp_alloc(object, M_KERNEL) != 0) {
object->type = OBJT_DEFAULT;
}
}
void
default_pager_convert_to_swapq(object)
vm_object_t object;
{
if (object &&
(object->type == OBJT_DEFAULT) &&
(object != kernel_object && object != kmem_object) &&
(object->size > ((cnt.v_page_count - cnt.v_wire_count) / 4)))
default_pager_convert_to_swap(object);
}
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