5f51836645
originally inspired by the Solaris vmem detailed in the proceedings of usenix 2001. The NetBSD version was heavily refactored for bugs and simplicity. - Use this resource allocator to allocate the buffer and transient maps. Buffer cache defrags are reduced by 25% when used by filesystems with mixed block sizes. Ultimately this may permit dynamic buffer cache sizing on low KVA machines. Discussed with: alc, kib, attilio Tested by: pho Sponsored by: EMC / Isilon Storage Division
211 lines
6.7 KiB
C
211 lines
6.7 KiB
C
/*-
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* Copyright (c) 1990 University of Utah.
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* Copyright (c) 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* the Systems Programming Group of the University of Utah Computer
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* Science Department.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)vm_pager.h 8.4 (Berkeley) 1/12/94
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* $FreeBSD$
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*/
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/*
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* Pager routine interface definition.
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*/
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#ifndef _VM_PAGER_
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#define _VM_PAGER_
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#include <sys/queue.h>
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TAILQ_HEAD(pagerlst, vm_object);
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typedef void pgo_init_t(void);
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typedef vm_object_t pgo_alloc_t(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t,
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struct ucred *);
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typedef void pgo_dealloc_t(vm_object_t);
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typedef int pgo_getpages_t(vm_object_t, vm_page_t *, int, int);
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typedef void pgo_putpages_t(vm_object_t, vm_page_t *, int, int, int *);
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typedef boolean_t pgo_haspage_t(vm_object_t, vm_pindex_t, int *, int *);
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typedef void pgo_pageunswapped_t(vm_page_t);
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struct pagerops {
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pgo_init_t *pgo_init; /* Initialize pager. */
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pgo_alloc_t *pgo_alloc; /* Allocate pager. */
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pgo_dealloc_t *pgo_dealloc; /* Disassociate. */
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pgo_getpages_t *pgo_getpages; /* Get (read) page. */
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pgo_putpages_t *pgo_putpages; /* Put (write) page. */
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pgo_haspage_t *pgo_haspage; /* Does pager have page? */
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pgo_pageunswapped_t *pgo_pageunswapped;
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};
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extern struct pagerops defaultpagerops;
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extern struct pagerops swappagerops;
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extern struct pagerops vnodepagerops;
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extern struct pagerops devicepagerops;
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extern struct pagerops physpagerops;
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extern struct pagerops sgpagerops;
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extern struct pagerops mgtdevicepagerops;
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/*
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* get/put return values
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* OK operation was successful
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* BAD specified data was out of the accepted range
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* FAIL specified data was in range, but doesn't exist
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* PEND operations was initiated but not completed
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* ERROR error while accessing data that is in range and exists
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* AGAIN temporary resource shortage prevented operation from happening
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*/
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#define VM_PAGER_OK 0
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#define VM_PAGER_BAD 1
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#define VM_PAGER_FAIL 2
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#define VM_PAGER_PEND 3
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#define VM_PAGER_ERROR 4
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#define VM_PAGER_AGAIN 5
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#define VM_PAGER_PUT_SYNC 0x0001
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#define VM_PAGER_PUT_INVAL 0x0002
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#define VM_PAGER_CLUSTER_OK 0x0008
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#ifdef _KERNEL
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extern struct pagerops *pagertab[];
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extern struct mtx_padalign pbuf_mtx;
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vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t,
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vm_ooffset_t, struct ucred *);
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void vm_pager_bufferinit(void);
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void vm_pager_deallocate(vm_object_t);
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static __inline int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int);
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static __inline boolean_t vm_pager_has_page(vm_object_t, vm_pindex_t, int *, int *);
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void vm_pager_init(void);
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vm_object_t vm_pager_object_lookup(struct pagerlst *, void *);
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/*
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* vm_page_get_pages:
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*
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* Retrieve pages from the VM system in order to map them into an object
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* ( or into VM space somewhere ). If the pagein was successful, we
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* must fully validate it.
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*/
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static __inline int
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vm_pager_get_pages(
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vm_object_t object,
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vm_page_t *m,
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int count,
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int reqpage
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) {
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int r;
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VM_OBJECT_ASSERT_WLOCKED(object);
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r = (*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage);
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if (r == VM_PAGER_OK && m[reqpage]->valid != VM_PAGE_BITS_ALL) {
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vm_page_zero_invalid(m[reqpage], TRUE);
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}
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return (r);
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}
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static __inline void
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vm_pager_put_pages(
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vm_object_t object,
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vm_page_t *m,
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int count,
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int flags,
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int *rtvals
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) {
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VM_OBJECT_ASSERT_WLOCKED(object);
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(*pagertab[object->type]->pgo_putpages)
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(object, m, count, flags, rtvals);
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}
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/*
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* vm_pager_haspage
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*
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* Check to see if an object's pager has the requested page. The
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* object's pager will also set before and after to give the caller
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* some idea of the number of pages before and after the requested
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* page can be I/O'd efficiently.
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*
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* The object must be locked.
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*/
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static __inline boolean_t
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vm_pager_has_page(
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vm_object_t object,
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vm_pindex_t offset,
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int *before,
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int *after
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) {
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boolean_t ret;
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VM_OBJECT_ASSERT_WLOCKED(object);
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ret = (*pagertab[object->type]->pgo_haspage)
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(object, offset, before, after);
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return (ret);
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}
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/*
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* vm_pager_page_unswapped
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*
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* Destroy swap associated with the page.
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*
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* The object containing the page must be locked.
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* This function may not block.
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*
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* XXX: A much better name would be "vm_pager_page_dirtied()"
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* XXX: It is not obvious if this could be profitably used by any
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* XXX: pagers besides the swap_pager or if it should even be a
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* XXX: generic pager_op in the first place.
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*/
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static __inline void
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vm_pager_page_unswapped(vm_page_t m)
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{
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VM_OBJECT_ASSERT_WLOCKED(m->object);
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if (pagertab[m->object->type]->pgo_pageunswapped)
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(*pagertab[m->object->type]->pgo_pageunswapped)(m);
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}
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struct cdev_pager_ops {
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int (*cdev_pg_fault)(vm_object_t vm_obj, vm_ooffset_t offset,
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int prot, vm_page_t *mres);
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int (*cdev_pg_ctor)(void *handle, vm_ooffset_t size, vm_prot_t prot,
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vm_ooffset_t foff, struct ucred *cred, u_short *color);
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void (*cdev_pg_dtor)(void *handle);
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};
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vm_object_t cdev_pager_allocate(void *handle, enum obj_type tp,
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struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot,
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vm_ooffset_t foff, struct ucred *cred);
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vm_object_t cdev_pager_lookup(void *handle);
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void cdev_pager_free_page(vm_object_t object, vm_page_t m);
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#endif /* _KERNEL */
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#endif /* _VM_PAGER_ */
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