41f1b2c460
the reduction of the pager map's size by 8M bytes. In other words, eight megabytes of largely wasted KVA are returned to the kernel map for use elsewhere.
191 lines
5.9 KiB
C
191 lines
5.9 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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struct bio;
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struct pagerops {
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void (*pgo_init)(void); /* Initialize pager. */
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vm_object_t (*pgo_alloc)(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t); /* Allocate pager. */
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void (*pgo_dealloc)(vm_object_t); /* Disassociate. */
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int (*pgo_getpages)(vm_object_t, vm_page_t *, int, int); /* Get (read) page. */
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void (*pgo_putpages)(vm_object_t, vm_page_t *, int, int, int *); /* Put (write) page. */
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boolean_t (*pgo_haspage)(vm_object_t, vm_pindex_t, int *, int *); /* Does pager have page? */
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void (*pgo_pageunswapped)(vm_page_t);
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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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/*
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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_IGNORE_CLEANCHK 0x0004
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#define VM_PAGER_CLUSTER_OK 0x0008
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#ifdef _KERNEL
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#ifdef MALLOC_DECLARE
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MALLOC_DECLARE(M_VMPGDATA);
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#endif
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extern vm_map_t pager_map;
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extern struct pagerops *pagertab[];
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extern struct mtx pbuf_mtx;
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vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t);
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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_LOCK_ASSERT(object, MA_OWNED);
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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_LOCK_ASSERT(object, MA_OWNED);
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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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* This routine does not have to be called at any particular spl.
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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_LOCK_ASSERT(object, MA_OWNED);
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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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* called at splvm() to destroy swap associated with the page.
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*
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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_LOCK_ASSERT(m->object, MA_OWNED);
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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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#endif /* _KERNEL */
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#endif /* _VM_PAGER_ */
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