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4e6586002d
This makes grepping for which pagers implement which methods easier.
211 lines
5.3 KiB
C
211 lines
5.3 KiB
C
/*
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* Copyright (c) 2000 Peter Wemm
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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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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS 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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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/linker_set.h>
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#include <sys/conf.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/proc.h>
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#include <sys/mutex.h>
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#include <sys/mman.h>
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#include <sys/sysctl.h>
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#include <vm/vm.h>
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#include <vm/vm_object.h>
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#include <vm/vm_page.h>
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#include <vm/vm_pager.h>
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/* prevent concurrant creation races */
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static int phys_pager_alloc_lock;
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/* list of device pager objects */
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static struct pagerlst phys_pager_object_list;
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/* protect access to phys_pager_object_list */
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static struct mtx phys_pager_mtx;
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static void
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phys_pager_init(void)
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{
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TAILQ_INIT(&phys_pager_object_list);
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mtx_init(&phys_pager_mtx, "phys_pager list", NULL, MTX_DEF);
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}
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/*
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* MPSAFE
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*/
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static vm_object_t
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phys_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
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vm_ooffset_t foff)
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{
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vm_object_t object;
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/*
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* Offset should be page aligned.
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*/
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if (foff & PAGE_MASK)
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return (NULL);
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size = round_page(size);
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if (handle != NULL) {
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mtx_lock(&Giant);
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/*
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* Lock to prevent object creation race condition.
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*/
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while (phys_pager_alloc_lock) {
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phys_pager_alloc_lock = -1;
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tsleep(&phys_pager_alloc_lock, PVM, "swpalc", 0);
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}
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phys_pager_alloc_lock = 1;
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/*
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* Look up pager, creating as necessary.
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*/
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object = vm_pager_object_lookup(&phys_pager_object_list, handle);
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if (object == NULL) {
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/*
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* Allocate object and associate it with the pager.
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*/
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object = vm_object_allocate(OBJT_PHYS,
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OFF_TO_IDX(foff + size));
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object->handle = handle;
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mtx_lock(&phys_pager_mtx);
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TAILQ_INSERT_TAIL(&phys_pager_object_list, object,
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pager_object_list);
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mtx_unlock(&phys_pager_mtx);
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} else {
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/*
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* Gain a reference to the object.
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*/
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vm_object_reference(object);
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if (OFF_TO_IDX(foff + size) > object->size)
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object->size = OFF_TO_IDX(foff + size);
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}
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if (phys_pager_alloc_lock == -1)
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wakeup(&phys_pager_alloc_lock);
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phys_pager_alloc_lock = 0;
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mtx_unlock(&Giant);
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} else {
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object = vm_object_allocate(OBJT_PHYS,
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OFF_TO_IDX(foff + size));
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}
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return (object);
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}
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/*
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* MPSAFE
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*/
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static void
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phys_pager_dealloc(vm_object_t object)
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{
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if (object->handle != NULL) {
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mtx_lock(&phys_pager_mtx);
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TAILQ_REMOVE(&phys_pager_object_list, object, pager_object_list);
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mtx_unlock(&phys_pager_mtx);
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}
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}
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static int
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phys_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
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{
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int i, s;
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s = splvm();
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vm_page_lock_queues();
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/*
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* Fill as many pages as vm_fault has allocated for us.
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*/
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for (i = 0; i < count; i++) {
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if ((m[i]->flags & PG_ZERO) == 0) {
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vm_page_unlock_queues();
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pmap_zero_page(m[i]);
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vm_page_lock_queues();
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}
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vm_page_flag_set(m[i], PG_ZERO);
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/* Switch off pv_entries */
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vm_page_unmanage(m[i]);
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m[i]->valid = VM_PAGE_BITS_ALL;
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m[i]->dirty = 0;
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/* The requested page must remain busy, the others not. */
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if (reqpage != i) {
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vm_page_flag_clear(m[i], PG_BUSY);
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m[i]->busy = 0;
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}
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}
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vm_page_unlock_queues();
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splx(s);
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return (VM_PAGER_OK);
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}
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static void
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phys_pager_putpages(vm_object_t object, vm_page_t *m, int count, boolean_t sync,
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int *rtvals)
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{
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panic("phys_pager_putpage called");
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}
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/*
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* Implement a pretty aggressive clustered getpages strategy. Hint that
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* everything in an entire 4MB window should be prefaulted at once.
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*
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* XXX 4MB (1024 slots per page table page) is convenient for x86,
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* but may not be for other arches.
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*/
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#ifndef PHYSCLUSTER
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#define PHYSCLUSTER 1024
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#endif
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static boolean_t
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phys_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
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int *after)
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{
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vm_pindex_t base, end;
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base = pindex & (~(PHYSCLUSTER - 1));
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end = base + (PHYSCLUSTER - 1);
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if (before != NULL)
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*before = pindex - base;
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if (after != NULL)
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*after = end - pindex;
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return (TRUE);
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}
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struct pagerops physpagerops = {
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.pgo_init = phys_pager_init,
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.pgo_alloc = phys_pager_alloc,
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.pgo_dealloc = phys_pager_dealloc,
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.pgo_getpages = phys_pager_getpages,
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.pgo_putpages = phys_pager_putpages,
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.pgo_haspage = phys_pager_haspage,
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};
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