85a376eb93
a condition when blocking can occur, and the daemon did not check properly for a page remaining on the expected queue. Additionally, the inactive target was being set much too large for small memory machines. It is now being calculated based upon the amount of user memory available on every pageout daemon run. Another problem was that if memory was very low, the pageout daemon could fail repeatedly to traverse the inactive queue.
980 lines
24 KiB
C
980 lines
24 KiB
C
/*
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* Copyright (c) 1991 Regents of the University of California.
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* All rights reserved.
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* Copyright (c) 1994 John S. Dyson
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* All rights reserved.
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* Copyright (c) 1994 David Greenman
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* 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 Mach Operating System project at Carnegie-Mellon University.
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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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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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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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* from: @(#)vm_pageout.c 7.4 (Berkeley) 5/7/91
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*
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*
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* Copyright (c) 1987, 1990 Carnegie-Mellon University.
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* All rights reserved.
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*
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* Authors: Avadis Tevanian, Jr., Michael Wayne Young
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*
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* Permission to use, copy, modify and distribute this software and
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* its documentation is hereby granted, provided that both the copyright
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* notice and this permission notice appear in all copies of the
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* software, derivative works or modified versions, and any portions
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* thereof, and that both notices appear in supporting documentation.
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*
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* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
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* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
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* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
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*
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* Carnegie Mellon requests users of this software to return to
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*
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* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
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* School of Computer Science
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* Carnegie Mellon University
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* Pittsburgh PA 15213-3890
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*
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* any improvements or extensions that they make and grant Carnegie the
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* rights to redistribute these changes.
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*
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* $Id: vm_pageout.c,v 1.72 1996/05/24 05:19:15 dyson Exp $
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*/
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/*
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* The proverbial page-out daemon.
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/proc.h>
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#include <sys/resourcevar.h>
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#include <sys/malloc.h>
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#include <sys/kernel.h>
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#include <sys/signalvar.h>
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#include <sys/vnode.h>
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#include <sys/vmmeter.h>
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <vm/vm_prot.h>
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#include <vm/lock.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_map.h>
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#include <vm/vm_pageout.h>
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#include <vm/vm_kern.h>
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#include <vm/vm_pager.h>
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#include <vm/swap_pager.h>
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#include <vm/vm_extern.h>
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/*
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* System initialization
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*/
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/* the kernel process "vm_pageout"*/
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static void vm_pageout __P((void));
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static int vm_pageout_clean __P((vm_page_t, int));
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static int vm_pageout_scan __P((void));
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struct proc *pageproc;
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static struct kproc_desc page_kp = {
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"pagedaemon",
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vm_pageout,
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&pageproc
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};
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SYSINIT_KT(pagedaemon, SI_SUB_KTHREAD_PAGE, SI_ORDER_FIRST, kproc_start, &page_kp)
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#ifndef NO_SWAPPING
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/* the kernel process "vm_daemon"*/
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static void vm_daemon __P((void));
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static struct proc *vmproc;
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static struct kproc_desc vm_kp = {
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"vmdaemon",
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vm_daemon,
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&vmproc
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};
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SYSINIT_KT(vmdaemon, SI_SUB_KTHREAD_VM, SI_ORDER_FIRST, kproc_start, &vm_kp)
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#endif /* !NO_SWAPPING */
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int vm_pages_needed; /* Event on which pageout daemon sleeps */
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int vm_pageout_pages_needed; /* flag saying that the pageout daemon needs pages */
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extern int npendingio;
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static int vm_pageout_req_swapout; /* XXX */
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static int vm_daemon_needed;
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extern int nswiodone;
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extern int vm_swap_size;
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extern int vfs_update_wakeup;
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#define MAXLAUNDER (cnt.v_page_count > 1800 ? 32 : 16)
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#define VM_PAGEOUT_PAGE_COUNT 16
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int vm_pageout_page_count = VM_PAGEOUT_PAGE_COUNT;
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int vm_page_max_wired; /* XXX max # of wired pages system-wide */
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typedef int freeer_fcn_t __P((vm_map_t, vm_object_t, int, int));
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static void vm_pageout_map_deactivate_pages __P((vm_map_t, vm_map_entry_t,
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int *, freeer_fcn_t *));
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static freeer_fcn_t vm_pageout_object_deactivate_pages;
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static void vm_req_vmdaemon __P((void));
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/*
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* vm_pageout_clean:
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*
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* Clean the page and remove it from the laundry.
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*
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* We set the busy bit to cause potential page faults on this page to
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* block.
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*
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* And we set pageout-in-progress to keep the object from disappearing
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* during pageout. This guarantees that the page won't move from the
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* inactive queue. (However, any other page on the inactive queue may
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* move!)
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*/
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static int
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vm_pageout_clean(m, sync)
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vm_page_t m;
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int sync;
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{
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register vm_object_t object;
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vm_page_t mc[2*VM_PAGEOUT_PAGE_COUNT];
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int pageout_count;
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int i, forward_okay, backward_okay, page_base;
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vm_pindex_t pindex = m->pindex;
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object = m->object;
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/*
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* If not OBJT_SWAP, additional memory may be needed to do the pageout.
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* Try to avoid the deadlock.
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*/
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if ((sync != VM_PAGEOUT_FORCE) &&
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(object->type != OBJT_SWAP) &&
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((cnt.v_free_count + cnt.v_cache_count) < cnt.v_pageout_free_min))
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return 0;
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/*
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* Don't mess with the page if it's busy.
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*/
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if ((!sync && m->hold_count != 0) ||
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((m->busy != 0) || (m->flags & PG_BUSY)))
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return 0;
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/*
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* Try collapsing before it's too late.
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*/
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if (!sync && object->backing_object) {
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vm_object_collapse(object);
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}
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mc[VM_PAGEOUT_PAGE_COUNT] = m;
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pageout_count = 1;
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page_base = VM_PAGEOUT_PAGE_COUNT;
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forward_okay = TRUE;
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if (pindex != 0)
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backward_okay = TRUE;
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else
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backward_okay = FALSE;
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/*
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* Scan object for clusterable pages.
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*
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* We can cluster ONLY if: ->> the page is NOT
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* clean, wired, busy, held, or mapped into a
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* buffer, and one of the following:
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* 1) The page is inactive, or a seldom used
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* active page.
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* -or-
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* 2) we force the issue.
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*/
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for (i = 1; (i < vm_pageout_page_count) && (forward_okay || backward_okay); i++) {
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vm_page_t p;
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/*
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* See if forward page is clusterable.
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*/
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if (forward_okay) {
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/*
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* Stop forward scan at end of object.
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*/
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if ((pindex + i) > object->size) {
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forward_okay = FALSE;
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goto do_backward;
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}
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p = vm_page_lookup(object, pindex + i);
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if (p) {
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if ((p->queue == PQ_CACHE) || (p->flags & PG_BUSY) || p->busy) {
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forward_okay = FALSE;
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goto do_backward;
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}
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vm_page_test_dirty(p);
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if ((p->dirty & p->valid) != 0 &&
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((p->queue == PQ_INACTIVE) ||
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(sync == VM_PAGEOUT_FORCE)) &&
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(p->wire_count == 0) &&
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(p->hold_count == 0)) {
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mc[VM_PAGEOUT_PAGE_COUNT + i] = p;
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pageout_count++;
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if (pageout_count == vm_pageout_page_count)
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break;
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} else {
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forward_okay = FALSE;
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}
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} else {
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forward_okay = FALSE;
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}
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}
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do_backward:
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/*
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* See if backward page is clusterable.
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*/
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if (backward_okay) {
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/*
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* Stop backward scan at beginning of object.
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*/
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if ((pindex - i) == 0) {
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backward_okay = FALSE;
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}
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p = vm_page_lookup(object, pindex - i);
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if (p) {
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if ((p->queue == PQ_CACHE) || (p->flags & PG_BUSY) || p->busy) {
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backward_okay = FALSE;
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continue;
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}
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vm_page_test_dirty(p);
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if ((p->dirty & p->valid) != 0 &&
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((p->queue == PQ_INACTIVE) ||
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(sync == VM_PAGEOUT_FORCE)) &&
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(p->wire_count == 0) &&
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(p->hold_count == 0)) {
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mc[VM_PAGEOUT_PAGE_COUNT - i] = p;
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pageout_count++;
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page_base--;
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if (pageout_count == vm_pageout_page_count)
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break;
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} else {
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backward_okay = FALSE;
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}
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} else {
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backward_okay = FALSE;
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}
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}
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}
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/*
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* we allow reads during pageouts...
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*/
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for (i = page_base; i < (page_base + pageout_count); i++) {
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mc[i]->flags |= PG_BUSY;
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vm_page_protect(mc[i], VM_PROT_READ);
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}
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return vm_pageout_flush(&mc[page_base], pageout_count, sync);
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}
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int
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vm_pageout_flush(mc, count, sync)
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vm_page_t *mc;
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int count;
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int sync;
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{
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register vm_object_t object;
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int pageout_status[count];
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int anyok = 0;
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int i;
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object = mc[0]->object;
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object->paging_in_progress += count;
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vm_pager_put_pages(object, mc, count,
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((sync || (object == kernel_object)) ? TRUE : FALSE),
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pageout_status);
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for (i = 0; i < count; i++) {
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vm_page_t mt = mc[i];
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switch (pageout_status[i]) {
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case VM_PAGER_OK:
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++anyok;
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break;
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case VM_PAGER_PEND:
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++anyok;
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break;
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case VM_PAGER_BAD:
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/*
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* Page outside of range of object. Right now we
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* essentially lose the changes by pretending it
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* worked.
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*/
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pmap_clear_modify(VM_PAGE_TO_PHYS(mt));
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mt->dirty = 0;
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break;
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case VM_PAGER_ERROR:
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case VM_PAGER_FAIL:
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/*
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* If page couldn't be paged out, then reactivate the
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* page so it doesn't clog the inactive list. (We
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* will try paging out it again later).
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*/
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if (mt->queue == PQ_INACTIVE)
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vm_page_activate(mt);
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break;
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case VM_PAGER_AGAIN:
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break;
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}
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/*
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* If the operation is still going, leave the page busy to
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* block all other accesses. Also, leave the paging in
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* progress indicator set so that we don't attempt an object
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* collapse.
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*/
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if (pageout_status[i] != VM_PAGER_PEND) {
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vm_object_pip_wakeup(object);
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PAGE_WAKEUP(mt);
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}
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}
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return anyok;
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}
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/*
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* vm_pageout_object_deactivate_pages
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*
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* deactivate enough pages to satisfy the inactive target
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* requirements or if vm_page_proc_limit is set, then
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* deactivate all of the pages in the object and its
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* backing_objects.
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*
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* The object and map must be locked.
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*/
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static int
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vm_pageout_object_deactivate_pages(map, object, count, map_remove_only)
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vm_map_t map;
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vm_object_t object;
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int count;
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int map_remove_only;
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{
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register vm_page_t p, next;
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int rcount;
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int dcount;
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int s;
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dcount = 0;
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if (count == 0)
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count = 1;
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if (object->type == OBJT_DEVICE)
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return 0;
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if (object->backing_object) {
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if (object->backing_object->ref_count == 1)
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dcount += vm_pageout_object_deactivate_pages(map,
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object->backing_object, count / 2 + 1, map_remove_only);
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else
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vm_pageout_object_deactivate_pages(map,
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object->backing_object, count, 1);
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}
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if (object->paging_in_progress)
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return dcount;
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/*
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* scan the objects entire memory queue
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*/
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rcount = object->resident_page_count;
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p = TAILQ_FIRST(&object->memq);
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while (p && (rcount-- > 0)) {
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next = TAILQ_NEXT(p, listq);
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cnt.v_pdpages++;
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if (p->wire_count != 0 ||
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p->hold_count != 0 ||
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p->busy != 0 ||
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(p->flags & PG_BUSY) ||
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!pmap_page_exists(vm_map_pmap(map), VM_PAGE_TO_PHYS(p))) {
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p = next;
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continue;
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}
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/*
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* if a page is active, not wired and is in the processes
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* pmap, then deactivate the page.
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*/
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if (p->queue == PQ_ACTIVE) {
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if (!pmap_is_referenced(VM_PAGE_TO_PHYS(p)) &&
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(p->flags & PG_REFERENCED) == 0) {
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vm_page_protect(p, VM_PROT_NONE);
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if (!map_remove_only)
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vm_page_deactivate(p);
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/*
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* see if we are done yet
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|
*/
|
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if (p->queue == PQ_INACTIVE) {
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--count;
|
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++dcount;
|
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if (count <= 0 &&
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cnt.v_inactive_count > cnt.v_inactive_target) {
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return dcount;
|
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}
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}
|
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} else {
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/*
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* Move the page to the bottom of the queue.
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*/
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pmap_clear_reference(VM_PAGE_TO_PHYS(p));
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p->flags &= ~PG_REFERENCED;
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|
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s = splvm();
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TAILQ_REMOVE(&vm_page_queue_active, p, pageq);
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TAILQ_INSERT_TAIL(&vm_page_queue_active, p, pageq);
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splx(s);
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}
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} else if (p->queue == PQ_INACTIVE) {
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vm_page_protect(p, VM_PROT_NONE);
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}
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p = next;
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}
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return dcount;
|
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}
|
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|
|
/*
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|
* deactivate some number of pages in a map, try to do it fairly, but
|
|
* that is really hard to do.
|
|
*/
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|
|
static void
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|
vm_pageout_map_deactivate_pages(map, entry, count, freeer)
|
|
vm_map_t map;
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|
vm_map_entry_t entry;
|
|
int *count;
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|
freeer_fcn_t *freeer;
|
|
{
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vm_map_t tmpm;
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vm_map_entry_t tmpe;
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vm_object_t obj;
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|
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if (*count <= 0)
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return;
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vm_map_reference(map);
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|
if (!lock_try_read(&map->lock)) {
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vm_map_deallocate(map);
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return;
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}
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|
if (entry == 0) {
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tmpe = map->header.next;
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while (tmpe != &map->header && *count > 0) {
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vm_pageout_map_deactivate_pages(map, tmpe, count, freeer);
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tmpe = tmpe->next;
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};
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} else if (entry->is_sub_map || entry->is_a_map) {
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tmpm = entry->object.share_map;
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tmpe = tmpm->header.next;
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while (tmpe != &tmpm->header && *count > 0) {
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vm_pageout_map_deactivate_pages(tmpm, tmpe, count, freeer);
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tmpe = tmpe->next;
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};
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} else if ((obj = entry->object.vm_object) != 0) {
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*count -= (*freeer) (map, obj, *count, TRUE);
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}
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lock_read_done(&map->lock);
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vm_map_deallocate(map);
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|
return;
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}
|
|
|
|
/*
|
|
* vm_pageout_scan does the dirty work for the pageout daemon.
|
|
*/
|
|
static int
|
|
vm_pageout_scan()
|
|
{
|
|
vm_page_t m;
|
|
int page_shortage, maxscan, maxlaunder, pcount;
|
|
int pages_freed;
|
|
vm_page_t next;
|
|
struct proc *p, *bigproc;
|
|
vm_offset_t size, bigsize;
|
|
vm_object_t object;
|
|
int force_wakeup = 0;
|
|
int vnodes_skipped = 0;
|
|
int usagefloor;
|
|
int i;
|
|
int s;
|
|
|
|
pages_freed = 0;
|
|
|
|
|
|
/*
|
|
* Start scanning the inactive queue for pages we can free. We keep
|
|
* scanning until we have enough free pages or we have scanned through
|
|
* the entire queue. If we encounter dirty pages, we start cleaning
|
|
* them.
|
|
*/
|
|
|
|
rescan0:
|
|
maxlaunder = (cnt.v_inactive_target > MAXLAUNDER) ?
|
|
MAXLAUNDER : cnt.v_inactive_target;
|
|
|
|
rescan1:
|
|
maxscan = cnt.v_inactive_count;
|
|
m = TAILQ_FIRST(&vm_page_queue_inactive);
|
|
while ((m != NULL) && (maxscan-- > 0) &&
|
|
((cnt.v_cache_count + cnt.v_free_count) <
|
|
(cnt.v_cache_min + cnt.v_free_target))) {
|
|
vm_page_t next;
|
|
|
|
cnt.v_pdpages++;
|
|
next = TAILQ_NEXT(m, pageq);
|
|
|
|
if (m->queue != PQ_INACTIVE) {
|
|
printf("vm_pageout_scan: page not inactive?\n");
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Dont mess with busy pages, keep in the front of the
|
|
* queue, most likely are being paged out.
|
|
*/
|
|
if (m->busy || (m->flags & PG_BUSY)) {
|
|
m = next;
|
|
continue;
|
|
}
|
|
if (m->hold_count) {
|
|
TAILQ_REMOVE(&vm_page_queue_inactive, m, pageq);
|
|
TAILQ_INSERT_TAIL(&vm_page_queue_inactive, m, pageq);
|
|
m = next;
|
|
continue;
|
|
}
|
|
|
|
if (((m->flags & PG_REFERENCED) == 0) &&
|
|
pmap_is_referenced(VM_PAGE_TO_PHYS(m))) {
|
|
m->flags |= PG_REFERENCED;
|
|
}
|
|
if (m->object->ref_count == 0) {
|
|
m->flags &= ~PG_REFERENCED;
|
|
pmap_clear_reference(VM_PAGE_TO_PHYS(m));
|
|
}
|
|
if ((m->flags & PG_REFERENCED) != 0) {
|
|
m->flags &= ~PG_REFERENCED;
|
|
pmap_clear_reference(VM_PAGE_TO_PHYS(m));
|
|
vm_page_activate(m);
|
|
m = next;
|
|
continue;
|
|
}
|
|
|
|
if (m->dirty == 0) {
|
|
vm_page_test_dirty(m);
|
|
} else if (m->dirty != 0) {
|
|
m->dirty = VM_PAGE_BITS_ALL;
|
|
}
|
|
if (m->valid == 0) {
|
|
vm_page_protect(m, VM_PROT_NONE);
|
|
vm_page_free(m);
|
|
cnt.v_dfree++;
|
|
++pages_freed;
|
|
} else if (m->dirty == 0) {
|
|
vm_page_cache(m);
|
|
++pages_freed;
|
|
} else if (maxlaunder > 0) {
|
|
int written;
|
|
struct vnode *vp = NULL;
|
|
|
|
object = m->object;
|
|
if (object->flags & OBJ_DEAD) {
|
|
TAILQ_REMOVE(&vm_page_queue_inactive, m, pageq);
|
|
TAILQ_INSERT_TAIL(&vm_page_queue_inactive, m, pageq);
|
|
m = next;
|
|
continue;
|
|
}
|
|
|
|
if (object->type == OBJT_VNODE) {
|
|
vp = object->handle;
|
|
if (VOP_ISLOCKED(vp) || vget(vp, 1)) {
|
|
if (m->queue == PQ_INACTIVE) {
|
|
TAILQ_REMOVE(&vm_page_queue_inactive, m, pageq);
|
|
TAILQ_INSERT_TAIL(&vm_page_queue_inactive, m, pageq);
|
|
}
|
|
if (object->flags & OBJ_MIGHTBEDIRTY)
|
|
++vnodes_skipped;
|
|
if (next->queue != PQ_INACTIVE) {
|
|
goto rescan0;
|
|
}
|
|
m = next;
|
|
continue;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If a page is dirty, then it is either being washed
|
|
* (but not yet cleaned) or it is still in the
|
|
* laundry. If it is still in the laundry, then we
|
|
* start the cleaning operation.
|
|
*/
|
|
written = vm_pageout_clean(m, 0);
|
|
|
|
if (vp)
|
|
vput(vp);
|
|
|
|
if (!next) {
|
|
break;
|
|
}
|
|
maxlaunder -= written;
|
|
/*
|
|
* if the next page has been re-activated, start
|
|
* scanning again
|
|
*/
|
|
if (next->queue != PQ_INACTIVE) {
|
|
vm_pager_sync();
|
|
goto rescan1;
|
|
}
|
|
}
|
|
m = next;
|
|
}
|
|
|
|
/*
|
|
* Compute the page shortage. If we are still very low on memory be
|
|
* sure that we will move a minimal amount of pages from active to
|
|
* inactive.
|
|
*/
|
|
|
|
page_shortage = cnt.v_inactive_target -
|
|
(cnt.v_free_count + cnt.v_inactive_count + cnt.v_cache_count);
|
|
if (page_shortage <= 0) {
|
|
if (pages_freed == 0) {
|
|
page_shortage = cnt.v_free_min - cnt.v_free_count;
|
|
} else {
|
|
page_shortage = 1;
|
|
}
|
|
}
|
|
|
|
pcount = cnt.v_active_count;
|
|
s = splvm();
|
|
m = TAILQ_FIRST(&vm_page_queue_active);
|
|
while ((m != NULL) && (pcount-- > 0) && (page_shortage > 0)) {
|
|
next = TAILQ_NEXT(m, pageq);
|
|
|
|
/*
|
|
* Don't deactivate pages that are busy.
|
|
*/
|
|
if ((m->busy != 0) ||
|
|
(m->flags & PG_BUSY) ||
|
|
(m->hold_count != 0)) {
|
|
TAILQ_REMOVE(&vm_page_queue_active, m, pageq);
|
|
TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq);
|
|
m = next;
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* The count for pagedaemon pages is done after checking the
|
|
* page for eligbility...
|
|
*/
|
|
cnt.v_pdpages++;
|
|
if ((m->flags & PG_REFERENCED) == 0) {
|
|
if (pmap_is_referenced(VM_PAGE_TO_PHYS(m))) {
|
|
pmap_clear_reference(VM_PAGE_TO_PHYS(m));
|
|
m->flags |= PG_REFERENCED;
|
|
}
|
|
} else {
|
|
pmap_clear_reference(VM_PAGE_TO_PHYS(m));
|
|
}
|
|
if ( (m->object->ref_count != 0) &&
|
|
(m->flags & PG_REFERENCED) ) {
|
|
m->flags &= ~PG_REFERENCED;
|
|
TAILQ_REMOVE(&vm_page_queue_active, m, pageq);
|
|
TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq);
|
|
} else {
|
|
m->flags &= ~PG_REFERENCED;
|
|
if (page_shortage > 0) {
|
|
--page_shortage;
|
|
if (m->dirty == 0)
|
|
vm_page_test_dirty(m);
|
|
if (m->dirty == 0) {
|
|
vm_page_cache(m);
|
|
} else {
|
|
vm_page_protect(m, VM_PROT_NONE);
|
|
vm_page_deactivate(m);
|
|
}
|
|
}
|
|
}
|
|
m = next;
|
|
}
|
|
splx(s);
|
|
|
|
/*
|
|
* We try to maintain some *really* free pages, this allows interrupt
|
|
* code to be guaranteed space.
|
|
*/
|
|
while (cnt.v_free_count < cnt.v_free_reserved) {
|
|
m = TAILQ_FIRST(&vm_page_queue_cache);
|
|
if (!m)
|
|
break;
|
|
vm_page_free(m);
|
|
cnt.v_dfree++;
|
|
}
|
|
|
|
/*
|
|
* If we didn't get enough free pages, and we have skipped a vnode
|
|
* in a writeable object, wakeup the sync daemon. And kick swapout
|
|
* if we did not get enough free pages.
|
|
*/
|
|
if ((cnt.v_cache_count + cnt.v_free_count) <
|
|
(cnt.v_free_target + cnt.v_cache_min) ) {
|
|
if (vnodes_skipped &&
|
|
(cnt.v_cache_count + cnt.v_free_count) < cnt.v_free_min) {
|
|
if (!vfs_update_wakeup) {
|
|
vfs_update_wakeup = 1;
|
|
wakeup(&vfs_update_wakeup);
|
|
}
|
|
}
|
|
#ifndef NO_SWAPPING
|
|
if (cnt.v_free_count + cnt.v_cache_count < cnt.v_free_target) {
|
|
vm_req_vmdaemon();
|
|
vm_pageout_req_swapout = 1;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
|
|
/*
|
|
* make sure that we have swap space -- if we are low on memory and
|
|
* swap -- then kill the biggest process.
|
|
*/
|
|
if ((vm_swap_size == 0 || swap_pager_full) &&
|
|
((cnt.v_free_count + cnt.v_cache_count) < cnt.v_free_min)) {
|
|
bigproc = NULL;
|
|
bigsize = 0;
|
|
for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) {
|
|
/*
|
|
* if this is a system process, skip it
|
|
*/
|
|
if ((p->p_flag & P_SYSTEM) || (p->p_pid == 1) ||
|
|
((p->p_pid < 48) && (vm_swap_size != 0))) {
|
|
continue;
|
|
}
|
|
/*
|
|
* if the process is in a non-running type state,
|
|
* don't touch it.
|
|
*/
|
|
if (p->p_stat != SRUN && p->p_stat != SSLEEP) {
|
|
continue;
|
|
}
|
|
/*
|
|
* get the process size
|
|
*/
|
|
size = p->p_vmspace->vm_pmap.pm_stats.resident_count;
|
|
/*
|
|
* if the this process is bigger than the biggest one
|
|
* remember it.
|
|
*/
|
|
if (size > bigsize) {
|
|
bigproc = p;
|
|
bigsize = size;
|
|
}
|
|
}
|
|
if (bigproc != NULL) {
|
|
killproc(bigproc, "out of swap space");
|
|
bigproc->p_estcpu = 0;
|
|
bigproc->p_nice = PRIO_MIN;
|
|
resetpriority(bigproc);
|
|
wakeup(&cnt.v_free_count);
|
|
}
|
|
}
|
|
return force_wakeup;
|
|
}
|
|
|
|
/*
|
|
* vm_pageout is the high level pageout daemon.
|
|
*/
|
|
static void
|
|
vm_pageout()
|
|
{
|
|
(void) spl0();
|
|
|
|
/*
|
|
* Initialize some paging parameters.
|
|
*/
|
|
|
|
cnt.v_interrupt_free_min = 2;
|
|
|
|
if (cnt.v_page_count > 1024)
|
|
cnt.v_free_min = 4 + (cnt.v_page_count - 1024) / 200;
|
|
else
|
|
cnt.v_free_min = 4;
|
|
/*
|
|
* free_reserved needs to include enough for the largest swap pager
|
|
* structures plus enough for any pv_entry structs when paging.
|
|
*/
|
|
cnt.v_pageout_free_min = 6 + cnt.v_page_count / 1024 +
|
|
cnt.v_interrupt_free_min;
|
|
cnt.v_free_reserved = cnt.v_pageout_free_min + 6;
|
|
cnt.v_free_target = 3 * cnt.v_free_min + cnt.v_free_reserved;
|
|
cnt.v_free_min += cnt.v_free_reserved;
|
|
|
|
if (cnt.v_free_count > 1024) {
|
|
cnt.v_cache_max = (cnt.v_free_count - 1024) / 2;
|
|
cnt.v_cache_min = (cnt.v_free_count - 1024) / 8;
|
|
cnt.v_inactive_target = 2*cnt.v_cache_min + 192;
|
|
} else {
|
|
cnt.v_cache_min = 0;
|
|
cnt.v_cache_max = 0;
|
|
cnt.v_inactive_target = cnt.v_free_count / 4;
|
|
}
|
|
|
|
/* XXX does not really belong here */
|
|
if (vm_page_max_wired == 0)
|
|
vm_page_max_wired = cnt.v_free_count / 3;
|
|
|
|
|
|
swap_pager_swap_init();
|
|
/*
|
|
* The pageout daemon is never done, so loop forever.
|
|
*/
|
|
while (TRUE) {
|
|
int inactive_target;
|
|
int s = splvm();
|
|
if (!vm_pages_needed ||
|
|
((cnt.v_free_count >= cnt.v_free_reserved) &&
|
|
(cnt.v_free_count + cnt.v_cache_count >= cnt.v_free_min))) {
|
|
vm_pages_needed = 0;
|
|
tsleep(&vm_pages_needed, PVM, "psleep", 0);
|
|
} else if (!vm_pages_needed) {
|
|
tsleep(&vm_pages_needed, PVM, "psleep", hz/3);
|
|
}
|
|
if (vm_pages_needed)
|
|
cnt.v_pdwakeups++;
|
|
vm_pages_needed = 0;
|
|
splx(s);
|
|
vm_pager_sync();
|
|
vm_pageout_scan();
|
|
inactive_target =
|
|
(cnt.v_page_count - cnt.v_wire_count) / 4;
|
|
if (inactive_target < 2*cnt.v_free_min)
|
|
inactive_target = 2*cnt.v_free_min;
|
|
cnt.v_inactive_target = inactive_target;
|
|
vm_pager_sync();
|
|
wakeup(&cnt.v_free_count);
|
|
}
|
|
}
|
|
|
|
#ifndef NO_SWAPPING
|
|
static void
|
|
vm_req_vmdaemon()
|
|
{
|
|
static int lastrun = 0;
|
|
|
|
if ((ticks > (lastrun + hz)) || (ticks < lastrun)) {
|
|
wakeup(&vm_daemon_needed);
|
|
lastrun = ticks;
|
|
}
|
|
}
|
|
|
|
static void
|
|
vm_daemon()
|
|
{
|
|
vm_object_t object;
|
|
struct proc *p;
|
|
|
|
(void) spl0();
|
|
|
|
while (TRUE) {
|
|
tsleep(&vm_daemon_needed, PUSER, "psleep", 0);
|
|
if (vm_pageout_req_swapout) {
|
|
swapout_procs();
|
|
vm_pageout_req_swapout = 0;
|
|
}
|
|
/*
|
|
* scan the processes for exceeding their rlimits or if
|
|
* process is swapped out -- deactivate pages
|
|
*/
|
|
|
|
for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) {
|
|
int overage;
|
|
quad_t limit;
|
|
vm_offset_t size;
|
|
|
|
/*
|
|
* if this is a system process or if we have already
|
|
* looked at this process, skip it.
|
|
*/
|
|
if (p->p_flag & (P_SYSTEM | P_WEXIT)) {
|
|
continue;
|
|
}
|
|
/*
|
|
* if the process is in a non-running type state,
|
|
* don't touch it.
|
|
*/
|
|
if (p->p_stat != SRUN && p->p_stat != SSLEEP) {
|
|
continue;
|
|
}
|
|
/*
|
|
* get a limit
|
|
*/
|
|
limit = qmin(p->p_rlimit[RLIMIT_RSS].rlim_cur,
|
|
p->p_rlimit[RLIMIT_RSS].rlim_max);
|
|
|
|
/*
|
|
* let processes that are swapped out really be
|
|
* swapped out set the limit to nothing (will force a
|
|
* swap-out.)
|
|
*/
|
|
if ((p->p_flag & P_INMEM) == 0)
|
|
limit = 0; /* XXX */
|
|
|
|
size = p->p_vmspace->vm_pmap.pm_stats.resident_count * PAGE_SIZE;
|
|
if (limit >= 0 && size >= limit) {
|
|
overage = (size - limit) >> PAGE_SHIFT;
|
|
vm_pageout_map_deactivate_pages(&p->p_vmspace->vm_map,
|
|
(vm_map_entry_t) 0, &overage, vm_pageout_object_deactivate_pages);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* we remove cached objects that have no RSS...
|
|
*/
|
|
restart:
|
|
object = TAILQ_FIRST(&vm_object_cached_list);
|
|
while (object) {
|
|
/*
|
|
* if there are no resident pages -- get rid of the object
|
|
*/
|
|
if (object->resident_page_count == 0) {
|
|
vm_object_reference(object);
|
|
pager_cache(object, FALSE);
|
|
goto restart;
|
|
}
|
|
object = TAILQ_NEXT(object, cached_list);
|
|
}
|
|
}
|
|
}
|
|
#endif /* !NO_SWAPPING */
|