ebccbfc1ff
of the various ad-hoc schemes. 2) When bringing in UPAGES, the pmap code needs to do another vm_page_lookup. 3) When appropriate, set the PG_A or PG_M bits a-priori to both avoid some processor errata, and to minimize redundant processor updating of page tables. 4) Modify pmap_protect so that it can only remove permissions (as it originally supported.) The additional capability is not needed. 5) Streamline read-only to read-write page mappings. 6) For pmap_copy_page, don't enable write mapping for source page. 7) Correct and clean-up pmap_incore. 8) Cluster initial kern_exec pagin. 9) Removal of some minor lint from kern_malloc. 10) Correct some ioopt code. 11) Remove some dead code from the MI swapout routine. 12) Correct vm_object_deallocate (to remove backing_object ref.) 13) Fix dead object handling, that had problems under heavy memory load. 14) Add minor vm_page_lookup improvements. 15) Some pages are not in objects, and make sure that the vm_page.c can properly support such pages. 16) Add some more page deficit handling. 17) Some minor code readability improvements.
513 lines
13 KiB
C
513 lines
13 KiB
C
/*
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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 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_glue.c 8.6 (Berkeley) 1/5/94
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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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* 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_glue.c,v 1.71 1998/02/04 22:33:44 eivind Exp $
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*/
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#include "opt_diagnostic.h"
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#include "opt_rlimit.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/proc.h>
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#include <sys/resourcevar.h>
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#include <sys/buf.h>
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#include <sys/shm.h>
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#include <sys/vmmeter.h>
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#include <sys/sysctl.h>
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#include <sys/kernel.h>
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#include <sys/unistd.h>
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#include <machine/limits.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 <sys/lock.h>
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#include <vm/pmap.h>
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#include <vm/vm_map.h>
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#include <vm/vm_page.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_extern.h>
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#include <sys/user.h>
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/*
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* System initialization
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*
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* Note: proc0 from proc.h
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*/
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static void vm_init_limits __P((void *));
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SYSINIT(vm_limits, SI_SUB_VM_CONF, SI_ORDER_FIRST, vm_init_limits, &proc0)
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/*
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* THIS MUST BE THE LAST INITIALIZATION ITEM!!!
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*
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* Note: run scheduling should be divorced from the vm system.
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*/
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static void scheduler __P((void *));
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SYSINIT(scheduler, SI_SUB_RUN_SCHEDULER, SI_ORDER_FIRST, scheduler, NULL)
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static void swapout __P((struct proc *));
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extern char kstack[];
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/* vm_map_t upages_map; */
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int
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kernacc(addr, len, rw)
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caddr_t addr;
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int len, rw;
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{
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boolean_t rv;
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vm_offset_t saddr, eaddr;
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vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE;
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saddr = trunc_page(addr);
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eaddr = round_page(addr + len);
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vm_map_lock_read(kernel_map);
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rv = vm_map_check_protection(kernel_map, saddr, eaddr, prot);
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vm_map_unlock_read(kernel_map);
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return (rv == TRUE);
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}
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int
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useracc(addr, len, rw)
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caddr_t addr;
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int len, rw;
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{
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boolean_t rv;
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vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE;
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vm_map_t map;
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vm_map_entry_t save_hint;
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/*
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* XXX - check separately to disallow access to user area and user
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* page tables - they are in the map.
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*
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* XXX - VM_MAXUSER_ADDRESS is an end address, not a max. It was once
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* only used (as an end address) in trap.c. Use it as an end address
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* here too. This bogusness has spread. I just fixed where it was
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* used as a max in vm_mmap.c.
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*/
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if ((vm_offset_t) addr + len > /* XXX */ VM_MAXUSER_ADDRESS
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|| (vm_offset_t) addr + len < (vm_offset_t) addr) {
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return (FALSE);
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}
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map = &curproc->p_vmspace->vm_map;
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vm_map_lock_read(map);
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/*
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* We save the map hint, and restore it. Useracc appears to distort
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* the map hint unnecessarily.
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*/
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save_hint = map->hint;
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rv = vm_map_check_protection(map,
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trunc_page(addr), round_page(addr + len), prot);
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map->hint = save_hint;
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vm_map_unlock_read(map);
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return (rv == TRUE);
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}
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void
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vslock(addr, len)
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caddr_t addr;
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u_int len;
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{
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vm_map_pageable(&curproc->p_vmspace->vm_map, trunc_page(addr),
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round_page(addr + len), FALSE);
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}
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void
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vsunlock(addr, len, dirtied)
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caddr_t addr;
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u_int len;
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int dirtied;
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{
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#ifdef lint
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dirtied++;
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#endif /* lint */
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vm_map_pageable(&curproc->p_vmspace->vm_map, trunc_page(addr),
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round_page(addr + len), TRUE);
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}
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/*
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* Implement fork's actions on an address space.
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* Here we arrange for the address space to be copied or referenced,
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* allocate a user struct (pcb and kernel stack), then call the
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* machine-dependent layer to fill those in and make the new process
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* ready to run. The new process is set up so that it returns directly
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* to user mode to avoid stack copying and relocation problems.
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*/
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void
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vm_fork(p1, p2, flags)
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register struct proc *p1, *p2;
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int flags;
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{
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register struct user *up;
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if (flags & RFMEM) {
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p2->p_vmspace = p1->p_vmspace;
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p1->p_vmspace->vm_refcnt++;
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}
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while ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_free_min) {
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vm_pageout_deficit += (UPAGES + VM_INITIAL_PAGEIN);
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VM_WAIT;
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}
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if ((flags & RFMEM) == 0) {
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p2->p_vmspace = vmspace_fork(p1->p_vmspace);
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if (p1->p_vmspace->vm_shm)
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shmfork(p1, p2);
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}
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pmap_new_proc(p2);
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up = p2->p_addr;
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/*
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* p_stats and p_sigacts currently point at fields in the user struct
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* but not at &u, instead at p_addr. Copy p_sigacts and parts of
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* p_stats; zero the rest of p_stats (statistics).
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*/
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p2->p_stats = &up->u_stats;
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p2->p_sigacts = &up->u_sigacts;
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up->u_sigacts = *p1->p_sigacts;
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bzero(&up->u_stats.pstat_startzero,
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(unsigned) ((caddr_t) &up->u_stats.pstat_endzero -
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(caddr_t) &up->u_stats.pstat_startzero));
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bcopy(&p1->p_stats->pstat_startcopy, &up->u_stats.pstat_startcopy,
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((caddr_t) &up->u_stats.pstat_endcopy -
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(caddr_t) &up->u_stats.pstat_startcopy));
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/*
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* cpu_fork will copy and update the pcb, set up the kernel stack,
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* and make the child ready to run.
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*/
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cpu_fork(p1, p2);
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}
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/*
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* Set default limits for VM system.
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* Called for proc 0, and then inherited by all others.
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*
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* XXX should probably act directly on proc0.
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*/
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static void
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vm_init_limits(udata)
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void *udata;
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{
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register struct proc *p = udata;
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int rss_limit;
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/*
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* Set up the initial limits on process VM. Set the maximum resident
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* set size to be half of (reasonably) available memory. Since this
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* is a soft limit, it comes into effect only when the system is out
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* of memory - half of main memory helps to favor smaller processes,
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* and reduces thrashing of the object cache.
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*/
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p->p_rlimit[RLIMIT_STACK].rlim_cur = DFLSSIZ;
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p->p_rlimit[RLIMIT_STACK].rlim_max = MAXSSIZ;
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p->p_rlimit[RLIMIT_DATA].rlim_cur = DFLDSIZ;
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p->p_rlimit[RLIMIT_DATA].rlim_max = MAXDSIZ;
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/* limit the limit to no less than 2MB */
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rss_limit = max(cnt.v_free_count, 512);
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p->p_rlimit[RLIMIT_RSS].rlim_cur = ptoa(rss_limit);
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p->p_rlimit[RLIMIT_RSS].rlim_max = RLIM_INFINITY;
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}
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void
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faultin(p)
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struct proc *p;
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{
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int s;
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if ((p->p_flag & P_INMEM) == 0) {
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++p->p_lock;
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pmap_swapin_proc(p);
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s = splhigh();
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if (p->p_stat == SRUN)
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setrunqueue(p);
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p->p_flag |= P_INMEM;
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/* undo the effect of setting SLOCK above */
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--p->p_lock;
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splx(s);
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}
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}
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/*
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* This swapin algorithm attempts to swap-in processes only if there
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* is enough space for them. Of course, if a process waits for a long
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* time, it will be swapped in anyway.
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*/
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/* ARGSUSED*/
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static void
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scheduler(dummy)
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void *dummy;
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{
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register struct proc *p;
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register int pri;
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struct proc *pp;
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int ppri;
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loop:
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while ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_free_min) {
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VM_WAIT;
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}
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pp = NULL;
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ppri = INT_MIN;
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for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) {
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if (p->p_stat == SRUN &&
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(p->p_flag & (P_INMEM | P_SWAPPING)) == 0) {
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pri = p->p_swtime + p->p_slptime;
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if ((p->p_flag & P_SWAPINREQ) == 0) {
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pri -= p->p_nice * 8;
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}
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/*
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* if this process is higher priority and there is
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* enough space, then select this process instead of
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* the previous selection.
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*/
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if (pri > ppri) {
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pp = p;
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ppri = pri;
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}
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}
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}
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/*
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* Nothing to do, back to sleep.
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*/
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if ((p = pp) == NULL) {
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tsleep(&proc0, PVM, "sched", 0);
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goto loop;
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}
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p->p_flag &= ~P_SWAPINREQ;
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/*
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* We would like to bring someone in. (only if there is space).
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*/
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faultin(p);
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p->p_swtime = 0;
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goto loop;
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}
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#ifndef NO_SWAPPING
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#define swappable(p) \
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(((p)->p_lock == 0) && \
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((p)->p_flag & (P_TRACED|P_NOSWAP|P_SYSTEM|P_INMEM|P_WEXIT|P_PHYSIO|P_SWAPPING)) == P_INMEM)
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/*
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* Swap_idle_threshold1 is the guaranteed swapped in time for a process
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*/
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int swap_idle_threshold1 = 2;
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SYSCTL_INT(_vm, OID_AUTO, swap_idle_threshold1,
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CTLFLAG_RW, &swap_idle_threshold1, 0, "");
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/*
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* Swap_idle_threshold2 is the time that a process can be idle before
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* it will be swapped out, if idle swapping is enabled.
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*/
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int swap_idle_threshold2 = 10;
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SYSCTL_INT(_vm, OID_AUTO, swap_idle_threshold2,
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CTLFLAG_RW, &swap_idle_threshold2, 0, "");
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/*
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* Swapout is driven by the pageout daemon. Very simple, we find eligible
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* procs and unwire their u-areas. We try to always "swap" at least one
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* process in case we need the room for a swapin.
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* If any procs have been sleeping/stopped for at least maxslp seconds,
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* they are swapped. Else, we swap the longest-sleeping or stopped process,
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* if any, otherwise the longest-resident process.
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*/
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void
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swapout_procs(action)
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int action;
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{
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register struct proc *p;
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struct proc *outp, *outp2;
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int outpri, outpri2;
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int didswap = 0;
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outp = outp2 = NULL;
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outpri = outpri2 = INT_MIN;
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retry:
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for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) {
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struct vmspace *vm;
|
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if (!swappable(p))
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continue;
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vm = p->p_vmspace;
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switch (p->p_stat) {
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default:
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continue;
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case SSLEEP:
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case SSTOP:
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/*
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|
* do not swapout a realtime process
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*/
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if (p->p_rtprio.type == RTP_PRIO_REALTIME)
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continue;
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|
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/*
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|
* Do not swapout a process waiting on a critical
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* event of some kind. Also guarantee swap_idle_threshold1
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* time in memory.
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*/
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if (((p->p_priority & 0x7f) < PSOCK) ||
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(p->p_slptime < swap_idle_threshold1))
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|
continue;
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|
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/*
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|
* If the system is under memory stress, or if we are swapping
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* idle processes >= swap_idle_threshold2, then swap the process
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|
* out.
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|
*/
|
|
if (((action & VM_SWAP_NORMAL) == 0) &&
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(((action & VM_SWAP_IDLE) == 0) ||
|
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(p->p_slptime < swap_idle_threshold2)))
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continue;
|
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|
|
++vm->vm_refcnt;
|
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/*
|
|
* do not swapout a process that is waiting for VM
|
|
* data structures there is a possible deadlock.
|
|
*/
|
|
if (lockmgr(&vm->vm_map.lock,
|
|
LK_EXCLUSIVE | LK_NOWAIT,
|
|
(void *)0, curproc)) {
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|
vmspace_free(vm);
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|
continue;
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|
}
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|
vm_map_unlock(&vm->vm_map);
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|
/*
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|
* If the process has been asleep for awhile and had
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|
* most of its pages taken away already, swap it out.
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|
*/
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|
if ((action & VM_SWAP_NORMAL) ||
|
|
((action & VM_SWAP_IDLE) &&
|
|
(p->p_slptime > swap_idle_threshold2))) {
|
|
swapout(p);
|
|
vmspace_free(vm);
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|
didswap++;
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|
goto retry;
|
|
}
|
|
}
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|
}
|
|
/*
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|
* If we swapped something out, and another process needed memory,
|
|
* then wakeup the sched process.
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|
*/
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|
if (didswap)
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|
wakeup(&proc0);
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|
}
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|
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static void
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|
swapout(p)
|
|
register struct proc *p;
|
|
{
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|
|
#if defined(SWAP_DEBUG)
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|
printf("swapping out %d\n", p->p_pid);
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|
#endif
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|
++p->p_stats->p_ru.ru_nswap;
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|
/*
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|
* remember the process resident count
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*/
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|
p->p_vmspace->vm_swrss =
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p->p_vmspace->vm_pmap.pm_stats.resident_count;
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(void) splhigh();
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|
p->p_flag &= ~P_INMEM;
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p->p_flag |= P_SWAPPING;
|
|
if (p->p_stat == SRUN)
|
|
remrq(p);
|
|
(void) spl0();
|
|
|
|
pmap_swapout_proc(p);
|
|
|
|
p->p_flag &= ~P_SWAPPING;
|
|
p->p_swtime = 0;
|
|
}
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#endif /* !NO_SWAPPING */
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