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918 lines
22 KiB
C
918 lines
22 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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* $FreeBSD$
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*/
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#include "opt_vm.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/resourcevar.h>
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#include <sys/shm.h>
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#include <sys/vmmeter.h>
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#include <sys/sx.h>
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#include <sys/sysctl.h>
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#include <sys/kernel.h>
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#include <sys/ktr.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/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_object.h>
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#include <vm/vm_kern.h>
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#include <vm/vm_extern.h>
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#include <vm/vm_pager.h>
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#include <vm/swap_pager.h>
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#include <sys/user.h>
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extern int maxslp;
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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(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(void *);
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SYSINIT(scheduler, SI_SUB_RUN_SCHEDULER, SI_ORDER_FIRST, scheduler, NULL)
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#ifndef NO_SWAPPING
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static void swapout(struct proc *);
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static void vm_proc_swapin(struct proc *p);
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static void vm_proc_swapout(struct proc *p);
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#endif
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/*
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* MPSAFE
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*
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* WARNING! This code calls vm_map_check_protection() which only checks
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* the associated vm_map_entry range. It does not determine whether the
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* contents of the memory is actually readable or writable. In most cases
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* just checking the vm_map_entry is sufficient within the kernel's address
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* space.
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*/
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int
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kernacc(addr, len, rw)
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void *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;
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KASSERT((rw & ~VM_PROT_ALL) == 0,
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("illegal ``rw'' argument to kernacc (%x)\n", rw));
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prot = rw;
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saddr = trunc_page((vm_offset_t)addr);
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eaddr = round_page((vm_offset_t)addr + len);
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rv = vm_map_check_protection(kernel_map, saddr, eaddr, prot);
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return (rv == TRUE);
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}
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/*
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* MPSAFE
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*
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* WARNING! This code calls vm_map_check_protection() which only checks
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* the associated vm_map_entry range. It does not determine whether the
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* contents of the memory is actually readable or writable. vmapbuf(),
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* vm_fault_quick(), or copyin()/copout()/su*()/fu*() functions should be
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* used in conjuction with this call.
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*/
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int
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useracc(addr, len, rw)
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void *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;
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vm_map_t map;
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KASSERT((rw & ~VM_PROT_ALL) == 0,
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("illegal ``rw'' argument to useracc (%x)\n", rw));
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prot = rw;
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map = &curproc->p_vmspace->vm_map;
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if ((vm_offset_t)addr + len > vm_map_max(map) ||
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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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rv = vm_map_check_protection(map, trunc_page((vm_offset_t)addr),
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round_page((vm_offset_t)addr + len), prot);
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return (rv == TRUE);
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}
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/*
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* MPSAFE
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*/
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void
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vslock(addr, len)
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void *addr;
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u_int len;
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{
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vm_map_wire(&curproc->p_vmspace->vm_map, trunc_page((vm_offset_t)addr),
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round_page((vm_offset_t)addr + len), FALSE);
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}
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/*
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* MPSAFE
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*/
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void
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vsunlock(addr, len)
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void *addr;
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u_int len;
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{
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vm_map_unwire(&curproc->p_vmspace->vm_map,
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trunc_page((vm_offset_t)addr),
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round_page((vm_offset_t)addr + len), FALSE);
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}
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/*
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* Create the U area for a new process.
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* This routine directly affects the fork perf for a process.
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*/
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void
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vm_proc_new(struct proc *p)
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{
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vm_page_t ma[UAREA_PAGES];
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vm_object_t upobj;
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vm_offset_t up;
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vm_page_t m;
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u_int i;
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/*
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* Allocate object for the upage.
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*/
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upobj = vm_object_allocate(OBJT_DEFAULT, UAREA_PAGES);
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p->p_upages_obj = upobj;
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/*
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* Get a kernel virtual address for the U area for this process.
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*/
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up = kmem_alloc_nofault(kernel_map, UAREA_PAGES * PAGE_SIZE);
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if (up == 0)
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panic("vm_proc_new: upage allocation failed");
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p->p_uarea = (struct user *)up;
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for (i = 0; i < UAREA_PAGES; i++) {
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/*
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* Get a uarea page.
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*/
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m = vm_page_grab(upobj, i,
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VM_ALLOC_NORMAL | VM_ALLOC_RETRY | VM_ALLOC_WIRED);
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ma[i] = m;
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vm_page_lock_queues();
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vm_page_wakeup(m);
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vm_page_flag_clear(m, PG_ZERO);
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m->valid = VM_PAGE_BITS_ALL;
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vm_page_unlock_queues();
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}
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/*
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* Enter the pages into the kernel address space.
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*/
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pmap_qenter(up, ma, UAREA_PAGES);
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}
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/*
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* Dispose the U area for a process that has exited.
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* This routine directly impacts the exit perf of a process.
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* XXX proc_zone is marked UMA_ZONE_NOFREE, so this should never be called.
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*/
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void
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vm_proc_dispose(struct proc *p)
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{
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vm_object_t upobj;
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vm_offset_t up;
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vm_page_t m;
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upobj = p->p_upages_obj;
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if (upobj->resident_page_count != UAREA_PAGES)
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panic("vm_proc_dispose: incorrect number of pages in upobj");
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vm_page_lock_queues();
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while ((m = TAILQ_FIRST(&upobj->memq)) != NULL) {
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vm_page_busy(m);
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vm_page_unwire(m, 0);
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vm_page_free(m);
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}
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vm_page_unlock_queues();
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up = (vm_offset_t)p->p_uarea;
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pmap_qremove(up, UAREA_PAGES);
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kmem_free(kernel_map, up, UAREA_PAGES * PAGE_SIZE);
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vm_object_deallocate(upobj);
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}
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#ifndef NO_SWAPPING
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/*
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* Allow the U area for a process to be prejudicially paged out.
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*/
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static void
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vm_proc_swapout(struct proc *p)
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{
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vm_object_t upobj;
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vm_offset_t up;
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vm_page_t m;
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upobj = p->p_upages_obj;
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if (upobj->resident_page_count != UAREA_PAGES)
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panic("vm_proc_dispose: incorrect number of pages in upobj");
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vm_page_lock_queues();
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TAILQ_FOREACH(m, &upobj->memq, listq) {
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vm_page_dirty(m);
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vm_page_unwire(m, 0);
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}
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vm_page_unlock_queues();
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up = (vm_offset_t)p->p_uarea;
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pmap_qremove(up, UAREA_PAGES);
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}
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/*
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* Bring the U area for a specified process back in.
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*/
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static void
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vm_proc_swapin(struct proc *p)
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{
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vm_page_t ma[UAREA_PAGES];
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vm_object_t upobj;
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vm_offset_t up;
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vm_page_t m;
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int rv;
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int i;
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upobj = p->p_upages_obj;
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for (i = 0; i < UAREA_PAGES; i++) {
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m = vm_page_grab(upobj, i, VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
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if (m->valid != VM_PAGE_BITS_ALL) {
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rv = vm_pager_get_pages(upobj, &m, 1, 0);
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if (rv != VM_PAGER_OK)
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panic("vm_proc_swapin: cannot get upage");
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}
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ma[i] = m;
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}
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if (upobj->resident_page_count != UAREA_PAGES)
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panic("vm_proc_swapin: lost pages from upobj");
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vm_page_lock_queues();
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TAILQ_FOREACH(m, &upobj->memq, listq) {
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m->valid = VM_PAGE_BITS_ALL;
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vm_page_wire(m);
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vm_page_wakeup(m);
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}
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vm_page_unlock_queues();
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up = (vm_offset_t)p->p_uarea;
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pmap_qenter(up, ma, UAREA_PAGES);
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}
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/*
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* Swap in the UAREAs of all processes swapped out to the given device.
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* The pages in the UAREA are marked dirty and their swap metadata is freed.
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*/
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void
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vm_proc_swapin_all(int devidx)
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{
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struct proc *p;
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vm_object_t object;
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vm_page_t m;
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retry:
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sx_slock(&allproc_lock);
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FOREACH_PROC_IN_SYSTEM(p) {
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PROC_LOCK(p);
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mtx_lock_spin(&sched_lock);
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object = p->p_upages_obj;
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if (object != NULL &&
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swap_pager_isswapped(p->p_upages_obj, devidx)) {
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sx_sunlock(&allproc_lock);
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faultin(p);
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mtx_unlock_spin(&sched_lock);
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PROC_UNLOCK(p);
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vm_page_lock_queues();
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TAILQ_FOREACH(m, &object->memq, listq)
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vm_page_dirty(m);
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vm_page_unlock_queues();
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swap_pager_freespace(object, 0,
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object->un_pager.swp.swp_bcount);
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goto retry;
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}
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mtx_unlock_spin(&sched_lock);
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PROC_UNLOCK(p);
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}
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sx_sunlock(&allproc_lock);
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}
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#endif
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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_forkproc(td, p2, td2, flags)
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struct thread *td;
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struct proc *p2;
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struct thread *td2;
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int flags;
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{
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struct proc *p1 = td->td_proc;
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struct user *up;
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GIANT_REQUIRED;
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if ((flags & RFPROC) == 0) {
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/*
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* Divorce the memory, if it is shared, essentially
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* this changes shared memory amongst threads, into
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* COW locally.
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*/
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if ((flags & RFMEM) == 0) {
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if (p1->p_vmspace->vm_refcnt > 1) {
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vmspace_unshare(p1);
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}
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}
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cpu_fork(td, p2, td2, flags);
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return;
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}
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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 (vm_page_count_severe()) {
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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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pmap_pinit2(vmspace_pmap(p2->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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|
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/* XXXKSE this is unsatisfactory but should be adequate */
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up = p2->p_uarea;
|
|
|
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/*
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* p_stats currently points at fields in the user struct
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* but not at &u, instead at p_addr. Copy parts of
|
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* p_stats; zero the rest of p_stats (statistics).
|
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*
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* If procsig->ps_refcnt is 1 and p2->p_sigacts is NULL we dont' need
|
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* to share sigacts, so we use the up->u_sigacts.
|
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*/
|
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p2->p_stats = &up->u_stats;
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if (p2->p_sigacts == NULL) {
|
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if (p2->p_procsig->ps_refcnt != 1)
|
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printf ("PID:%d NULL sigacts with refcnt not 1!\n",p2->p_pid);
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p2->p_sigacts = &up->u_sigacts;
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up->u_sigacts = *p1->p_sigacts;
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}
|
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|
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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));
|
|
|
|
|
|
/*
|
|
* cpu_fork will copy and update the pcb, set up the kernel stack,
|
|
* and make the child ready to run.
|
|
*/
|
|
cpu_fork(td, p2, td2, flags);
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}
|
|
|
|
/*
|
|
* Called after process has been wait(2)'ed apon and is being reaped.
|
|
* The idea is to reclaim resources that we could not reclaim while
|
|
* the process was still executing.
|
|
*/
|
|
void
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vm_waitproc(p)
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|
struct proc *p;
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{
|
|
|
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GIANT_REQUIRED;
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cpu_wait(p);
|
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vmspace_exitfree(p); /* and clean-out the vmspace */
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|
}
|
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|
|
/*
|
|
* Set default limits for VM system.
|
|
* Called for proc 0, and then inherited by all others.
|
|
*
|
|
* XXX should probably act directly on proc0.
|
|
*/
|
|
static void
|
|
vm_init_limits(udata)
|
|
void *udata;
|
|
{
|
|
struct proc *p = udata;
|
|
int rss_limit;
|
|
|
|
/*
|
|
* Set up the initial limits on process VM. Set the maximum resident
|
|
* set size to be half of (reasonably) available memory. Since this
|
|
* is a soft limit, it comes into effect only when the system is out
|
|
* of memory - half of main memory helps to favor smaller processes,
|
|
* and reduces thrashing of the object cache.
|
|
*/
|
|
p->p_rlimit[RLIMIT_STACK].rlim_cur = dflssiz;
|
|
p->p_rlimit[RLIMIT_STACK].rlim_max = maxssiz;
|
|
p->p_rlimit[RLIMIT_DATA].rlim_cur = dfldsiz;
|
|
p->p_rlimit[RLIMIT_DATA].rlim_max = maxdsiz;
|
|
/* limit the limit to no less than 2MB */
|
|
rss_limit = max(cnt.v_free_count, 512);
|
|
p->p_rlimit[RLIMIT_RSS].rlim_cur = ptoa(rss_limit);
|
|
p->p_rlimit[RLIMIT_RSS].rlim_max = RLIM_INFINITY;
|
|
}
|
|
|
|
void
|
|
faultin(p)
|
|
struct proc *p;
|
|
{
|
|
|
|
GIANT_REQUIRED;
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
#ifdef NO_SWAPPING
|
|
if ((p->p_sflag & PS_INMEM) == 0)
|
|
panic("faultin: proc swapped out with NO_SWAPPING!");
|
|
#else
|
|
if ((p->p_sflag & PS_INMEM) == 0) {
|
|
struct thread *td;
|
|
|
|
++p->p_lock;
|
|
/*
|
|
* If another process is swapping in this process,
|
|
* just wait until it finishes.
|
|
*/
|
|
if (p->p_sflag & PS_SWAPPINGIN) {
|
|
mtx_unlock_spin(&sched_lock);
|
|
msleep(&p->p_sflag, &p->p_mtx, PVM, "faultin", 0);
|
|
mtx_lock_spin(&sched_lock);
|
|
--p->p_lock;
|
|
return;
|
|
}
|
|
|
|
p->p_sflag |= PS_SWAPPINGIN;
|
|
mtx_unlock_spin(&sched_lock);
|
|
PROC_UNLOCK(p);
|
|
|
|
vm_proc_swapin(p);
|
|
FOREACH_THREAD_IN_PROC (p, td) {
|
|
pmap_swapin_thread(td);
|
|
TD_CLR_SWAPPED(td);
|
|
}
|
|
|
|
PROC_LOCK(p);
|
|
mtx_lock_spin(&sched_lock);
|
|
p->p_sflag &= ~PS_SWAPPINGIN;
|
|
p->p_sflag |= PS_INMEM;
|
|
FOREACH_THREAD_IN_PROC (p, td)
|
|
if (TD_CAN_RUN(td))
|
|
setrunnable(td);
|
|
|
|
wakeup(&p->p_sflag);
|
|
|
|
/* undo the effect of setting SLOCK above */
|
|
--p->p_lock;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* This swapin algorithm attempts to swap-in processes only if there
|
|
* is enough space for them. Of course, if a process waits for a long
|
|
* time, it will be swapped in anyway.
|
|
*
|
|
* XXXKSE - process with the thread with highest priority counts..
|
|
*
|
|
* Giant is still held at this point, to be released in tsleep.
|
|
*/
|
|
/* ARGSUSED*/
|
|
static void
|
|
scheduler(dummy)
|
|
void *dummy;
|
|
{
|
|
struct proc *p;
|
|
struct thread *td;
|
|
int pri;
|
|
struct proc *pp;
|
|
int ppri;
|
|
|
|
mtx_assert(&Giant, MA_OWNED | MA_NOTRECURSED);
|
|
/* GIANT_REQUIRED */
|
|
|
|
loop:
|
|
if (vm_page_count_min()) {
|
|
VM_WAIT;
|
|
goto loop;
|
|
}
|
|
|
|
pp = NULL;
|
|
ppri = INT_MIN;
|
|
sx_slock(&allproc_lock);
|
|
FOREACH_PROC_IN_SYSTEM(p) {
|
|
struct ksegrp *kg;
|
|
if (p->p_sflag & (PS_INMEM | PS_SWAPPING | PS_SWAPPINGIN)) {
|
|
continue;
|
|
}
|
|
mtx_lock_spin(&sched_lock);
|
|
FOREACH_THREAD_IN_PROC(p, td) {
|
|
/*
|
|
* An otherwise runnable thread of a process
|
|
* swapped out has only the TDI_SWAPPED bit set.
|
|
*
|
|
*/
|
|
if (td->td_inhibitors == TDI_SWAPPED) {
|
|
kg = td->td_ksegrp;
|
|
pri = p->p_swtime + kg->kg_slptime;
|
|
if ((p->p_sflag & PS_SWAPINREQ) == 0) {
|
|
pri -= kg->kg_nice * 8;
|
|
}
|
|
|
|
/*
|
|
* if this ksegrp is higher priority
|
|
* and there is enough space, then select
|
|
* this process instead of the previous
|
|
* selection.
|
|
*/
|
|
if (pri > ppri) {
|
|
pp = p;
|
|
ppri = pri;
|
|
}
|
|
}
|
|
}
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
sx_sunlock(&allproc_lock);
|
|
|
|
/*
|
|
* Nothing to do, back to sleep.
|
|
*/
|
|
if ((p = pp) == NULL) {
|
|
tsleep(&proc0, PVM, "sched", maxslp * hz / 2);
|
|
goto loop;
|
|
}
|
|
PROC_LOCK(p);
|
|
mtx_lock_spin(&sched_lock);
|
|
|
|
/*
|
|
* Another process may be bringing or may have already
|
|
* brought this process in while we traverse all threads.
|
|
* Or, this process may even be being swapped out again.
|
|
*/
|
|
if (p->p_sflag & (PS_INMEM|PS_SWAPPING|PS_SWAPPINGIN)) {
|
|
mtx_unlock_spin(&sched_lock);
|
|
PROC_UNLOCK(p);
|
|
goto loop;
|
|
}
|
|
|
|
p->p_sflag &= ~PS_SWAPINREQ;
|
|
|
|
/*
|
|
* We would like to bring someone in. (only if there is space).
|
|
* [What checks the space? ]
|
|
*/
|
|
faultin(p);
|
|
PROC_UNLOCK(p);
|
|
p->p_swtime = 0;
|
|
mtx_unlock_spin(&sched_lock);
|
|
goto loop;
|
|
}
|
|
|
|
#ifndef NO_SWAPPING
|
|
|
|
/*
|
|
* Swap_idle_threshold1 is the guaranteed swapped in time for a process
|
|
*/
|
|
static int swap_idle_threshold1 = 2;
|
|
SYSCTL_INT(_vm, OID_AUTO, swap_idle_threshold1,
|
|
CTLFLAG_RW, &swap_idle_threshold1, 0, "");
|
|
|
|
/*
|
|
* Swap_idle_threshold2 is the time that a process can be idle before
|
|
* it will be swapped out, if idle swapping is enabled.
|
|
*/
|
|
static int swap_idle_threshold2 = 10;
|
|
SYSCTL_INT(_vm, OID_AUTO, swap_idle_threshold2,
|
|
CTLFLAG_RW, &swap_idle_threshold2, 0, "");
|
|
|
|
/*
|
|
* Swapout is driven by the pageout daemon. Very simple, we find eligible
|
|
* procs and unwire their u-areas. We try to always "swap" at least one
|
|
* process in case we need the room for a swapin.
|
|
* If any procs have been sleeping/stopped for at least maxslp seconds,
|
|
* they are swapped. Else, we swap the longest-sleeping or stopped process,
|
|
* if any, otherwise the longest-resident process.
|
|
*/
|
|
void
|
|
swapout_procs(action)
|
|
int action;
|
|
{
|
|
struct proc *p;
|
|
struct thread *td;
|
|
struct ksegrp *kg;
|
|
struct proc *outp, *outp2;
|
|
int outpri, outpri2;
|
|
int didswap = 0;
|
|
|
|
GIANT_REQUIRED;
|
|
|
|
outp = outp2 = NULL;
|
|
outpri = outpri2 = INT_MIN;
|
|
retry:
|
|
sx_slock(&allproc_lock);
|
|
FOREACH_PROC_IN_SYSTEM(p) {
|
|
struct vmspace *vm;
|
|
int minslptime = 100000;
|
|
|
|
/*
|
|
* Watch out for a process in
|
|
* creation. It may have no
|
|
* address space or lock yet.
|
|
*/
|
|
mtx_lock_spin(&sched_lock);
|
|
if (p->p_state == PRS_NEW) {
|
|
mtx_unlock_spin(&sched_lock);
|
|
continue;
|
|
}
|
|
mtx_unlock_spin(&sched_lock);
|
|
|
|
/*
|
|
* An aio daemon switches its
|
|
* address space while running.
|
|
* Perform a quick check whether
|
|
* a process has P_SYSTEM.
|
|
*/
|
|
PROC_LOCK(p);
|
|
if ((p->p_flag & P_SYSTEM) != 0) {
|
|
PROC_UNLOCK(p);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Do not swapout a process that
|
|
* is waiting for VM data
|
|
* structures as there is a possible
|
|
* deadlock. Test this first as
|
|
* this may block.
|
|
*
|
|
* Lock the map until swapout
|
|
* finishes, or a thread of this
|
|
* process may attempt to alter
|
|
* the map.
|
|
*/
|
|
vm = p->p_vmspace;
|
|
KASSERT(vm != NULL,
|
|
("swapout_procs: a process has no address space"));
|
|
++vm->vm_refcnt;
|
|
PROC_UNLOCK(p);
|
|
if (!vm_map_trylock(&vm->vm_map))
|
|
goto nextproc1;
|
|
|
|
PROC_LOCK(p);
|
|
if (p->p_lock != 0 ||
|
|
(p->p_flag & (P_STOPPED_SINGLE|P_TRACED|P_SYSTEM|P_WEXIT)
|
|
) != 0) {
|
|
goto nextproc2;
|
|
}
|
|
/*
|
|
* only aiod changes vmspace, however it will be
|
|
* skipped because of the if statement above checking
|
|
* for P_SYSTEM
|
|
*/
|
|
mtx_lock_spin(&sched_lock);
|
|
if ((p->p_sflag & (PS_INMEM|PS_SWAPPING|PS_SWAPPINGIN)) != PS_INMEM)
|
|
goto nextproc;
|
|
|
|
switch (p->p_state) {
|
|
default:
|
|
/* Don't swap out processes in any sort
|
|
* of 'special' state. */
|
|
goto nextproc;
|
|
|
|
case PRS_NORMAL:
|
|
/*
|
|
* do not swapout a realtime process
|
|
* Check all the thread groups..
|
|
*/
|
|
FOREACH_KSEGRP_IN_PROC(p, kg) {
|
|
if (PRI_IS_REALTIME(kg->kg_pri_class))
|
|
goto nextproc;
|
|
|
|
/*
|
|
* Guarantee swap_idle_threshold1
|
|
* time in memory.
|
|
*/
|
|
if (kg->kg_slptime < swap_idle_threshold1)
|
|
goto nextproc;
|
|
|
|
/*
|
|
* Do not swapout a process if it is
|
|
* waiting on a critical event of some
|
|
* kind or there is a thread whose
|
|
* pageable memory may be accessed.
|
|
*
|
|
* This could be refined to support
|
|
* swapping out a thread.
|
|
*/
|
|
FOREACH_THREAD_IN_GROUP(kg, td) {
|
|
if ((td->td_priority) < PSOCK ||
|
|
!thread_safetoswapout(td))
|
|
goto nextproc;
|
|
}
|
|
/*
|
|
* If the system is under memory stress,
|
|
* or if we are swapping
|
|
* idle processes >= swap_idle_threshold2,
|
|
* then swap the process out.
|
|
*/
|
|
if (((action & VM_SWAP_NORMAL) == 0) &&
|
|
(((action & VM_SWAP_IDLE) == 0) ||
|
|
(kg->kg_slptime < swap_idle_threshold2)))
|
|
goto nextproc;
|
|
|
|
if (minslptime > kg->kg_slptime)
|
|
minslptime = kg->kg_slptime;
|
|
}
|
|
|
|
/*
|
|
* If the process has been asleep for awhile and had
|
|
* most of its pages taken away already, swap it out.
|
|
*/
|
|
if ((action & VM_SWAP_NORMAL) ||
|
|
((action & VM_SWAP_IDLE) &&
|
|
(minslptime > swap_idle_threshold2))) {
|
|
swapout(p);
|
|
didswap++;
|
|
|
|
/*
|
|
* swapout() unlocks a proc lock. This is
|
|
* ugly, but avoids superfluous lock.
|
|
*/
|
|
mtx_unlock_spin(&sched_lock);
|
|
vm_map_unlock(&vm->vm_map);
|
|
vmspace_free(vm);
|
|
sx_sunlock(&allproc_lock);
|
|
goto retry;
|
|
}
|
|
}
|
|
nextproc:
|
|
mtx_unlock_spin(&sched_lock);
|
|
nextproc2:
|
|
PROC_UNLOCK(p);
|
|
vm_map_unlock(&vm->vm_map);
|
|
nextproc1:
|
|
vmspace_free(vm);
|
|
continue;
|
|
}
|
|
sx_sunlock(&allproc_lock);
|
|
/*
|
|
* If we swapped something out, and another process needed memory,
|
|
* then wakeup the sched process.
|
|
*/
|
|
if (didswap)
|
|
wakeup(&proc0);
|
|
}
|
|
|
|
static void
|
|
swapout(p)
|
|
struct proc *p;
|
|
{
|
|
struct thread *td;
|
|
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
mtx_assert(&sched_lock, MA_OWNED | MA_NOTRECURSED);
|
|
#if defined(SWAP_DEBUG)
|
|
printf("swapping out %d\n", p->p_pid);
|
|
#endif
|
|
|
|
/*
|
|
* The states of this process and its threads may have changed
|
|
* by now. Assuming that there is only one pageout daemon thread,
|
|
* this process should still be in memory.
|
|
*/
|
|
KASSERT((p->p_sflag & (PS_INMEM|PS_SWAPPING|PS_SWAPPINGIN)) == PS_INMEM,
|
|
("swapout: lost a swapout race?"));
|
|
|
|
#if defined(INVARIANTS)
|
|
/*
|
|
* Make sure that all threads are safe to be swapped out.
|
|
*
|
|
* Alternatively, we could swap out only safe threads.
|
|
*/
|
|
FOREACH_THREAD_IN_PROC(p, td) {
|
|
KASSERT(thread_safetoswapout(td),
|
|
("swapout: there is a thread not safe for swapout"));
|
|
}
|
|
#endif /* INVARIANTS */
|
|
|
|
++p->p_stats->p_ru.ru_nswap;
|
|
/*
|
|
* remember the process resident count
|
|
*/
|
|
p->p_vmspace->vm_swrss = vmspace_resident_count(p->p_vmspace);
|
|
|
|
PROC_UNLOCK(p);
|
|
p->p_sflag &= ~PS_INMEM;
|
|
p->p_sflag |= PS_SWAPPING;
|
|
mtx_unlock_spin(&sched_lock);
|
|
|
|
vm_proc_swapout(p);
|
|
FOREACH_THREAD_IN_PROC(p, td) {
|
|
pmap_swapout_thread(td);
|
|
TD_SET_SWAPPED(td);
|
|
}
|
|
mtx_lock_spin(&sched_lock);
|
|
p->p_sflag &= ~PS_SWAPPING;
|
|
p->p_swtime = 0;
|
|
}
|
|
#endif /* !NO_SWAPPING */
|