92ce8c6a3d
into modules. By and large this commit: - shuffles header files and ifdefs - splits code out where necessary to be modular - adds module glue for each of the components - adds/replaces hooks for things that can be installed at runtime
815 lines
19 KiB
C
815 lines
19 KiB
C
/* $NetBSD: uvm_glue.c,v 1.134 2008/11/19 18:36:10 ad Exp $ */
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/*
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* Copyright (c) 1997 Charles D. Cranor and Washington University.
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* Copyright (c) 1991, 1993, The Regents of the University of California.
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*
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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 Charles D. Cranor,
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* Washington University, the University of California, Berkeley and
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* 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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* @(#)vm_glue.c 8.6 (Berkeley) 1/5/94
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* from: Id: uvm_glue.c,v 1.1.2.8 1998/02/07 01:16:54 chs Exp
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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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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: uvm_glue.c,v 1.134 2008/11/19 18:36:10 ad Exp $");
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#include "opt_kgdb.h"
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#include "opt_kstack.h"
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#include "opt_uvmhist.h"
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/*
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* uvm_glue.c: glue functions
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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/proc.h>
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#include <sys/resourcevar.h>
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#include <sys/buf.h>
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#include <sys/user.h>
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#include <sys/syncobj.h>
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#include <sys/cpu.h>
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#include <sys/atomic.h>
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#include <uvm/uvm.h>
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/*
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* local prototypes
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*/
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static void uvm_swapout(struct lwp *);
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static int uarea_swapin(vaddr_t);
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/*
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* XXXCDC: do these really belong here?
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*/
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/*
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* uvm_kernacc: can the kernel access a region of memory
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*
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* - used only by /dev/kmem driver (mem.c)
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*/
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bool
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uvm_kernacc(void *addr, size_t len, int rw)
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{
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bool rv;
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vaddr_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((vaddr_t)addr);
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eaddr = round_page((vaddr_t)addr + len);
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vm_map_lock_read(kernel_map);
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rv = uvm_map_checkprot(kernel_map, saddr, eaddr, prot);
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vm_map_unlock_read(kernel_map);
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return(rv);
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}
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#ifdef KGDB
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/*
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* Change protections on kernel pages from addr to addr+len
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* (presumably so debugger can plant a breakpoint).
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*
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* We force the protection change at the pmap level. If we were
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* to use vm_map_protect a change to allow writing would be lazily-
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* applied meaning we would still take a protection fault, something
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* we really don't want to do. It would also fragment the kernel
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* map unnecessarily. We cannot use pmap_protect since it also won't
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* enforce a write-enable request. Using pmap_enter is the only way
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* we can ensure the change takes place properly.
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*/
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void
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uvm_chgkprot(void *addr, size_t len, int rw)
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{
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vm_prot_t prot;
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paddr_t pa;
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vaddr_t sva, eva;
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prot = rw == B_READ ? VM_PROT_READ : VM_PROT_READ|VM_PROT_WRITE;
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eva = round_page((vaddr_t)addr + len);
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for (sva = trunc_page((vaddr_t)addr); sva < eva; sva += PAGE_SIZE) {
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/*
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* Extract physical address for the page.
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*/
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if (pmap_extract(pmap_kernel(), sva, &pa) == false)
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panic("%s: invalid page", __func__);
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pmap_enter(pmap_kernel(), sva, pa, prot, PMAP_WIRED);
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}
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pmap_update(pmap_kernel());
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}
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#endif
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/*
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* uvm_vslock: wire user memory for I/O
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*
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* - called from physio and sys___sysctl
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* - XXXCDC: consider nuking this (or making it a macro?)
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*/
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int
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uvm_vslock(struct vmspace *vs, void *addr, size_t len, vm_prot_t access_type)
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{
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struct vm_map *map;
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vaddr_t start, end;
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int error;
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map = &vs->vm_map;
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start = trunc_page((vaddr_t)addr);
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end = round_page((vaddr_t)addr + len);
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error = uvm_fault_wire(map, start, end, access_type, 0);
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return error;
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}
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/*
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* uvm_vsunlock: unwire user memory wired by uvm_vslock()
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*
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* - called from physio and sys___sysctl
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* - XXXCDC: consider nuking this (or making it a macro?)
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*/
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void
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uvm_vsunlock(struct vmspace *vs, void *addr, size_t len)
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{
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uvm_fault_unwire(&vs->vm_map, trunc_page((vaddr_t)addr),
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round_page((vaddr_t)addr + len));
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}
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/*
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* uvm_proc_fork: fork a virtual address space
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*
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* - the address space is copied as per parent map's inherit values
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*/
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void
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uvm_proc_fork(struct proc *p1, struct proc *p2, bool shared)
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{
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if (shared == true) {
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p2->p_vmspace = NULL;
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uvmspace_share(p1, p2);
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} else {
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p2->p_vmspace = uvmspace_fork(p1->p_vmspace);
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}
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cpu_proc_fork(p1, p2);
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}
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/*
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* uvm_lwp_fork: fork a thread
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*
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* - a new "user" structure is allocated for the child process
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* [filled in by MD layer...]
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* - if specified, the child gets a new user stack described by
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* stack and stacksize
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* - NOTE: the kernel stack may be at a different location in the child
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* process, and thus addresses of automatic variables may be invalid
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* after cpu_lwp_fork returns in the child process. We do nothing here
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* after cpu_lwp_fork returns.
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* - XXXCDC: we need a way for this to return a failure value rather
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* than just hang
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*/
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void
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uvm_lwp_fork(struct lwp *l1, struct lwp *l2, void *stack, size_t stacksize,
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void (*func)(void *), void *arg)
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{
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int error;
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/*
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* Wire down the U-area for the process, which contains the PCB
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* and the kernel stack. Wired state is stored in l->l_flag's
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* L_INMEM bit rather than in the vm_map_entry's wired count
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* to prevent kernel_map fragmentation. If we reused a cached U-area,
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* L_INMEM will already be set and we don't need to do anything.
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*
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* Note the kernel stack gets read/write accesses right off the bat.
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*/
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if ((l2->l_flag & LW_INMEM) == 0) {
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vaddr_t uarea = USER_TO_UAREA(l2->l_addr);
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if ((error = uarea_swapin(uarea)) != 0)
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panic("%s: uvm_fault_wire failed: %d", __func__, error);
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#ifdef PMAP_UAREA
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/* Tell the pmap this is a u-area mapping */
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PMAP_UAREA(uarea);
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#endif
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l2->l_flag |= LW_INMEM;
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}
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#ifdef KSTACK_CHECK_MAGIC
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/*
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* fill stack with magic number
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*/
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kstack_setup_magic(l2);
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#endif
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/*
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* cpu_lwp_fork() copy and update the pcb, and make the child ready
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* to run. If this is a normal user fork, the child will exit
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* directly to user mode via child_return() on its first time
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* slice and will not return here. If this is a kernel thread,
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* the specified entry point will be executed.
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*/
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cpu_lwp_fork(l1, l2, stack, stacksize, func, arg);
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}
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static int
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uarea_swapin(vaddr_t addr)
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{
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return uvm_fault_wire(kernel_map, addr, addr + USPACE,
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VM_PROT_READ | VM_PROT_WRITE, 0);
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}
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static void
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uarea_swapout(vaddr_t addr)
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{
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uvm_fault_unwire(kernel_map, addr, addr + USPACE);
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}
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#ifndef USPACE_ALIGN
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#define USPACE_ALIGN 0
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#endif
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static pool_cache_t uvm_uarea_cache;
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static int
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uarea_ctor(void *arg, void *obj, int flags)
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{
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KASSERT((flags & PR_WAITOK) != 0);
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return uarea_swapin((vaddr_t)obj);
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}
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static void *
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uarea_poolpage_alloc(struct pool *pp, int flags)
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{
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return (void *)uvm_km_alloc(kernel_map, pp->pr_alloc->pa_pagesz,
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USPACE_ALIGN, UVM_KMF_PAGEABLE |
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((flags & PR_WAITOK) != 0 ? UVM_KMF_WAITVA :
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(UVM_KMF_NOWAIT | UVM_KMF_TRYLOCK)));
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}
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static void
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uarea_poolpage_free(struct pool *pp, void *addr)
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{
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uvm_km_free(kernel_map, (vaddr_t)addr, pp->pr_alloc->pa_pagesz,
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UVM_KMF_PAGEABLE);
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}
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static struct pool_allocator uvm_uarea_allocator = {
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.pa_alloc = uarea_poolpage_alloc,
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.pa_free = uarea_poolpage_free,
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.pa_pagesz = USPACE,
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};
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void
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uvm_uarea_init(void)
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{
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int flags = PR_NOTOUCH;
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/*
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* specify PR_NOALIGN unless the alignment provided by
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* the backend (USPACE_ALIGN) is sufficient to provide
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* pool page size (UPSACE) alignment.
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*/
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if ((USPACE_ALIGN == 0 && USPACE != PAGE_SIZE) ||
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(USPACE_ALIGN % USPACE) != 0) {
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flags |= PR_NOALIGN;
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}
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uvm_uarea_cache = pool_cache_init(USPACE, USPACE_ALIGN, 0, flags,
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"uarea", &uvm_uarea_allocator, IPL_NONE, uarea_ctor, NULL, NULL);
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}
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/*
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* uvm_uarea_alloc: allocate a u-area
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*/
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bool
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uvm_uarea_alloc(vaddr_t *uaddrp)
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{
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*uaddrp = (vaddr_t)pool_cache_get(uvm_uarea_cache, PR_WAITOK);
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return true;
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}
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/*
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* uvm_uarea_free: free a u-area
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*/
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void
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uvm_uarea_free(vaddr_t uaddr, struct cpu_info *ci)
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{
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pool_cache_put(uvm_uarea_cache, (void *)uaddr);
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}
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/*
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* uvm_proc_exit: exit a virtual address space
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*
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* - borrow proc0's address space because freeing the vmspace
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* of the dead process may block.
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*/
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void
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uvm_proc_exit(struct proc *p)
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{
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struct lwp *l = curlwp; /* XXX */
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struct vmspace *ovm;
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KASSERT(p == l->l_proc);
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ovm = p->p_vmspace;
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/*
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* borrow proc0's address space.
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*/
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KPREEMPT_DISABLE(l);
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pmap_deactivate(l);
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p->p_vmspace = proc0.p_vmspace;
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pmap_activate(l);
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KPREEMPT_ENABLE(l);
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uvmspace_free(ovm);
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}
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void
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uvm_lwp_exit(struct lwp *l)
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{
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vaddr_t va = USER_TO_UAREA(l->l_addr);
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l->l_flag &= ~LW_INMEM;
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uvm_uarea_free(va, l->l_cpu);
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l->l_addr = NULL;
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}
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/*
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* uvm_init_limit: init per-process VM limits
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*
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* - called for process 0 and then inherited by all others.
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*/
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void
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uvm_init_limits(struct proc *p)
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{
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/*
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* Set up the initial limits on process VM. Set the maximum
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* resident set size to be all of (reasonably) available memory.
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* This causes any single, large process to start random page
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* replacement once it fills memory.
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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 = maxsmap;
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p->p_rlimit[RLIMIT_DATA].rlim_cur = DFLDSIZ;
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p->p_rlimit[RLIMIT_DATA].rlim_max = maxdmap;
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p->p_rlimit[RLIMIT_RSS].rlim_cur = ptoa(uvmexp.free);
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}
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#ifdef DEBUG
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int enableswap = 1;
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int swapdebug = 0;
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#define SDB_FOLLOW 1
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#define SDB_SWAPIN 2
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#define SDB_SWAPOUT 4
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#endif
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/*
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* uvm_swapin: swap in an lwp's u-area.
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*
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* - must be called with the LWP's swap lock held.
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* - naturally, must not be called with l == curlwp
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*/
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void
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uvm_swapin(struct lwp *l)
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{
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int error;
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/* XXXSMP notyet KASSERT(mutex_owned(&l->l_swaplock)); */
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KASSERT(l != curlwp);
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error = uarea_swapin(USER_TO_UAREA(l->l_addr));
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if (error) {
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panic("%s: rewiring stack failed: %d", __func__, error);
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}
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|
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/*
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* Some architectures need to be notified when the user area has
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* moved to new physical page(s) (e.g. see mips/mips/vm_machdep.c).
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*/
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cpu_swapin(l);
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lwp_lock(l);
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if (l->l_stat == LSRUN)
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sched_enqueue(l, false);
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l->l_flag |= LW_INMEM;
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l->l_swtime = 0;
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lwp_unlock(l);
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++uvmexp.swapins;
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}
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|
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/*
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|
* uvm_kick_scheduler: kick the scheduler into action if not running.
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*
|
|
* - called when swapped out processes have been awoken.
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|
*/
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|
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void
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uvm_kick_scheduler(void)
|
|
{
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|
|
if (uvm.swap_running == false)
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return;
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|
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mutex_enter(&uvm_scheduler_mutex);
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uvm.scheduler_kicked = true;
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cv_signal(&uvm.scheduler_cv);
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mutex_exit(&uvm_scheduler_mutex);
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}
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|
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/*
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|
* uvm_scheduler: process zero main loop
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|
*
|
|
* - attempt to swapin every swaped-out, runnable process in order of
|
|
* priority.
|
|
* - if not enough memory, wake the pagedaemon and let it clear space.
|
|
*/
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|
|
void
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uvm_scheduler(void)
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|
{
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struct lwp *l, *ll;
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int pri;
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int ppri;
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l = curlwp;
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lwp_lock(l);
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l->l_priority = PRI_VM;
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l->l_class = SCHED_FIFO;
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lwp_unlock(l);
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|
|
for (;;) {
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|
#ifdef DEBUG
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|
mutex_enter(&uvm_scheduler_mutex);
|
|
while (!enableswap)
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|
cv_wait(&uvm.scheduler_cv, &uvm_scheduler_mutex);
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mutex_exit(&uvm_scheduler_mutex);
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|
#endif
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ll = NULL; /* process to choose */
|
|
ppri = INT_MIN; /* its priority */
|
|
|
|
mutex_enter(proc_lock);
|
|
LIST_FOREACH(l, &alllwp, l_list) {
|
|
/* is it a runnable swapped out process? */
|
|
if (l->l_stat == LSRUN && !(l->l_flag & LW_INMEM)) {
|
|
pri = l->l_swtime + l->l_slptime -
|
|
(l->l_proc->p_nice - NZERO) * 8;
|
|
if (pri > ppri) { /* higher priority? */
|
|
ll = l;
|
|
ppri = pri;
|
|
}
|
|
}
|
|
}
|
|
#ifdef DEBUG
|
|
if (swapdebug & SDB_FOLLOW)
|
|
printf("%s: running, procp %p pri %d\n", __func__, ll,
|
|
ppri);
|
|
#endif
|
|
/*
|
|
* Nothing to do, back to sleep
|
|
*/
|
|
if ((l = ll) == NULL) {
|
|
mutex_exit(proc_lock);
|
|
mutex_enter(&uvm_scheduler_mutex);
|
|
if (uvm.scheduler_kicked == false)
|
|
cv_wait(&uvm.scheduler_cv,
|
|
&uvm_scheduler_mutex);
|
|
uvm.scheduler_kicked = false;
|
|
mutex_exit(&uvm_scheduler_mutex);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* we have found swapped out process which we would like
|
|
* to bring back in.
|
|
*
|
|
* XXX: this part is really bogus cuz we could deadlock
|
|
* on memory despite our feeble check
|
|
*/
|
|
if (uvmexp.free > atop(USPACE)) {
|
|
#ifdef DEBUG
|
|
if (swapdebug & SDB_SWAPIN)
|
|
printf("swapin: pid %d(%s)@%p, pri %d "
|
|
"free %d\n", l->l_proc->p_pid,
|
|
l->l_proc->p_comm, l->l_addr, ppri,
|
|
uvmexp.free);
|
|
#endif
|
|
mutex_enter(&l->l_swaplock);
|
|
mutex_exit(proc_lock);
|
|
uvm_swapin(l);
|
|
mutex_exit(&l->l_swaplock);
|
|
continue;
|
|
} else {
|
|
/*
|
|
* not enough memory, jab the pageout daemon and
|
|
* wait til the coast is clear
|
|
*/
|
|
mutex_exit(proc_lock);
|
|
#ifdef DEBUG
|
|
if (swapdebug & SDB_FOLLOW)
|
|
printf("%s: no room for pid %d(%s),"
|
|
" free %d\n", __func__, l->l_proc->p_pid,
|
|
l->l_proc->p_comm, uvmexp.free);
|
|
#endif
|
|
uvm_wait("schedpwait");
|
|
#ifdef DEBUG
|
|
if (swapdebug & SDB_FOLLOW)
|
|
printf("%s: room again, free %d\n", __func__,
|
|
uvmexp.free);
|
|
#endif
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* swappable: is LWP "l" swappable?
|
|
*/
|
|
|
|
static bool
|
|
swappable(struct lwp *l)
|
|
{
|
|
|
|
if ((l->l_flag & (LW_INMEM|LW_SYSTEM|LW_WEXIT)) != LW_INMEM)
|
|
return false;
|
|
if ((l->l_pflag & LP_RUNNING) != 0)
|
|
return false;
|
|
if (l->l_holdcnt != 0)
|
|
return false;
|
|
if (l->l_class != SCHED_OTHER)
|
|
return false;
|
|
if (l->l_syncobj == &rw_syncobj || l->l_syncobj == &mutex_syncobj)
|
|
return false;
|
|
if (l->l_proc->p_stat != SACTIVE && l->l_proc->p_stat != SSTOP)
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* swapout_threads: find threads that can be swapped and unwire their
|
|
* u-areas.
|
|
*
|
|
* - called by the pagedaemon
|
|
* - try and swap at least one processs
|
|
* - processes that are sleeping or stopped for maxslp or more seconds
|
|
* are swapped... otherwise the longest-sleeping or stopped process
|
|
* is swapped, otherwise the longest resident process...
|
|
*/
|
|
|
|
void
|
|
uvm_swapout_threads(void)
|
|
{
|
|
struct lwp *l;
|
|
struct lwp *outl, *outl2;
|
|
int outpri, outpri2;
|
|
int didswap = 0;
|
|
extern int maxslp;
|
|
bool gotit;
|
|
|
|
/* XXXCDC: should move off to uvmexp. or uvm., also in uvm_meter */
|
|
|
|
#ifdef DEBUG
|
|
if (!enableswap)
|
|
return;
|
|
#endif
|
|
|
|
/*
|
|
* outl/outpri : stop/sleep thread with largest sleeptime < maxslp
|
|
* outl2/outpri2: the longest resident thread (its swap time)
|
|
*/
|
|
outl = outl2 = NULL;
|
|
outpri = outpri2 = 0;
|
|
|
|
restart:
|
|
mutex_enter(proc_lock);
|
|
LIST_FOREACH(l, &alllwp, l_list) {
|
|
KASSERT(l->l_proc != NULL);
|
|
if (!mutex_tryenter(&l->l_swaplock))
|
|
continue;
|
|
if (!swappable(l)) {
|
|
mutex_exit(&l->l_swaplock);
|
|
continue;
|
|
}
|
|
switch (l->l_stat) {
|
|
case LSONPROC:
|
|
break;
|
|
|
|
case LSRUN:
|
|
if (l->l_swtime > outpri2) {
|
|
outl2 = l;
|
|
outpri2 = l->l_swtime;
|
|
}
|
|
break;
|
|
|
|
case LSSLEEP:
|
|
case LSSTOP:
|
|
if (l->l_slptime >= maxslp) {
|
|
mutex_exit(proc_lock);
|
|
uvm_swapout(l);
|
|
/*
|
|
* Locking in the wrong direction -
|
|
* try to prevent the LWP from exiting.
|
|
*/
|
|
gotit = mutex_tryenter(proc_lock);
|
|
mutex_exit(&l->l_swaplock);
|
|
didswap++;
|
|
if (!gotit)
|
|
goto restart;
|
|
continue;
|
|
} else if (l->l_slptime > outpri) {
|
|
outl = l;
|
|
outpri = l->l_slptime;
|
|
}
|
|
break;
|
|
}
|
|
mutex_exit(&l->l_swaplock);
|
|
}
|
|
|
|
/*
|
|
* If we didn't get rid of any real duds, toss out the next most
|
|
* likely sleeping/stopped or running candidate. We only do this
|
|
* if we are real low on memory since we don't gain much by doing
|
|
* it (USPACE bytes).
|
|
*/
|
|
if (didswap == 0 && uvmexp.free <= atop(round_page(USPACE))) {
|
|
if ((l = outl) == NULL)
|
|
l = outl2;
|
|
#ifdef DEBUG
|
|
if (swapdebug & SDB_SWAPOUT)
|
|
printf("%s: no duds, try procp %p\n", __func__, l);
|
|
#endif
|
|
if (l) {
|
|
mutex_enter(&l->l_swaplock);
|
|
mutex_exit(proc_lock);
|
|
if (swappable(l))
|
|
uvm_swapout(l);
|
|
mutex_exit(&l->l_swaplock);
|
|
return;
|
|
}
|
|
}
|
|
|
|
mutex_exit(proc_lock);
|
|
}
|
|
|
|
/*
|
|
* uvm_swapout: swap out lwp "l"
|
|
*
|
|
* - currently "swapout" means "unwire U-area" and "pmap_collect()"
|
|
* the pmap.
|
|
* - must be called with l->l_swaplock held.
|
|
* - XXXCDC: should deactivate all process' private anonymous memory
|
|
*/
|
|
|
|
static void
|
|
uvm_swapout(struct lwp *l)
|
|
{
|
|
struct vm_map *map;
|
|
|
|
KASSERT(mutex_owned(&l->l_swaplock));
|
|
|
|
#ifdef DEBUG
|
|
if (swapdebug & SDB_SWAPOUT)
|
|
printf("%s: lid %d.%d(%s)@%p, stat %x pri %d free %d\n",
|
|
__func__, l->l_proc->p_pid, l->l_lid, l->l_proc->p_comm,
|
|
l->l_addr, l->l_stat, l->l_slptime, uvmexp.free);
|
|
#endif
|
|
|
|
/*
|
|
* Mark it as (potentially) swapped out.
|
|
*/
|
|
lwp_lock(l);
|
|
if (!swappable(l)) {
|
|
KDASSERT(l->l_cpu != curcpu());
|
|
lwp_unlock(l);
|
|
return;
|
|
}
|
|
l->l_flag &= ~LW_INMEM;
|
|
l->l_swtime = 0;
|
|
if (l->l_stat == LSRUN)
|
|
sched_dequeue(l);
|
|
lwp_unlock(l);
|
|
l->l_ru.ru_nswap++;
|
|
++uvmexp.swapouts;
|
|
|
|
/*
|
|
* Do any machine-specific actions necessary before swapout.
|
|
* This can include saving floating point state, etc.
|
|
*/
|
|
cpu_swapout(l);
|
|
|
|
/*
|
|
* Unwire the to-be-swapped process's user struct and kernel stack.
|
|
*/
|
|
uarea_swapout(USER_TO_UAREA(l->l_addr));
|
|
map = &l->l_proc->p_vmspace->vm_map;
|
|
if (vm_map_lock_try(map)) {
|
|
pmap_collect(vm_map_pmap(map));
|
|
vm_map_unlock(map);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* uvm_lwp_hold: prevent lwp "l" from being swapped out, and bring
|
|
* back into memory if it is currently swapped.
|
|
*/
|
|
|
|
void
|
|
uvm_lwp_hold(struct lwp *l)
|
|
{
|
|
|
|
if (l == curlwp) {
|
|
atomic_inc_uint(&l->l_holdcnt);
|
|
} else {
|
|
mutex_enter(&l->l_swaplock);
|
|
if (atomic_inc_uint_nv(&l->l_holdcnt) == 1 &&
|
|
(l->l_flag & LW_INMEM) == 0)
|
|
uvm_swapin(l);
|
|
mutex_exit(&l->l_swaplock);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* uvm_lwp_rele: release a hold on lwp "l". when the holdcount
|
|
* drops to zero, it's eligable to be swapped.
|
|
*/
|
|
|
|
void
|
|
uvm_lwp_rele(struct lwp *l)
|
|
{
|
|
|
|
KASSERT(l->l_holdcnt != 0);
|
|
|
|
atomic_dec_uint(&l->l_holdcnt);
|
|
}
|