587 lines
16 KiB
C
587 lines
16 KiB
C
/* $NetBSD: uvm_glue.c,v 1.9 1998/04/30 06:28:59 thorpej Exp $ */
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/*
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* XXXCDC: "ROUGH DRAFT" QUALITY UVM PRE-RELEASE FILE!
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* >>>USE AT YOUR OWN RISK, WORK IS NOT FINISHED<<<
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*/
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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 "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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#ifdef SYSVSHM
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#include <sys/shm.h>
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#endif
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#include <vm/vm.h>
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#include <vm/vm_page.h>
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#include <vm/vm_kern.h>
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#include <uvm/uvm.h>
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#include <machine/cpu.h>
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/*
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* local prototypes
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*/
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static void uvm_swapout __P((struct proc *));
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/*
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* XXXCDC: do these really belong here?
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*/
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unsigned maxdmap = MAXDSIZ; /* kern_resource.c: RLIMIT_DATA max */
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unsigned maxsmap = MAXSSIZ; /* kern_resource.c: RLIMIT_STACK max */
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int readbuffers = 0; /* allow KGDB to read kern buffer pool */
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/* XXX: see uvm_kernacc */
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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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* - called from malloc [DIAGNOSTIC], and /dev/kmem driver (mem.c)
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*/
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boolean_t
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uvm_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 = uvm_map_checkprot(kernel_map, saddr, eaddr, prot);
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vm_map_unlock_read(kernel_map);
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/*
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* XXX there are still some things (e.g. the buffer cache) that
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* are managed behind the VM system's back so even though an
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* address is accessible in the mind of the VM system, there may
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* not be physical pages where the VM thinks there is. This can
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* lead to bogus allocation of pages in the kernel address space
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* or worse, inconsistencies at the pmap level. We only worry
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* about the buffer cache for now.
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*/
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if (!readbuffers && rv && (eaddr > (vm_offset_t)buffers &&
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saddr < (vm_offset_t)buffers + MAXBSIZE * nbuf))
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rv = FALSE;
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return(rv);
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}
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/*
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* uvm_useracc: can the user access it?
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*
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* - called from physio() and sys___sysctl().
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*/
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boolean_t
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uvm_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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#if defined(i386) || defined(pc532)
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/*
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* XXX - specially disallow access to user page tables - they are
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* in the map. This is here until i386 & pc532 pmaps are fixed...
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*/
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if ((vm_offset_t) addr >= VM_MAXUSER_ADDRESS
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|| (vm_offset_t) addr + len > 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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#endif
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rv = uvm_map_checkprot(&curproc->p_vmspace->vm_map,
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trunc_page(addr), round_page(addr+len), prot);
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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(addr, len, rw)
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register caddr_t addr;
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int len, rw;
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{
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vm_prot_t prot;
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vm_offset_t pa, 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(addr + len);
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for (sva = trunc_page(addr); sva < eva; sva += PAGE_SIZE) {
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/*
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* Extract physical address for the page.
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* We use a cheezy hack to differentiate physical
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* page 0 from an invalid mapping, not that it
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* really matters...
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*/
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pa = pmap_extract(pmap_kernel(), sva|1);
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if (pa == 0)
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panic("chgkprot: invalid page");
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pmap_enter(pmap_kernel(), sva, pa&~1, prot, TRUE);
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}
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}
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#endif
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/*
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* 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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void
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uvm_vslock(p, addr, len)
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struct proc *p;
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caddr_t addr;
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u_int len;
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{
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uvm_fault_wire(&p->p_vmspace->vm_map, trunc_page(addr),
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round_page(addr+len));
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}
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/*
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* 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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void
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uvm_vsunlock(p, addr, len)
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struct proc *p;
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caddr_t addr;
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u_int len;
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{
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uvm_fault_unwire(curproc->p_vmspace->vm_map.pmap, trunc_page(addr),
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round_page(addr+len));
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}
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/*
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* uvm_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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* - a new "user" structure is allocated for the child process
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* [filled in by MD layer...]
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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_fork returns in the child process. We do nothing here
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* after cpu_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_fork(p1, p2, shared)
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struct proc *p1, *p2;
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boolean_t shared;
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{
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struct user *up = p2->p_addr;
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int rv;
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if (shared == TRUE)
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uvmspace_share(p1, p2); /* share vmspace */
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else
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p2->p_vmspace = uvmspace_fork(p1->p_vmspace); /* fork vmspace */
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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 p->p_flag's
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* P_INMEM bit rather than in the vm_map_entry's wired count
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* to prevent kernel_map fragmentation.
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*/
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rv = uvm_fault_wire(kernel_map, (vm_offset_t)up,
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(vm_offset_t)up + USPACE);
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if (rv != KERN_SUCCESS)
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panic("uvm_fork: uvm_fault_wire failed: %d", rv);
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/*
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* p_stats and p_sigacts currently point at fields in the user
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* struct but not at &u, instead at p_addr. Copy p_sigacts and
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* parts of 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 kernel stack and pcb, and make
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* the child ready to run. The child will exit directly to user
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* mode on its first time slice, and will not return here.
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*/
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cpu_fork(p1, p2);
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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(p)
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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 = 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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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 a process's u-area.
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*/
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void
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uvm_swapin(p)
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struct proc *p;
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{
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vm_offset_t addr;
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int s;
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addr = (vm_offset_t)p->p_addr;
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/* make P_INMEM true */
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uvm_fault_wire(kernel_map, addr, addr + USPACE);
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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(p);
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s = splstatclock();
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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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splx(s);
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p->p_swtime = 0;
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++uvmexp.swapins;
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}
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/*
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* uvm_scheduler: process zero main loop
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*
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* - attempt to swapin every swaped-out, runnable process in order of
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* priority.
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* - if not enough memory, wake the pagedaemon and let it clear space.
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*/
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void
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uvm_scheduler()
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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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UVMHIST_FUNC("uvm_scheduler"); UVMHIST_CALLED(maphist);
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loop:
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#ifdef DEBUG
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while (!enableswap)
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tsleep((caddr_t)&proc0, PVM, "noswap", 0);
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#endif
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pp = NULL; /* process to choose */
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ppri = INT_MIN; /* its priority */
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for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) {
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/* is it a runnable swapped out process? */
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if (p->p_stat == SRUN && (p->p_flag & P_INMEM) == 0) {
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pri = p->p_swtime + p->p_slptime -
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(p->p_nice - NZERO) * 8;
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if (pri > ppri) { /* higher priority? remember it. */
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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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#ifdef DEBUG
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if (swapdebug & SDB_FOLLOW)
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printf("scheduler: running, procp %p pri %d\n", pp, ppri);
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#endif
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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((caddr_t)&proc0, PVM, "scheduler", 0);
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goto loop;
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}
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/*
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* we have found swapped out process which we would like to bring
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* back in.
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*
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* XXX: this part is really bogus cuz we could deadlock on memory
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* despite our feeble check
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*/
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if (uvmexp.free > atop(USPACE)) {
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#ifdef DEBUG
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if (swapdebug & SDB_SWAPIN)
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printf("swapin: pid %d(%s)@%p, pri %d free %d\n",
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p->p_pid, p->p_comm, p->p_addr, ppri, uvmexp.free);
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#endif
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uvm_swapin(p);
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goto loop;
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}
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/*
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* not enough memory, jab the pageout daemon and wait til the coast
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* is clear
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*/
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#ifdef DEBUG
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if (swapdebug & SDB_FOLLOW)
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printf("scheduler: no room for pid %d(%s), free %d\n",
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p->p_pid, p->p_comm, uvmexp.free);
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#endif
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printf("scheduler: no room for pid %d(%s), free %d\n",
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p->p_pid, p->p_comm, uvmexp.free);/*XXXCDC: HIGHLY BOGUS */
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(void) splhigh();
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uvm_wait("schedpwait");
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(void) spl0();
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#ifdef DEBUG
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if (swapdebug & SDB_FOLLOW)
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printf("scheduler: room again, free %d\n", uvmexp.free);
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#endif
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goto loop;
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}
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/*
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* swappable: is process "p" swappable?
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*/
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#define swappable(p) \
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(((p)->p_flag & (P_SYSTEM | P_INMEM | P_WEXIT)) == P_INMEM && \
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(p)->p_holdcnt == 0)
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/*
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* swapout_threads: find threads that can be swapped and unwire their
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* u-areas.
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*
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* - called by the pagedaemon
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* - try and swap at least one processs
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* - processes that are sleeping or stopped for maxslp or more seconds
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* are swapped... otherwise the longest-sleeping or stopped process
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* is swapped, otherwise the longest resident process...
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*/
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void
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uvm_swapout_threads()
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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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extern int maxslp;
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/* XXXCDC: should move off to uvmexp. or uvm., also in uvm_meter */
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#ifdef DEBUG
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if (!enableswap)
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return;
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#endif
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/*
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* outp/outpri : stop/sleep process with largest sleeptime < maxslp
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* outp2/outpri2: the longest resident process (its swap time)
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*/
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outp = outp2 = NULL;
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outpri = outpri2 = 0;
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for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) {
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if (!swappable(p))
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continue;
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switch (p->p_stat) {
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case SRUN:
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if (p->p_swtime > outpri2) {
|
|
outp2 = p;
|
|
outpri2 = p->p_swtime;
|
|
}
|
|
continue;
|
|
|
|
case SSLEEP:
|
|
case SSTOP:
|
|
if (p->p_slptime >= maxslp) {
|
|
uvm_swapout(p); /* zap! */
|
|
didswap++;
|
|
} else if (p->p_slptime > outpri) {
|
|
outp = p;
|
|
outpri = p->p_slptime;
|
|
}
|
|
continue;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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 ((p = outp) == NULL)
|
|
p = outp2;
|
|
#ifdef DEBUG
|
|
if (swapdebug & SDB_SWAPOUT)
|
|
printf("swapout_threads: no duds, try procp %p\n", p);
|
|
#endif
|
|
if (p)
|
|
uvm_swapout(p);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* uvm_swapout: swap out process "p"
|
|
*
|
|
* - currently "swapout" means "unwire U-area" and "pmap_collect()"
|
|
* the pmap.
|
|
* - XXXCDC: should deactivate all process' private anonymous memory
|
|
*/
|
|
|
|
static void
|
|
uvm_swapout(p)
|
|
register struct proc *p;
|
|
{
|
|
vm_offset_t addr;
|
|
int s;
|
|
|
|
#ifdef DEBUG
|
|
if (swapdebug & SDB_SWAPOUT)
|
|
printf("swapout: pid %d(%s)@%p, stat %x pri %d free %d\n",
|
|
p->p_pid, p->p_comm, p->p_addr, p->p_stat,
|
|
p->p_slptime, uvmexp.free);
|
|
#endif
|
|
|
|
/*
|
|
* Do any machine-specific actions necessary before swapout.
|
|
* This can include saving floating point state, etc.
|
|
*/
|
|
cpu_swapout(p);
|
|
|
|
/*
|
|
* Unwire the to-be-swapped process's user struct and kernel stack.
|
|
*/
|
|
addr = (vm_offset_t)p->p_addr;
|
|
uvm_fault_unwire(kernel_map->pmap, addr, addr + USPACE); /* !P_INMEM */
|
|
pmap_collect(vm_map_pmap(&p->p_vmspace->vm_map));
|
|
|
|
/*
|
|
* Mark it as (potentially) swapped out.
|
|
*/
|
|
s = splstatclock();
|
|
p->p_flag &= ~P_INMEM;
|
|
if (p->p_stat == SRUN)
|
|
remrunqueue(p);
|
|
splx(s);
|
|
p->p_swtime = 0;
|
|
++uvmexp.swapouts;
|
|
}
|
|
|