/*
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)vm_glue.c 8.6 (Berkeley) 1/5/94
*
*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*
* $FreeBSD$
*/
#include "opt_rlimit.h"
#include "opt_vm.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/buf.h>
#include <sys/shm.h>
#include <sys/vmmeter.h>
#include <sys/sysctl.h>
#include <sys/kernel.h>
#include <sys/unistd.h>
#include <machine/limits.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <sys/lock.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_kern.h>
#include <vm/vm_extern.h>
#include <sys/user.h>
/*
* System initialization
*
* Note: proc0 from proc.h
*/
static void vm_init_limits __P((void *));
SYSINIT(vm_limits, SI_SUB_VM_CONF, SI_ORDER_FIRST, vm_init_limits, &proc0)
/*
* THIS MUST BE THE LAST INITIALIZATION ITEM!!!
*
* Note: run scheduling should be divorced from the vm system.
*/
static void scheduler __P((void *));
SYSINIT(scheduler, SI_SUB_RUN_SCHEDULER, SI_ORDER_FIRST, scheduler, NULL)
static void swapout __P((struct proc *));
int
kernacc(addr, len, rw)
caddr_t addr;
int len, rw;
{
boolean_t rv;
vm_offset_t saddr, eaddr;
vm_prot_t prot;
KASSERT(rw & (~VM_PROT_ALL),
("illegal ``rw'' argument to kernacc (%x)\n", rw));
prot = rw;
saddr = trunc_page((vm_offset_t)addr);
eaddr = round_page((vm_offset_t)addr + len);
vm_map_lock_read(kernel_map);
rv = vm_map_check_protection(kernel_map, saddr, eaddr, prot);
vm_map_unlock_read(kernel_map);
return (rv == TRUE);
}
int
useracc(addr, len, rw)
caddr_t addr;
int len, rw;
{
boolean_t rv;
vm_prot_t prot;
vm_map_t map;
vm_map_entry_t save_hint;
KASSERT(rw & (~VM_PROT_ALL),
("illegal ``rw'' argument to useracc (%x)\n", rw));
prot = rw;
/*
* XXX - check separately to disallow access to user area and user
* page tables - they are in the map.
*
* XXX - VM_MAXUSER_ADDRESS is an end address, not a max. It was once
* only used (as an end address) in trap.c. Use it as an end address
* here too. This bogusness has spread. I just fixed where it was
* used as a max in vm_mmap.c.
*/
if ((vm_offset_t) addr + len > /* XXX */ VM_MAXUSER_ADDRESS
|| (vm_offset_t) addr + len < (vm_offset_t) addr) {
return (FALSE);
}
map = &curproc->p_vmspace->vm_map;
vm_map_lock_read(map);
/*
* We save the map hint, and restore it. Useracc appears to distort
* the map hint unnecessarily.
*/
save_hint = map->hint;
rv = vm_map_check_protection(map,
trunc_page((vm_offset_t)addr), round_page((vm_offset_t)addr + len), prot);
map->hint = save_hint;
vm_map_unlock_read(map);
return (rv == TRUE);
}
void
vslock(addr, len)
caddr_t addr;
u_int len;
{
vm_map_pageable(&curproc->p_vmspace->vm_map, trunc_page((vm_offset_t)addr),
round_page((vm_offset_t)addr + len), FALSE);
}
void
vsunlock(addr, len, dirtied)
caddr_t addr;
u_int len;
int dirtied;
{
#ifdef lint
dirtied++;
#endif /* lint */
vm_map_pageable(&curproc->p_vmspace->vm_map, trunc_page((vm_offset_t)addr),
round_page((vm_offset_t)addr + len), TRUE);
}
/*
* Implement fork's actions on an address space.
* Here we arrange for the address space to be copied or referenced,
* allocate a user struct (pcb and kernel stack), then call the
* machine-dependent layer to fill those in and make the new process
* ready to run. The new process is set up so that it returns directly
* to user mode to avoid stack copying and relocation problems.
*/
void
vm_fork(p1, p2, flags)
register struct proc *p1, *p2;
int flags;
{
register struct user *up;
if (flags & RFMEM) {
p2->p_vmspace = p1->p_vmspace;
p1->p_vmspace->vm_refcnt++;
}
while (vm_page_count_severe()) {
VM_WAIT;
}
if ((flags & RFMEM) == 0) {
p2->p_vmspace = vmspace_fork(p1->p_vmspace);
pmap_pinit2(vmspace_pmap(p2->p_vmspace));
if (p1->p_vmspace->vm_shm)
shmfork(p1, p2);
}
pmap_new_proc(p2);
up = p2->p_addr;
/*
* p_stats currently points at fields in the user struct
* but not at &u, instead at p_addr. Copy parts of
* p_stats; zero the rest of p_stats (statistics).
*
* If procsig->ps_refcnt is 1 and p2->p_sigacts is NULL we dont' need
* to share sigacts, so we use the up->u_sigacts.
*/
p2->p_stats = &up->u_stats;
if (p2->p_sigacts == NULL) {
if (p2->p_procsig->ps_refcnt != 1)
printf ("PID:%d NULL sigacts with refcnt not 1!\n",p2->p_pid);
p2->p_sigacts = &up->u_sigacts;
up->u_sigacts = *p1->p_sigacts;
}
bzero(&up->u_stats.pstat_startzero,
(unsigned) ((caddr_t) &up->u_stats.pstat_endzero -
(caddr_t) &up->u_stats.pstat_startzero));
bcopy(&p1->p_stats->pstat_startcopy, &up->u_stats.pstat_startcopy,
((caddr_t) &up->u_stats.pstat_endcopy -
(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(p1, p2);
}
/*
* 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;
{
register 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;
{
int s;
if ((p->p_flag & P_INMEM) == 0) {
++p->p_lock;
pmap_swapin_proc(p);
s = splhigh();
if (p->p_stat == SRUN)
setrunqueue(p);
p->p_flag |= P_INMEM;
/* undo the effect of setting SLOCK above */
--p->p_lock;
splx(s);
}
}
/*
* 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.
*/
/* ARGSUSED*/
static void
scheduler(dummy)
void *dummy;
{
register struct proc *p;
register int pri;
struct proc *pp;
int ppri;
loop:
if (vm_page_count_min()) {
VM_WAIT;
goto loop;
}
pp = NULL;
ppri = INT_MIN;
for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) {
if (p->p_stat == SRUN &&
(p->p_flag & (P_INMEM | P_SWAPPING)) == 0) {
pri = p->p_swtime + p->p_slptime;
if ((p->p_flag & P_SWAPINREQ) == 0) {
pri -= p->p_nice * 8;
}
/*
* if this process is higher priority and there is
* enough space, then select this process instead of
* the previous selection.
*/
if (pri > ppri) {
pp = p;
ppri = pri;
}
}
}
/*
* Nothing to do, back to sleep.
*/
if ((p = pp) == NULL) {
tsleep(&proc0, PVM, "sched", 0);
goto loop;
}
p->p_flag &= ~P_SWAPINREQ;
/*
* We would like to bring someone in. (only if there is space).
*/
faultin(p);
p->p_swtime = 0;
goto loop;
}
#ifndef NO_SWAPPING
#define swappable(p) \
(((p)->p_lock == 0) && \
((p)->p_flag & (P_TRACED|P_SYSTEM|P_INMEM|P_WEXIT|P_SWAPPING)) == P_INMEM)
/*
* 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;
{
register struct proc *p;
struct proc *outp, *outp2;
int outpri, outpri2;
int didswap = 0;
outp = outp2 = NULL;
outpri = outpri2 = INT_MIN;
retry:
for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) {
struct vmspace *vm;
if (!swappable(p))
continue;
vm = p->p_vmspace;
switch (p->p_stat) {
default:
continue;
case SSLEEP:
case SSTOP:
/*
* do not swapout a realtime process
*/
if (RTP_PRIO_IS_REALTIME(p->p_rtprio.type))
continue;
/*
* Do not swapout a process waiting on a critical
* event of some kind. Also guarantee swap_idle_threshold1
* time in memory.
*/
if (((p->p_priority & 0x7f) < PSOCK) ||
(p->p_slptime < swap_idle_threshold1))
continue;
/*
* 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) ||
(p->p_slptime < swap_idle_threshold2)))
continue;
++vm->vm_refcnt;
/*
* do not swapout a process that is waiting for VM
* data structures there is a possible deadlock.
*/
if (lockmgr(&vm->vm_map.lock,
LK_EXCLUSIVE | LK_NOWAIT,
(void *)0, curproc)) {
vmspace_free(vm);
continue;
}
vm_map_unlock(&vm->vm_map);
/*
* 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) &&
(p->p_slptime > swap_idle_threshold2))) {
swapout(p);
vmspace_free(vm);
didswap++;
goto retry;
}
}
}
/*
* If we swapped something out, and another process needed memory,
* then wakeup the sched process.
*/
if (didswap)
wakeup(&proc0);
}
static void
swapout(p)
register struct proc *p;
{
#if defined(SWAP_DEBUG)
printf("swapping out %d\n", p->p_pid);
#endif
++p->p_stats->p_ru.ru_nswap;
/*
* remember the process resident count
*/
p->p_vmspace->vm_swrss = vmspace_resident_count(p->p_vmspace);
(void) splhigh();
p->p_flag &= ~P_INMEM;
p->p_flag |= P_SWAPPING;
if (p->p_stat == SRUN)
remrunqueue(p);
(void) spl0();
pmap_swapout_proc(p);
p->p_flag &= ~P_SWAPPING;
p->p_swtime = 0;
}
#endif /* !NO_SWAPPING */
