freebsd-dev/sys/vm/vm_glue.c
Garrett Wollman f23b4c91c4 Fix up some sloppy coding practices:
- Delete redundant declarations.
- Add -Wredundant-declarations to Makefile.i386 so they don't come back.
- Delete sloppy COMMON-style declarations of uninitialized data in
  header files.
- Add a few prototypes.
- Clean up warnings resulting from the above.

NB: ioconf.c will still generate a redundant-declaration warning, which
is unavoidable unless somebody volunteers to make `config' smarter.
1994-08-18 22:36:09 +00:00

684 lines
17 KiB
C

/*
* 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.
*
* $Id: vm_glue.c,v 1.5 1994/08/09 10:42:41 davidg Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/buf.h>
#include <sys/user.h>
#include <sys/kernel.h>
#include <sys/dkstat.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_kern.h>
#include <machine/stdarg.h>
extern char kstack[];
int avefree = 0; /* XXX */
int readbuffers = 0; /* XXX allow kgdb to read kernel buffer pool */
/* vm_map_t upages_map; */
int
kernacc(addr, len, rw)
caddr_t addr;
int len, rw;
{
boolean_t rv;
vm_offset_t saddr, eaddr;
vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE;
saddr = trunc_page(addr);
eaddr = round_page(addr+len);
rv = vm_map_check_protection(kernel_map, saddr, eaddr, prot);
return(rv == TRUE);
}
int
useracc(addr, len, rw)
caddr_t addr;
int len, rw;
{
boolean_t rv;
vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE;
/*
* 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);
}
rv = vm_map_check_protection(&curproc->p_vmspace->vm_map,
trunc_page(addr), round_page(addr+len), prot);
return(rv == TRUE);
}
#ifdef KGDB
/*
* Change protections on kernel pages from addr to addr+len
* (presumably so debugger can plant a breakpoint).
* All addresses are assumed to reside in the Sysmap,
*/
chgkprot(addr, len, rw)
register caddr_t addr;
int len, rw;
{
vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE;
vm_map_protect(kernel_map, trunc_page(addr),
round_page(addr+len), prot, FALSE);
}
#endif
void
vslock(addr, len)
caddr_t addr;
u_int len;
{
vm_map_pageable(&curproc->p_vmspace->vm_map, trunc_page(addr),
round_page(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(addr),
round_page(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.
* NOTE: the kernel stack may be at a different location in the child
* process, and thus addresses of automatic variables may be invalid
* after cpu_fork returns in the child process. We do nothing here
* after cpu_fork returns.
*/
int
vm_fork(p1, p2, isvfork)
register struct proc *p1, *p2;
int isvfork;
{
register struct user *up;
vm_offset_t addr, ptaddr;
int i;
struct vm_map *vp;
while( cnt.v_free_count < cnt.v_free_min)
VM_WAIT;
/*
* avoid copying any of the parent's pagetables or other per-process
* objects that reside in the map by marking all of them non-inheritable
*/
(void)vm_map_inherit(&p1->p_vmspace->vm_map,
UPT_MIN_ADDRESS - UPAGES * NBPG, VM_MAX_ADDRESS, VM_INHERIT_NONE);
p2->p_vmspace = vmspace_fork(p1->p_vmspace);
#ifdef SYSVSHM
if (p1->p_vmspace->vm_shm)
shmfork(p1, p2, isvfork);
#endif
/*
* Allocate a wired-down (for now) pcb and kernel stack for the process
*/
addr = (vm_offset_t) kstack;
vp = &p2->p_vmspace->vm_map;
/* ream out old pagetables and kernel stack */
(void)vm_deallocate(vp, addr, UPT_MAX_ADDRESS - addr);
/* get new pagetables and kernel stack */
(void)vm_allocate(vp, &addr, UPT_MAX_ADDRESS - addr, FALSE);
/* force in the page table encompassing the UPAGES */
ptaddr = trunc_page((u_int)vtopte(addr));
vm_map_pageable(vp, ptaddr, ptaddr + NBPG, FALSE);
/* and force in (demand-zero) the UPAGES */
vm_map_pageable(vp, addr, addr + UPAGES * NBPG, FALSE);
/* get a kernel virtual address for the UPAGES for this proc */
up = (struct user *)kmem_alloc_pageable(kernel_map, UPAGES * NBPG);
/* and force-map the upages into the kernel pmap */
for (i = 0; i < UPAGES; i++)
pmap_enter(vm_map_pmap(kernel_map),
((vm_offset_t) up) + NBPG * i,
pmap_extract(vp->pmap, addr + NBPG * i),
VM_PROT_READ|VM_PROT_WRITE, 1);
/* and allow the UPAGES page table entry to be paged (at the vm system level) */
vm_map_pageable(vp, ptaddr, ptaddr + NBPG, TRUE);
p2->p_addr = up;
/*
* p_stats and p_sigacts currently point at fields
* in the user struct but not at &u, instead at p_addr.
* Copy p_sigacts and parts of p_stats; zero the rest
* of p_stats (statistics).
*/
p2->p_stats = &up->u_stats;
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 kernel stack and pcb,
* and make the child ready to run. It marks the child
* so that it can return differently than the parent.
* It returns twice, once in the parent process and
* once in the child.
*/
return (cpu_fork(p1, p2));
}
/*
* Set default limits for VM system.
* Called for proc 0, and then inherited by all others.
*/
void
vm_init_limits(p)
register struct proc *p;
{
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 128K */
rss_limit = max(cnt.v_free_count / 2, 32);
p->p_rlimit[RLIMIT_RSS].rlim_cur = ptoa(rss_limit);
p->p_rlimit[RLIMIT_RSS].rlim_max = RLIM_INFINITY;
}
#ifdef DEBUG
int enableswap = 1;
int swapdebug = 0;
#define SDB_FOLLOW 1
#define SDB_SWAPIN 2
#define SDB_SWAPOUT 4
#endif
void
faultin(p)
struct proc *p;
{
vm_offset_t i;
vm_offset_t vaddr, ptaddr;
vm_offset_t v, v1;
struct user *up;
int s;
int opflag;
if ((p->p_flag & P_INMEM) == 0) {
int rv0, rv1;
vm_map_t map;
++p->p_lock;
map = &p->p_vmspace->vm_map;
/* force the page table encompassing the kernel stack (upages) */
ptaddr = trunc_page((u_int)vtopte(kstack));
vm_map_pageable(map, ptaddr, ptaddr + NBPG, FALSE);
/* wire in the UPAGES */
vm_map_pageable(map, (vm_offset_t) kstack,
(vm_offset_t) kstack + UPAGES * NBPG, FALSE);
/* and map them nicely into the kernel pmap */
for (i = 0; i < UPAGES; i++) {
vm_offset_t off = i * NBPG;
vm_offset_t pa = (vm_offset_t)
pmap_extract(&p->p_vmspace->vm_pmap,
(vm_offset_t) kstack + off);
pmap_enter(vm_map_pmap(kernel_map),
((vm_offset_t)p->p_addr) + off,
pa, VM_PROT_READ|VM_PROT_WRITE, 1);
}
/* and let the page table pages go (at least above pmap level) */
vm_map_pageable(map, ptaddr, ptaddr + NBPG, TRUE);
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);
}
}
int swapinreq;
int percentactive;
/*
* 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.
*/
void
scheduler()
{
register struct proc *p;
register int pri;
struct proc *pp;
int ppri;
vm_offset_t addr;
int lastidle, lastrun;
int curidle, currun;
int forceload;
int percent;
int ntries;
lastidle = 0;
lastrun = 0;
loop:
ntries = 0;
curidle = cp_time[CP_IDLE];
currun = cp_time[CP_USER] + cp_time[CP_SYS] + cp_time[CP_NICE];
percent = (100*(currun-lastrun)) / ( 1 + (currun-lastrun) + (curidle-lastidle));
lastrun = currun;
lastidle = curidle;
if( percent > 100)
percent = 100;
percentactive = percent;
if( percentactive < 25)
forceload = 1;
else
forceload = 0;
loop1:
pp = NULL;
ppri = INT_MIN;
for (p = (struct proc *)allproc; p != NULL; p = p->p_next) {
if (p->p_stat == SRUN && (p->p_flag & P_INMEM) == 0) {
int mempri;
pri = p->p_swtime + p->p_slptime - p->p_nice * 8;
mempri = pri > 0 ? pri : 0;
/*
* if this process is higher priority and there is
* enough space, then select this process instead
* of the previous selection.
*/
if (pri > ppri &&
(((cnt.v_free_count + (mempri * (4*PAGE_SIZE) / PAGE_SIZE) >= (p->p_vmspace->vm_swrss)) || (ntries > 0 && forceload)))) {
pp = p;
ppri = pri;
}
}
}
if ((pp == NULL) && (ntries == 0) && forceload) {
++ntries;
goto loop1;
}
/*
* Nothing to do, back to sleep
*/
if ((p = pp) == NULL) {
tsleep((caddr_t)&proc0, PVM, "sched", 0);
goto loop;
}
/*
* We would like to bring someone in. (only if there is space).
*/
/*
printf("swapin: %d, free: %d, res: %d, min: %d\n",
p->p_pid, cnt.v_free_count, cnt.v_free_reserved, cnt.v_free_min);
*/
(void) splhigh();
if ((forceload && (cnt.v_free_count > (cnt.v_free_reserved + UPAGES + 1))) ||
(cnt.v_free_count >= cnt.v_free_min)) {
spl0();
faultin(p);
p->p_swtime = 0;
goto loop;
}
/*
* log the memory shortage
*/
swapinreq += p->p_vmspace->vm_swrss;
/*
* Not enough memory, jab the pageout daemon and wait til the
* coast is clear.
*/
if( cnt.v_free_count < cnt.v_free_min) {
VM_WAIT;
} else {
tsleep((caddr_t)&proc0, PVM, "sched", 0);
}
(void) spl0();
goto loop;
}
#define swappable(p) \
(((p)->p_lock == 0) && \
((p)->p_flag & (P_TRACED|P_NOSWAP|P_SYSTEM|P_INMEM|P_WEXIT|P_PHYSIO)) == P_INMEM)
extern int vm_pageout_free_min;
/*
* 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_threads()
{
register struct proc *p;
struct proc *outp, *outp2;
int outpri, outpri2;
int tpri;
int didswap = 0;
int swapneeded = swapinreq;
extern int maxslp;
int runnablenow;
int s;
swapmore:
runnablenow = 0;
outp = outp2 = NULL;
outpri = outpri2 = INT_MIN;
for (p = (struct proc *)allproc; p != NULL; p = p->p_next) {
if (!swappable(p))
continue;
switch (p->p_stat) {
case SRUN:
++runnablenow;
/*
* count the process as being in a runnable state
*/
if ((tpri = p->p_swtime + p->p_nice * 8) > outpri2) {
outp2 = p;
outpri2 = tpri;
}
continue;
case SSLEEP:
case SSTOP:
/*
* do not swapout a process that is waiting for VM datastructures
* there is a possible deadlock.
*/
if (!lock_try_write( &p->p_vmspace->vm_map.lock)) {
continue;
}
vm_map_unlock( &p->p_vmspace->vm_map);
if (p->p_slptime > maxslp) {
swapout(p);
didswap++;
} else if ((tpri = p->p_slptime + p->p_nice * 8) > outpri) {
outp = p;
outpri = tpri ;
}
continue;
}
}
/*
* We swapout only if there are more than two runnable processes or if
* another process needs some space to swapin.
*/
if ((swapinreq || ((percentactive > 90) && (runnablenow > 2))) &&
(((cnt.v_free_count + cnt.v_inactive_count) <= (cnt.v_free_target + cnt.v_inactive_target)) ||
(cnt.v_free_count < cnt.v_free_min))) {
if ((p = outp) == 0) {
p = outp2;
}
if (p) {
swapout(p);
didswap = 1;
}
}
/*
* if we previously had found a process to swapout, and we need to swapout
* more then try again.
*/
#if 0
if( p && swapinreq)
goto swapmore;
#endif
/*
* If we swapped something out, and another process needed memory,
* then wakeup the sched process.
*/
if (didswap) {
if (swapneeded)
wakeup((caddr_t)&proc0);
swapinreq = 0;
}
}
void
swapout(p)
register struct proc *p;
{
vm_offset_t addr;
struct pmap *pmap = &p->p_vmspace->vm_pmap;
vm_map_t map = &p->p_vmspace->vm_map;
vm_offset_t ptaddr;
int i;
++p->p_stats->p_ru.ru_nswap;
/*
* remember the process resident count
*/
p->p_vmspace->vm_swrss =
p->p_vmspace->vm_pmap.pm_stats.resident_count;
/*
* and decrement the amount of needed space
*/
swapinreq -= min(swapinreq, p->p_vmspace->vm_pmap.pm_stats.resident_count);
(void) splhigh();
p->p_flag &= ~P_INMEM;
if (p->p_stat == SRUN)
remrq(p);
(void) spl0();
++p->p_lock;
/* let the upages be paged */
pmap_remove(vm_map_pmap(kernel_map),
(vm_offset_t) p->p_addr, ((vm_offset_t) p->p_addr) + UPAGES * NBPG);
vm_map_pageable(map, (vm_offset_t) kstack,
(vm_offset_t) kstack + UPAGES * NBPG, TRUE);
--p->p_lock;
p->p_swtime = 0;
}
/*
* The rest of these routines fake thread handling
*/
#ifndef assert_wait
void
assert_wait(event, ruptible)
int event;
boolean_t ruptible;
{
#ifdef lint
ruptible++;
#endif
curproc->p_thread = event;
}
#endif
void
thread_block(char *msg)
{
if (curproc->p_thread)
tsleep((caddr_t)curproc->p_thread, PVM, msg, 0);
}
void
thread_sleep_(event, lock, wmesg)
int event;
simple_lock_t lock;
char *wmesg;
{
curproc->p_thread = event;
simple_unlock(lock);
if (curproc->p_thread) {
tsleep((caddr_t)event, PVM, wmesg, 0);
}
}
#ifndef thread_wakeup
void
thread_wakeup(event)
int event;
{
wakeup((caddr_t)event);
}
#endif
/*
* DEBUG stuff
*/
int indent = 0;
#include <machine/stdarg.h> /* see subr_prf.c */
/*ARGSUSED2*/
void
#if __STDC__
iprintf(const char *fmt, ...)
#else
iprintf(fmt /* , va_alist */)
char *fmt;
/* va_dcl */
#endif
{
register int i;
va_list ap;
for (i = indent; i >= 8; i -= 8)
printf("\t");
while (--i >= 0)
printf(" ");
va_start(ap, fmt);
printf("%r", fmt, ap);
va_end(ap);
}