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Diffstat (limited to 'sys/vm/vm_glue.c')
| -rw-r--r-- | sys/vm/vm_glue.c | 611 |
1 files changed, 611 insertions, 0 deletions
diff --git a/sys/vm/vm_glue.c b/sys/vm/vm_glue.c new file mode 100644 index 00000000000..d5c22223ad2 --- /dev/null +++ b/sys/vm/vm_glue.c @@ -0,0 +1,611 @@ +/* $NetBSD: vm_glue.c,v 1.47 1995/08/13 09:04:47 mycroft Exp $ */ + +/* + * 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. + * + * @(#)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. + */ + +#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 <vm/vm.h> +#include <vm/vm_page.h> +#include <vm/vm_kern.h> + +#include <machine/cpu.h> + +int avefree = 0; /* XXX */ +unsigned maxdmap = MAXDSIZ; /* XXX */ +unsigned maxsmap = MAXSSIZ; /* XXX */ +int readbuffers = 0; /* XXX allow kgdb to read kernel buffer pool */ + +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); + /* + * XXX there are still some things (e.g. the buffer cache) that + * are managed behind the VM system's back so even though an + * address is accessible in the mind of the VM system, there may + * not be physical pages where the VM thinks there is. This can + * lead to bogus allocation of pages in the kernel address space + * or worse, inconsistencies at the pmap level. We only worry + * about the buffer cache for now. + */ + if (!readbuffers && rv && (eaddr > (vm_offset_t)buffers && + saddr < (vm_offset_t)buffers + MAXBSIZE * nbuf)) + rv = FALSE; + 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; + +#if defined(i386) || defined(pc532) + /* + * XXX - specially disallow access to user page tables - they are + * in the map. This is here until i386 & pc532 pmaps are fixed... + */ + if ((vm_offset_t) addr >= VM_MAXUSER_ADDRESS + || (vm_offset_t) addr + len > VM_MAXUSER_ADDRESS + || (vm_offset_t) addr + len <= (vm_offset_t) addr) + return (FALSE); +#endif + + 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). + * + * We force the protection change at the pmap level. If we were + * to use vm_map_protect a change to allow writing would be lazily- + * applied meaning we would still take a protection fault, something + * we really don't want to do. It would also fragment the kernel + * map unnecessarily. We cannot use pmap_protect since it also won't + * enforce a write-enable request. Using pmap_enter is the only way + * we can ensure the change takes place properly. + */ +void +chgkprot(addr, len, rw) + register caddr_t addr; + int len, rw; +{ + vm_prot_t prot; + vm_offset_t pa, sva, eva; + + prot = rw == B_READ ? VM_PROT_READ : VM_PROT_READ|VM_PROT_WRITE; + eva = round_page(addr + len); + for (sva = trunc_page(addr); sva < eva; sva += PAGE_SIZE) { + /* + * Extract physical address for the page. + * We use a cheezy hack to differentiate physical + * page 0 from an invalid mapping, not that it + * really matters... + */ + pa = pmap_extract(pmap_kernel(), sva|1); + if (pa == 0) + panic("chgkprot: invalid page"); + pmap_enter(pmap_kernel(), sva, pa&~1, prot, TRUE); + } +} +#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 + 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; + +#if defined(i386) || defined(pc532) + /* + * 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, + VM_MAXUSER_ADDRESS, VM_MAX_ADDRESS, VM_INHERIT_NONE); +#endif + p2->p_vmspace = vmspace_fork(p1->p_vmspace); + +#ifdef SYSVSHM + if (p1->p_vmspace->vm_shm) + shmfork(p1, p2, isvfork); +#endif + +#if !defined(i386) && !defined(pc532) + /* + * Allocate a wired-down (for now) pcb and kernel stack for the process + */ + addr = kmem_alloc_pageable(kernel_map, USPACE); + if (addr == 0) + panic("vm_fork: no more kernel virtual memory"); + vm_map_pageable(kernel_map, addr, addr + USPACE, FALSE); +#else + /* + * XXX somehow, on 386, ocassionally pageout removes active, wired down + * kstack and pagetables, WITHOUT going thru vm_page_unwire! Why this + * appears to work is not yet clear, yet it does... + */ + addr = kmem_alloc(kernel_map, USPACE); + if (addr == 0) + panic("vm_fork: no more kernel virtual memory"); +#endif + up = (struct user *)addr; + 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)); + +#if defined(i386) || defined(pc532) + { vm_offset_t addr = VM_MAXUSER_ADDRESS; struct vm_map *vp; + + /* ream out old pagetables and kernel stack */ + vp = &p2->p_vmspace->vm_map; + (void)vm_deallocate(vp, addr, VM_MAX_ADDRESS - addr); + (void)vm_allocate(vp, &addr, VM_MAX_ADDRESS - addr, FALSE); + (void)vm_map_inherit(vp, addr, VM_MAX_ADDRESS, VM_INHERIT_NONE); + } +#endif + /* + * 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; +{ + + /* + * Set up the initial limits on process VM. + * Set the maximum resident set size to be all + * of (reasonably) available memory. This causes + * any single, large process to start random page + * replacement once it fills memory. + */ + 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; + p->p_rlimit[RLIMIT_RSS].rlim_cur = ptoa(cnt.v_free_count); +} + +#include <vm/vm_pageout.h> + +#ifdef DEBUG +int enableswap = 1; +int swapdebug = 0; +#define SDB_FOLLOW 1 +#define SDB_SWAPIN 2 +#define SDB_SWAPOUT 4 +#endif + +/* + * Swap in a process's u-area. + */ +void +swapin(p) + struct proc *p; +{ + vm_offset_t addr; + int s; + + addr = (vm_offset_t)p->p_addr; + vm_map_pageable(kernel_map, addr, addr + USPACE, FALSE); + /* + * Some architectures need to be notified when the + * user area has moved to new physical page(s) (e.g. + * see pmax/pmax/vm_machdep.c). + */ + cpu_swapin(p); + s = splstatclock(); + if (p->p_stat == SRUN) + setrunqueue(p); + p->p_flag |= P_INMEM; + splx(s); + p->p_swtime = 0; +} + +/* + * Brutally simple: + * 1. Attempt to swapin every swaped-out, runnable process in + * order of priority. + * 2. If not enough memory, wake the pageout daemon and let it + * clear some space. + */ +void +scheduler() +{ + register struct proc *p; + register int pri; + struct proc *pp; + int ppri; + +loop: +#ifdef DEBUG + while (!enableswap) + tsleep((caddr_t)&proc0, PVM, "noswap", 0); +#endif + 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) == 0) { + pri = p->p_swtime + p->p_slptime - p->p_nice * 8; + if (pri > ppri) { + pp = p; + ppri = pri; + } + } + } +#ifdef DEBUG + if (swapdebug & SDB_FOLLOW) + printf("scheduler: running, procp %x pri %d\n", pp, ppri); +#endif + /* + * Nothing to do, back to sleep + */ + if ((p = pp) == NULL) { + tsleep((caddr_t)&proc0, PVM, "scheduler", 0); + goto loop; + } + + /* + * We would like to bring someone in. + * This part is really bogus cuz we could deadlock on memory + * despite our feeble check. + */ + if (cnt.v_free_count > atop(USPACE)) { +#ifdef DEBUG + if (swapdebug & SDB_SWAPIN) + printf("swapin: pid %d(%s)@%x, pri %d free %d\n", + p->p_pid, p->p_comm, p->p_addr, + ppri, cnt.v_free_count); +#endif + swapin(p); + goto loop; + } + /* + * Not enough memory, jab the pageout daemon and wait til the + * coast is clear. + */ +#ifdef DEBUG + if (swapdebug & SDB_FOLLOW) + printf("scheduler: no room for pid %d(%s), free %d\n", + p->p_pid, p->p_comm, cnt.v_free_count); +#endif + (void) splhigh(); + VM_WAIT; + (void) spl0(); +#ifdef DEBUG + if (swapdebug & SDB_FOLLOW) + printf("scheduler: room again, free %d\n", cnt.v_free_count); +#endif + goto loop; +} + +#define swappable(p) \ + (((p)->p_flag & (P_SYSTEM | P_INMEM | P_WEXIT)) == P_INMEM && \ + (p)->p_holdcnt == 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_threads() +{ + register struct proc *p; + struct proc *outp, *outp2; + int outpri, outpri2; + int didswap = 0; + extern int maxslp; + +#ifdef DEBUG + if (!enableswap) + return; +#endif + outp = outp2 = NULL; + outpri = outpri2 = 0; + for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { + if (!swappable(p)) + continue; + switch (p->p_stat) { + case SRUN: + if (p->p_swtime > outpri2) { + outp2 = p; + outpri2 = p->p_swtime; + } + continue; + + case SSLEEP: + case SSTOP: + if (p->p_slptime >= maxslp) { + swapout(p); + 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 && + cnt.v_free_count <= atop(round_page(USPACE))) { + if ((p = outp) == 0) + p = outp2; +#ifdef DEBUG + if (swapdebug & SDB_SWAPOUT) + printf("swapout_threads: no duds, try procp %x\n", p); +#endif + if (p) + swapout(p); + } +} + +void +swapout(p) + register struct proc *p; +{ + vm_offset_t addr; + vm_size_t size; + +#ifdef DEBUG + if (swapdebug & SDB_SWAPOUT) + printf("swapout: pid %d(%s)@%x, stat %x pri %d free %d\n", + p->p_pid, p->p_comm, p->p_addr, p->p_stat, + p->p_slptime, cnt.v_free_count); +#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; + size = round_page(USPACE); + vm_map_pageable(kernel_map, addr, addr+size, TRUE); + pmap_collect(vm_map_pmap(&p->p_vmspace->vm_map)); + + /* + * Mark it as (potentially) swapped out. + */ + (void) splhigh(); + p->p_flag &= ~P_INMEM; + if (p->p_stat == SRUN) + remrq(p); + (void) spl0(); + p->p_swtime = 0; +} + +/* + * The rest of these routines fake thread handling + */ + +void +assert_wait(event, ruptible) + void *event; + boolean_t ruptible; +{ +#ifdef lint + ruptible++; +#endif + curproc->p_thread = event; +} + +void +thread_block() +{ + int s = splhigh(); + + if (curproc->p_thread) + tsleep(curproc->p_thread, PVM, "thrd_block", 0); + splx(s); +} + +void +thread_sleep(event, lock, ruptible) + void *event; + simple_lock_t lock; + boolean_t ruptible; +{ + int s = splhigh(); + +#ifdef lint + ruptible++; +#endif + curproc->p_thread = event; + simple_unlock(lock); + if (curproc->p_thread) + tsleep(event, PVM, "thrd_sleep", 0); + splx(s); +} + +void +thread_wakeup(event) + void *event; +{ + int s = splhigh(); + + wakeup(event); + splx(s); +} + +/* + * DEBUG stuff + */ + +int indent = 0; + +#include <machine/stdarg.h> /* see subr_prf.c */ + +/*ARGSUSED2*/ +void +#if __STDC__ +iprintf(void (*pr)(const char *, ...), const char *fmt, ...) +#else +iprintf(pr, fmt /* , va_alist */) + void (*pr)(); + char *fmt; + /* va_dcl */ +#endif +{ + register int i; + va_list ap; + + for (i = indent; i >= 8; i -= 8) + (*pr)("\t"); + while (--i >= 0) + (*pr)(" "); + va_start(ap, fmt); + (*pr)("%r", fmt, ap); + va_end(ap); +} |