From: William F. Jolitz Date: Mon, 24 Feb 1992 20:46:28 +0000 (-0800) Subject: 386BSD 0.0 development X-Git-Tag: 386BSD-0.0~129 X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/commitdiff_plain/26d44e35505a486a0223c8759747e1436d18a134 386BSD 0.0 development Work on file usr/src/sys.386bsd/vm/vm_glue.c Co-Authored-By: Lynne Greer Jolitz Synthesized-from: 386BSD-0.0/src --- diff --git a/usr/src/sys.386bsd/vm/vm_glue.c b/usr/src/sys.386bsd/vm/vm_glue.c new file mode 100644 index 0000000000..c6fb9d31f0 --- /dev/null +++ b/usr/src/sys.386bsd/vm/vm_glue.c @@ -0,0 +1,540 @@ +/* + * Copyright (c) 1991 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 7.8 (Berkeley) 5/15/91 + * + * + * 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. + */ +static char rcsid[] = "$Header: /usr/bill/working/sys/vm/RCS/vm_glue.c,v 1.2 92/01/21 21:58:21 william Exp $"; + +#include "param.h" +#include "systm.h" +#include "proc.h" +#include "resourcevar.h" +#include "buf.h" +#include "user.h" + +#include "vm.h" +#include "vm_page.h" +#include "vm_kern.h" + +int avefree = 0; /* XXX */ +unsigned maxdmap = MAXDSIZ; /* XXX */ +int readbuffers = 0; /* XXX allow kgdb to read kernel buffer pool */ + +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-1); + 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); +} + +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; + + rv = vm_map_check_protection(&curproc->p_vmspace->vm_map, + trunc_page(addr), round_page(addr+len-1), 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-1), prot, FALSE); +} +#endif + +vslock(addr, len) + caddr_t addr; + u_int len; +{ + vm_map_pageable(&curproc->p_vmspace->vm_map, trunc_page(addr), + round_page(addr+len-1), FALSE); +} + +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-1), 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. + */ +vm_fork(p1, p2, isvfork) + register struct proc *p1, *p2; + int isvfork; +{ + register struct user *up; + vm_offset_t addr; + +#ifdef i386 + /* + * 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); +#endif + 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 + */ +#ifdef notyet + addr = kmem_alloc_pageable(kernel_map, ctob(UPAGES)); + vm_map_pageable(kernel_map, addr, addr + ctob(UPAGES), FALSE); +#else + addr = kmem_alloc(kernel_map, ctob(UPAGES)); +#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)); + +#ifdef i386 + { u_int addr = UPT_MIN_ADDRESS - UPAGES*NBPG; struct vm_map *vp; + + vp = &p2->p_vmspace->vm_map; + + /* ream out old pagetables and kernel stack */ + (void)vm_deallocate(vp, addr, UPT_MAX_ADDRESS - addr); + (void)vm_allocate(vp, &addr, UPT_MAX_ADDRESS - addr, FALSE); + } +#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. + */ +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 = p->p_rlimit[RLIMIT_RSS].rlim_max = + ptoa(vm_page_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 + +/* + * 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. + */ +sched() +{ + register struct proc *p; + register int pri; + struct proc *pp; + int ppri; + vm_offset_t addr; + vm_size_t size; + +loop: +#ifdef DEBUG + if (!enableswap) { + pp = NULL; + goto noswap; + } +#endif + pp = NULL; + ppri = INT_MIN; + for (p = allproc; p != NULL; p = p->p_nxt) + if (p->p_stat == SRUN && (p->p_flag & SLOAD) == 0) { + pri = p->p_time + p->p_slptime - p->p_nice * 8; + if (pri > ppri) { + pp = p; + ppri = pri; + } + } +#ifdef DEBUG + if (swapdebug & SDB_FOLLOW) + printf("sched: running, procp %x pri %d\n", pp, ppri); +noswap: +#endif + /* + * Nothing to do, back to sleep + */ + if ((p = pp) == NULL) { + sleep((caddr_t)&proc0, PVM); + goto loop; + } + + /* + * We would like to bring someone in. + * This part is really bogus cuz we could deadlock on memory + * despite our feeble check. + */ + size = round_page(ctob(UPAGES)); + addr = (vm_offset_t) p->p_addr; + if (vm_page_free_count > atop(size)) { +#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, vm_page_free_count); +#endif + vm_map_pageable(kernel_map, addr, addr+size, FALSE); + (void) splclock(); + if (p->p_stat == SRUN) + setrq(p); + p->p_flag |= SLOAD; + (void) spl0(); + p->p_time = 0; + goto loop; + } + /* + * Not enough memory, jab the pageout daemon and wait til the + * coast is clear. + */ +#ifdef DEBUG + if (swapdebug & SDB_FOLLOW) + printf("sched: no room for pid %d(%s), free %d\n", + p->p_pid, p->p_comm, vm_page_free_count); +#endif + (void) splhigh(); + VM_WAIT; + (void) spl0(); +#ifdef DEBUG + if (swapdebug & SDB_FOLLOW) + printf("sched: room again, free %d\n", vm_page_free_count); +#endif + goto loop; +} + +#define swappable(p) \ + (((p)->p_flag & (SSYS|SLOAD|SKEEP|SWEXIT|SPHYSIO)) == SLOAD) + +/* + * 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. + */ +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; p != NULL; p = p->p_nxt) { + if (!swappable(p)) + continue; + switch (p->p_stat) { + case SRUN: + if (p->p_time > outpri2) { + outp2 = p; + outpri2 = p->p_time; + } + 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 (UPAGES pages). + */ + if (didswap == 0 && + vm_page_free_count <= atop(round_page(ctob(UPAGES)))) { + 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); + } +} + +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, vm_page_free_count); +#endif + size = round_page(ctob(UPAGES)); + addr = (vm_offset_t) p->p_addr; +#ifdef notyet +#ifdef hp300 + /* + * Ugh! u-area is double mapped to a fixed address behind the + * back of the VM system and accesses are usually through that + * address rather than the per-process address. Hence reference + * and modify information are recorded at the fixed address and + * lost at context switch time. We assume the u-struct and + * kernel stack are always accessed/modified and force it to be so. + */ + { + register int i; + volatile long tmp; + + for (i = 0; i < UPAGES; i++) { + tmp = *(long *)addr; *(long *)addr = tmp; + addr += NBPG; + } + addr = (vm_offset_t) p->p_addr; + } +#endif + vm_map_pageable(kernel_map, addr, addr+size, TRUE); + pmap_collect(vm_map_pmap(&p->p_vmspace->vm_map)); +#endif + (void) splhigh(); + p->p_flag &= ~SLOAD; + if (p->p_stat == SRUN) + remrq(p); + (void) spl0(); + p->p_time = 0; +} + +/* + * The rest of these routines fake thread handling + */ + +void +assert_wait(event, ruptible) + int event; + boolean_t ruptible; +{ +#ifdef lint + ruptible++; +#endif + curproc->p_thread = event; +} + +void +thread_block() +{ + int s = splhigh(); + + if (curproc->p_thread) + sleep((caddr_t)curproc->p_thread, PVM); + splx(s); +} + +thread_sleep(event, lock, ruptible) + int event; + simple_lock_t lock; + boolean_t ruptible; +{ +#ifdef lint + ruptible++; +#endif + int s = splhigh(); + + curproc->p_thread = event; + simple_unlock(lock); + if (curproc->p_thread) + sleep((caddr_t)event, PVM); + splx(s); +} + +thread_wakeup(event) + int event; +{ + int s = splhigh(); + + wakeup((caddr_t)event); + splx(s); +} + +/* + * DEBUG stuff + */ + +int indent = 0; + +/*ARGSUSED2*/ +iprintf(a, b, c, d, e, f, g, h) + char *a; +{ + register int i; + + i = indent; + while (i >= 8) { + printf("\t"); + i -= 8; + } + for (; i > 0; --i) + printf(" "); + printf(a, b, c, d, e, f, g, h); +}