1 /* 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * The Mach Operating System project at Carnegie-Mellon University. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: @(#)vm_glue.c 8.6 (Berkeley) 1/5/94 37 * 38 * 39 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 40 * All rights reserved. 41 * 42 * Permission to use, copy, modify and distribute this software and 43 * its documentation is hereby granted, provided that both the copyright 44 * notice and this permission notice appear in all copies of the 45 * software, derivative works or modified versions, and any portions 46 * thereof, and that both notices appear in supporting documentation. 47 * 48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 51 * 52 * Carnegie Mellon requests users of this software to return to 53 * 54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 55 * School of Computer Science 56 * Carnegie Mellon University 57 * Pittsburgh PA 15213-3890 58 * 59 * any improvements or extensions that they make and grant Carnegie the 60 * rights to redistribute these changes. 61 * 62 * $Id: vm_glue.c,v 1.50 1996/05/31 00:37:57 dyson Exp $ 63 */ 64 65 #include "opt_ddb.h" 66 67 #include <sys/param.h> 68 #include <sys/systm.h> 69 #include <sys/proc.h> 70 #include <sys/resourcevar.h> 71 #include <sys/buf.h> 72 #include <sys/shm.h> 73 #include <sys/vmmeter.h> 74 75 #include <sys/kernel.h> 76 #include <sys/dkstat.h> 77 78 #include <vm/vm.h> 79 #include <vm/vm_param.h> 80 #include <vm/vm_inherit.h> 81 #include <vm/vm_prot.h> 82 #include <vm/lock.h> 83 #include <vm/pmap.h> 84 #include <vm/vm_map.h> 85 #include <vm/vm_page.h> 86 #include <vm/vm_pageout.h> 87 #include <vm/vm_kern.h> 88 #include <vm/vm_extern.h> 89 #include <vm/vm_object.h> 90 #include <vm/vm_pager.h> 91 92 #include <sys/user.h> 93 94 #include <machine/stdarg.h> 95 96 /* 97 * System initialization 98 * 99 * Note: proc0 from proc.h 100 */ 101 102 static void vm_init_limits __P((void *)); 103 SYSINIT(vm_limits, SI_SUB_VM_CONF, SI_ORDER_FIRST, vm_init_limits, &proc0) 104 105 /* 106 * THIS MUST BE THE LAST INITIALIZATION ITEM!!! 107 * 108 * Note: run scheduling should be divorced from the vm system. 109 */ 110 static void scheduler __P((void *)); 111 SYSINIT(scheduler, SI_SUB_RUN_SCHEDULER, SI_ORDER_FIRST, scheduler, NULL) 112 113 114 static void swapout __P((struct proc *)); 115 116 extern char kstack[]; 117 118 /* vm_map_t upages_map; */ 119 120 int 121 kernacc(addr, len, rw) 122 caddr_t addr; 123 int len, rw; 124 { 125 boolean_t rv; 126 vm_offset_t saddr, eaddr; 127 vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE; 128 129 saddr = trunc_page(addr); 130 eaddr = round_page(addr + len); 131 rv = vm_map_check_protection(kernel_map, saddr, eaddr, prot); 132 return (rv == TRUE); 133 } 134 135 int 136 useracc(addr, len, rw) 137 caddr_t addr; 138 int len, rw; 139 { 140 boolean_t rv; 141 vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE; 142 143 /* 144 * XXX - check separately to disallow access to user area and user 145 * page tables - they are in the map. 146 * 147 * XXX - VM_MAXUSER_ADDRESS is an end address, not a max. It was once 148 * only used (as an end address) in trap.c. Use it as an end address 149 * here too. This bogusness has spread. I just fixed where it was 150 * used as a max in vm_mmap.c. 151 */ 152 if ((vm_offset_t) addr + len > /* XXX */ VM_MAXUSER_ADDRESS 153 || (vm_offset_t) addr + len < (vm_offset_t) addr) { 154 return (FALSE); 155 } 156 rv = vm_map_check_protection(&curproc->p_vmspace->vm_map, 157 trunc_page(addr), round_page(addr + len), prot); 158 return (rv == TRUE); 159 } 160 161 void 162 vslock(addr, len) 163 caddr_t addr; 164 u_int len; 165 { 166 vm_map_pageable(&curproc->p_vmspace->vm_map, trunc_page(addr), 167 round_page(addr + len), FALSE); 168 } 169 170 void 171 vsunlock(addr, len, dirtied) 172 caddr_t addr; 173 u_int len; 174 int dirtied; 175 { 176 #ifdef lint 177 dirtied++; 178 #endif /* lint */ 179 vm_map_pageable(&curproc->p_vmspace->vm_map, trunc_page(addr), 180 round_page(addr + len), TRUE); 181 } 182 183 /* 184 * Implement fork's actions on an address space. 185 * Here we arrange for the address space to be copied or referenced, 186 * allocate a user struct (pcb and kernel stack), then call the 187 * machine-dependent layer to fill those in and make the new process 188 * ready to run. 189 * NOTE: the kernel stack may be at a different location in the child 190 * process, and thus addresses of automatic variables may be invalid 191 * after cpu_fork returns in the child process. We do nothing here 192 * after cpu_fork returns. 193 */ 194 int 195 vm_fork(p1, p2) 196 register struct proc *p1, *p2; 197 { 198 register struct user *up; 199 int i; 200 pmap_t pvp; 201 vm_object_t upobj; 202 203 while ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_free_min) { 204 VM_WAIT; 205 } 206 207 p2->p_vmspace = vmspace_fork(p1->p_vmspace); 208 209 if (p1->p_vmspace->vm_shm) 210 shmfork(p1, p2); 211 212 /* 213 * Allocate a wired-down (for now) pcb and kernel stack for the 214 * process 215 */ 216 217 pvp = &p2->p_vmspace->vm_pmap; 218 219 /* 220 * allocate object for the upages 221 */ 222 p2->p_vmspace->vm_upages_obj = upobj = vm_object_allocate( OBJT_DEFAULT, 223 UPAGES); 224 225 /* get a kernel virtual address for the UPAGES for this proc */ 226 up = (struct user *) kmem_alloc_pageable(u_map, UPAGES * PAGE_SIZE); 227 if (up == NULL) 228 panic("vm_fork: u_map allocation failed"); 229 230 for(i=0;i<UPAGES;i++) { 231 vm_page_t m; 232 233 /* 234 * Get a kernel stack page 235 */ 236 while ((m = vm_page_alloc(upobj, 237 i, VM_ALLOC_NORMAL)) == NULL) { 238 VM_WAIT; 239 } 240 241 /* 242 * Wire the page 243 */ 244 vm_page_wire(m); 245 PAGE_WAKEUP(m); 246 247 /* 248 * Enter the page into both the kernel and the process 249 * address space. 250 */ 251 pmap_enter( pvp, (vm_offset_t) kstack + i * PAGE_SIZE, 252 VM_PAGE_TO_PHYS(m), VM_PROT_READ|VM_PROT_WRITE, TRUE); 253 pmap_kenter(((vm_offset_t) up) + i * PAGE_SIZE, 254 VM_PAGE_TO_PHYS(m)); 255 m->flags &= ~PG_ZERO; 256 m->flags |= PG_MAPPED; 257 m->valid = VM_PAGE_BITS_ALL; 258 } 259 260 p2->p_addr = up; 261 262 /* 263 * p_stats and p_sigacts currently point at fields in the user struct 264 * but not at &u, instead at p_addr. Copy p_sigacts and parts of 265 * p_stats; zero the rest of p_stats (statistics). 266 */ 267 p2->p_stats = &up->u_stats; 268 p2->p_sigacts = &up->u_sigacts; 269 up->u_sigacts = *p1->p_sigacts; 270 bzero(&up->u_stats.pstat_startzero, 271 (unsigned) ((caddr_t) &up->u_stats.pstat_endzero - 272 (caddr_t) &up->u_stats.pstat_startzero)); 273 bcopy(&p1->p_stats->pstat_startcopy, &up->u_stats.pstat_startcopy, 274 ((caddr_t) &up->u_stats.pstat_endcopy - 275 (caddr_t) &up->u_stats.pstat_startcopy)); 276 277 278 /* 279 * cpu_fork will copy and update the kernel stack and pcb, and make 280 * the child ready to run. It marks the child so that it can return 281 * differently than the parent. It returns twice, once in the parent 282 * process and once in the child. 283 */ 284 return (cpu_fork(p1, p2)); 285 } 286 287 /* 288 * Set default limits for VM system. 289 * Called for proc 0, and then inherited by all others. 290 * 291 * XXX should probably act directly on proc0. 292 */ 293 static void 294 vm_init_limits(udata) 295 void *udata; 296 { 297 register struct proc *p = udata; 298 int rss_limit; 299 300 /* 301 * Set up the initial limits on process VM. Set the maximum resident 302 * set size to be half of (reasonably) available memory. Since this 303 * is a soft limit, it comes into effect only when the system is out 304 * of memory - half of main memory helps to favor smaller processes, 305 * and reduces thrashing of the object cache. 306 */ 307 p->p_rlimit[RLIMIT_STACK].rlim_cur = DFLSSIZ; 308 p->p_rlimit[RLIMIT_STACK].rlim_max = MAXSSIZ; 309 p->p_rlimit[RLIMIT_DATA].rlim_cur = DFLDSIZ; 310 p->p_rlimit[RLIMIT_DATA].rlim_max = MAXDSIZ; 311 /* limit the limit to no less than 2MB */ 312 rss_limit = max(cnt.v_free_count, 512); 313 p->p_rlimit[RLIMIT_RSS].rlim_cur = ptoa(rss_limit); 314 p->p_rlimit[RLIMIT_RSS].rlim_max = RLIM_INFINITY; 315 } 316 317 void 318 faultin(p) 319 struct proc *p; 320 { 321 vm_offset_t i; 322 int s; 323 324 if ((p->p_flag & P_INMEM) == 0) { 325 pmap_t pmap = &p->p_vmspace->vm_pmap; 326 vm_page_t m; 327 vm_object_t upobj = p->p_vmspace->vm_upages_obj; 328 329 ++p->p_lock; 330 #if defined(SWAP_DEBUG) 331 printf("swapping in %d\n", p->p_pid); 332 #endif 333 334 for(i=0;i<UPAGES;i++) { 335 int s; 336 s = splvm(); 337 retry: 338 if ((m = vm_page_lookup(upobj, i)) == NULL) { 339 if ((m = vm_page_alloc(upobj, i, VM_ALLOC_NORMAL)) == NULL) { 340 VM_WAIT; 341 goto retry; 342 } 343 } else { 344 if ((m->flags & PG_BUSY) || m->busy) { 345 m->flags |= PG_WANTED; 346 tsleep(m, PVM, "swinuw",0); 347 goto retry; 348 } 349 m->flags |= PG_BUSY; 350 } 351 vm_page_wire(m); 352 splx(s); 353 354 pmap_enter( pmap, (vm_offset_t) kstack + i * PAGE_SIZE, 355 VM_PAGE_TO_PHYS(m), VM_PROT_READ|VM_PROT_WRITE, TRUE); 356 pmap_kenter(((vm_offset_t) p->p_addr) + i * PAGE_SIZE, 357 VM_PAGE_TO_PHYS(m)); 358 if (m->valid != VM_PAGE_BITS_ALL) { 359 int rv; 360 rv = vm_pager_get_pages(upobj, 361 &m, 1, 0); 362 if (rv != VM_PAGER_OK) 363 panic("faultin: cannot get upages for proc: %d\n", p->p_pid); 364 m->valid = VM_PAGE_BITS_ALL; 365 } 366 PAGE_WAKEUP(m); 367 m->flags |= PG_MAPPED; 368 } 369 370 s = splhigh(); 371 372 if (p->p_stat == SRUN) 373 setrunqueue(p); 374 375 p->p_flag |= P_INMEM; 376 377 /* undo the effect of setting SLOCK above */ 378 --p->p_lock; 379 splx(s); 380 381 } 382 } 383 384 /* 385 * This swapin algorithm attempts to swap-in processes only if there 386 * is enough space for them. Of course, if a process waits for a long 387 * time, it will be swapped in anyway. 388 */ 389 /* ARGSUSED*/ 390 static void 391 scheduler(dummy) 392 void *dummy; 393 { 394 register struct proc *p; 395 register int pri; 396 struct proc *pp; 397 int ppri; 398 399 spl0(); 400 loop: 401 while ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_free_min) { 402 VM_WAIT; 403 } 404 405 pp = NULL; 406 ppri = INT_MIN; 407 for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { 408 if (p->p_stat == SRUN && 409 (p->p_flag & (P_INMEM | P_SWAPPING)) == 0) { 410 int mempri; 411 412 pri = p->p_swtime + p->p_slptime - p->p_nice * 8; 413 mempri = pri > 0 ? pri : 0; 414 /* 415 * if this process is higher priority and there is 416 * enough space, then select this process instead of 417 * the previous selection. 418 */ 419 if (pri > ppri) { 420 pp = p; 421 ppri = pri; 422 } 423 } 424 } 425 426 /* 427 * Nothing to do, back to sleep 428 */ 429 if ((p = pp) == NULL) { 430 tsleep(&proc0, PVM, "sched", 0); 431 goto loop; 432 } 433 /* 434 * We would like to bring someone in. (only if there is space). 435 */ 436 faultin(p); 437 p->p_swtime = 0; 438 goto loop; 439 } 440 441 #ifndef NO_SWAPPING 442 443 #define swappable(p) \ 444 (((p)->p_lock == 0) && \ 445 ((p)->p_flag & (P_TRACED|P_NOSWAP|P_SYSTEM|P_INMEM|P_WEXIT|P_PHYSIO|P_SWAPPING)) == P_INMEM) 446 447 /* 448 * Swapout is driven by the pageout daemon. Very simple, we find eligible 449 * procs and unwire their u-areas. We try to always "swap" at least one 450 * process in case we need the room for a swapin. 451 * If any procs have been sleeping/stopped for at least maxslp seconds, 452 * they are swapped. Else, we swap the longest-sleeping or stopped process, 453 * if any, otherwise the longest-resident process. 454 */ 455 void 456 swapout_procs() 457 { 458 register struct proc *p; 459 struct proc *outp, *outp2; 460 int outpri, outpri2; 461 int didswap = 0; 462 463 outp = outp2 = NULL; 464 outpri = outpri2 = INT_MIN; 465 retry: 466 for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { 467 struct vmspace *vm; 468 if (!swappable(p)) 469 continue; 470 471 vm = p->p_vmspace; 472 473 switch (p->p_stat) { 474 default: 475 continue; 476 477 case SSLEEP: 478 case SSTOP: 479 /* 480 * do not swapout a realtime process 481 */ 482 if (p->p_rtprio.type == RTP_PRIO_REALTIME) 483 continue; 484 485 /* 486 * do not swapout a process waiting on a critical 487 * event of some kind 488 */ 489 if (((p->p_priority & 0x7f) < PSOCK) || 490 (p->p_slptime <= 10)) 491 continue; 492 493 ++vm->vm_refcnt; 494 vm_map_reference(&vm->vm_map); 495 /* 496 * do not swapout a process that is waiting for VM 497 * datastructures there is a possible deadlock. 498 */ 499 if (!lock_try_write(&vm->vm_map.lock)) { 500 vm_map_deallocate(&vm->vm_map); 501 vmspace_free(vm); 502 continue; 503 } 504 vm_map_unlock(&vm->vm_map); 505 /* 506 * If the process has been asleep for awhile and had 507 * most of its pages taken away already, swap it out. 508 */ 509 swapout(p); 510 vm_map_deallocate(&vm->vm_map); 511 vmspace_free(vm); 512 didswap++; 513 goto retry; 514 } 515 } 516 /* 517 * If we swapped something out, and another process needed memory, 518 * then wakeup the sched process. 519 */ 520 if (didswap) 521 wakeup(&proc0); 522 } 523 524 static void 525 swapout(p) 526 register struct proc *p; 527 { 528 pmap_t pmap = &p->p_vmspace->vm_pmap; 529 int i; 530 531 #if defined(SWAP_DEBUG) 532 printf("swapping out %d\n", p->p_pid); 533 #endif 534 ++p->p_stats->p_ru.ru_nswap; 535 /* 536 * remember the process resident count 537 */ 538 p->p_vmspace->vm_swrss = 539 p->p_vmspace->vm_pmap.pm_stats.resident_count; 540 541 (void) splhigh(); 542 p->p_flag &= ~P_INMEM; 543 p->p_flag |= P_SWAPPING; 544 if (p->p_stat == SRUN) 545 remrq(p); 546 (void) spl0(); 547 548 /* 549 * let the upages be paged 550 */ 551 for(i=0;i<UPAGES;i++) { 552 vm_page_t m; 553 if ((m = vm_page_lookup(p->p_vmspace->vm_upages_obj, i)) == NULL) 554 panic("swapout: upage already missing???"); 555 m->dirty = VM_PAGE_BITS_ALL; 556 vm_page_unwire(m); 557 vm_page_deactivate(m); 558 pmap_kremove( (vm_offset_t) p->p_addr + PAGE_SIZE * i); 559 } 560 pmap_remove(pmap, (vm_offset_t) kstack, 561 (vm_offset_t) kstack + PAGE_SIZE * UPAGES); 562 563 p->p_flag &= ~P_SWAPPING; 564 p->p_swtime = 0; 565 } 566 #endif /* !NO_SWAPPING */ 567 568 #ifdef DDB 569 /* 570 * DEBUG stuff 571 */ 572 573 int indent; 574 575 #include <machine/stdarg.h> /* see subr_prf.c */ 576 577 /*ARGSUSED2*/ 578 void 579 #if __STDC__ 580 iprintf(const char *fmt,...) 581 #else 582 iprintf(fmt /* , va_alist */ ) 583 char *fmt; 584 585 /* va_dcl */ 586 #endif 587 { 588 register int i; 589 va_list ap; 590 591 for (i = indent; i >= 8; i -= 8) 592 printf("\t"); 593 while (--i >= 0) 594 printf(" "); 595 va_start(ap, fmt); 596 vprintf(fmt, ap); 597 va_end(ap); 598 } 599 #endif /* DDB */ 600