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 1.52 1996/07/02 02:07:56 dyson Exp $ 63 */ 64 65 #include <sys/param.h> 66 #include <sys/systm.h> 67 #include <sys/proc.h> 68 #include <sys/resourcevar.h> 69 #include <sys/buf.h> 70 #include <sys/shm.h> 71 #include <sys/vmmeter.h> 72 73 #include <sys/kernel.h> 74 #include <sys/dkstat.h> 75 76 #include <vm/vm.h> 77 #include <vm/vm_param.h> 78 #include <vm/vm_inherit.h> 79 #include <vm/vm_prot.h> 80 #include <vm/lock.h> 81 #include <vm/pmap.h> 82 #include <vm/vm_map.h> 83 #include <vm/vm_page.h> 84 #include <vm/vm_pageout.h> 85 #include <vm/vm_kern.h> 86 #include <vm/vm_extern.h> 87 #include <vm/vm_object.h> 88 #include <vm/vm_pager.h> 89 90 #include <sys/user.h> 91 92 /* 93 * System initialization 94 * 95 * Note: proc0 from proc.h 96 */ 97 98 static void vm_init_limits __P((void *)); 99 SYSINIT(vm_limits, SI_SUB_VM_CONF, SI_ORDER_FIRST, vm_init_limits, &proc0) 100 101 /* 102 * THIS MUST BE THE LAST INITIALIZATION ITEM!!! 103 * 104 * Note: run scheduling should be divorced from the vm system. 105 */ 106 static void scheduler __P((void *)); 107 SYSINIT(scheduler, SI_SUB_RUN_SCHEDULER, SI_ORDER_FIRST, scheduler, NULL) 108 109 110 static void swapout __P((struct proc *)); 111 112 extern char kstack[]; 113 114 /* vm_map_t upages_map; */ 115 116 int 117 kernacc(addr, len, rw) 118 caddr_t addr; 119 int len, rw; 120 { 121 boolean_t rv; 122 vm_offset_t saddr, eaddr; 123 vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE; 124 125 saddr = trunc_page(addr); 126 eaddr = round_page(addr + len); 127 rv = vm_map_check_protection(kernel_map, saddr, eaddr, prot); 128 return (rv == TRUE); 129 } 130 131 int 132 useracc(addr, len, rw) 133 caddr_t addr; 134 int len, rw; 135 { 136 boolean_t rv; 137 vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE; 138 139 /* 140 * XXX - check separately to disallow access to user area and user 141 * page tables - they are in the map. 142 * 143 * XXX - VM_MAXUSER_ADDRESS is an end address, not a max. It was once 144 * only used (as an end address) in trap.c. Use it as an end address 145 * here too. This bogusness has spread. I just fixed where it was 146 * used as a max in vm_mmap.c. 147 */ 148 if ((vm_offset_t) addr + len > /* XXX */ VM_MAXUSER_ADDRESS 149 || (vm_offset_t) addr + len < (vm_offset_t) addr) { 150 return (FALSE); 151 } 152 rv = vm_map_check_protection(&curproc->p_vmspace->vm_map, 153 trunc_page(addr), round_page(addr + len), prot); 154 return (rv == TRUE); 155 } 156 157 void 158 vslock(addr, len) 159 caddr_t addr; 160 u_int len; 161 { 162 vm_map_pageable(&curproc->p_vmspace->vm_map, trunc_page(addr), 163 round_page(addr + len), FALSE); 164 } 165 166 void 167 vsunlock(addr, len, dirtied) 168 caddr_t addr; 169 u_int len; 170 int dirtied; 171 { 172 #ifdef lint 173 dirtied++; 174 #endif /* lint */ 175 vm_map_pageable(&curproc->p_vmspace->vm_map, trunc_page(addr), 176 round_page(addr + len), TRUE); 177 } 178 179 /* 180 * Implement fork's actions on an address space. 181 * Here we arrange for the address space to be copied or referenced, 182 * allocate a user struct (pcb and kernel stack), then call the 183 * machine-dependent layer to fill those in and make the new process 184 * ready to run. 185 * NOTE: the kernel stack may be at a different location in the child 186 * process, and thus addresses of automatic variables may be invalid 187 * after cpu_fork returns in the child process. We do nothing here 188 * after cpu_fork returns. 189 */ 190 int 191 vm_fork(p1, p2) 192 register struct proc *p1, *p2; 193 { 194 register struct user *up; 195 int i; 196 pmap_t pvp; 197 vm_object_t upobj; 198 199 while ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_free_min) { 200 VM_WAIT; 201 } 202 203 p2->p_vmspace = vmspace_fork(p1->p_vmspace); 204 205 if (p1->p_vmspace->vm_shm) 206 shmfork(p1, p2); 207 208 /* 209 * Allocate a wired-down (for now) pcb and kernel stack for the 210 * process 211 */ 212 213 pvp = &p2->p_vmspace->vm_pmap; 214 215 /* 216 * allocate object for the upages 217 */ 218 p2->p_vmspace->vm_upages_obj = upobj = vm_object_allocate( OBJT_DEFAULT, 219 UPAGES); 220 221 /* get a kernel virtual address for the UPAGES for this proc */ 222 up = (struct user *) kmem_alloc_pageable(u_map, UPAGES * PAGE_SIZE); 223 if (up == NULL) 224 panic("vm_fork: u_map allocation failed"); 225 226 for(i=0;i<UPAGES;i++) { 227 vm_page_t m; 228 229 /* 230 * Get a kernel stack page 231 */ 232 while ((m = vm_page_alloc(upobj, 233 i, VM_ALLOC_NORMAL)) == NULL) { 234 VM_WAIT; 235 } 236 237 /* 238 * Wire the page 239 */ 240 vm_page_wire(m); 241 PAGE_WAKEUP(m); 242 243 /* 244 * Enter the page into both the kernel and the process 245 * address space. 246 */ 247 pmap_enter( pvp, (vm_offset_t) kstack + i * PAGE_SIZE, 248 VM_PAGE_TO_PHYS(m), VM_PROT_READ|VM_PROT_WRITE, TRUE); 249 pmap_kenter(((vm_offset_t) up) + i * PAGE_SIZE, 250 VM_PAGE_TO_PHYS(m)); 251 m->flags &= ~PG_ZERO; 252 m->flags |= PG_MAPPED|PG_WRITEABLE; 253 m->valid = VM_PAGE_BITS_ALL; 254 } 255 256 p2->p_addr = up; 257 258 /* 259 * p_stats and p_sigacts currently point at fields in the user struct 260 * but not at &u, instead at p_addr. Copy p_sigacts and parts of 261 * p_stats; zero the rest of p_stats (statistics). 262 */ 263 p2->p_stats = &up->u_stats; 264 p2->p_sigacts = &up->u_sigacts; 265 up->u_sigacts = *p1->p_sigacts; 266 bzero(&up->u_stats.pstat_startzero, 267 (unsigned) ((caddr_t) &up->u_stats.pstat_endzero - 268 (caddr_t) &up->u_stats.pstat_startzero)); 269 bcopy(&p1->p_stats->pstat_startcopy, &up->u_stats.pstat_startcopy, 270 ((caddr_t) &up->u_stats.pstat_endcopy - 271 (caddr_t) &up->u_stats.pstat_startcopy)); 272 273 274 /* 275 * cpu_fork will copy and update the kernel stack and pcb, and make 276 * the child ready to run. It marks the child so that it can return 277 * differently than the parent. It returns twice, once in the parent 278 * process and once in the child. 279 */ 280 return (cpu_fork(p1, p2)); 281 } 282 283 /* 284 * Set default limits for VM system. 285 * Called for proc 0, and then inherited by all others. 286 * 287 * XXX should probably act directly on proc0. 288 */ 289 static void 290 vm_init_limits(udata) 291 void *udata; 292 { 293 register struct proc *p = udata; 294 int rss_limit; 295 296 /* 297 * Set up the initial limits on process VM. Set the maximum resident 298 * set size to be half of (reasonably) available memory. Since this 299 * is a soft limit, it comes into effect only when the system is out 300 * of memory - half of main memory helps to favor smaller processes, 301 * and reduces thrashing of the object cache. 302 */ 303 p->p_rlimit[RLIMIT_STACK].rlim_cur = DFLSSIZ; 304 p->p_rlimit[RLIMIT_STACK].rlim_max = MAXSSIZ; 305 p->p_rlimit[RLIMIT_DATA].rlim_cur = DFLDSIZ; 306 p->p_rlimit[RLIMIT_DATA].rlim_max = MAXDSIZ; 307 /* limit the limit to no less than 2MB */ 308 rss_limit = max(cnt.v_free_count, 512); 309 p->p_rlimit[RLIMIT_RSS].rlim_cur = ptoa(rss_limit); 310 p->p_rlimit[RLIMIT_RSS].rlim_max = RLIM_INFINITY; 311 } 312 313 void 314 faultin(p) 315 struct proc *p; 316 { 317 vm_offset_t i; 318 int s; 319 320 if ((p->p_flag & P_INMEM) == 0) { 321 pmap_t pmap = &p->p_vmspace->vm_pmap; 322 vm_page_t m; 323 vm_object_t upobj = p->p_vmspace->vm_upages_obj; 324 325 ++p->p_lock; 326 #if defined(SWAP_DEBUG) 327 printf("swapping in %d\n", p->p_pid); 328 #endif 329 330 for(i=0;i<UPAGES;i++) { 331 int s; 332 s = splvm(); 333 retry: 334 if ((m = vm_page_lookup(upobj, i)) == NULL) { 335 if ((m = vm_page_alloc(upobj, i, VM_ALLOC_NORMAL)) == NULL) { 336 VM_WAIT; 337 goto retry; 338 } 339 } else { 340 if ((m->flags & PG_BUSY) || m->busy) { 341 m->flags |= PG_WANTED; 342 tsleep(m, PVM, "swinuw",0); 343 goto retry; 344 } 345 m->flags |= PG_BUSY; 346 } 347 vm_page_wire(m); 348 splx(s); 349 350 pmap_enter( pmap, (vm_offset_t) kstack + i * PAGE_SIZE, 351 VM_PAGE_TO_PHYS(m), VM_PROT_READ|VM_PROT_WRITE, TRUE); 352 pmap_kenter(((vm_offset_t) p->p_addr) + i * PAGE_SIZE, 353 VM_PAGE_TO_PHYS(m)); 354 if (m->valid != VM_PAGE_BITS_ALL) { 355 int rv; 356 rv = vm_pager_get_pages(upobj, 357 &m, 1, 0); 358 if (rv != VM_PAGER_OK) 359 panic("faultin: cannot get upages for proc: %d\n", p->p_pid); 360 m->valid = VM_PAGE_BITS_ALL; 361 } 362 PAGE_WAKEUP(m); 363 m->flags |= PG_MAPPED|PG_WRITEABLE; 364 } 365 366 s = splhigh(); 367 368 if (p->p_stat == SRUN) 369 setrunqueue(p); 370 371 p->p_flag |= P_INMEM; 372 373 /* undo the effect of setting SLOCK above */ 374 --p->p_lock; 375 splx(s); 376 377 } 378 } 379 380 /* 381 * This swapin algorithm attempts to swap-in processes only if there 382 * is enough space for them. Of course, if a process waits for a long 383 * time, it will be swapped in anyway. 384 */ 385 /* ARGSUSED*/ 386 static void 387 scheduler(dummy) 388 void *dummy; 389 { 390 register struct proc *p; 391 register int pri; 392 struct proc *pp; 393 int ppri; 394 395 spl0(); 396 loop: 397 while ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_free_min) { 398 VM_WAIT; 399 } 400 401 pp = NULL; 402 ppri = INT_MIN; 403 for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { 404 if (p->p_stat == SRUN && 405 (p->p_flag & (P_INMEM | P_SWAPPING)) == 0) { 406 int mempri; 407 408 pri = p->p_swtime + p->p_slptime - p->p_nice * 8; 409 mempri = pri > 0 ? pri : 0; 410 /* 411 * if this process is higher priority and there is 412 * enough space, then select this process instead of 413 * the previous selection. 414 */ 415 if (pri > ppri) { 416 pp = p; 417 ppri = pri; 418 } 419 } 420 } 421 422 /* 423 * Nothing to do, back to sleep 424 */ 425 if ((p = pp) == NULL) { 426 tsleep(&proc0, PVM, "sched", 0); 427 goto loop; 428 } 429 /* 430 * We would like to bring someone in. (only if there is space). 431 */ 432 faultin(p); 433 p->p_swtime = 0; 434 goto loop; 435 } 436 437 #ifndef NO_SWAPPING 438 439 #define swappable(p) \ 440 (((p)->p_lock == 0) && \ 441 ((p)->p_flag & (P_TRACED|P_NOSWAP|P_SYSTEM|P_INMEM|P_WEXIT|P_PHYSIO|P_SWAPPING)) == P_INMEM) 442 443 /* 444 * Swapout is driven by the pageout daemon. Very simple, we find eligible 445 * procs and unwire their u-areas. We try to always "swap" at least one 446 * process in case we need the room for a swapin. 447 * If any procs have been sleeping/stopped for at least maxslp seconds, 448 * they are swapped. Else, we swap the longest-sleeping or stopped process, 449 * if any, otherwise the longest-resident process. 450 */ 451 void 452 swapout_procs() 453 { 454 register struct proc *p; 455 struct proc *outp, *outp2; 456 int outpri, outpri2; 457 int didswap = 0; 458 459 outp = outp2 = NULL; 460 outpri = outpri2 = INT_MIN; 461 retry: 462 for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { 463 struct vmspace *vm; 464 if (!swappable(p)) 465 continue; 466 467 vm = p->p_vmspace; 468 469 switch (p->p_stat) { 470 default: 471 continue; 472 473 case SSLEEP: 474 case SSTOP: 475 /* 476 * do not swapout a realtime process 477 */ 478 if (p->p_rtprio.type == RTP_PRIO_REALTIME) 479 continue; 480 481 /* 482 * do not swapout a process waiting on a critical 483 * event of some kind 484 */ 485 if (((p->p_priority & 0x7f) < PSOCK) || 486 (p->p_slptime <= 10)) 487 continue; 488 489 ++vm->vm_refcnt; 490 vm_map_reference(&vm->vm_map); 491 /* 492 * do not swapout a process that is waiting for VM 493 * datastructures there is a possible deadlock. 494 */ 495 if (!lock_try_write(&vm->vm_map.lock)) { 496 vm_map_deallocate(&vm->vm_map); 497 vmspace_free(vm); 498 continue; 499 } 500 vm_map_unlock(&vm->vm_map); 501 /* 502 * If the process has been asleep for awhile and had 503 * most of its pages taken away already, swap it out. 504 */ 505 swapout(p); 506 vm_map_deallocate(&vm->vm_map); 507 vmspace_free(vm); 508 didswap++; 509 goto retry; 510 } 511 } 512 /* 513 * If we swapped something out, and another process needed memory, 514 * then wakeup the sched process. 515 */ 516 if (didswap) 517 wakeup(&proc0); 518 } 519 520 static void 521 swapout(p) 522 register struct proc *p; 523 { 524 pmap_t pmap = &p->p_vmspace->vm_pmap; 525 int i; 526 527 #if defined(SWAP_DEBUG) 528 printf("swapping out %d\n", p->p_pid); 529 #endif 530 ++p->p_stats->p_ru.ru_nswap; 531 /* 532 * remember the process resident count 533 */ 534 p->p_vmspace->vm_swrss = 535 p->p_vmspace->vm_pmap.pm_stats.resident_count; 536 537 (void) splhigh(); 538 p->p_flag &= ~P_INMEM; 539 p->p_flag |= P_SWAPPING; 540 if (p->p_stat == SRUN) 541 remrq(p); 542 (void) spl0(); 543 544 /* 545 * let the upages be paged 546 */ 547 for(i=0;i<UPAGES;i++) { 548 vm_page_t m; 549 if ((m = vm_page_lookup(p->p_vmspace->vm_upages_obj, i)) == NULL) 550 panic("swapout: upage already missing???"); 551 m->dirty = VM_PAGE_BITS_ALL; 552 vm_page_unwire(m); 553 vm_page_deactivate(m); 554 pmap_kremove( (vm_offset_t) p->p_addr + PAGE_SIZE * i); 555 } 556 pmap_remove(pmap, (vm_offset_t) kstack, 557 (vm_offset_t) kstack + PAGE_SIZE * UPAGES); 558 559 p->p_flag &= ~P_SWAPPING; 560 p->p_swtime = 0; 561 } 562 #endif /* !NO_SWAPPING */ 563